ascorbic-acid and Cardiovascular-Diseases

Endothelial dysfunction (ED) is an early marker of vascular damage linked to the loss of integrity of the endothelial lining and represents a key step in the pathogenesis of atherosclerosis and cardiovascular diseases (CVDs). ED may be reversible, hence the development and testing of effective early interventions could be beneficial for the prevention and treatment of CVDs. Recent studies have demonstrated that the consumption of dietary nitrate (NO

Topics: Ascorbic Acid; Blood Pressure; Cardiovascular Diseases; Dietary Supplements; Humans; Nitrates; Nitric Oxide; Vitamins

The purpose of this article was to assess the existing systematic reviews and meta-analyses for the association between vitamin C intake and multiple health outcomes. A total of 76 meta-analyses (51 papers) of randomised controlled trials and observational studies with 63 unique health outcomes were identified. Dose-response analysis showed that vitamin C intake was associated with reduced risk of all-cause mortality, cardiovascular disease (CVD), oesophageal cancer, gastric cancer, cervical cancer and lung cancer with an increment of 50-100 mg per day. Beneficial associations were also identified for respiratory, neurological, ophthalmologic, musculoskeletal, renal and dental outcomes. Harmful associations were found for breast cancer and kidney stones for vitamin C supplement intake. The benefits of vitamin C intake outweigh the disadvantages for a range of health outcomes. However, the recommendation of vitamin C supplements needs to be cautious. More prospective studies and well-designed randomised controlled trials (RCTs) are needed.

Topics: Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Humans; Meta-Analysis as Topic; Nutritional Status; Systematic Reviews as Topic

Evidence suggests that vitamin C supplementation could be a potential therapy in type 2 diabetes. However, its effectiveness and evidence quality require further evaluation.. To investigate the efficacy of oral vitamin C supplementation in improving glycemic control, cardiovascular risk factors, and oxidative stress in people with type 2 diabetes.. Databases (PubMed, Embase, Scopus, Cochrane Library) and clinical trial registries were searched for randomized controlled trials up to 8 September 2020.. Trials in adults with type 2 diabetes were included. Trials were excluded if supplements were not exclusive to vitamin C and if <2 weeks in duration.. Primary outcomes were HbA. Twenty-eight studies (. Studies were predominantly short term (<6 months) with a small number of participants (. While evidence from short-term studies suggests that vitamin C supplementation may improve glycemic control and BP in people with type 2 diabetes, vitamin C supplementation cannot currently be recommended as a therapy until larger, long-term, and high-quality trials confirm these findings.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dietary Supplements; Glycemic Control; Heart Disease Risk Factors; Humans; Randomized Controlled Trials as Topic; Risk Factors

Atherosclerosis is a pro-oxidative and pro-inflammatory disease state, which is the underlying cause of most cardiovascular events, estimated to affect 5.2% of the Australian population. Diet, and specifically vitamin C, through its antioxidant properties can play a role in impeding the development and progression of atherosclerosis. This systematic review conducted comprehensive searches in Medline, Emcare, Scopus, PubMed, and Cochrane using key search terms for vitamin C, plasma vitamin C, supplementation, and cardiovascular disease (CVD). The results demonstrated that vitamin C supplementation resulted in a significant increase in vitamin C levels in populations with or without CVD, except for one study on the CVD population. It was also seen that the healthy population baseline and post-intervention vitamin C levels were high compared to the CVD population. However, further research is indicated for CVD population groups with varying baseline vitamin C levels, such as low baseline vitamin C, within a more representative elderly cohort in order to formulate and update vitamin C repletion guidelines.

Topics: Antioxidants; Ascorbic Acid; Atherosclerosis; Cardiovascular Diseases; Diet; Dietary Supplements; Eating; Female; Heart Disease Risk Factors; Humans; Male; Middle Aged; Nutritional Status

The present review aimed to quantify the association of dietary intake and circulating concentration of major dietary antioxidants with risk of total CVD mortality.. Systematic review and meta-analysis.. Systematic search in PubMed and Scopus, up to October 2017.ParticipantsProspective observational studies reporting risk estimates of CVD mortality across three or more categories of dietary intakes and/or circulating concentrations of vitamin C, vitamin E and β-carotene were included. A random-effects meta-analysis was conducted.. A total of fifteen prospective cohort studies and three prospective evaluations within interventional studies (320 548 participants and 16 974 cases) were analysed. The relative risks of CVD mortality for the highest v. the lowest category of antioxidant intakes were as follows: vitamin C, 0·79 (95 % CI 0·68, 0·89; I 2=46 %, n 10); vitamin E, 0·91 (95 % CI 0·79, 1·03; I 2=51 %, n 8); β-carotene, 0·89 (95 % CI 0·73, 1·05; I 2=34 %, n 4). The relative risks for circulating concentrations were: vitamin C, 0·60 (95 % CI 0·42, 0·78; I 2=65 %, n 6); α-tocopherol, 0·82 (95 % CI 0·76, 0·88; I 2=0 %, n 5); β-carotene, 0·68 (95 % CI 0·52, 0·83; I 2=50 %, n 6). Dose-response meta-analyses demonstrated that the circulating biomarkers of antioxidants were more strongly associated with risk of CVD mortality than dietary intakes.. The present meta-analysis demonstrates that higher vitamin C intake and higher circulating concentrations of vitamin C, vitamin E and β-carotene are associated with a lower risk of CVD mortality.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Biomarkers; Cardiovascular Diseases; Diet; Eating; Female; Humans; Male; Middle Aged; Nutritional Status; Observational Studies as Topic; Prospective Studies; Risk; Risk Factors; Vitamin E

Vitamin C is an essential nutrient with important antioxidant properties. Higher vitamin C intake appears to be associated with positive effects on cardiovascular risk factors in cohort studies, whereas large randomized controlled clinical trials did not confirm the benefits of supplemental vitamin C on cardiovascular disease (CVD) outcomes. In this overview of systematic reviews and meta-analyses, an "umbrella review," we investigated the effects of vitamin C supplementation on biomarkers of cardiovascular risk, that is, arterial stiffness, blood pressure, endothelial function, glycemic control, and lipid profile. In addition, we assessed the strength of the evidence and the methodological qualities of available studies. Two independent investigators searched 4 databases (Medline, Embase, Scopus, and The Cochrane Library databases) from inception until February 2018. After full text examination, 10 systematic reviews and meta-analyses were included in the umbrella review which included 6409 participants. Three systematic reviews investigated the effects of vitamin C on endothelial function with contrasting results (2 reviews reported a significant effect, and all 3 showed a high heterogeneity [I

Topics: Antioxidants; Ascorbic Acid; Biomarkers; Blood Pressure; Body Mass Index; Cardiovascular Diseases; Dietary Supplements; Humans; Lipids; Meta-Analysis as Topic; Systematic Reviews as Topic; Vascular Stiffness; Vitamins

For decades, there has been epidemiologic evidence linking chronic toxic metal exposure with cardiovascular disease, suggesting a therapeutic role for metal chelation. Given the lack of compelling scientific evidence, however, the indications for metal chelation were never clearly defined. To determine the safety and efficacy of chelation therapy, the National Institutes of Health funded the Trial to Assess Chelation Therapy (TACT). TACT was the first double-blind, randomized, controlled trial to demonstrate an improvement in cardiovascular outcomes with edetate disodium therapy in patients with prior myocardial infarction. The therapeutic benefit was striking among the prespecified subgroup of patients with diabetes.. We review the published literature focusing on the atherogenic nature of diabetes, as well as available evidence from clinical trials, complete and in progress, of metal chelation with edetate disodium therapy in patients with diabetes.. The TACT results support the concept that ubiquitous toxic metals such as lead and cadmium may be modifiable risk factors for cardiovascular disease, particularly in patients with diabetes.. The purpose of this review is to discuss the potential mechanisms unifying the pathogenesis of atherogenic factors in diabetes with toxic metal exposure, and the potential role of metal chelation.

Topics: Antioxidants; Arsenic; Ascorbic Acid; Atherosclerosis; Cadmium; Calcium Chelating Agents; Cardiovascular Diseases; Chelating Agents; Chelation Therapy; Copper; Diabetes Complications; Diabetes Mellitus; Edetic Acid; Glycation End Products, Advanced; Hospitalization; Humans; Iron; Lead; Lipid Metabolism; Mercury; Myocardial Infarction; Myocardial Revascularization; Oxidative Stress; Randomized Controlled Trials as Topic; Stroke

High dietary intake or blood concentrations (as biomarkers of dietary intake) of vitamin C, carotenoids, and vitamin E have been associated with reduced risk of cardiovascular disease, cancer, and mortality, but these associations have not been systematically assessed.. We conducted a systematic review and meta-analysis of prospective studies of dietary intake and blood concentrations of vitamin C, carotenoids, and vitamin E in relation to these outcomes.. We searched PubMed and Embase up to 14 February 2018. Summary RRs and 95% CIs were calculated with the use of random-effects models.. Sixty-nine prospective studies (99 publications) were included. The summary RR per 100-mg/d increment of dietary vitamin C intake was 0.88 (95% CI: 0.79, 0.98, I2 = 65%, n = 11) for coronary heart disease, 0.92 (95% CI: 0.87, 0.98, I2 = 68%, n = 12) for stroke, 0.89 (95% CI: 0.85, 0.94, I2 = 27%, n = 10) for cardiovascular disease, 0.93 (95% CI: 0.87, 0.99, I2 = 46%, n = 8) for total cancer, and 0.89 (95% CI: 0.85, 0.94, I2 = 80%, n = 14) for all-cause mortality. Corresponding RRs per 50-μmol/L increase in blood concentrations of vitamin C were 0.74 (95% CI: 0.65, 0.83, I2 = 0%, n = 4), 0.70 (95% CI: 0.61, 0.81, I2 = 0%, n = 4), 0.76 (95% CI: 0.65, 0.87, I2 = 56%, n = 6), 0.74 (95% CI: 0.66, 0.82, I2 = 0%, n = 5), and 0.72 (95% CI: 0.66, 0.79, I2 = 0%, n = 8). Dietary intake and/or blood concentrations of carotenoids (total, β-carotene, α-carotene, β-cryptoxanthin, lycopene) and α-tocopherol, but not dietary vitamin E, were similarly inversely associated with coronary heart disease, stroke, cardiovascular disease, cancer, and/or all-cause mortality.. Higher dietary intake and/or blood concentrations of vitamin C, carotenoids, and α-tocopherol (as markers of fruit and vegetable intake) were associated with reduced risk of cardiovascular disease, total cancer, and all-cause mortality. These results support recommendations to increase fruit and vegetable intake, but not antioxidant supplement use, for chronic disease prevention.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Cause of Death; Diet; Feeding Behavior; Humans; Neoplasms; Nutritional Status; Vitamin E

The beneficial role of the Mediterranean diet in the prevention of chronic diseases, including cardiovascular diseases, diabetes, and obesity, is well-recognized. In this context,

Topics: Ascorbic Acid; Biofortification; Brassicaceae; Cardiovascular Diseases; Carotenoids; Chronic Disease; Diabetes Mellitus; Glucosinolates; Humans; Hydroxybenzoates; Obesity; Phytochemicals; Vegetables

Carotid intima media thickness (IMT) is a noninvasive marker of the extent and severity of subclinical atherosclerosis. Micronutrient intake may affect atherosclerosis and play a major role in the development of cardiovascular diseases (CVDs).. The primary aim of this review was to synthesize the evidence regarding the association between carotid IMT and selected micronutrients.. The authors searched PubMed, Cochrane, and EMBASE databases from inception to June 2016 for selected micronutrients, CVD, carotid IMT, and antioxidants. Thirty-five original studies met the inclusion criteria and were reviewed following preferred reporting items for systematic review and meta-analysis guidelines.. Although not all studies found consistent results, the weight of the evidence suggests that high intakes and/or circulatory levels of magnesium, as well as vitamin D and the vitamin B group, may be associated with lower carotid IMT or reduced progression of carotid IMT. The majority of studies did not find any significant association between vitamin E and C and carotid IMT. Less evidence was available for associations of retinol, zinc, and iron with carotid IMT.. In general, the current evidence concerning micronutrient intake and carotid IMT is largely inconclusive. Pragmatic clinical trials are required to determine whether dietary or supplemental intake of specific micronutrients alters carotid IMT, which is a surrogate measure of cardiovascular risk.

Topics: Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Carotid Intima-Media Thickness; Databases, Factual; Disease Progression; Humans; Iron; Magnesium; Micronutrients; Nutritional Status; Randomized Controlled Trials as Topic; Risk Factors; Vitamin A; Vitamin B Complex; Vitamin D; Vitamin E; Zinc

Obesity means the accumulation of excessive fat that may interfere with the maintenance of optimal state of health. Obesity causes cardiac and vascular disease through well-known mediators such as hypertension, type-2 diabetes mellitus, and dyslipidemia, but there are evidences for other mediators such as chronic inflammation, oxidative stress, and thrombosis. The decreased levels of antioxidants factors and nitric oxide predispose to further cardiovascular adverse events. To reduce the risks, antioxidants can help by neutralizing the free radicals and protecting from damage by donating electrons. Having the capacity, vitamin C protects from oxidative stress, prevention of non-enzymatic glycosylation of proteins, and enhances arterial dilation through its effect on nitric oxide release. It also decreases lipid peroxidation, and alleviates inflammation. The anti-inflammatory property of vitamin C could be attributed to ability to modulate the NF-

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Humans; Inflammation; Obesity; Oxidative Stress

Vitamin C is an essential micronutrient and powerful antioxidant. Observational studies have shown an inverse relationship between vitamin C intake and major cardiovascular events and cardiovascular disease (CVD) risk factors. Results from clinical trials are less consistent.. To determine the effectiveness of vitamin C supplementation as a single supplement for the primary prevention of CVD.. We searched the following electronic databases on 11 May 2016: the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (Ovid); Embase Classic and Embase (Ovid); Web of Science Core Collection (Thomson Reuters); Database of Abstracts of Reviews of Effects (DARE); Health Technology Assessment Database and Health Economics Evaluations Database in the Cochrane Library. We searched trial registers on 13 April 2016 and reference lists of reviews for further studies. We applied no language restrictions.. Randomised controlled trials of vitamin C supplementation as a single nutrient supplement lasting at least three months and involving healthy adults or adults at moderate and high risk of CVD were included. The comparison group was no intervention or placebo. The outcomes of interest were CVD clinical events and CVD risk factors.. Two review authors independently selected trials for inclusion, abstracted the data and assessed the risk of bias.. We included eight trials with 15,445 participants randomised. The largest trial with 14,641 participants provided data on our primary outcomes. Seven trials reported on CVD risk factors. Three of the eight trials were regarded at high risk of bias for either reporting or attrition bias, most of the 'Risk of bias' domains for the remaining trials were judged as unclear, with the exception of the largest trial where most domains were judged to be at low risk of bias.The composite endpoint, major CVD events was not different between the vitamin C and placebo group (hazard ratio (HR) 0.99, 95% confidence interval (CI) 0.89 to 1.10; 1 study; 14,641 participants; low-quality evidence) in the Physicians Health Study II over eight years of follow-up. Similar results were obtained for all-cause mortality HR 1.07, 95% CI 0.97 to 1.18; 1 study; 14,641 participants; very low-quality evidence, total myocardial infarction (MI) (fatal and non-fatal) HR 1.04 (95% CI 0.87 to 1.24); 1 study; 14,641 participants; low-quality evidence, total stroke (fatal and non-fatal) HR 0.89 (95% CI 0.74 to 1.07); 1 study; 14,641 participants; low-quality evidence, CVD mortality HR 1.02 (95% 0.85 to 1.22); 1 study; 14,641 participants; very low-quality evidence, self-reported coronary artery bypass grafting (CABG)/percutaneous transluminal coronary angioplasty (PTCA) HR 0.96 (95% CI 0.86 to 1.07); 1 study; 14,641 participants; low-quality evidence, self-reported angina HR 0.93 (95% CI 0.84 to 1.03); 1 study; 14,641 participants; low-quality evidence.The evidence for the majority of primary outcomes was downgraded (low quality) because of indirectness and imprecision. For all-cause mortality and CVD mortality, the evidence was very low because more factors affected the directness of the evidence and because of inconsistency.Four studies did not state sources of funding, two studies declared non-commercial funding and two studies declared both commercial and non-commercial funding.. Currently, there is no evidence to suggest that vitamin C supplementation reduces the risk of CVD in healthy participants and those at increased risk of CVD, but current evidence is limited to one trial of middle-aged and older male physicians from the USA. There is limited low- and very low-quality evidence currently on the effect of vitamin C supplementation and risk of CVD risk factors.

Topics: Angioplasty, Balloon, Coronary; Ascorbic Acid; Cardiovascular Diseases; Coronary Artery Bypass; Dietary Supplements; Humans; Male; Middle Aged; Myocardial Infarction; Physicians; Primary Prevention; Publication Bias; Randomized Controlled Trials as Topic; Stroke; Vitamins

Randomised controlled trials (RCTs) in humans revealed contradictory results regarding the effect of vitamin C supplementation on blood lipids. We aimed to conduct a systematic review and meta-analysis of RCTs investigating the effect of vitamin C supplementation on total cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C) and triglycerides and to determine whether the effects are modified by the participants' or intervention characteristics.. Four databases (PubMed, Embase, Scopus and Cochrane Library) were searched from inception until August 2014 for RCTs supplementing adult participants with vitamin C for ≥ 2 weeks and reporting changes in blood lipids.. Overall, vitamin C supplementation did not change blood lipids concentration significantly. However, supplementation reduced total cholesterol in younger participants (≤52 years age) (-0.26 mmol/L, 95% CI: -0.45, -0.07) and LDL-C in healthy participants (-0.32 mmol/L, 95% CI: -0.57, -0.07). In diabetics, vitamin C supplementation reduced triglycerides significantly (-0.15 mmol/L, 95% CI: -0.30, -0.002) and increased HDL-C significantly (0.06 mmol/L, 95% CI: 0.02, 0.11). Meta-regression analyses showed the changes in total cholesterol (β: -0.24, CI: -0.36, -0.11) and in triglycerides (β: -0.17, CI: -0.30, -0.05) following vitamin C supplementation were greater in those with higher concentrations of these lipids at baseline. Greater increase in HDL-C was observed in participants with lower baseline plasma concentrations of vitamin C (β: -0.002, CI: -0.003, -0.0001).. Overall, vitamin C supplementation had no significant effect on lipid profile. However, subgroup and sensitivity analyses showed significant reductions in blood lipids following supplementation in sub-populations with dyslipidaemia or low vitamin C status at baseline. PROSPERO Database registration: CRD42014013487, http://www.crd.york.ac.uk/prospero/.

Topics: Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Agents; Cardiovascular Diseases; Dyslipidemias; Humans; Hyperlipidemias; Hypolipidemic Agents; Oxidative Stress; Randomized Controlled Trials as Topic; Reproducibility of Results; Risk

Vitamin C is a powerful dietary antioxidant that has received considerable attention in the literature related to its possible role in heart health. Although classical vitamin C deficiency, marked by scurvy, is rare in most parts of the world, some research has shown variable heart disease risks depending on plasma vitamin C concentration, even within the normal range. Furthermore, other studies have suggested possible heart-related benefits to vitamin C taken in doses beyond the minimal amounts required to prevent classically defined deficiency. The objective of this review is to systematically review the findings of existing epidemiologic research on vitamin C and its potential role in cardiovascular disease (CVD). It is well established that vitamin C inhibits oxidation of LDL-protein, thereby reducing atherosclerosis, but the cardiovascular outcomes related to this action and other actions of vitamin C are not fully understood. Randomized controlled trials as well as observational cohort studies have investigated this topic with varying results. Vitamin C has been linked in some work to improvements in lipid profiles, arterial stiffness, and endothelial function. However, other studies have failed to confirm these results, and observational cohort studies are varied in their findings on the vitamin's effect on CVD risk and mortality. Overall, current research suggests that vitamin C deficiency is associated with a higher risk of mortality from CVD and that vitamin C may slightly improve endothelial function and lipid profiles in some groups, especially those with low plasma vitamin C levels. However, the current literature provides little support for the widespread use of vitamin C supplementation to reduce CVD risk or mortality.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Epidemiologic Studies; Humans; Oxidation-Reduction

Observational studies showed that circulating L-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation.. We assessed the relation between L-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating L-ascorbic acid concentrations. The observed association between rs33972313 and cardiometabolic outcomes was compared with that expected given the rs33972313-L-ascorbic acid and L-ascorbic acid-outcome associations.. A meta-analysis was performed in the following 5 independent studies: the British Women's Heart and Health Study (n = 1833), the MIDSPAN study (n = 1138), the Ten Towns study (n = 1324), the British Regional Heart Study (n = 2521), and the European Prospective Investigation into Cancer (n = 3737).. With the use of a meta-analysis of observational estimates, inverse associations were shown between L-ascorbic acid and systolic blood pressure, triglycerides, and the waist-hip ratio [the strongest of which was the waist-hip ratio (-0.13-SD change; 95% CI: -0.20-, -0.07-SD change; P = 0.0001) per SD increase in L-ascorbic acid], and a positive association was shown with high-density lipoprotein (HDL) cholesterol. The variation at rs33972313 was associated with a 0.18-SD (95% CI: 0.10-, 0.25-SD; P = 3.34 × 10⁻⁶) increase in L-ascorbic acid per effect allele. There was no evidence of a relation between the variation at rs33972313 and any cardiometabolic outcome. Although observed estimates were not statistically different from expected associations between rs33972313 and cardiometabolic outcomes, estimates for low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, glucose, and body mass index were in the opposite direction to those expected.. The nature of the genetic association exploited in this study led to limited statistical application, but despite this, when all cardiometabolic traits were assessed, there was no evidence of any trend supporting a protective role of L-ascorbic acid. In the context of existing work, these results add to the suggestion that observational relations between L-ascorbic acid and cardiometabolic health may be attributable to confounding and reverse causation.

Topics: Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Cholesterol, HDL; Europe; Genetic Association Studies; Humans; Observational Studies as Topic; Polymorphism, Single Nucleotide; Sodium-Coupled Vitamin C Transporters; Up-Regulation

The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing results of antioxidant therapy for cardiovascular risk factors in large-scale long-term randomised controlled trials. Apart from the limitations of our knowledge, limitations in methodology and assessment of the body's endogenous and exogenous oxidant-antioxidant status are a serious handicap. The pleiotropic effects of antioxidant and anti-inflammation that are shown by some well-established antihypertensive agents and statins partly support the idea of using antioxidants in vascular diseases as still relevant. This review aims to provide an overview of the links between oxidative stress, vascular inflammation, endothelial dysfunction and cardiovascular risk factors, importantly focusing on blood pressure regulation and atherosclerosis. In view of the potential benefits of antioxidants, this review will also examine the proposed role of vitamin C, vitamin E and polyphenols in cardiovascular diseases as well as the success or failure of antioxidant therapy for cardiovascular diseases in clinical trials.

Topics: Animals; Antihypertensive Agents; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Endothelium, Vascular; Humans; Hypertension; Inflammation; Oxidative Stress; Reactive Oxygen Species; Risk Factors; Vitamin E

The role of vitamin C and vitamin E in the prevention and treatment of diseases is analyzed from the standpoint of evidence-based medicine. The high provision of a patient with the vitamins has a therapeutic and preventive impact on the development and course of a number of diseases. Furthermore, when additionally prescribing the vitamins as part of combination therapy, it is necessary to take into account possible drug interactions, including those due to the inducing effect of the above antioxidants on cytochrome P450 3A4.. Проанализирована роль витаминов С и Е в профилактике и терапии заболеваний с точки зрения доказательной медицины. Высокий статус по обеспеченности организма пациента витаминами оказывает лечебно-профилактическое действие на развитие и течение ряда заболеваний. Кроме того, при дополнительном назначении витаминов в составе комплексной терапии необходимо учитывать возможные межлекарственные взаимодействия, в том числе вследствие индуцирующего действия перечисленных антиоксидантов на цитохром Р450 3А4.

Topics: Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus; Evidence-Based Medicine; Humans; Tocopherols; Vitamins

Ascorbate (Asc) has been shown to increase nitric oxide (NO) bioavailability and thereby improve endothelial function in patients showing signs of endothelial dysfunction. Tetrahydrobiopterin (BH₄) is a co-factor of endothelial nitric oxide synthase (eNOS) which may easily become oxidized to the inactive form dihydrobiopterin (BH₂). Asc may increase NO bioavailability by a number of mechanisms involving BH₄ and eNOS. Asc increases BH₄ bioavailability by either reducing oxidized BH₄ or preventing BH₄ from becoming oxidized in the first place. Asc could also increase NO bioavailability in a BH₄-independent manner by increasing eNOS activity by changing its phosphorylation and S-nitrosylation status or by upregulating eNOS expression. In this review, we discuss the putative mechanisms by which Asc may increase NO bioavailability through its interactions with BH₄ and eNOS.

Topics: Animals; Ascorbic Acid; Biomarkers; Biopterins; Cardiovascular Diseases; Guinea Pigs; Humans; Mice; Nitric Oxide; Nitric Oxide Synthase Type III; Nitrogen; Oxygen; Phosphorylation; Rats; Reactive Oxygen Species; Risk; Vasodilation

Observational studies indicate that higher vitamin C intake is associated with reduced risk for cardiovascular diseases. However, randomised controlled trials (RCT) examining the effect of vitamin C on endothelial function (EF) have reported inconsistent results. The aims of this systematic review and meta-analysis were to determine the effect of vitamin C supplementation on EF and to investigate whether the effect was influenced by health status, study duration, dose and route of vitamin C administration.. We searched the Medline, Embase, Cochrane Library, and Scopus databases from inception to May 2013 for studies that met the following criteria: 1) RCT with adult participants, 2) vitamin C administered alone, 3) studies that quantified EF using commonly applied methods including ultrasound, plethysmography and pulse wave analysis.. Pooling the data from 44 clinical trials showed a significant positive effect of vitamin C on EF (SMD: 0.50, 95% CI: 0.34, 0.66, P < 0.001). Stratification of the analysis by health outcome revealed improved EF in atherosclerotic (SMD: 0.84, 95% CI: 0.41, 1.26, P < 0.001), diabetic (SMD: 0.52, 95% CI: 0.21, 0.82, P < 0.001) and heart failure patients (SMD: 0.48, 95% CI: 0.08, 0.88, P < 0.02) after vitamin C supplementation. The effect size appeared to be unaffected by study design, duration, baseline plasma vitamin C concentration or route of administration of vitamin C. The meta-regression showed a significant positive association between vitamin C dose and improvement in EF (β: 0.00011, 95% CI: 0.00001, 0.00021, P = 0.03).. Vitamin C supplementation improved EF. The effect of vitamin C supplementation appeared to be dependent on health status, with stronger effects in those at higher cardiovascular disease risk. PROSPERO Database registration: CRD42013004567, http://www.crd.york.ac.uk/prospero/

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Atherosclerosis; Cardiovascular Diseases; Dietary Supplements; Endothelium; Female; Healthy Volunteers; Humans; Inflammation; Male; Middle Aged; Randomized Controlled Trials as Topic; Regression Analysis; Young Adult

Cardiovascular disease is the major cause of death in patients with type 1 diabetes. Vascular endothelial dysfunction is an early pathophysiological precursor of cardiovascular disease. There is extensive evidence that hyperglycemia causes acute perturbations in endothelial function likely due to increases in oxidative damage. Interestingly, oscillating hyperglycemia may cause more damage than persistent hyperglycemia. Many, but not all, studies indicate that vascular endothelial dysfunction occurs early in the course of type 1 diabetes and is present even in adolescents. Ascorbic acid has been shown to diminish the acute effects of hyperglycemia on endothelial function in type 1 diabetes and in conjunction with euglycemia to restore endothelial function to normal values in adults with well-controlled diabetes. In vitro and in vivo animal evidence suggests potential benefit from two other small molecule antioxidants, nicotinamide and taurine. Early studies suggested that folate supplementation may improve endothelial function in adolescents with type 1 diabetes but this has not been confirmed by more recent studies. Epidemiological evidence suggests a possible role for vitamin D therapy although intervention studies in type 2 diabetes have yielded varying results and have not been done in type 1 diabetes. Further exploration of these and other compounds is clearly appropriate if we are to reduce cardiovascular risk in type 1 diabetes.

Topics: Adolescent; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Child; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Dietary Supplements; Disease Progression; Endothelium, Vascular; Folic Acid; Humans; Hyperglycemia; Oxidative Stress; Taurine; Vitamin D

Atherosclerosis, the hardening of arteries under oxidative stress is related to oxidative changes of low density lipoproteins (LDL). The antioxidants prevent the formation of oxidized LDL during atherogenesis. Perhaps more than one mechanism is involved in the atherosclerosis disease where LDL is oxidized in all the cells of arterial wall during the development of this disease. The oxidation of LDL produces lipid peroxidation products such as isoprostans from arachidonic, eicosapentaenoic and docosahexaenoic acids, oxysterols from cholesterol, hydroxyl fatty acids, lipid peroxides and aldehydes. The lipid peroxidation bioassay can serve as a marker for the risk of cardiovascular. An in vivo test of levels of oxidative lipid damage is an early prediction of development of cardiovascular disease (CVD). Serum paraoxonase (PON) activity is correlated to severity of the coronary artery disease. The antioxidants level in the serum and serum paraoxonase activity provides information for the risk of CVD. The antioxidant enzyme superoxide dismutase is responsible for dismutation of superoxide, a free radical chain initiator. The subcellular changes in the equilibrium in favor of free radicals can cause increase in the oxidative stress which leads to cardiomyopathy, heart attack or cardiac dysfunction. The oxidative damage and defense of heart disease has been reported where dietary antioxidants protect the free radical damage to DNA, proteins and lipids. The ascorbic acid, vitamin C is an effective antioxidant and high vitamin E intake can reduce the risk of coronary heart disease (CHD) by inhibition of atherogenic forms of oxidized LDL. The vitamin A and beta-carotene protect lipid peroxidation and provitamin-A activity. It has been recently suggested that the protection of oxidative damage and related CVD is best served by antioxidants found in the fruits and vegetables. The oxidative damage and antioxidant protection of CVD have been described here.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diet; Free Radicals; Humans; Lipid Peroxidation; Lipid Peroxides; Lipoproteins, LDL; Oxidation-Reduction; Oxidative Stress; Superoxide Dismutase

Antioxidant vitamin (vitamin E, beta-carotene, and vitamin C) are widely used for preventing major cardiovascular outcomes. However, the effect of antioxidant vitamin on cardiovascular events remains unclear.. We searched PubMed, EmBase, the Cochrane Central Register of Controlled Trials, and the proceedings of major conferences for relevant literature. Eligible studies were randomized controlled trials that reported on the effects of antioxidant vitamin on cardiovascular outcomes as compared to placebo. Outcomes analyzed were major cardiovascular events, myocardial infarction, stroke, cardiac death, total death, and any possible adverse events. We used the I(2) statistic to measure heterogeneity between trials and calculated risk estimates for cardiovascular outcomes with random-effect meta-analysis. Independent extraction was performed by two reviewers and consensus was reached. Of 293 identified studies, we included 15 trials reporting data on 188209 participants. These studies reported 12749 major cardiovascular events, 6699 myocardial infarction, 3749 strokes, 14122 total death, and 5980 cardiac deaths. Overall, antioxidant vitamin supplementation as compared to placebo had no effect on major cardiovascular events (RR, 1.00; 95%CI, 0.96-1.03), myocardial infarction (RR, 0.98; 95%CI, 0.92-1.04), stroke (RR, 0.99; 95%CI, 0.93-1.05), total death (RR, 1.03; 95%CI, 0.98-1.07), cardiac death (RR, 1.02; 95%CI, 0.97-1.07), revascularization (RR, 1.00; 95%CI, 0.95-1.05), total CHD (RR, 0.96; 95%CI, 0.87-1.05), angina (RR, 0.98; 95%CI, 0.90-1.07), and congestive heart failure (RR, 1.07; 95%CI, 0.96 to 1.19).. Antioxidant vitamin supplementation has no effect on the incidence of major cardiovascular events, myocardial infarction, stroke, total death, and cardiac death.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Dietary Supplements; Humans; Odds Ratio; Publication Bias; Randomized Controlled Trials as Topic; Risk; Vitamin E; Vitamins

Despite continuous advances in the prevention of cardiovascular disease (CVD), critical issues associated with an unhealthy lifestyle remain an increasing cause of morbidity and mortality in industrialized countries.. A growing body of literature supports a specific role for vitamin C in a number of reactions that are associated with vascular function and control including, for example, nitric oxide bioavailability, lipid metabolism, and vascular integrity.. A large body of epidemiological evidence supports a relationship between poor vitamin C status and increased risk of developing CVD, and the prevalence of deficiency continues to be around 10%-20% of the general Western population although this problem could easily and cheaply be solved by supplementation. However, large intervention studies using vitamin C have not found a beneficial effect of supplementation. This review outlines the proposed mechanism by which vitamin C deficiency worsens CVD progression. In addition, it discusses problems with the currently available literature, including the discrepancies between the large intervention studies and the experimental and epidemiological literature.. Increased insights into vitamin C deficiency-mediated CVD progression will enable the design of future randomized controlled trials that are better suited to test the efficacy of vitamin C in disease prevention as well as the identification of high-risk individuals which could possibly benefit from supplementation.

Topics: Animals; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Disease Progression; Humans; Life Style; Obesity; Oxidation-Reduction; Randomized Controlled Trials as Topic; Smoking

Vitamin C is an essential dietary nutrient for the biosynthesis of collagen and a co-factor in the biosynthesis of catecholamines, L-carnitine, cholesterol, amino acids, and some peptide hormones. The lack of vitamin C causes scurvy, a pathological condition leading to blood vessel fragility and connective tissue damage due to failure in producing collagen, and, finally, to death as result of a general collapse. Vitamin C is potentially involved also in cancer and cardiovascular diseases prevention. In addition, vitamin C effects on nervous system and chronically ill patients have been also documented. This review attempts to summarize recent and well established advances in vitamin C research and its clinical implications. Since vitamin C has the potential to counteract inflammation and subsequent oxidative damage that play a major role in the initiation and progression of several chronic and acute diseases, it represents a practical tool to administer for the early prevention of these pathologic conditions.

Topics: Anticarcinogenic Agents; Ascorbic Acid; Cardiovascular Diseases; Critical Illness; Eye Diseases; Humans; Nervous System

Extensive evidence has demonstrated that many antioxidants such as vitamin C, vitamin E, carotenoids and polyphenols have protective effects in preventing cardiovascular disease (CVD), a chronic disease that is mediated by oxidative stress and inflammation. This review focuses on evidence from prospective cohort studies and clinical trials in regard to the associations between plasma/dietary antioxidants and cardiovascular events. Long-term, large-scale, population-based cohort studies have found that higher levels of serum albumin, bilirubin, glutathione, vitamin E, vitamin C, and carotenoids were associated with a lower risk of CVD. Evidence from the cohort studies in regard to dietary antioxidants also supported the protective effects of dietary vitamin E, vitamin C, carotenoids, and polyphenols on CVD risk. However, results from large randomized controlled trials did not support long-term use of single antioxidant supplements for CVD prevention due to their null or even adverse effects on major cardiovascular events or cancer. Diet quality indexes that consider overall diet quality rather than single nutrients have been drawing increasing attention. Cohort studies and intervention studies that focused on diet patterns such as high total antioxidant capacity have documented protective effects on CVD risk. This review provides a perspective for future studies that investigate antioxidant intake and risk of CVD.

Topics: Antioxidants; Ascorbic Acid; Bilirubin; Biomarkers; Cardiovascular Diseases; Carotenoids; Dietary Supplements; Glutathione; Humans; Nutritional Status; Oxidative Stress; Polyphenols; Randomized Controlled Trials as Topic; Risk Factors; Serum Albumin; Vitamin E

Antioxidants have been used as therapies to decrease oxidative stress and improve CVD risk in hemodialysis (HD) patients. A systematic search of the Medline database (search date 30 April 2011) found 56 studies investigating the effects of antioxidant therapies on biomarkers of oxidative stress (53 studies) or clinical outcomes (3 studies). The majority were small trials using a nonrandomized open-label design with a single HD group (no HD controls). Alpha-tocopherol was the most investigated antioxidant, with 20/25 studies reporting that this vitamin decreased oxidative stress, and one clinical outcome trial in 196 patients finding that it protected against secondary CVD. Studies using vitamin C were more equivocal, with 4/11 showing decreased oxidative stress and one clinical outcome trial showing no effect on morbidity or mortality. N-acetylcysteine was the most efficacious agent, with 4/4 studies indicating a decrease in oxidative stress and one trial (n=134) showing reduced CVD events. Seven studies have used therapy containing a combination of antioxidants, with five of these reporting decreased oxidative stress. Most intervention studies in HD patients, such as statin therapy and increased dialysis dose, have failed to show improvement in CVD outcomes. Two intervention trials using different antioxidants have found CVD benefits, suggesting that this line of therapy is effective in this resistant population. These studies require validation in larger, adequately powered trials.

Topics: Acetylcysteine; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Oxidative Stress; Renal Dialysis; Vitamin E

The recommended dietary allowance (RDA) of vitamin C has traditionally been based on the prevention of the vitamin C deficiency disease, scurvy. While higher intakes of vitamin C may exert additional health benefits, the limited Phase III randomized placebo-controlled trials (RCTs) of vitamin C supplementation have not found consistent benefit with respect to chronic disease prevention. To date, this has precluded upward adjustments of the current RDA. Here we argue that Phase III RCTs-designed principally to test the safety and efficacy of pharmaceutical drugs-are ill suited to assess the health benefits of essential nutrients; and the currently available scientific evidence is sufficient to determine the optimum intake of vitamin C in humans. This evidence establishes biological plausibility and mechanisms of action for vitamin C in the primary prevention of coronary heart disease, stroke, and cancer; and is buttressed by consistent data from prospective cohort studies based on blood analysis or dietary intake and well-designed Phase II RCTs. These RCTs show that vitamin C supplementation lowers hypertension, endothelial dysfunction, chronic inflammation, and Helicobacter pylori infection, which are independent risk factors of cardiovascular diseases and certain cancers. Furthermore, vitamin C acts as a biological antioxidant that can lower elevated levels of oxidative stress, which also may contribute to chronic disease prevention. Based on the combined evidence from human metabolic, pharmacokinetic, and observational studies and Phase II RCTs, we conclude that 200 mg per day is the optimum dietary intake of vitamin C for the majority of the adult population to maximize the vitamin's potential health benefits with the least risk of inadequacy or adverse health effects.

Topics: Adult; Animals; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Dietary Supplements; Health Promotion; Humans; Nutrition Policy; Nutritional Requirements; Oxidative Stress; Randomized Controlled Trials as Topic

Atherosclerotic cardiovascular diseases (CVD) are a major source of mortality and morbidity in the general population. Oxidative modification of low-density lipoprotein cholesterol (LDL-C) represents the most important determinant factor in the development and progression of atherosclerotic lesions. Oxidative damage and the production of free radicals (FRs) in the endothelium are some of the main factors involved in the pathogenesis of the atherosclerotic process that causes CVD. Appropriate nutritional practices are of central importance in managing risk and treatment of CVD; in fact, many current guidelines for a healthy general population contain nutritional recommendations to reduce the risk of these diseases. Observational studies of vitamins C and E, the most prevalent natural antioxidant vitamins, suggest that supplemental use of these vitamins may lower the risk for coronary events. Despite these data, several large, randomized controlled trials have failed to confirm the benefits of vitamin C and E in cardiovascular prevention. The aim of this review is to examine the published studies regarding the effect of vitamins (C and E) and beta-carotene supplementation in the prevention of CVD due to atherosclerosis.

Topics: Antioxidants; Ascorbic Acid; Atherosclerosis; Cardiovascular Diseases; Carotenoids; Dietary Supplements; Humans; Oxidative Stress; Vitamin E

Atherosclerosis remains one of the leading causes of death in Western populations. Subsequent to the discovery that oxidative stress plays a pivotal role in the development and progression of atherosclerosis, vitamins C and E, along with other antioxidants, were studied as potential therapies for the disease. However, while in vitro and in vivo studies showed promising antiatherogenic effects for vitamins C and E, clinical trials in which patients were given high doses of vitamin E or C showed no benefit and even possible harm. This review will attempt to summarize the known mechanistic data regarding the biochemical effects of vitamins C and E and their relevance to atherosclerosis, and offer an explanation for the failure of clinical trials to show that supplementation with these vitamins provides any benefit when given indiscriminately. We provide one example of how pharmacogenomics may be used to identify a sub-population which may indeed benefit from antioxidant supplementation.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Oxidative Stress; Vitamin E; Vitamins

Oxygen reactive species (ROS) are generated during cellular processes. In excess, they may cause damages to the cell. Oxidative stress is an imbalance in the redox state that favors oxidation. Endogenous enzymes and some vitamins and minerals participate in the plasma antioxidant defense. Vitamin E is found in the plasma and in the LDL particle, avoiding lipid peroxidation. Observational studies reported an inverse association between vitamin E consumption and cardiometabolic (CM) risk. However, clinical trials were not able to prove the efficacy of its supplementation on CM endpoints. Vitamin C participates in the vitamin E regeneration system, keeping the plasma's antioxidant potential. Data about beneficial effects of its supplementation in CM risk reduction are inconclusive. The antioxidant activity of carotenoids is partially responsible for its protective role against cardiovascular diseases and cancer. Supplementation of this nutrient did not provide consistent findings in terms of CM risk reduction. Recently, zinc and selenium's participation in the antioxidant defense has been studied, yet its supplementation in individuals with normal levels and adequate ingestion of these nutrients does not seem necessary. In summary, the role of these micronutrients for CM risk is still very controversial. Epidemiological studies suggest that diets rich in antioxidants, or simply in fruit and vegetables intake, can reduce CM risk. Further studies are needed before recommending antioxidant supplements for this purpose.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Humans; Minerals; Oxidative Stress; Vitamin A; Vitamin E; Vitamins

Humans have relatively low plasma ascorbate levels and high serum uric acid levels compared to most mammals due to the presence of genetic mutations in l-gulonolactone oxidase and uricase, respectively. We review the major hypotheses for why these mutations may have occurred. In particular, we suggest that both mutations may have provided a survival advantage to early primates by helping maintain blood pressure during periods of dietary change and environmental stress. We further propose that these mutations have the inadvertent disadvantage of increasing our risk for hypertension and cardiovascular disease in today's society characterized by Western diet and increasing physical inactivity. Finally, we suggest that a "planetary biology" approach in which genetic changes are analyzed in relation to their biological action and historical context may provide the ideal approach towards understanding the biology of the past, present and future.

Topics: Animals; Antioxidants; Ascorbic Acid; Biological Evolution; Blood Pressure; Cardiovascular Diseases; Disease Outbreaks; Humans; L-Gulonolactone Oxidase; Models, Biological; Mutation; Obesity; Primates; Urate Oxidase; Uric Acid

The free radical theory of aging posits that oxidative stress is among the major mechanisms in aging and age-related disease, including cardiovascular disease (CVD). Numerous in vitro and animal studies have supported the role of low-density lipoprotein (LDL) oxidation in atherosclerosis. This has led to the hypothesis that antioxidants could be used as an inexpensive means of prevention and possibly, treatment of coronary artery disease, stroke, peripheral vascular disease, and other CVD-related diseases. Epidemiologic cohort studies with large numbers of men, women, and diverse populations have been largely supportive of this hypothesis. However, interventional trials have been controversial, with some positive findings, many null findings, and some suggestion of harm in certain high-risk populations. Because of the mismatch between the epidemiologic studies and the interventional trials, some researchers have advocated ending antioxidant work. Others have questioned the validity of the LDL oxidative hypothesis itself. Clearly, further research is needed to understand the reasons for the mismatch between the epidemiologic and interventional work. Recent smaller interventional studies with carefully chosen populations, such as those under high levels of oxidative stress, have yielded largely positive results. This suggests that we need more hypothesis-driven and rigorous clinical trial designs. This should help clarify the true potential utility of antioxidants in CVD and may lead to a better understanding of the role of oxidative stress in atherosclerosis.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Carotenoids; Cholesterol, LDL; Confounding Factors, Epidemiologic; Female; Free Radicals; Humans; Lipid Peroxidation; Male; Oxidative Stress; Research Design

Cardiovascular disease is the most important adult health problem in wealthy countries, where biological factors such as obesity, hypertension, dyslipidemia, diabetes, inappropriate diet, cigarette smoking, and sedentary life-style have contributed to its dissemination. Research concerning nutritional regimens has shown that persons who consume large amounts of fruit and vegetables have lower incidences of cardiovascular diseases, stroke, and tumors, although the precise mechanisms for this protective effect are elusive. Possible explanations include (a) increased consumption of dietary fiber, (b) reduced consumption of dietary cholesterol and other lipids, and (c) increased intake of the antioxidant vitamins (A, C, and E). Numerous studies have raised the question whether vitamin supplements help to prevent cardiovascular diseases. Results of randomized controlled trials of antioxidant vitamin supplements in large numbers of participants has been ambiguous or contradictory. This minireview examines the relevant clinical reports on dietary supplements of vitamins A, C, and E to determine whether they support the premise that patients at risk of cardiovascular disease may be candidates for this therapeutic option.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Humans; Vitamin A; Vitamin E

Diet, along with genetic and environmental factors, is considered a major aspect affecting longevity as well as vascular disease outcome. Yet, inadequate nutritional intake is rampant among the elderly, affecting nearly 44% of otherwise healthy, community-dwellers in developed countries. Thus, malnutrition, both in quali- and quantitative terms and especially as related to micronutrient intake, may exacerbate intrinsic cardiovascular maladaptation associated with aging, affecting vascular disease outcomes as well as longevity. Conversely, there is accumulating evidence that diets enriched in micronutrients, including vitamins, polyphenols, and essential fatty acids, maintain cellular antioxidant status and stress response enzymes, which otherwise decrease with age. Thus, adequate intakes of micronutrients, either consequent to a correct diet or through supplementation, might afford the elderly protection from cardiovascular diseases. In this article we review the known effects of micronutrients on the aging heart and we propose strategies for dietary improvements.

Topics: Aging; Animals; Ascorbic Acid; Cardiovascular Diseases; Fatty Acids, Omega-3; Flavonoids; Humans; Lipoproteins, LDL; Micronutrients; Phenols; Polyphenols; Vitamin B Complex; Vitamin E

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Cardiovascular Diseases; Cataract; Common Cold; Humans; Nutrition Policy; Nutritional Requirements

Oxidative reactions caused by cigarette smoke (CS) chemicals have been shown to initiate crucial events in atherogenesis. However, physicians and scientists are confronted with the paradoxical situation that an antioxidative treatment of smokers improves acute smoking effects but hardly has any impact on long term outcome of cardiovascular diseases (CVD). In this review we make an attempt to explain this paradox. First, smoke-derived free radicals and oxidants are part of CS causing a pro-oxidative state in the circulatory system. Further, smoke chemicals down-regulate antioxidant defence enzymes that would counteract the oxidative burden by cigarette smoke. With the prolonged exposure to smoke, oxidation catalysing metals accumulate in the vessel wall and mediate local oxidation reactions. Therefore, pharmacological intervention relying on non-selective antioxidants often appears to be ineffective. Consequently a novel strategy for the prevention and treatment of CVD caused by smoking is suggest, relying on a combined application of antioxidants, substitution of factors important for physiological oxidant defence, and metal-detoxifying agents.

Topics: Antioxidants; Ascorbic Acid; Atherosclerosis; Calcium; Cardiovascular Diseases; Humans; Inflammation; Oxidants; Oxidative Stress; Smoking; Vitamin E

1. In the present review, we addressed studies in humans and rats to determine the role that oxidative stress may play in mediating cardiovascular outcomes. 2. Biochemical evaluation of oxidative stress in both humans and spontaneously hypertensive rats gives equivocal results as to the relative levels in males versus females. Clinical trials with anti-oxidants in humans have not shown consistent results in protecting against detrimental cardiovascular outcomes. In spontaneously hypertensive rats (SHR), blockade studies using tempol or apocynin reduce renal oxidative stress and blood pressure in male SHR, but not in female rats. In addition, increasing oxidative stress with molsidomine increases blood pressure in male, but not female, SHR. Treatment with vitamins E and C reduces blood pressure in young male, but not aged, animals. Furthermore tempol is unable to reduce blood pressure in young male SHR in the absence of a functional nitric oxide system. 3. Neither human nor animal studies are consistent in terms of whether oxidative stress levels are higher in males or females. Furthermore, anti-oxidant therapy in humans often does not ameliorate, or even attenuate, the negative cardiovascular consequences of increased oxidative stress. Our studies in SHR shed light on why these outcomes occur.

Topics: Acetophenones; Animals; Antioxidants; Ascorbic Acid; Blood Pressure; Cardiovascular Diseases; Catalase; Cyclic N-Oxides; Enzyme Inhibitors; Female; Glutathione Peroxidase; Humans; Hypertension; Kidney; Male; Molsidomine; NADPH Oxidases; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Oxidative Stress; Rats; Rats, Inbred SHR; Sex Factors; Spin Labels; Superoxide Dismutase; Vitamin E

Vitamin C is required for collagen synthesis and biosynthesis of certain hormones and recommended dietary intake levels are largely based these requirements. However, to function effectively as an antioxidant (or a pro-oxidant), relatively high levels of this vitamin must be maintained in the body. The instability of vitamin C combined with its relatively poor intestinal absorption and ready excretion from the body reduce physiological availability of this vitamin. This inability to maintain high serum levels of vitamin C may have serious health implications and is particularly relevant in the onset and progression of degenerative disease, such as cancer and cardiovascular disease (CVD), which have a strong contributing oxidative damage factor. In this review, we examine recent studies on the regulation of transport mechanisms for vitamin C, related clinical ramifications, and potential implications in high-dose vitamin C therapy. We also evaluate recent clinical and scientific evidence on the effects of this vitamin on cancer and CVD, with focus on the key mechanisms of action that may contribute to the therapeutic potential of this vitamin in these diseases. Several animal models that could be utilized to address unresolved questions regarding the feasibility of vitamin C therapy are also discussed.

Topics: Ascorbic Acid; Biological Transport; Cardiovascular Diseases; Humans; Neoplasms

The studies on experimental animals (guinea pigs, monkeys, fish) have confirmed the important role of ascorbic acid deficiency in the development of hypercholesterolemia and atherosclerosis, but the clinical experience is not quite uniform. Metaanalyses of randomized controlled trials performed on subjects without established vitamin C-deficiency conclud that the evidence of the presence or absence of benefits derived from the ability of ascorbic acid to prevent cardiovascular diseases is not sufficient. This review is an outline of numerous clinical, epidemiological and prospective studies that have found a positive role of vitamin C in the prevention of atherosclerosis. If we admit the possibility that vitamin C deficiency is a significant risk factor of atherogenesis, due to ethical reasons it is impossible to perform long-term controlled trials on subjects with proved vitamin C deficiency, to recommend them not to change their nutrition and lifestyle, and to administer placebo to the control group. Therefore the proof of atherogenic effect of chronic vitamin C deficiency is limited to indirect evidence only. In this review many new data on the positive effects of ascorbic acid on human cardiovascular system are summarized and the mechanisms of its protective influence on blood vessels are discussed (Fig.5, Ref. 45). Full Text (Free, PDF) www.bmj.sk.

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Atherosclerosis; Cardiovascular Diseases; Humans; Risk Factors

The promising theoretical possibilities of antioxidant prevention and protection against vascular diseases and neoplasms could not have been realized as yet. The author searches into the causes of this failure by analyzing data of recent literature. Previous preventive trials as well as newly discovered pharmacological and molecular biological effects of antioxidants are reviewed. Results of meta-analyses on prevention trials of vascular disease by vitamin-E and those of gastrointestinal cancers are also included. The lately recognized properties of antioxidants are surveyed with special regard to their capability of modulating apoptosis, inducing gene expressions and their transformation into pro-oxidants. The harmful consequence of high doses of a single antioxidant is emphasized. The retinoids, vitamins D and K possess both pro-apoptotic and antiproliferative activity, while N-acetylcysteine exerts mainly anti-apoptotic effects. Since the effects of the eight vitamin E homologues are different in many respects, alpha-tocopherol can not be regarded as vitamin E of full value. Antioxidant supply from natural sources does not seem to be sufficient for an adequate preventive effect. The author recommends such a combination in which physiological amounts of vitamins C, D, K and B-complex, N-acetylcysteine, vitamin E of natural origin might be complemented by allopurinol, co-enzyme Q-10 and alpha-lipoic acid. A diet rich in flavonoids and carotenoids is essential. Application of appropriate laboratory methods is of great value in the individualization, monitoring and control of antioxidant treatment.

Topics: Acetylcysteine; Allopurinol; Antioxidants; Apoptosis; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Coenzymes; Flavonoids; Humans; Meta-Analysis as Topic; Neoplasms; Selenium; Ubiquinone; Vitamin A; Vitamin D; Vitamin E; Vitamin K; Vitamins

For more than 50 years, the Food and Nutrition Board of the National Academy of Sciences has been reviewing nutrition research and defining nutrient requirements for healthy people, referred to as the Recommended Dietary Allowances (RDA). As new nutrition research is published, the importance of vitamins as vital nutrients is underscored, and new physiologic roles and applications to human health are examined and considered with regard to updating the RDA. Each year a substantial amount of new research is published on vitamins. This review examines recent research published on the importance of vitamin C with regard to general health.

Topics: Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Asthma; Cardiovascular Diseases; Diabetes Mellitus; Exercise; Humans; Hypersensitivity; Neoplasms

Diabetes represents a serious risk factor for the development of cardiovascular problems such as coronary heart disease, peripheral arterial disease, hypertension, stroke, cardiomyopathy, nephropathy and retinopathy. Identifying the pathogenesis of this increased risk provides a basis for secondary intervention to reduce morbidity and mortality in diabetic patients. Hyperglycemia and protein glycation, increased inflammation, a prothrombotic state and endothelial dysfunction have all been implicated as possible mechanisms for such complications. A linking element between many of these phenomena could possibly be, among other factors, increased production of reactive oxygen species. Vascular endothelial cells have several physiological actions that are essential for the normal function of the cardiovascular system. These include the production of nitric oxide (NO), which regulates vasodilatation, anticoagulation, leukocyte adhesion, smooth muscle proliferation and the antioxidative capacity of endothelial cells. However, under conditions of hyperglycemia, excessive amounts of superoxide radicals are produced inside vascular cells and this can interfere with NO production leading to the possible complications. This article aims at reviewing the links between reactive oxygen species, diabetes and vascular disease and whether or not antioxidants can alter the course of vascular complications in diabetic patients and animal models. A possible beneficial effect of antioxidants might present a new addition to the range of secondary preventive measures used in diabetic patients.

Topics: alpha-Tocopherol; Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Diabetes Complications; Dyslipidemias; Endothelium, Vascular; Glucose; Humans; Hyperglycemia; Hypertension; Insulin Resistance; Nitric Oxide; Oxidative Stress; Reactive Oxygen Species; Risk Factors; Vitamin E

Some observational and randomized, clinical interventional studies have indicated that the antioxidative vitamins C (ascorbic acid) and E (alpha-tocopherol) can reduce intima-media thickness of the carotid arteries. It is, however, not clarified whether these vitamins may have a preventive effect against cardiovascular events.. The literature on the effects in relation to several cardiovascular endpoints of vitamins C and E, also used in combination, has been evaluated. The literature has been continuously and systematically collected over many years and supplemented by recent studies retrieved from Medline.. Observational studies including mainly healthy individuals have shown a favourable relationship between intake of vitamins C and E, also taken in combination, and subsequent cardiovascular events. However, most randomized, clinical interventional studies including patients with manifest atherosclerotic disease have not been able to document such a relationship.. The discrepancy found between observational studies and clinical interventional studies may be due to different study populations (healthy/ill individuals) and differences regarding age, sex, diet, smoking, degree of oxidative stress and other probable confounding factors. The significance of vitamins C and E in preventing cardiovascular disease is in our opinion not yet clarified.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotid Stenosis; Humans; Vitamin E

Results from experimental and epidemiologic studies suggest an influence of oxidative stress on development and progression of atherosclerosis in man. Prospective endpoint studies failed to support this hypothesis. The current literature is summarized in this review.

Topics: Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Antioxidants; Arteriosclerosis; Ascorbic Acid; Aspirin; beta Carotene; Cardiovascular Diseases; Controlled Clinical Trials as Topic; Double-Blind Method; Female; Follow-Up Studies; Free Radicals; Humans; Male; Nutritional Physiological Phenomena; Oxidative Stress; Placebos; Platelet Aggregation Inhibitors; Primary Prevention; Prospective Studies; Ramipril; Randomized Controlled Trials as Topic; Risk Factors; Time Factors; Tocopherols; Vitamins

Vitamins are essential to maintain normal metabolic processes and homeostasis within the body. The amount of a specific vitamin required by an individual varies considerably and it is influenced by such factors as body size, growth rate, physical activity, and pregnancy. Most vitamins are stored minimally in human cells, but some are stored in liver cells to a greater extent. Vitamins A and D, for example, may be stored in sufficient amounts to maintain an individual without any intake for 5 to 10 months and 2 to 4 months, respectively. However, a deficiency of vitamin B compounds (except vitamin B12) may be noted within days, and the lack of vitamin C will manifest within weeks and may result in death in 5 to 6 months. The current recommended dietary allowance (RDA) of vitamin C is 75 mg for woman and 90 mg for men, based on the vitamin's role as an antioxidant as well as protection from deficiency. High intakes of the vitamin are generally well tolerated, however, a Tolerable Upper Level (TUL) was recently set at 2 g based on gastrointestinal upset that sometimes accompanies excessive dosages. Several populations warrant special attention with respect to vitamin C requirements. These include patients with periodontal disease, smokers, pregnant and lactating women, and the elderly.

Topics: Alzheimer Disease; Animals; Antioxidants; Ascorbic Acid; Ascorbic Acid Deficiency; Bone Regeneration; Cardiovascular Diseases; Chondrogenesis; Diabetes Mellitus; Female; Humans; Male; Maximum Tolerated Dose; Nutrition Policy; Periodontal Diseases; Pregnancy; Virus Diseases

Vitamin C in humans must be ingested for survival. Vitamin C is an electron donor, and this property accounts for all its known functions. As an electron donor, vitamin C is a potent water-soluble antioxidant in humans. Antioxidant effects of vitamin C have been demonstrated in many experiments in vitro. Human diseases such as atherosclerosis and cancer might occur in part from oxidant damage to tissues. Oxidation of lipids, proteins and DNA results in specific oxidation products that can be measured in the laboratory. While these biomarkers of oxidation have been measured in humans, such assays have not yet been validated or standardized, and the relationship of oxidant markers to human disease conditions is not clear. Epidemiological studies show that diets high in fruits and vegetables are associated with lower risk of cardiovascular disease, stroke and cancer, and with increased longevity. Whether these protective effects are directly attributable to vitamin C is not known. Intervention studies with vitamin C have shown no change in markers of oxidation or clinical benefit. Dose concentration studies of vitamin C in healthy people showed a sigmoidal relationship between oral dose and plasma and tissue vitamin C concentrations. Hence, optimal dosing is critical to intervention studies using vitamin C. Ideally, future studies of antioxidant actions of vitamin C should target selected patient groups. These groups should be known to have increased oxidative damage as assessed by a reliable biomarker or should have high morbidity and mortality due to diseases thought to be caused or exacerbated by oxidant damage.

Topics: Animals; Antioxidants; Ascorbic Acid; Biological Availability; Cardiovascular Diseases; DNA; DNA Damage; Dose-Response Relationship, Drug; Fruit; Humans; Lipid Peroxidation; Neoplasms; Oxidation-Reduction; Proteins; Vegetables

Diet is believed to play a complex role in the development of cardiovascular disease, the leading cause of death in the Western world. Tomatoes, the second most produced and consumed vegetable nationwide, are a rich source of lycopene, beta-carotene, folate, potassium, vitamin C, flavonoids, and vitamin E. The processing of tomatoes may significantly affect the bioavailability of these nutrients. Homogenization, heat treatment, and the incorporation of oil in processed tomato products leads to increased lycopene bioavailability, while some of the same processes cause significant loss of other nutrients. Nutrient content is also affected by variety and maturity. Many of these nutrients may function individually, or in concert, to protect lipoproteins and vascular cells from oxidation, the most widely accepted theory for the genesis of atherosclerosis. This hypothesis has been supported by in vitro, limited in vivo, and many epidemiological studies that associate reduced cardiovascular risk with consumption of antioxidant-rich foods. Other cardioprotective functions provided by the nutrients in tomatoes may include the reduction of low-density lipoprotein (LDL) cholesterol, homocysteine, platelet aggregation, and blood pressure. Because tomatoes include several nutrients associated with theoretical or proven effects and are widely consumed year round, they may be considered a valuable component of a cardioprotective diet.

Topics: Antioxidants; Ascorbic Acid; Biological Availability; Cardiovascular Diseases; Carotenoids; Diet; Flavonoids; Folic Acid; Food Handling; Hot Temperature; Humans; Lycopene; Nutritive Value; Solanum lycopersicum; Vitamin E

Microparticles are membrane vesicles released from many different cell types. There are two mechanisms that can result in their formation, cell activation and apoptosis. In these two mechanisms, different pathways are involved in microparticle generation. Microparticle generation seems to be a well regulated process. Microparticles vary in size, phospholipid and protein composition. They have a potent pro-inflammatory effect, promote coagulation and affect vascular function. Since these processes are all involved in the pathogenesis of cardiovascular disease and circulating microparticle numbers are altered in many cardiovascular diseases, a role for microparticles in the pathogenesis of cardiovascular diseases is likely. Although hard evidence for a role of microparticles in cardiovascular diseases at present is still only limited, new evidence is accumulating rapidly to support this theory. Elucidation of the microparticle composition and the mechanisms involved in exertion of their effects will supply this evidence and enable us to develop additional intervention strategies for prevention and treatment of cardiovascular diseases.

Topics: Abciximab; Antibodies, Monoclonal; Anticoagulants; Antioxidants; Apoptosis; Ascorbic Acid; Blood Coagulation; Blood Platelets; Calcium; Calcium Channel Blockers; Cardiovascular Diseases; Endothelium, Vascular; Female; Humans; Immunoglobulin Fab Fragments; Inflammation; Lipid Metabolism; Male; Membrane Lipids; Platelet Activation; Subcellular Fractions

Oxidative stress is involved in the pathogenesis of atherosclerosis, while a variety of antioxidants has been used in clinical studies, during the past few years, for the prevention and treatment of atherosclerosis. In small clinical studies it was found that both vitamins C and E may improve endothelial function in patients with risk factors for atherosclerosis such as diabetes mellitus, smoking, hypertension, or hypercholesterolemia. However, the initial, hopeful reports regarding the beneficial role of antioxidant vitamins against atherosclerosis, derived from purely observational studies, were followed by the negative results of almost all large randomized trials. Therefore, treatment with antioxidant vitamins C and E should not be recommended for the prevention or treatment of coronary atherosclerosis. New antioxidant strategies are needed to clarify the exact role of antioxidant treatment in coronary atherosclerosis.

Topics: Adult; Aged; Aged, 80 and over; Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Cohort Studies; Coronary Artery Disease; Diabetes Complications; Diet; Endothelium, Vascular; Female; Follow-Up Studies; Free Radicals; Humans; Hypercholesterolemia; Hypertension; Male; Middle Aged; Oxidative Stress; Prospective Studies; Randomized Controlled Trials as Topic; Risk; Risk Factors; Smoking; Time Factors; Vitamin E

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Feeding Behavior; Female; Humans; Male; Vitamin E

People who consume a diet rich in fruit and vegetables have lower risks of cancer, cardiovascular disease and all-cause mortality. Many prospective cohort studies have reported inverse associations between dietary intake or blood levels of beta-carotene and risks of cancer. Several large-scale trials were set up to assess whether beta-carotene supplementation might reduce the risk of cancer. Subsequently, evidence emerged from basic research which indicated that oxidative modification of low-density lipoprotein cholesterol increases its atherogenicity. The evidence from basic research, and epidemiological evidence for a possible protective effect of antioxidant vitamins for cardiovascular disease was strongest for vitamin E. More recently, further trials were set up to examine if supplementation with anti-oxidant vitamins might also reduce the risk of cardiovascular disease. This review summarises the available randomised evidence from published trials of beta-carotene supplementation involving 70,000 people from 3 large-scale trials in healthy populations and on vitamin E supplementation involving 29,000 patients at high-risk of cardiovascular disease from 5 large-scale trials. The results of these trials have been disappointing and failed to confirm any protective effect of these vitamins for either cancer or for cardiovascular disease.

Topics: Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Cholesterol, LDL; Humans; Lycopene; Oxidative Stress; Randomized Controlled Trials as Topic; Risk Assessment; Vitamin E; Vitamins

Topics: Adrenergic beta-Antagonists; Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Coenzymes; Free Radicals; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Lipoproteins, LDL; Lycopene; Oxidative Stress; Primary Prevention; Risk Factors; Ubiquinone; Vitamin E

Evidence that fruit and vegetables may protect against coronary heart disease is accumulating. It is unclear which constituents of fruit and vegetables are responsible for this protective effect. Folate as a co-substrate in homocysteine metabolism may be important. An intake of about 400 micrograms folate equivalents/day seems to be required to achieve stable low homocysteine blood levels. Five of eight epidemiologic studies show significant inverse associations between folate and cardiovascular disease. These associations could be confounded by antioxidant vitamins and/or other substances. In trials examining an association between folate and cardiovascular disease such confounding must be excluded, before specific recommendations can be given. Observational studies suggest that vitamin C plays a role in the aetiology of cardiovascular disease, but there are no completed intervention trials of this vitamin alone. With regard to vitamin E two cohort studies point to cardiovascular benefits with the long-term use of supplements of at least 100 IU/day, but the results of controlled trials are inconclusive. There is some evidence from observational studies of an inverse association between beta-carotene and cardiovascular disease, particularly in smokers. Intervention trials do not support this hypothesis, rather, they suggest a possible harmful effect of beta-carotene supplements in smokers. Nevertheless, protective effects of beta-carotene and vitamin E in different dosages, durations of administration, or different combinations are still possible. The last paragraph of this review discusses limitations of the present and priorities of future research.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Epidemiologic Studies; Folic Acid; Fruit; Homocysteine; Humans; Vegetables; Vitamin E

The human organism is incapable of producing vitamin C by biosynthesis. We are therefore totally dependent on the presence of this vitamin in our diet. Vitamin C is capable of essentially influencing the course of many metabolic processes, and it is therefore used in the treatment and prophylaxis of many diseases, including those that are a consequence of the activity of the so-called reactive forms of oxygen. The presence of vitamin C in the anti-oxidant protective system is believed to be very important, since it can react with the free radicals of oxygen and other oxidants, and "sweep" them away. Therefore, attention is more and more frequently focused on the possibility of using vitamin C in the treatment of those circulatory diseases that are believed to be associated with the action of free radicals. Routine administration of vitamin C should be therefore recommended in the treatment of patients with coronary arterial disease, treatment of patients after cardiac infarction or cerebral stroke, or in the treatment of arterial hypertension.

Topics: Antioxidants; Ascorbic Acid; Blood Coagulation Disorders; Cardiovascular Diseases; Dietary Supplements; Fruit; Humans; Magnoliopsida; Vegetables

Potentially damaging species (reactive oxygen, nitrogen and chlorine species) arise as by-products of metabolism and as physiological mediators and signalling molecules. Levels of these species are controlled by the antioxidant defence system. Several components of this system are micronutrients (e.g. vitamins C and E) or are dependent upon dietary micronutrients (e.g. CuZn and Mn superoxide dismutase). The antioxidant defences act as a coordinated system where deficiencies in one component may affect the efficiency of the others. Oxidative stress may be an important factor in infection if micronutrients are deficient.

Topics: Antioxidants; Arthritis, Rheumatoid; Ascorbic Acid; Cardiovascular Diseases; Copper; Deficiency Diseases; Developing Countries; Disease Susceptibility; HIV Infections; Humans; Iron; Magnesium; Manganese; Micronutrients; Nutritional Status; Oxidative Stress; Virus Diseases; Vitamin E; Zinc

Naturally occurring antioxidants such as vitamin E, beta-carotene, and vitamin C can inhibit the oxidative modification of low density lipoproteins. This action could positively influence the atherosclerotic process and, as a consequence, the progression of coronary heart disease. A wealth of experimental studies provide a sound biological rationale for the mechanisms of action of antioxidants, whereas epidemiologic studies strongly sustain the "antioxidant hypothesis." To date, however, clinical trials with beta-carotene supplements have been disappointing, and their use as a preventive intervention for cancer and coronary heart disease should be discouraged. Only scanty data from clinical trials are available for vitamin C. As to vitamin E, discrepant results have been obtained by the Alpha-Tocopherol, Beta Carotene Cancer Prevention Study with a low-dose vitamin E supplementation (50 mg/d) and the Cambridge Heart Antioxidant Study (400-800 mg/d). The results of the GISSI-Prevenzione (300 mg/d) and HOPE (400 mg/d) trials suggest the absence of relevant clinical effects of vitamin E on the risk of cardiovascular events. Currently ongoing are several large-scale clinical trials that will help in clarifying the role of vitamin E in association with other antioxidants in the prevention of atherosclerotic coronary disease.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Clinical Trials as Topic; Female; Humans; Lipid Peroxidation; Male; MEDLINE; Randomized Controlled Trials as Topic; Vitamin E; Vitamins

To assess the balance of benefits and risks of supplementation with beta-carotene, vitamin E, vitamin C, and multivitamins on cancer, cardiovascular (CVD), and eye diseases.. Physicians' Health Study II (PHS II) is a randomized, double-blind, placebo-controlled trial enrolling 15,000 willing and eligible physicians aged 55 years and older. PHS II will utilize a 2 x 2 x 2 x 2 factorial design to test alternate day beta-carotene, alternate day vitamin E, daily vitamin C, and a daily multivitamin, in the prevention of total and prostate cancer, CVD, and the age-related eye diseases, cataract and macular degeneration. PRIOR RESULTS: The final results of the recently completed Physicians' Health Study I (PHS I), a randomized, double-blind, placebo-controlled trial in 22,071 healthy US male physicians, indicated that beta-carotene supplementation (50 mg on alternate days) had no significant benefit or harm on cancer or CVD during more than 12 years of treatment and follow-up. In regards to cancer, there were possible benefits on total and prostate cancer in those with low baseline levels assigned to beta-carotene, a finding compatible with the Chinese Cancer Prevention Study for combined treatment with beta-carotene, vitamin E, and selenium in a poorly nourished population. Further, with respect to CVD, there were apparent benefits of beta-carotene supplementation on subsequent vascular events among a small subgroup of 333 men with prior angina or revascularization. The currently available data from randomized trials of primary prevention are sparse and inconsistent for vitamin E and non-existent for vitamin C and multivitamins. For eye diseases, namely cataract and age-related macular degeneration, there are no completed large-scale randomized trials of antioxidant vitamins.. PHS II is unique in several respects. PHS II is the only primary prevention trial in apparently healthy men testing the balance of benefits and risks of vitamin E on cancer and CVD. In addition, PHS II is the only primary prevention trial in apparently healthy men to test the balance of benefits and risks of vitamin C, multivitamins, as well as any single antioxidant vitamin, alone and in combination, on cancer, CVD, and eye diseases. Finally, PHS II is the only trial testing a priori the hypotheses that beta-carotene and vitamin E may reduce the risks of prostate cancer. Thus, PHS II will add unique as well as importantly relevant and complementary information to the totality of evidence from other completed and ongoing large-scale randomized trials on the balance of benefits and risks of beta-carotene, vitamin E, vitamin C, and multivitamins alone and in combination on prevention of cancer, CVD and eye diseases.

Topics: Aged; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cataract; Double-Blind Method; Female; Follow-Up Studies; Humans; Macular Degeneration; Male; Middle Aged; Neoplasms; Sample Size; Vitamin E

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Diet; Free Radicals; Humans; Lipid Peroxidation; Neoplasms; Vitamin E

Observational studies have shown an inverse relationship between consumption of fruits and vegetables high in beta-carotene, vitamins C and E, and ischemic heart disease (IHD) and stroke. In large observational studies, beta- carotene reduced the risk of IHD events in men, particularly in smokers. In contrast, four large randomized trials did not reveal a reduction in cardiovascular events with beta-carotene use, and may, in fact, increase IHD and total mortality in male smokers. There have been only a few large observational studies and one randomized trial with vitamin C, which have shown no beneficial or deleterious impact of this vitamin on cardiovascular events. Most large observational studies have shown an inverse relationship between vitamin E and IHD. However, a meta-analysis of the four randomized trials done in Europe and America involving a total of 51,000 participants allocated to vitamin E or placebo for 1.4 to 6 years, did not demonstrate a reduction in cardiovascular and IHD mortality and nonfatal myocardial infarction. Currently, there are no data to support the use of these vitamins to reduce the risk of cardiovascular events. Trials are in progress to determine whether a longer duration of administration of vitamin E or the association of vitamin E with cofactors may reduce cardiovascular events.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Dietary Supplements; Endothelium, Vascular; Humans; Male; Myocardial Ischemia; Randomized Controlled Trials as Topic; Vitamin E

The faith that an oxidizing of LDL is necessary for he foam cell formation is basically for the so called oxidative hypothesis of atherosclerosis. The role of LDL-oxidation for the atherosclerotic plaque formation, as well as its association with inflammatory processes in the vascular wall, are well established. The important conclusion of this hypothesis is the possible role of the antioxidants attenuating atherosclerotic mechanisms. The advances in studying the principal antioxidant vitamins E, C and beta-carotene effects, revealed a great part of their molecular mechanisms, which are not necessarily antioxidative. The important aspects of the cooperative antioxidant action are revealed too, including the so called tocopherol-mediated peroxidation, suggesting the need for the co-antioxidants for effective antioxidant defense. In the recent years many vitamin antioxidant supplementations are used. The epidemiological results of such supplementation do not always reveal the same beneficial effects as expected theoretically or based on the observations made with a diet rich in fruits and vegetables. The present paper generalizes the thought concerning the impact of oxidized LDL in atherosclerosis, as well as mechanisms of action and pharmacokinetiks of the most widely used antioxidant vitamins--E, C and beta-carotene, and the perspectives of their usage in cardiovascular prophylaxy bazed upon the recent experience in antioxidant vitamin supplementation.

Topics: Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Dietary Supplements; Humans; Lipoproteins, LDL; Oxidative Stress; Vitamin E

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diet; Drug Therapy, Combination; Humans; Risk Factors; Vitamin E

The current recommended dietary allowance (RDA) for vitamin C for adult nonsmoking men and women is 60 mg/d, which is based on a mean requirement of 46 mg/d to prevent the deficiency disease scurvy. However, recent scientific evidence indicates that an increased intake of vitamin C is associated with a reduced risk of chronic diseases such as cancer, cardiovascular disease, and cataract, probably through antioxidant mechanisms. It is likely that the amount of vitamin C required to prevent scurvy is not sufficient to optimally protect against these diseases. Because the RDA is defined as "the average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all healthy individuals in a group," it is appropriate to reevaluate the RDA for vitamin C. Therefore, we reviewed the biochemical, clinical, and epidemiologic evidence to date for a role of vitamin C in chronic disease prevention. The totality of the reviewed data suggests that an intake of 90-100 mg vitamin C/d is required for optimum reduction of chronic disease risk in nonsmoking men and women. This amount is about twice the amount on which the current RDA for vitamin C is based, suggesting a new RDA of 120 mg vitamin C/d.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cataract; Clinical Trials as Topic; Female; Humans; Lipid Peroxidation; Male; Neoplasms; Nutrition Policy; Scurvy

Haemodialysis is associated with increased oxidant stress. This appears to be due to (1) an increased production of free radicals during haemodialysis, (2) a net reduction of many antioxidants and (3) factors intrinsic to the uremic state. These alterations can lead to cardiovascular disease and many of the pathologies associated with chronic renal failure. Haemolipodialysis (HLD) is a new haemodialytic technique aimed at reducing oxidant stress and removing hydrophobic or protein bound toxins. The technique uses dialysate containing ascorbic acid (vitamin C) and polyunsaturated unilamellar liposomes containing alpha-tocopherol (vitamin E). The liposomes interact with blood components at the haemodialysis membrane without passage through the membrane. Vitamin C and vitamin E are added to the system to protect the cell and plasma components from reactive oxygen species produced from activated inflammatory cells. This technique may provide a new approach in preventing free radical-associated pathologies in chronic haemodialysis patients.

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Liposomes; Oxidative Stress; Renal Dialysis; Vitamin E

Interest in the role of vitamin E in disease prevention has encouraged the search for reliable indices of vitamin E status. Most studies in human subjects make use of static markers, usually alpha-tocopherol concentrations in plasma or serum. Plasma or serum alpha-tocopherol concentrations of < 11.6, 11.6-16.2, and > 16.2 mumol/l are normally regarded as indicating deficient, low and acceptable vitamin E status respectively, although more recently it has been suggested that the optimal plasma alpha-tocopherol concentration for protection against cardiovascular disease and cancer is > 30 mumol/l at common plasma lipid concentrations in combination with plasma vitamin C concentrations of > 50 mumol/l and > 0.4 mumol beta-carotene/l. Assessment of vitamin E status has also been based on alpha-tocopherol concentrations in erythrocytes, lymphocytes, platelets, lipoproteins, adipose tissue, buccal mucosal cells and LDL, and on alpha-tocopherol: gamma-tocopherol in serum or plasma. Erythrocyte susceptibility to haemolysis or lipid oxidation, breath hydrocarbon exhalation, oxidative resistance of LDL, and alpha-tocopheryl quinone concentrations in cerebrospinal fluid have been used as functional markers of vitamin E status. However, many of these tests tend to be non-specific and poorly standardized. The recognition that vitamin E has important roles in platelet, vascular and immune function in addition to its antioxidant properties may lead to the identification of more specific biomarkers of vitamin E status.

Topics: Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Humans; Lipoproteins, LDL; Neoplasms; Nutritional Physiological Phenomena; Nutritional Status; Reference Values; Vitamin E

Naturally occurring antioxidants like vitamin E, beta-carotene, and vitamin C can inhibit the oxidative modification of low-density lipoproteins. This action could positively influence the atherosclerotic process and, as a consequence, the progression of coronary heart disease. A wealth of experimental studies provide a sound biological rationale for the mechanisms of action of antioxidants, whereas epidemiological studies strongly sustain the 'antioxidant hypothesis'. To data, however, clinical trials with beta-carotene supplements have been disappointing and their use as a preventive intervention for cancer and coronary heart disease should be discouraged. Only scant data from clinical trials are available for vitamin C. As for vitamin E, discrepant results have been obtained by the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study with a low-dose vitamin E supplementation (50 mg daily) and the Cambridge Heart Antioxidant Study (400-800 mg daily). Currently ongoing are several large-scale clinical trials that will help in clarifying the role of vitamin E in the prevention of atherosclerotic coronary disease.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Case-Control Studies; Cohort Studies; Humans; Lipoproteins, LDL; Randomized Controlled Trials as Topic; Vitamin E

Unlike most animals, which form ascorbic acid by metabolizing glucose, humans require an exogenous source. Vitamin C occurs primarily in fruits and vegetables, and scurvy develops from inadequate consumption of these sources, usually because of ignorance about proper nutrition, psychiatric disorders, alcoholism, or social isolation. The earliest symptom of scurvy, occurring only after many weeks of deficient intake, is fatigue. The most common cutaneous findings are follicular hyperkeratosis, perifollicular hemorrhages, ecchymoses, xerosis, leg edema, poor wound healing, and bent or coiled body hairs. Gum abnormalities, which occur only in patients with teeth, include gingival swelling, purplish discoloration, and hemorrhages. Pain in the back and joints is common, sometimes accompanied by obvious hemorrhage into the soft tissue and joints. Syncope and sudden death may occur. Anemia is frequent, leukopenia occasional. Treatment with vitamin C results in rapid, often dramatic, improvement. (J Am Acad Dermatol 1999;41:895-906.). At the conclusion of this learning activity, participants should be familiar with the history, pathogenesis, clinical features, and treatment of scurvy in adults.

Topics: Adult; Animals; Ascorbic Acid; Cardiovascular Diseases; History, 15th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Nutrition Policy; Respiratory Tract Diseases; Scurvy; Skin Diseases

Several nutritional interventions for cardiovascular disease (CVD) prevention and therapy have recently appeared in the biomedical literature. These include appropriate use of several vitamins (E, C, B6, folate) and conditionally essential nutrients (CoQ10, L-arginine, propionyl L-carnitine). Possible undesirable consequences of long term nutritional supplementation with vitamin E and of adverse drug-nutrient interactions between the statins and CoQ10 are also considered. Although additional intervention studies are needed, current scientific evidence generally supports nutritional supplementation with these nutrients as an effective adjunctive strategy for CVD control.

Topics: Antioxidants; Arginine; Ascorbic Acid; Cardiovascular Diseases; Carnitine; Coenzymes; Cost-Benefit Analysis; Free Radical Scavengers; Humans; Nutritional Requirements; Primary Prevention; Ubiquinone; Vitamin B Complex; Vitamin E

Cardiovascular disease (CVD), particularly in the form of coronary artery disease, is the leading cause of death in the United States. Research in the past 10 years links pathogenic low-density lipoprotein (LDL) modification to oxidation damage by free radicals. This review summarizes the major findings of CVD-related epidemiologic research and clinical trials conducted in the past 5 years on vitamins A, C, and E. Vitamin supplementation behaviors are discussed. In prospective studies, the intake of vitamins A, C, and E has been correlated with lower mortality rates. When recent clinical trials and oxidation studies are analyzed, the weight of evidence suggests that 100-400 IU of daily vitamin E over 2 years or more may be most efficacious in reducing low-density lipoprotein oxidation and positively influencing mortality rates from CVD in primary care. Research also supports vitamin E supplementation in patients with known CAD or a history of transient ischemic attacks. Persons with diabetes or hypertension as well as smokers may benefit from supplemental vitamin C intake. Targeted antioxidant vitamin intake should be included in CVD risk assessment and primary preventive counseling efforts.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Child; Cholesterol, LDL; Counseling; Dietary Supplements; Energy Intake; Female; Humans; Male; Nutrition Policy; Oxidation-Reduction; Oxidative Stress; Patient Education as Topic; Primary Prevention; Risk Assessment; Risk Factors; United States; Vitamin A; Vitamin E

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Female; Humans; Male; Randomized Controlled Trials as Topic; Vitamin E

Antioxidants are crucial components of fruit/vegetable rich diets preventing cardiovascular disease (CVD) and cancer: plasma vitamins C, E, carotenoids from diet correlate prevalence of CVD and cancer inversely, low levels predict an increased risk of individuals which is potentiated by combined inadequacy (e.g., vitamins C + E, C + carotene, A + carotene); self-prescribed rectification of vitamins C and E at adequacy of other micronutrients reduce forthcoming CVD, of vitamins A, C, E, carotene and conutrients also cancer; randomized exclusive supplementation of beta-carotene +/- vitamin A or E lack benefits except prostate cancer reduction by vitamin E, and overall cancer reduction by selenium; randomized intervention with synchronous rectification of vitamins A + C + E + B + minerals reduces CVD and counteracts precancerous lesions; high vitamin E supplements reveal potentials in secondary CVD prevention. Plasma values desirable for primary prevention: > or = 30 mumol/l lipid-standardized vitamin E (alpha-tocopherol/cholesterol > or = 5.0 mumol/mmol); > or = 50 mumol/l vitamin C aiming at vitamin C/vitamin E ratio > 1.3-1.5; > or = 0.4 mumol/l beta- (> or = 0.5 mumol/l alpha+ beta-) carotene.. In CVD vitamin E acts as first risk discriminator, vitamin C as second one; optimal health requires synchronously optimized vitamins C + E, A, carotenoids and vegetable conutrients.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Health Promotion; Humans; Micronutrients; Neoplasms; Nutritional Physiological Phenomena; Randomized Controlled Trials as Topic; Risk Factors; Vitamin E

Topics: Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Humans; Primary Prevention; Prospective Studies; Vitamin A; Vitamin E

Considerable interest has risen in the idea that oxidative stress is instrumental in the etiology of numerous human diseases. Oxidative stress can arise through the increased production of reactive oxygen species (ROS) and/or because of a deficiency of antioxidant defenses. Antioxidant deficiencies can develop as a result of decreased antioxidant intake (such as vitamins C and E), synthesis of enzymes (such as superoxide dismutase and glutathione peroxidase) or increased antioxidant utilization. Insufficient antioxidant enzyme synthesis may in turn be due to decreased micronutrient availability (such as selenium, magnese, copper and zinc). Of those diseases linked with oxidative stress, cardiovascular disease provides the strongest evidence for the protective role of antioxidants. A high consumption of fruit and vegetables, which are good sources of antioxidants, is associated with a lower coronary risk. More specifically, there is evidence of a reduced coronary risk in populations with high blood levels of the antioxidant nutrients, vitamins C and E. Evidence is also accumulating that diabetes, and microvascular complications associated with diabetes, involve oxidative stress and have compromised antioxidant status. In addition, patients who develop acute respiratory distress syndrome (ARDS) also exhibit clear evidence of oxidative stress. Definitive proof for active oxygen formation and oxidative cell damage being causative rather than a result of other underlying these pathologies remains elusive; however, evidence is sufficiently compelling to suggest that antioxidants are potential therapeutic agents in the above conditions.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diabetes Mellitus; Humans; Oxidative Stress; Respiratory Distress Syndrome; Vitamin E

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Humans; Nutritional Requirements; Randomized Controlled Trials as Topic; Vitamin A; Vitamins

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diet; Health Status; Humans; Neoplasms

To review prospective epidemiological studies and randomized clinical trials regarding the role of antioxidant vitamins (vitamins E and C and beta-carotene) in the prevention of cardiovascular diseases.. Computerized (MEDLINE and Science Citation Index) and manual searches on the role of antioxidant vitamins in cardiovascular disease management.. Only prospective epidemiological studies and double-blind, controlled, randomized clinical trials, including at least 100 participants and providing sufficient data to allow quantitative estimation of the effects of vitamin intake were included. Retrospective epidemiological evaluations and other retrospective studies were excluded. Geographic correlation studies of population-based intake of antioxidants and cardiovascular disease rates were also excluded due to the potential large impact of confounders in cross-sectional analyses.. Relative risk was evaluated for all prospective epidemiological studies. Relative risk reductions were evaluated for clinical trials. The Mantel-Haenszel method was used to estimate the relative risk reduction in clinical trials when not calculated in the original publication. A formal meta-analysis was not performed because very significant differences among study populations, type (supplemental versus dietary) and dosage of antioxidant vitamins, duration of follow-up and overall study design exist for both epidemiological investigations and clinical trials, and the pooling of study results could be misleading.. Prospective epidemiological investigations suggest a reduction in cardiovascular risk associated with increased intake of antioxidant vitamins, particularly vitamin E. Randomized clinical trials remain inconclusive with regard to the role of vitamin E in cardiovascular protection. The large, randomized clinical trials of beta-carotene in primary prevention show no effect and potential for harm associated with the use of beta-carotene. There are inconclusive and insufficient epidemiological and clinical trial data with regard to the role of vitamin C in cardiovascular protection. Overall, it is recommended that wide-spread use of antioxidant vitamins in cardiovascular protection should not be instituted and should await the results of further ongoing clinical trials.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Clinical Trials as Topic; Epidemiologic Studies; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prospective Studies; Randomized Controlled Trials as Topic; Treatment Outcome; Vitamin E; Vitamins

Topics: Angioplasty, Balloon; Animals; Ascorbic Acid; Cardiovascular Diseases; Coronary Vessels; Oxidative Stress; Superoxides; Vitamin E

This review summarizes the scientific evidence for a possible role of antioxidants in the prevention of coronary heart disease (CHD). Dietary antioxidants include vitamin E, vitamin C and beta-carotene, whereas selenium is an integral part of the antioxidant enzyme glutathione peroxidase. Experimental studies suggest that the oxidation of low-density lipoproteins (LDL) in the vessel wall plays an important role in the development of atherosclerotic lesions. The resistance of LDL to oxidation is increased by antioxidant supplementation, at least in vitro. Epidemiological studies have not demonstrated unequivocally that a high intake of antioxidants leads to a decreased risk of CHD. Studies on dietary intake and serum levels of antioxidants do point in the direction of a preventive effect of antioxidants, whereas the results of intervention studies are less conclusive. Beta-carotene supplementation is not associated with any decrease in CHD; high doses of vitamin E may be beneficial, but results from large trials are to be awaited. General preventive measures based on antioxidant supplementation are not yet justifiable.

Topics: Animals; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Coronary Disease; Diet; Female; Free Radicals; Humans; Lipoproteins, LDL; Male; Oxidation-Reduction; Prospective Studies; Risk Factors; Selenium; Vitamin E

The recent scientific literature indicates that beyond merely protecting against scurvy vitamin C contributes to many aspects of human health. The main areas of research reviewed include: 1. Vitamin C requirements of smokers. The data indicate that the vitamin C requirement of smokers is higher by at least 60 mg per day (up to 140 mg per day) than that of nonsmokers. 2. Important functions of the body, such as immune response, pulmonary function, and iron absorption are related to vitamin C intakes. Daily vitamin C intake of at least 150-200 mg per day enhance these functions. 3. Vitamin C may play critical roles in the prevention of CHD, cancer and cataract. Based on the available data, vitamin C intakes of at least 80-120 mg per day are associated with lowering the risk of these chronic diseases. 4. The literature documents that these and much higher intake levels of vitamin C are safe.

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Cataract; Diet; Health Status; Humans; Neoplasms; Nutrition Policy; Nutritional Requirements

Advances in diagnosis and treatment of cancer, as well as increased understanding of the mechanisms of the disease, have provided and will certainly continue to provide enormous benefit to affected individuals. At the same time, interventions that may prevent common cancers from developing in healthy people could, at least in theory, afford even greater benefits to society as a whole. The hypothesis that antioxidant vitamins might reduce cancer risk is based on a large body of both basic and human epidemiologic research. A large number of case-control and cohort studies provide remarkably consistent data suggesting that consumption of foods rich in antioxidant vitamins reduce risks of developing epithelial cancers. These data raise the question of a possible role of antioxidants, such as vitamins C and E, and beta carotene, in the primary prevention of cancer as well ar cardiovascular disease but do not provide a definitive answer. Despite the lack of clear benefit, there has been a rapid increase in the consumption of supplements of these micronutrients. Limited randomized trial data on the role of supplemental antioxidants are available. A number of randomized trials are currently underway designed to test the hypothesis that antioxidants prevent chronic diseases and to evaluate the long term safety of the widespread practice of supplementation. Well designed and well conducted large-scale randomized trials are necessary to provide a definitive positive or negative result on which public policy can be based, or a null result that is truly informative and that can then safely permit the rechanneling of already limited resources to other areas of research.

Topics: Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Humans; Neoplasms; Randomized Controlled Trials as Topic; Vitamin E

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diet; Female; Humans; Male; Middle Aged; Risk Factors; Treatment Outcome; Vitamin E

In this chapter, we have briefly reviewed the current scientific knowledge of the role of vitamin C in the prevention of atherosclerosis and its associated clinical manifestations. There is good evidence from animal studies that vitamin C can slow the progression of experimental atherosclerosis. Most of these studies, however, were done either in guinea pigs, using ascorbic acid depletion, or in cholesterol-fed rabbits, using ascorbic acid supplementation. Both animal models have limitations, as guinea pigs are not a well-established (nor well-studied) model of atherosclerosis, and rabbits develop atherosclerosis at high serum beta-VLDL cholesterol levels, and in addition can synthesize ascorbic acid. In contrast, humans develop atherosclerosis spontaneously and readily at moderately elevated serum LDL cholesterol levels and have lost the ability to synthesize ascorbic acid. Thus, the animal studies discussed, although quite promising and suggestive of an anti-atherogenic effect of ascorbic acid, need to be expanded to primates before more definitive conclusions can be drawn. Similar to the animal data, the current evidence from epidemiological studies on the role of vitamin C in the prevention of CVD is inconclusive, with some studies showing a very strong correlation between increased vitamin C intake and incidence of CVD events and other studies showing no correlation at all. Studies on CVD risk factors indicate that vitamin C may moderately decrease total serum cholesterol levels, increase HDL levels, and exert a hypotensive effect. These findings are particularly intriguing and should be pursued vigorously in basic research studies to elucidate biological mechanisms. In addition, it appears that large placebo-controlled, double-blind, randomized trials of vitamin C supplementation (without simultaneous supplementation with vitamin E) in populations with a wide range of vitamin C body levels are needed in order to confirm or refute a role for vitamin C in the prevention of CVD. Unfortunately, no such trials are currently being conducted. The possible mechanisms by which ascorbic acid may affect the development of atherosclerosis and the onset of acute coronary events include effects on arterial wall integrity related to biosynthesis of collagen and GAGs, altered cholesterol metabolism mediated by vitamin C-dependent conversion of cholesterol to bile acids, and effects on triglyceride levels via modulation of lipoprotein lipase activity. A particularly

Topics: Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Diet, Atherogenic; Disease Models, Animal; Epidemiologic Methods; Extracellular Matrix Proteins; Guinea Pigs; Humans; Lipoproteins; Rabbits; Risk Factors

Laboratory studies suggest that antioxidants, such as Vitamin C, are important inhibitors of atherosclerotic lesions. Most epidemiological reviews have considered all antioxidants together. This review seeks to clarify the current state of knowledge specifically concerned with vitamin C.. All ecological studies, case-control studies, prospective studies and trials in humans that examined the association between vitamin C intake or blood levels of vitamin C and cardiovascular disease were included. Relevant references were located by MEDLINE search for articles published from 1966 to 1996, by an EMBASE search for articles published from 1980 to 1996, by searching personal bibliographies, books and reviews and from citations in located articles.. For coronary heart disease four of seven ecological studies, one of four case-control studies and three of 12 cohort studies found a significant protective association with vitamin C intake or status. For strokes two of two ecological studies, none of one case-control study and two of seven cohort studies found a significant protective association. For total circulatory disease, two of three cohort studies reported a significant protective association.. The evidence, albeit limited, is consistent with vitamin C having protective effect against stroke whereas the evidence that vitamin C is protective against coronary heart disease is less consistent. The lack of an association for coronary heart disease could be explained in terms of there being a true lack of effect, dietary measurement error, a threshold effect, and effect of seasonal variations in intake, an interaction with other dietary constituents or a relatively short duration of follow-up.

Topics: Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Cohort Studies; Diet; Epidemiologic Factors; Female; Food, Fortified; Humans; Male; Prospective Studies

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Eye Diseases; Health Promotion; Humans; Neoplasms; Preventive Medicine; Vitamin E

To review prospective epidemiologic studies and randomized trials regarding the role of antioxidant vitamins (vitamins E and C and beta-carotene) in the prevention of cardiovascular disease, with emphasis on differences in results obtained by these two types of studies.. Computerized and manual searches of the literature on antioxidant vitamins and cardiovascular disease.. Prospective epidemiologic studies and randomized trials that included 100 or more participants and provided quantified estimates of antioxidant vitamin intake.. Comparisons of relative risk reductions (RRR) across observational studies and randomized trials, including assessment of dose-response relations.. All three large epidemiologic cohort studies of vitamin E noted that high-level vitamin E intake or supplementation was associated with a significant reduction in cardiovascular disease (RRR range, 31% to 65%), as measured by various fatal and nonfatal cardiovascular end points. To obtain these reductions, vitamin E supplementation must last at least 2 years. Less consistent reductions were seen in studies of beta-carotene (RRR range, -2% to 46%) and vitamin C (RRR range, -25% to 51%). Considerable biases in observational studies, such as different health behaviors of persons using antioxidants, may account for the observed benefit. By contrast, none of the completed randomized trials showed any clear reduction in cardiovascular disease with vitamin E, vitamin C, or beta-carotene supplementation. The trials were not specifically designed to assess cardiovascular disease, did not provide data on nonfatal cardiovascular end points, may have had insufficient treatment durations, and used suboptimal vitamin E doses. The completed trials were of adequate size to indicate that the true therapeutic benefit of vitamin E and other antioxidants in reducing fatal cardiovascular disease (a survival benefit as long as 5 years) is probably more modest than the epidemiologic data suggest.. The epidemiologic data suggest that antioxidant vitamins reduce cardiovascular disease, with the clearest effect for vitamin E; however, completed randomized trials do not support this finding. Much of this controversy should be resolved by the ongoing large-scale and long-term randomized trials designed specifically to evaluate effects on cardiovascular disease.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Epidemiologic Methods; Humans; Randomized Controlled Trials as Topic; Vitamin E

The hypothesis that antioxidant vitamins might decrease the risk of cardiovascular disease (CVD) is a promising area of research. At present, however, it is far from certain whether antioxidant vitamins confer protection against CVD. Evidence for the antioxidant vitamin-cardiovascular disease hypothesis has accumulated from several lines of research. Laboratory research has identified biochemical properties of antioxidant vitamins that could explain their possible role in inhibiting and delaying coronary atherosclerosis. Epidemiologic studies have provided support for the hypothesis by showing that people who consume high amounts of antioxidant vitamins through diet or supplements, or those with high concentrations of these nutrients in their blood, tend to have lower risks of CVD. In the case of the former, however, laboratory findings may not have relevance to free-living humans. Observational epidemiologic studies cannot exclude the possibility that people who consume antioxidant-rich diets or who take vitamin supplements also share other lifestyle or dietary practices that actually account for their lower disease rates. Because of these uncertainties, the only way to determine reliably whether antioxidants play any role in reducing the risk of CVD is to conduct large-scale, randomized trials of these agents, in which adequate doses of antioxidant vitamins are tested for a sufficient duration to allow for any benefits to emerge. Several large-scale trials are now ongoing in both primary and secondary prevention. The results of these trials over the next several years should provide reliable evidence for this promising, but as yet unproven, hypothesis.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Humans; Randomized Controlled Trials as Topic; Vitamin E

The heart is the most susceptible of all the organs to premature aging and free radical oxidative stress. Clinical research has clearly documented the role of free radical damage and the progression of numerous degenerative diseases, particularly cardiovascular disease. This may be the result of acute ischemia-reperfusion injury, endothelial damage of hyperhomocysteinemia, as well as chronic oxidative damage secondary to lipid peroxidation. Fortunately, although highly responsive, and therefore vulnerable to the effects of oxidative stress, the heart is also receptive to the benefits of targeted phytonutrients, antioxidants, and nutritionals. The effects of antioxidant nutrients have been extensively evaluated in epidemiological, population, and clinical studies. Phytonutrients such as the natural flavonoids and carotenoids found in fresh fruits and vegetables or vitamins C, E, and beta-carotene have powerful antioxidant effects. In addition, minerals like selenium and nutrients such as coenzyme Q10 will minimize free radical risk and optimize a favorable outcome from the ubiquitous presence of oxidative stress on the cardiovascular system. The B complex, particularly folic acid, B12, and B6 are also essential in the prevention of hyperhomocysteinemia, another major risk factor for the circulatory system. Measures to minimize accumulation of heavy metals in the body, especially iron and copper, which are capable of initiating adverse free radical reactions, will also help to assuage oxidative stress. Thus, the combination of a healthy diet supplemented with antioxidants and phytonutrients may be useful in the prevention and promotion of optimum cardiovascular health.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diet; Free Radicals; Humans; Lipoproteins, LDL; Oxidation-Reduction; Oxidative Stress; Vitamin E

Epidemiological studies strongly suggest that high intakes of foods rich in beta carotene, as well as those rich in vitamin E or vitamin C, reduce the risk of some but not all cancers and cardiovascular disease. It is difficult to determine whether these antioxidant nutrients per se are the sole protective agents or whether other factors associated with foods containing them contribute to the foods' protective effects. With respect to vitamin E, a number of studies where dietary and supplementary vitamin E were clearly differentiated, a reduced risk of certain cancers or cardiovascular disease from supplemental vitamin E but not from dietary vitamin E was demonstrated. This provides strong presumptive evidence that high intakes of vitamin E per se provide a health benefit. Only a few intervention studies with specific nutrients are available and results are inconsistent.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Humans; Neoplasms; Risk Factors; Selenium; Vitamin E

A comprehensive review of the literature indicates that populations with long-term consumption of higher than RDA levels of vitamin C (> or = 60 mg/day) from foods and/or supplements have reduced risks of cancer at several sites, cardiovascular disease, and cataracts. The safety of higher than RDA intakes of vitamin C is confirmed in eight placebo-controlled, double-blind studies and six non-placebo clinical trials in which up to 10,000 mg of vitamin C was consumed daily for up to 3 years. There are no clinical data which suggest that vitamin C's enhancement of non-heme iron absorption in individuals with low iron status could be a critical factor in the possible increased risk of heterozygous hemochromatosis-related cardiovascular disease. In fact, the cumulative data do not confirm that iron status is related to risk of cardiovascular disease. Moreover, higher than RDA intakes of vitamin C have been associated with several indices of lowered cardiovascular disease risk including increases in HDL, and decreases in LDL oxidation, blood pressure and cardiovascular mortality.

Topics: Ascorbic Acid; Cardiovascular Diseases; Cataract; Female; Humans; Iron; Iron Deficiencies; Male; Neoplasms

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Free Radicals; Fruit; Humans; Neoplasms; Nutritional Physiological Phenomena; Reactive Oxygen Species; Vegetables; Vitamin A; Vitamin E

Increasing evidence is accumulating that a synergistic role of the so-called antioxidant vitamins (C, E, beta-carotene) may have a dominant role in the prevention of cancer, cardiovascular diseases and cataract formation. Controversy still exists regarding the optimum intake of vitamin C. This is partly due to lack of accurate and easily accessible health-relevant end-points, and lack of knowledge of the role of vitamin C in biochemical functions. Today, it is clearly recognized and broadly accepted that optimal health is a consequence of dietary optimization. Attainment of optimal health rather than prevention of deficiency symptoms is the goal. There can be little doubt that in this respect the requirements for vitamin C are greater than the amount required for the mere prevention of overt or classical scurvy. The recommendation of varying levels of requirement could overcome the controversy. The following is therefore proposed: The lowest level is that value which prevents deficiency symptoms. The second level is valid for healthy populations (< 200 mg/d). This level would take into account needs which differ according to age, sex, physical activity, physiological status (e.g. pregnancy or lactation) and environmental factors such as smoking, pollution and alcohol intake. Finally, a third level should be determined for the prevention of the above-mentioned non-communicable diseases. These diseases are an important cause of disability, resulting in costs of billions of dollars annually in medical costs. Many of the above-mentioned diseases can be prevented by supplementation with vitamin C. Medical costs could thereby also be dramatically reduced.

Topics: Ascorbic Acid; Cardiovascular Diseases; Common Cold; Humans; Neoplasms; Nutritional Requirements; Reference Standards

Vitamin C functions as a regulator of the catabolism of cholesterol to bile acids in the guinea pig and has been demonstrated to be an important factor in lipid regulation of the guinea pig, rabbit and rat. Correlation studies in humans have shown an inverse relationship between vitamin C intake and cardiovascular disease mortality. Observational and experimental studies in humans have yielded inconsistent results, but taken together indicate that for individuals with high total cholesterol concentrations, greater than or equal to 5.20 mmol/L (200 mg/dl) and less than full tissue saturation, increasing the concentration of vitamin C may have a salutary effect on total cholesterol. Vitamin C's effect on promoting the production and inhibiting the degradation of prostacyclin is reviewed, as are implications of these findings regarding thrombosis and atherogenesis. Evidence indicative of a protective effect on lipid peroxidation by vitamin C is examined. Analysis of the literature regarding groups at high risk for coronary heart disease reveals that men, the elderly, smokers, diabetics, hypertensives and perhaps oral estrogen-containing contraceptive users have lowered plasma vitamin C levels. Evidence linking vitamin C to human cardiovascular disease is largely circumstantial, but taken in total, is suggestive of an association. Further examination of the relationship between vitamin C and cardiovascular disease is warranted.

Topics: Animals; Ascorbic Acid; Blood Pressure; Cardiovascular Diseases; Cholesterol; Hemostasis; Humans; Lipid Peroxidation; Risk Factors

Vitamins are a group of organic compounds occurring naturally in food and are necessary for good health. Lack of a vitamin may lead to a specific deficiency syndrome, which may be primary (due to inadequate diet) or secondary (due to malabsorption or to increased metabolic need), and it is rational to use high-dose vitamin supplementation in situations where these clinical conditions exist. However, pharmacological doses of vitamins are claimed to be of value in a wide variety of conditions which have no, or only a superficial, resemblance to the classic vitamin deficiency syndromes. The enormous literature on which these claims are based consists mainly of uncontrolled clinical trials or anecdotal reports. Only a few studies have made use of the techniques of randomisation and double-blinding. Evidence from such studies reveals a beneficial therapeutic effect of vitamin E in intermittent claudication and fibrocystic breast disease and of vitamin C in pressure sores, but the use of vitamin A in acne vulgaris, vitamin E in angina pectoris, hyperlipidaemia and enhancement of athletic capacity, of vitamin C in advanced cancer, and niacin in schizophrenia has been rejected. Evidence is conflicting or inconclusive as to the use of vitamin C in the common cold, asthma and enhancement of athletic capacity, of pantothenic acid in osteoarthritis, and folic acid (folacin) in neural tube defects. Most of the vitamins have been reported to cause adverse effects when ingested in excessive doses. It is therefore worthwhile to consider the risk-benefit ratio before embarking upon the use of high-dose vitamin supplementation for disorders were proof of efficacy is lacking.

Topics: Acne Vulgaris; Ascorbic Acid; Asthma; Cardiovascular Diseases; Common Cold; Fibrocystic Breast Disease; Humans; Neoplasms; Osteoporosis; Vitamin A; Vitamin B Complex; Vitamin D; Vitamin E; Vitamin K; Vitamins

Antioxidants have been reported to have anti-inflammatory effects, but there is a lack of research comparing food to supplement antioxidant sources. The aim of this study was to determine if increases in intake of foods naturally rich in antioxidants would lower blood levels of inflammatory markers more than consuming antioxidant supplements among adults with cardiovascular disease risk factors. Eighty-eight generally healthy adults with ≥1 elevated risk factor for cardiovascular disease were randomized in a single-blind (diets)/double-blind (supplements), parallel-group study for 8 weeks. Participants consumed (1) usual diet and placebo pills (n = 29), (2) usual diet and antioxidant supplements (n = 29), or (3) antioxidant-rich foods closely matched to antioxidant content of supplements and placebo (n = 30). Usual diet combined with antioxidant supplements or increased antioxidant-rich food intake was designed to approximately double daily habitual antioxidant intake. Antioxidant pills included carotenoids, mixed tocopherols, vitamin C, and selenium. Fasting blood samples were analyzed for inflammatory marker concentrations of interleukin-6, monocyte chemotactic protein-1, and soluble intercellular adhesion molecule-1. Participants in the intervention groups successfully doubled most antioxidants as verified by diet records and elevated blood concentrations in treatment groups. Baseline levels of inflammatory markers for the entire study group were 110 ± 65 pg/mL for monocyte chemotactic protein-1, 0.9 ± 0.7 pg/mL for interleukin-6, and 217 ± 56 ng/mL for soluble intercellular adhesion molecule-1 (means ± standard deviation) and did not differ by treatment arm. After 8 weeks, there were no significant within-group changes or between-group 8-week change differences in inflammatory marker concentrations. In conclusion, no beneficial effects were detected on the inflammatory markers investigated in response to antioxidants from foods or supplements.

Topics: Adult; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Carotenoids; Chemokine CCL2; Diet; Dietary Supplements; Double-Blind Method; Female; Humans; Inflammation; Intercellular Adhesion Molecule-1; Interleukin-6; Male; Middle Aged; Pilot Projects; Selenium; Single-Blind Method; Tocopherols; Vitamins

We aimed to investigate the efficacy of ascorbic acid and acetylsalicylic acid among type II diabetes mellitus patients using metformin (only) for diabetes management therapy.. A 12-month single blinded multicenter randomized control trial was designed to investigate the measured variables [Glycated Hemoglobin (HbA1c), Renal function, Albumin Creatinine Ratio (ACR) etc.]. The trial was randomized into 2 experimental parallel arms (ascorbic acid vs acetylsalicylic acid) were blinded with study supplements in combination with metformin and findings were compared to control arm with metformin alone and blinded with placebo. Withdrawal criteria was defined to maintain the equity and balance in the participants in the whole trial.. Patients with metformin and ascorbic acid (parallel arm I) was twice more likely to reduce HbA1c than metformin alone (control arm) in a year (OR 2.31 (95% CI 1.87-4.42) p < 0.001). Also Parallel arm I was ten times more likely to reduced risk factors contributing to long-term diabetes complications than participants of arm II in a year (OR 10.38 (95% CI 6.91-15.77) p < 0.001). In contrast, parallel arm II patients were seven times more effective to reduce the risk of expected CVD development in 10 years than arm I (OR 7.54 (95% CI 3.76-10.32) p < 0.001).. The trial concluded that ascorbic acid with metformin is more effective against reducing risks for diabetes related long-term complications (including ACR). TRIAL details Registration No: NTR-6100, Registry Name: Netherlands Trial Registry, URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6100 , Date of Registration: 20th October, 2016, Date of first Enrollment: 1 November, 2015.

Topics: Adult; Ascorbic Acid; Aspirin; Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Female; Humans; Hypoglycemic Agents; Male; Metformin; Middle Aged; Single-Blind Method

Patients at nutritional risk are particularly vulnerable to adverse outcomes of acute stroke. We previously found that increased energy- and protein intervention improved short-term survival among stroke patients with the highest baseline antioxidant capacity. We now examined survival of these patients after 5-7 years.. We studied 165 patients >65 years admitted to hospital for acute stroke and enrolled in a randomized nutritional intervention study in 2005-2007. Cox regression analysis was used to estimate the associations between all-cause mortality (through 2011) and baseline plasma levels of antioxidant markers (glutathione reducing capacity, alpha-tocopherol, vitamin C and total carotenoids).. We found no significant difference (P = 0.86) in survival between the intervention and control group. Among the tested antioxidant markers, plasma levels above the median for total carotenoids were associated with reduced risk of death in the intervention group (adjusted hazard ratio, 0.29; 95% confidence interval, 0.12-0.71).. Hospitalized patients that received enhanced dietary energy- and protein after acute stroke and with baseline plasma total carotenoids above median level, had reduced risk of death after 5-7 years. Further trials testing intervention with diets rich in antioxidants are warranted.

Topics: Aged; Aged, 80 and over; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Carotenoids; Diet; Dietary Proteins; Energy Intake; Female; Follow-Up Studies; Hospitalization; Humans; Male; Middle Aged; Oxidative Stress; Proportional Hazards Models; Stroke

Blond orange juice is the most consumed fruit juice in the world. It is a source of hesperidin, a bioavailable flavonoid reported to exhibit potential vascular protective actions. However, the specific impact on vascular function of Citrus phytomicronutrients, is unknown. For the first time, we investigated the effects of blond orange juice compared with a control beverage mimicking the composition of orange juice (including Vitamin C but no phytomicronutrients), on antioxidant markers, cardiovascular risk factors and endothelial function.. Twenty five male volunteers with two cardiovascular risk factors (age over 50 years and LDL-cholesterol between 130 and 190 mg/L) were enrolled in a randomized cross-over study. They received 3 times daily 200 mL of either blond orange juice or control beverage for 4 weeks, spaced by a 5-week wash-out. Endothelial function (flow mediated dilatation and plasma markers), oxidative status, lipid profile and inflammatory markers were assessed.. Daily intakes of orange juice significantly led to a marked antioxidant effect which was correlated to hesperetin plasma levels and related with a decrease in reactive oxygen species. A tendency towards reduction of endothelial dysfunction and modest increase in plasma apoA-I concentration were also observed. This allows further experiments demonstrating the specific effect of phytomicronutrients from orange juice.. These findings suggest that daily intake of nutritionally relevant dose of blond orange juice may contribute for a significant antioxidant effect through the phytochemicals contained in. Orange juice may be associated to other healthy foods to achieve a significant effect on the vascular function. This study is recorded in ClinicalTrials.com as NCT00539916.

Topics: Antioxidants; Apolipoprotein A-I; Ascorbic Acid; Biomarkers; Body Mass Index; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Citrus sinensis; Cross-Over Studies; Flavonoids; Fruit and Vegetable Juices; Hesperidin; Humans; Hypercholesterolemia; Male; Middle Aged; Oxidative Stress; Phytochemicals; Reactive Oxygen Species; Risk Factors; Single-Blind Method; Triglycerides

Limited robust randomised controlled trials investigating fruit and vegetable (F&V) intake in people at risk of cardiovascular disease (CVD) exist. We aimed to design and validate a dietary strategy of increasing flavonoid-rich versus flavonoid-poor F&V consumption on nutrient biomarker profile.. A parallel, randomised, controlled, dose-response dietary intervention study. Participants with a CVD relative risk of 1.5 assessed by risk scores were randomly assigned to one of the 3 groups: habitual (control, CT), high-flavonoid (HF) or low-flavonoid (LF) diets. While the CT group (n = 57) consumed their habitual diet throughout, the HF (n = 58) and LF (n = 59) groups sequentially increased their daily F&V intake by an additional 2, 4 and 6 portions for 6-week periods during the 18-week study.. Compliance to target numbers and types of F&V was broadly met and verified by dietary records, and plasma and urinary biomarkers. Mean (± SEM) number of F&V portions/day consumed by the HF and LF groups at baseline (3.8 ± 0.3 and 3.4 ± 0.3), 6 weeks (6.3 ± 0.4 and 5.8 ± 0.3), 12 weeks (7.0 ± 0.3 and 6.8 ± 0.3) and 18 weeks (7.6 ± 0.4 and 8.1 ± 0.4), respectively, was similar at baseline yet higher than the CT group (3.9 ± 0.3, 4.3 ± 0.3, 4.6 ± 0.4, 4.5 ± 0.3) (P = 0.015). There was a dose-dependent increase in dietary and urinary flavonoids in the HF group, with no change in other groups (P = 0.0001). Significantly higher dietary intakes of folate (P = 0.035), non-starch polysaccharides (P = 0.001), vitamin C (P = 0.0001) and carotenoids (P = 0.0001) were observed in both intervention groups compared with CT, which were broadly supported by nutrient biomarker analysis.. The success of improving nutrient profile by active encouragement of F&V intake in an intervention study implies the need for a more hands-on public health approach.

Topics: Adipose Tissue; Ascorbic Acid; Biomarkers; Body Mass Index; Body Weight; Cardiovascular Diseases; Carotenoids; Diet; Diet Records; Dietary Carbohydrates; Feeding Behavior; Female; Flavonoids; Folic Acid; Fruit; Humans; Male; Micronutrients; Middle Aged; Patient Compliance; Risk Factors; Surveys and Questionnaires; Vegetables; Vitamins

Fruit and vegetable-rich diets are associated with a reduced cardiovascular disease (CVD) risk. This protective effect may be a result of the phytochemicals present within fruits and vegetables (F&V). However, there can be considerable variation in the content of phytochemical composition of whole F&V depending on growing location, cultivar, season and agricultural practices, etc. Therefore, the present study investigated the effects of consuming fruits and vegetables as puree-based drinks (FVPD) daily on vasodilation, phytochemical bioavailability, antioxidant status and other CVD risk factors. FVPD was chosen to provide a standardised source of F&V material that could be delivered from the same batch to all subjects during each treatment arm of the study.. Thirty-nine subjects completed the randomised, controlled, cross-over dietary intervention. Subjects were randomised to consume 200 mL of FVPD (or fruit-flavoured control), daily for 6 weeks with an 8-week washout period between treatments. Dietary intake was measured using two 5-day diet records during each cross-over arm of the study. Blood and urine samples were collected before and after each intervention and vasodilation assessed in 19 subjects using laser Doppler imaging with iontophoresis.. FVPD significantly increased dietary vitamin C and carotenoids (P < 0.001), and concomitantly increased plasma α- and β-carotene (P < 0.001) with a near-significant increase in endothelium-dependent vasodilation (P = 0.060).. Overall, the findings obtained in the present study showed that FVPD were a useful vehicle to increase fruit and vegetable intake, significantly increasing dietary and plasma phytochemical concentrations with a trend towards increased endothelium-dependent vasodilation.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Beverages; Cardiovascular Diseases; Carotenoids; Cross-Over Studies; Female; Fruit; Humans; Male; Middle Aged; Oxidation-Reduction; Oxygen; Seasons; Vasodilation; Vegetables

The study's purpose was to examine the effects of whey protein supplementation and resistance training on antioxidant status and cardiovascular risk factors in overweight young men. Thirty healthy male subjects (age, 23.4±3.6years; body mass index, 25-30kg/m(2)) were randomly divided into three groups of 10 persons including; Experimental group 1: resistance training+whey supplement (RW); Experimental group 2: resistance training+placebo (RP), and Control group (C). Subjects in intervention groups underwent 3 resistance training sessions per week, each session with 60-70% 1RM, for 6weeks. No significant changes in fibrinogen level, fasting blood glucose, resting systolic and diastolic blood pressures, waist to hip ratio (WHR), and body mass index were observed in any of the groups. Total antioxidant capacity (TAC), cholesterol and HDL varied significantly in the RW group compared with the pre-test. We found significant changes in both RW and RP groups for glutathione, vitamin C, LDL, and triglyceride levels. In addition, in the post-test, TAC, glutathione, and HDL levels were higher in the RW in comparison to C group. Research findings showed that although exercise can lead to antioxidant system improvement and reduce some cardiovascular risk factors among overweight subjects, the combination of resistance training and whey consumption is more effective.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Dietary Proteins; Dietary Supplements; Glutathione; Humans; Lipids; Male; Milk Proteins; Overweight; Reference Values; Resistance Training; Risk Factors; Triglycerides; Whey Proteins; Young Adult

Currently there is debate on whether hypoglycemia is an independent risk factor for atherosclerosis, but little attention has been paid to the effects of recovery from hypoglycemia. In normal control individuals and in people with type 1 diabetes, recovery from a 2-h induced hypoglycemia was obtained by reaching normoglycemia or hyperglycemia for another 2 h and then maintaining normal glycemia for the following 6 h. Hyperglycemia after hypoglycemia was also repeated with the concomitant infusion of vitamin C. Recovery with normoglycemia is accompanied by a significant improvement in endothelial dysfunction, oxidative stress, and inflammation, which are affected by hypoglycemia; however, a period of hyperglycemia after hypoglycemia worsens all of these parameters, an effect that persists even after the additional 6 h of normoglycemia. This effect is partially counterbalanced when hyperglycemia after hypoglycemia is accompanied by the simultaneous infusion of vitamin C, suggesting that when hyperglycemia follows hypoglycemia, an ischemia-reperfusion-like effect is produced. This study shows that the way in which recovery from hypoglycemia takes place in people with type 1 diabetes could play an important role in favoring the appearance of endothelial dysfunction, oxidative stress, and inflammation, widely recognized cardiovascular risk factors.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cross-Over Studies; Diabetes Mellitus, Type 1; Endothelium, Vascular; Female; Glucose; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Inflammation Mediators; Infusions, Intravenous; Insulin; Male; Oxidative Stress; Risk Factors; Vasodilation; Young Adult

In vitro data indicate quercetin has antioxidative and anti-inflammatory functions with the potential to lower disease risk factors, but data in human beings are limited.. The objective of this study was to investigate the effect of quercetin, vitamin C, and niacin supplements (500 mg quercetin, 125 mg vitamin C, and 5 mg niacin [Q-500]; 1,000 mg quercetin, 250 mg vitamin C, and 10 mg niacin [Q-1,000]), on disease risk factors in a large group of community adults (n=1,002, 60% women) varying widely in age and body mass index.. Subjects were randomized into one of three groups (placebo, Q-500, or Q-1,000) and ingested supplements for 12 weeks. Blood samples were taken pre- and postsupplementation, and plasma quercetin, inflammatory markers (ie, C-reactive protein and five cytokines), diagnostic blood chemistries, blood pressure, and blood lipid profiles were measured.. Plasma quercetin increased in the Q-500 and Q-1,000 groups. No differences in blood chemistries were found except for a small decrease in serum creatinine and increase in glomerular filtration rate in Q-500 and Q-1,000 groups. A small decrease in mean arterial blood pressure was measured for Q-500 and Q-1,000 groups compared to placebo. A difference in serum total cholesterol was measured between Q-500 and placebo groups, and there was small decrease in high-density lipoprotein cholesterol levels in the Q-1,000 group. Change in inflammatory measures did not differ between groups except for a slight decrease in interleukin-6 for the Q-1,000 group.. Q-500 or Q-1,000 supplementation for 12 weeks had a negligible influence on disease risk factors.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Analysis of Variance; Antioxidants; Ascorbic Acid; Blood Pressure; Body Mass Index; C-Reactive Protein; Cardiovascular Diseases; Chronic Disease; Cytokines; Dietary Supplements; Dose-Response Relationship, Drug; Female; Humans; Lipid Metabolism; Male; Middle Aged; Niacin; Quercetin; Risk Factors; Young Adult

There are concerns that weight-loss (WL) diets based on very low carbohydrate (LC) intake have a negative impact on antioxidant status and biomarkers of cardiovascular and metabolic health. Obese men (n 16) participated in a randomised, cross-over design diet trial, with food provided daily, at approximately 8.3 MJ/d (approximately 70 % of energy maintenance requirements). They were provided with two high-protein diets (30 % of energy), each for a 4-week period, involving a LC (4 % carbohydrate) and a moderate carbohydrate (MC, 35 % carbohydrate) content. Body weight was measured daily, and weekly blood samples were collected. On average, subjects lost 6.75 and 4.32 kg of weight on the LC and MC diets, respectively (P < 0.001, SED 0.350). Although the LC and MC diets were associated with a small reduction in plasma concentrations of retinol, vitamin E (α-tocopherol) and β-cryptoxanthin (P < 0.005), these were still above the values indicative of deficiency. Interestingly, plasma vitamin C concentrations increased on consumption of the LC diet (P < 0.05). Plasma markers of insulin resistance (P < 0.001), lipaemia and inflammation (P < 0.05, TNF-α and IL-10) improved similarly on both diets. There was no change in other cardiovascular markers with WL. The present data suggest that a LC WL diet does not impair plasma indices of cardiometabolic health, at least within 4 weeks, in otherwise healthy obese subjects. In general, improvements in metabolic health associated with WL were similar between the LC and MC diets. Antioxidant supplements may be warranted if LC WL diets are consumed for a prolonged period.

Topics: Adult; Aged; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Cross-Over Studies; Cryptoxanthins; Diet, Carbohydrate-Restricted; Diet, Reducing; Dietary Carbohydrates; Dietary Proteins; Endothelium, Vascular; Energy Intake; Humans; Hyperlipidemias; Inflammation Mediators; Insulin Resistance; Male; Metabolic Diseases; Middle Aged; Nutritional Requirements; Obesity; Risk Factors; Vitamin A; Weight Loss; Xanthophylls

The modern Western lifestyle is characterized by the consumption of high-heat-treated foods because of their characteristic taste and flavor. However, it has been shown that treating food at high temperatures can generate potentially harmful compounds that promote inflammation and cardiovascular disease in subjects with diabetes.. The aim of this study was to determine whether high-heat-treated foods also pose a risk for healthy subjects.. A randomized, crossover, diet-controlled intervention trial with 62 volunteers was designed to compare the potential metabolic effects of 2 diets, one that was based on mild steam cooking and another that was based on high-temperature cooking. These 2 diets differed mainly in their contents of Maillard reaction products (MRPs). MRPs were assessed in the diet and in subjects' feces, blood, and urine samples, with N(epsilon)-carboxymethyllysine as an indicator of MRPs. Biological indicators of glucose and lipid metabolism as well as oxidative stress were analyzed in subjects after 1 mo on each diet.. In comparison with the steamed diet, 1 mo of consuming the high-heat-treated diet induced significantly lower insulin sensitivity and plasma concentrations of long-chain n-3 (omega-3) fatty acids and vitamins C and E [-17% (P < 0.002), -13% (P < 0.0001), and -8% (P < 0.01), respectively]. However, concentrations of plasma cholesterol and triglycerides increased [+5% (P < 0.01) and +9% (P < 0.01), respectively].. A diet that is based on high-heat-treated foods increases markers associated with an enhanced risk of type 2 diabetes and cardiovascular diseases in healthy people. Replacing high-heat-treatment techniques by mild cooking techniques may help to positively modulate biomarkers associated with an increased risk of diabetes mellitus and cardiovascular diseases.

Topics: Ascorbic Acid; Body Mass Index; Cardiovascular Diseases; Cholesterol; Cooking; Cross-Over Studies; Diabetes Mellitus, Type 2; Fatty Acids, Omega-3; Female; Hot Temperature; Humans; Inflammation; Insulin; Life Style; Maillard Reaction; Male; Risk Factors; Triglycerides; Vitamin E; Young Adult

Cardiovascular risk factors such as elevated levels of asymmetric dimethylarginine (ADMA)/C-reactive protein (CRP) and homocysteine are potentially related to essential micronutrients such as certain B vitamins and antioxidant vitamins. The aim of the present study was to investigate whether supplementation with moderate doses of B vitamins and/or antioxidants could alter either ADMA and/or CRP concentrations in middle-aged, apparently healthy men with mildly elevated homocysteine levels.. A randomised, double-blind, factorial design, intervention study was carried out on 132 men with mildly elevated homocysteine levels, allocated to four groups (a) B vitamins alone--1 mg folic acid, 7.2 mg pyridoxine, 0.02 mg cyanocobalamin daily, (b) antioxidants alone--150 mg ascorbic acid, 67 mg vitamin E, 9 mg β-carotene daily, (c) B vitamins with antioxidant vitamins, or (d) placebo. A total of 101 men completed the study to 8 weeks.. When the percentage of baseline ADMA and CRP was examined at 8 weeks, no statistically significant differences were observed between the four groups (p = 0.21 and p = 0.90, respectively). Similar non-significant results were observed when analysis was stratified based on baseline CRP levels (<1.0 mg/L, p = 0.10; ≥1.0 mg/L, p = 0.64) and smoking status (all p ≥ 0.05).. Supplementation with moderate doses of B vitamins and/or antioxidants did not alter either ADMA or CRP concentrations in these middle-aged, apparently healthy men with mildly elevated homocysteine levels.

Topics: Adult; Antioxidants; Arginine; Ascorbic Acid; beta Carotene; Biomarkers; Blood Pressure; C-Reactive Protein; Cardiovascular Diseases; Cholesterol; Dietary Supplements; Double-Blind Method; Homocysteine; Humans; Male; Middle Aged; Protective Agents; Triglycerides; Vitamin B Complex; Vitamin E

Two hundred broiler chicks were randomly assigned to 3 dietary treatments: control [CTL; 3,200 kcal of ME/kg, 23% CP, 1.55% Arg, and 40 IU of vitamin E (VE)/kg of feed], high-Arg (HA; CTL+0.8% Arg), or high-Arg and high antioxidant-vitamin diet (AEC; HA+200 IU of VE/kg of feed and 500 mg of vitamin C/L of water). The chicks were housed in wire cages in hypobaric chambers simulating 3,000 m above sea level. From d 28 to 42, clinically healthy birds were selected for cardiovascular performance (n=7 to 12/treatment). After surgery, pulmonary arterial pressure (PAP) and mean arterial pressure (MAP) readings were taken at 180, 120, and 60 s (basal values) before an epinephrine (EPI) challenge and then at 30, 60, 120, 180, 300, 600, and 1,200 s after the challenge, followed by a second EPI challenge with similar sample readings. There were no differences in the basal PAP values among chicken groups. The PAP increased within 30 s after both EPI challenges in all groups. It took 180 s after the first EPI challenge for the CTL chickens to return to the basal PAP values, whereas HA and AEC chickens returned to basal PAP values in 120 s. After the second EPI challenge, it took 60, 180, and 300 s for the AEC, HA, and CTL groups, respectively, to return to basal PAP values. The MAP response pattern to the EPI challenges mimicked that of PAP, but there were no differences among treatments in MAP at any sampling point. Supplemental Arg, VE, and vitamin C did not reduce ascites incidence in hypoxic broilers. In conclusion, supplemental Arg improved the pulmonary vascular performance of hypoxic broiler chickens and its effects were further improved by the addition of the antioxidant VE and vitamin C. Arginine and antioxidant vitamins may have played synergistic roles to increase NO bioavailability and reduce oxidative stress damage, thus improving cardiopulmonary performance.

Topics: Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Arginine; Ascorbic Acid; Cardiovascular Diseases; Diet; Dietary Supplements; Hypoxia; Poultry Diseases; Pressure; Time Factors; Vitamin E

Oxidative stress plays an important role in the pathogenesis of cardiovascular disease (CVD). Growing evidence suggest that antioxidant vitamins might reduce the risk of disease outcomes by their ability to scavenge free radicals. The aim of the present study was to evaluate the supplementation of vitamins E and C on oxidant and antioxidant status in CVD patients. We conducted a case-control study with vitamin E (400 IU/d) and vitamin C (500 mg/d) supplementation in 40 CVD patients for 2 mo. Antioxidant (enzymatic and non-enzymatic) and oxidant status were analyzed pre and post supplementation. In the initial stage the activity of both enzymatic and non-enzymatic antioxidants were lower, while the malondialdehyde (MDA) level was elevated (p<0.0001). After intervention, a significant increase in superoxide dismutase (SOD) activity (61.7%), glutathione peroxidase (GPx) activity (59.3%), the levels of vitamin E (83.7%), C (145.3%), total antioxidant capacity (TAC) (62.8%) and a significant decrease in MDA (40%) value were observed (p<0.0001). There was a significant negative correlation between MDA and TAC. The results suggest that supplementation with a combination of vitamins E and C reduced lipid peroxidation and strengthened the antioxidant defense system. Hence, there will be beneficial effects on the heart by reducing oxidative stress in CVD patients.

Topics: Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Dietary Supplements; Drug Therapy, Combination; Female; Free Radical Scavengers; Glutathione Peroxidase; Humans; Iran; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Superoxide Dismutase; Vitamin E; Vitamins

Plasma C-reactive protein (CRP) is an inflammatory biomarker that predicts cardiovascular disease. Lowering elevated CRP with statins has reduced the incidence of cardiovascular disease. We investigated whether vitamin C or E could reduce CRP. Healthy nonsmokers (N=396) were randomized to three groups, 1000 mg/day vitamin C, 800 IU/day vitamin E, or placebo, for 2 months. Median baseline CRP was low, 0.85 mg/L. No treatment effect was seen when all participants were included. However, a significant interaction was found, indicating that treatment effect depends on baseline CRP concentration. Among participants with CRP indicative of elevated cardiovascular risk (> or =1.0 mg/L), vitamin C reduced the median CRP by 25.3% vs placebo (p=0.02) (median reduction in the vitamin C group, 0.25 mg/L, 16.7%). These effects are similar to those of statins. The vitamin E effect was not significant. In summary, treatment with vitamin C but not vitamin E significantly reduced CRP among individuals with CRP > or =1.0 mg/L. Among the obese, 75% had CRP > or =1.0 mg/L. Research is needed to determine whether reducing this inflammatory biomarker with vitamin C could reduce diseases associated with obesity. But research on clinical benefits of antioxidants should limit participants to persons with elevations in the target biomarkers.

Topics: Adult; Age Factors; Ascorbic Acid; Biomarkers; Body Mass Index; C-Reactive Protein; Cardiovascular Diseases; Ethnicity; Female; Humans; Male; Menopause; Middle Aged; Sex Factors; Vitamin E

Observational studies suggested that a diet high in fruits and vegetables, both of which are rich with antioxidants, may prevent cancer development. However, findings from randomized trials of the association between antioxidant use and cancer risk have been mostly negative.. From 8171 women who were randomly assigned in the Women's Antioxidant Cardiovascular Study, a double-blind, placebo-controlled 2 x 2 x 2 factorial trial of vitamin C (500 mg of ascorbic acid daily), natural-source vitamin E (600 IU of alpha-tocopherol every other day), and beta carotene (50 mg every other day), 7627 women who were free of cancer before random assignment were selected for this study. Diagnoses and deaths from cancer at a specific site were confirmed by use of hospital reports and the National Death Index. Cox proportional hazards regression models were used to assess hazard ratios (represented as relative risks [RRs]) of common cancers associated with use of antioxidants, either individually or in combination. Subgroup analyses were conducted to determine if duration of use modified the association of supplement use with cancer risk. All statistical tests were two-sided.. During an average 9.4 years of treatment, 624 women developed incident invasive cancer and 176 women died from cancer. There were no statistically significant effects of use of any antioxidant on total cancer incidence. Compared with the placebo group, the RRs were 1.11 (95% confidence interval [CI] = 0.95 to 1.30) in the vitamin C group, 0.93 (95% CI = 0.79 to 1.09) in the vitamin E group, and 1.00 (95% CI = 0.85 to 1.17) in the beta carotene group. Similarly, no effects of these antioxidants were observed on cancer mortality. Compared with the placebo group, the RRs were 1.28 (95% CI = 0.95 to 1.73) in the vitamin C group, 0.87 (95% CI = 0.65 to 1.17) in the vitamin E group, and 0.84 (95% CI = 0.62 to 1.13) in the beta carotene group. Duration and combined use of the three antioxidants also had no effect on cancer incidence and cancer death.. Supplementation with vitamin C, vitamin E, or beta carotene offers no overall benefits in the primary prevention of total cancer incidence or cancer mortality.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Dietary Supplements; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Incidence; Middle Aged; Neoplasms; Primary Prevention; Proportional Hazards Models; Risk Assessment; Risk Factors; United States; Vitamin E

The average UK adult consumes less than three portions of fruit and vegetables daily, despite evidence to suggest that consuming five portions daily could help prevent chronic diseases. It is recommended that fruit juice should only count as one of these portions, as juicing removes fibre and releases sugars. However, fruit juices contain beneficial compounds such as vitamin C and flavonoids and could be a useful source of dietary phytochemicals. Two randomised controlled cross-over intervention studies investigating the effects of chronic and acute consumption of commercially-available fruit- and vegetable-puree-based drinks (FVPD) on bioavailability, antioxidant status and CVD risk factors are described. Blood and urine samples were collected during both studies and vascular tone was measured using laser Doppler imaging. In the chronic intervention study FVPD consumption was found to significantly increase dietary carotenoids (P=0.001) and vitamin C (P=0.003). Plasma carotenoids were increased (P=0.001), but the increase in plasma vitamin C was not significant. There were no significant effects on oxidative stress, antioxidant status and other CVD risk factors. In the acute intervention study FVPD were found to increase total plasma nitrate and nitrite (P=0.001) and plasma vitamin C (P=0.002). There was no effect on plasma lipids or uric acid, but there was a lower glucose and insulin peak concentration after consumption of the FVPD compared with the sugar-matched control. There was a trend towards increased vasodilation following both chronic and acute FVPD consumption. All volunteers were retrospectively genotyped for the eNOS G298T polymorphism and the effect of genotype on the measurements is discussed. Overall, there was a non-significant trend towards increased endothelium-dependent vasodilation following both acute and chronic FVPD consumption. However, there was a significant time x treatment effect (P<0.05) of acute FVPD consumption in individuals with the GG variant of the eNOS gene.

Topics: Adult; Ascorbic Acid; Beverages; Blood Glucose; Cardiovascular Diseases; Carotenoids; Cross-Over Studies; Diet; Endothelium, Vascular; Female; Fruit; Genotype; Humans; Insulin; Male; Middle Aged; Nitric Oxide Synthase Type III; Polymorphism, Genetic; Risk Factors; Vasodilation; Vegetables; Vitamin E

Cardiovascular factors are associated with cognitive decline. Antioxidants may be beneficial.. The Women's Antioxidant Cardiovascular Study was a trial of vitamin E (402 mg every other day), beta carotene (50 mg every other day), and vitamin C (500 mg daily) for the secondary prevention of cardiovascular disease. From 1995 to 1996, women > or =40 years of age with cardiovascular disease or > or =3 coronary risk factors were randomized. From 1998 to 1999, a cognitive function substudy was initiated among 2824 participants > or =65 years of age. With 5 cognitive tests, cognition was assessed by telephone 4 times over 5.4 years. The primary outcome was a global composite score averaging all scores; repeated-measures analyses were used to examine cognitive change over time. Vitamin E supplementation and beta carotene supplementation were not associated with slower rates of cognitive change (mean difference in change for vitamin E versus placebo, -0.01; 95% confidence interval, -0.05 to 0.04; P=0.78; for beta carotene, 0.03; 95% confidence interval, -0.02 to 0.07; P=0.28). Although vitamin C supplementation was associated with better performance at the last assessment (mean difference, 0.13; 95% confidence interval, 0.06 to 0.20; P=0.0005), it was not associated with cognitive change over time (mean difference in change, 0.02; 95% confidence interval, -0.03 to 0.07; P=0.39). Vitamin C was more protective against cognitive change among those with new cardiovascular events during the trial (P for interaction=0.009).. Antioxidant supplementation did not slow cognitive change among women with preexisting cardiovascular disease or cardiovascular disease risk factors. A possible late effect of vitamin C or beta carotene among those with low dietary intake on cognition warrants further study.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cognition Disorders; Female; Follow-Up Studies; Humans; Memory Disorders; Middle Aged; Neuroprotective Agents; Neuropsychological Tests; Oxidative Stress; Risk Factors; Single-Blind Method; Treatment Failure; Vitamin E

Homocysteinemia may play an etiologic role in the pathogenesis of type 2 diabetes by promoting oxidative stress, systemic inflammation, and endothelial dysfunction. We investigated whether homocysteine-lowering treatment by B vitamin supplementation prevents the risk of type 2 diabetes.. The Women's Antioxidant and Folic Acid Cardiovascular Study (WAFACS), a randomized, double-blind, placebo-controlled trial of 5,442 female health professionals aged > or = 40 years with a history of cardiovascular disease (CVD) or three or more CVD risk factors, included 4,252 women free of diabetes at baseline. Participants were randomly assigned to either an active treatment group (daily intake of a combination pill of 2.5 mg folic acid, 50 mg vitamin B6, and 1 mg vitamin B12) or to the placebo group.. During a median follow-up of 7.3 years, 504 women had an incident diagnosis of type 2 diabetes. Overall, there was no significant difference between the active treatment group and the placebo group in diabetes risk (relative risk 0.94 [95% CI 0.79-1.11]; P = 0.46), despite significant lowering of homocysteine levels. Also, there was no evidence for effect modifications by baseline intakes of dietary folate, vitamin B6, and vitamin B12. In a sensitivity analysis, the null result remained for women compliant with their study pills (0.92 [0.76-1.10]; P = 0.36).. Lowering homocysteine levels by daily supplementation with folic acid and vitamins B6 and B12 did not reduce the risk of developing type 2 diabetes among women at high risk for CVD.

Topics: Adult; Aged; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Folic Acid; Follow-Up Studies; Homocysteine; Humans; Middle Aged; Placebos; Proportional Hazards Models; Risk Factors; Vitamin B 12; Vitamin B 6; Vitamin E

Vitamin C, vitamin E, and beta-carotene are major antioxidants and as such may protect against the development of type 2 diabetes via reduction of oxidative stress.. The purpose of this study was to investigate the long-term effects of supplementation with vitamin C, vitamin E, and beta-carotene for primary prevention of type 2 diabetes.. In the Women's Antioxidant Cardiovascular Study, a randomized trial that occurred between 1995 and 2005, 8171 female health professionals aged > or =40 y with either a history of cardiovascular disease (CVD) or > or =3 CVD risk factors were randomly assigned to receive vitamin C (ascorbic acid, 500 mg every day), vitamin E (RRR-alpha-tocopherol acetate, 600 IU every other day), beta-carotene (50 mg every other day), or their respective placebos.. During a median follow-up of 9.2 y, a total of 895 incident cases occurred among 6574 women who were free of diabetes at baseline. There was a trend toward a modest reduction in diabetes risk in women assigned to receive vitamin C compared with those assigned to receive placebo [relative risk (RR): 0.89; 95% CI: 0.78, 1.02; P = 0.09], whereas a trend for a slight elevation in diabetes risk was observed for vitamin E treatment (RR: 1.13; 95% CI: 0.99, 1.29; P = 0.07). However, neither of these effects reached statistical significance. No significant effect was observed for beta-carotene treatment (RR: 0.97; 95% CI: 0.85, 1.11; P = 0.68).. Our randomized trial data showed no significant overall effects of vitamin C, vitamin E, and beta-carotene on risk of developing type 2 diabetes in women at high risk of CVD. This trial was registered at clinicaltrials.gov as NCT00000541.

Topics: Aged; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Dietary Supplements; Double-Blind Method; Female; Follow-Up Studies; Humans; Incidence; Middle Aged; Odds Ratio; Oxidative Stress; Primary Prevention; Risk Assessment; Risk Factors; United States; Vitamin E

Vitamin E and C given separately improve insulin sensitivity due to an inhibitory effect on oxidative stress and inflammation, however their combined effect on glucose control and inflammation is unknown. To investigate combined effect of Vitamin E and C in elderly with Impaired Fasting Glucose (IFG) on insulin action and substrate oxidation.. Controlled-trial administration of Vitamin E (1000 mg/day) and Vitamin C (1000 UI/day) for four weeks. Hyperinsulinemic euglycemic glucose clamp was performed before and following supplementation.. Out-patient clinic.. Thirteen older men with IFG.. Variations in whole body glucose disposal (WBGD), anti-oxidant, and inflammatory cytokines plasma levels.. An increase in plasma Vitamin E (8.3 + 0.8 vs. 64.9 + 2.1 micromol/l; p < 0.001] and C (35.9 + 5.4 vs. 79.4 + 7.4 micromol/l; p < 0.001) was found. Vitamin administration reduced insulin, glucose, lipid, TNF-alpha and [8-]isoprostane levels. Increase in plasma vitamin E levels correlated with decline in both plasma [8-]isoprostane levels (r = -0.58; p = 0.048) and TNF-alpha levels (r = - 0.62; p = 0.025), while no correlations were found for Vitamin C. Whole body glucose disposal (WBGD) (22.7 + 0.6 vs. 30.4 + 0.8 mmol x kg-1 x min-1; p = 0.001) and non-oxidative glucose metabolism rose after supplementation. Rise in plasma levels of Vitamin C and E correlated with WBGD. Multivariate linear regression models showed independent associations among the change in Vitamin E and the decline in TNF-alpha and [8-]isoprostane levels.. Combined administration of Vitamin E and C lowered inflammation and improved insulin action through a rise in non-oxidative glucose metabolism.

Topics: Aged; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Blood Glucose; Cardiovascular Diseases; Cytokines; Diabetes Mellitus, Type 2; Dietary Supplements; Fasting; Humans; Insulin; Insulin Resistance; Lipids; Male; Oxidative Stress; Vitamin E

Basic research and observational studies suggest vitamin E or vitamin C may reduce the risk of cardiovascular disease. However, few long-term trials have evaluated men at initially low risk of cardiovascular disease, and no previous trial in men has examined vitamin C alone in the prevention of cardiovascular disease.. To evaluate whether long-term vitamin E or vitamin C supplementation decreases the risk of major cardiovascular events among men.. The Physicians' Health Study II was a randomized, double-blind, placebo-controlled factorial trial of vitamin E and vitamin C that began in 1997 and continued until its scheduled completion on August 31, 2007. There were 14,641 US male physicians enrolled, who were initially aged 50 years or older, including 754 men (5.1%) with prevalent cardiovascular disease at randomization.. Individual supplements of 400 IU of vitamin E every other day and 500 mg of vitamin C daily.. A composite end point of major cardiovascular events (nonfatal myocardial infarction, nonfatal stroke, and cardiovascular disease death).. During a mean follow-up of 8 years, there were 1245 confirmed major cardiovascular events. Compared with placebo, vitamin E had no effect on the incidence of major cardiovascular events (both active and placebo vitamin E groups, 10.9 events per 1000 person-years; hazard ratio [HR], 1.01 [95% confidence interval {CI}, 0.90-1.13]; P = .86), as well as total myocardial infarction (HR, 0.90 [95% CI, 0.75-1.07]; P = .22), total stroke (HR, 1.07 [95% CI, 0.89-1.29]; P = .45), and cardiovascular mortality (HR, 1.07 [95% CI, 0.90-1.28]; P = .43). There also was no significant effect of vitamin C on major cardiovascular events (active and placebo vitamin E groups, 10.8 and 10.9 events per 1000 person-years, respectively; HR, 0.99 [95% CI, 0.89-1.11]; P = .91), as well as total myocardial infarction (HR, 1.04 [95% CI, 0.87-1.24]; P = .65), total stroke (HR, 0.89 [95% CI, 0.74-1.07]; P = .21), and cardiovascular mortality (HR, 1.02 [95% CI, 0.85-1.21]; P = .86). Neither vitamin E (HR, 1.07 [95% CI, 0.97-1.18]; P = .15) nor vitamin C (HR, 1.07 [95% CI, 0.97-1.18]; P = .16) had a significant effect on total mortality but vitamin E was associated with an increased risk of hemorrhagic stroke (HR, 1.74 [95% CI, 1.04-2.91]; P = .04).. In this large, long-term trial of male physicians, neither vitamin E nor vitamin C supplementation reduced the risk of major cardiovascular events. These data provide no support for the use of these supplements for the prevention of cardiovascular disease in middle-aged and older men.. clinicaltrials.gov Identifier: NCT00270647.

Topics: Aged; alpha-Tocopherol; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Double-Blind Method; Follow-Up Studies; Humans; Male; Middle Aged; Vitamin E; Vitamins

Recent research suggests that cardiovascular disease (CVD) and bone loss are functionally interwoven. This study examined the concomitant effects of a nutritional treatment of osteopaenia on CVD-risk factors.. A 1-year placebo-controlled trial was conducted on middle-aged women with normal (group A) or low (groups B and C) bone mineral density. Subjects (n = 20 per group) took daily either a placebo, calcium carbonate alone or combined to a vitamin (C and B(6))-proline capsule, respectively. Urinary pyridoxic acid (used to assess treatment compliance), plasma homocysteine, serum lipids and lipoproteins were measured before and after nutritional intervention.. Groups were comparable at baseline in most parameters of interest. No changes occurred in groups A and B. The 4%, 7% and 25% reductions of total cholesterol, LDL and triglycerides, and 14% elevation of HDL were all significant in group C. A trend toward reduction was observed for homocysteine in this group.. Vitamins C (500 mg) and B(6) (75 mg) combined with proline had consistent beneficial effects on CVD-risk factors, whereas calcium alone did not. This study also underlined the importance of considering vitamin B(6) status as a potential CVD risk factor.

Topics: Adult; Ascorbic Acid; Bone Density; Bone Density Conservation Agents; Bone Diseases, Metabolic; Calcium Carbonate; Calcium, Dietary; Cardiovascular Diseases; Cholesterol; Drug Therapy, Combination; Female; Homocysteine; Humans; Middle Aged; Patient Compliance; Postmenopause; Proline; Pyridoxic Acid; Risk Factors; Vitamin B 6

The role of antioxidants in preventing vascular disease remains controversial. Vascular endothelial growth factor (VEGF-A) is important for endothelial and monocyte function. This study investigated the negative effects of smoking on monocyte migratory responsiveness to VEGF-A and the usefulness of vitamin C to prevent smoking-induced monocyte dysfunction.. The chemotactic response of isolated monocytes from a cohort of 17 non-smokers and 10 smokers toward VEGF-A was assessed. VEGF-A significantly stimulated the migration of monocytes in non-smokers; the monocytes from smokers failed to respond to VEGF-A. Repeated analysis after 2 weeks of vitamin C intake (2 g/d) showed a fully restored VEGF-A-induced monocyte migration in smokers. VEGF-A serum levels were not altered by vitamin C. VEGF-A-inducible kinase activity was intact in monocytes from smokers as assessed by in vitro kinase assay. Monocyte dysfunction can be mimicked in vitro by challenging monocytes with a range of reactive oxygen species (ROS).. Stimulation of monocyte migration by VEGF-A was severely attenuated in smokers, and the deficit observed was surmounted by vitamin C supplementation. The negative effects of smoking on monocyte function may translate into adverse impacts on VEGF-A-dependent repair processes such as arteriogenesis. These results propose a causative role of oxidative stress in smoking-induced monocyte dysfunction.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cell Movement; Chemotaxis; Dietary Supplements; Humans; Male; Monocytes; Oxidative Stress; Reactive Oxygen Species; Risk Factors; Smoking; Vascular Endothelial Growth Factor A

Volume supplementation by saline infusion combined with N-acetylcysteine (NAC) represents an effective strategy to prevent contrast agent-induced nephrotoxicity (CIN). Preliminary data support the concept that sodium bicarbonate and ascorbic acid also may be effective in preventing CIN.. Three hundred twenty-six consecutive patients with chronic kidney disease, referred to our institutions for coronary and/or peripheral procedures, were randomly assigned to prophylactic administration of 0.9% saline infusion plus NAC (n=111), sodium bicarbonate infusion plus NAC (n=108), and 0.9% saline plus ascorbic acid plus NAC (n=107). All enrolled patients had serum creatinine > or = 2.0 mg/dL and/or estimated glomerular filtration rate < 40 mL x min(-1) x 1.73 m(-2). Contrast nephropathy risk score was calculated in each patient. In all cases, iodixanol (an iso-osmolar, nonionic contrast agent) was administered. The primary end point was an increase of > or = 25% in the creatinine concentration 48 hours after the procedure (CIN). The amount of contrast media administered (179+/-102, 169+/-92, and 169+/-94 mL, respectively; P=0.69) and risk scores (9.1+/-3.4, 9.5+/-3.6, and 9.3+/-3.6; P=0.21) were similar in the 3 groups. CIN occurred in 11 of 111 patients (9.9%) in the saline plus NAC group, in 2 of 108 (1.9%) in the bicarbonate plus NAC group (P=0.019 by Fisher exact test versus saline plus NAC group), and in 11 of 107 (10.3%) in the saline plus ascorbic acid plus NAC group (P=1.00 versus saline plus NAC group).. The strategy of volume supplementation by sodium bicarbonate plus NAC seems to be superior to the combination of normal saline with NAC alone or with the addition of ascorbic acid in preventing CIN in patients at medium to high risk.

Topics: Acetylcysteine; Administration, Oral; Aged; Ascorbic Acid; Cardiovascular Diseases; Contrast Media; Creatinine; Double-Blind Method; Drug Therapy, Combination; Female; Glomerular Filtration Rate; Humans; Infusions, Intravenous; Kidney Diseases; Male; Renal Insufficiency; Risk Factors; Sodium Bicarbonate; Sodium Chloride; Treatment Outcome; Triiodobenzoic Acids

High dietary intakes of tomato products are often associated with a reduced risk of CVD, but the atheroprotective mechanisms have not been established. This study was conducted to investigate the effects of increased dietary intake of tomato products on plasma lipids and LDL oxidation. The diet intervention included a baseline period, a 3-week low tomato diet (no tomato products allowed) and a 3-week high tomato diet (400 ml tomato juice and 30 mg tomato ketchup daily). Twenty-one healthy study subjects participated in the study. Total cholesterol concentration was reduced by 5.9 (sd 10) % (P = 0.002) and LDL cholesterol concentration by 12.9 (sd 17.0) % (P = 0.0002) with the high tomato diet compared to the low tomato diet. The changes in total and LDL cholesterol concentrations correlated significantly with the changes in serum lycopene (r 0.56, P = 0.009; r 0.60, P = 0.004, total and LDL, respectively), beta-carotene (r 0.58, P = 0.005; r 0.70, P < 0.001) and gamma-carotene concentrations (r 0.64, P = 0.002; r 0.64, P = 0.002). The level of circulating LDL to resist formation of oxidized phospholipids increased 13 % (P = 0.02) in response to the high tomato diet. In conclusion, a high dietary intake of tomato products had atheroprotective effects, it significantly reduced LDL cholesterol levels, and increased LDL resistance to oxidation in healthy normocholesterolaemic adults. These atheroprotective features associated with changes in serum lycopene, beta-carotene and gamma-carotene levels.

Topics: Adult; Antioxidants; Ascorbic Acid; beta Carotene; Beverages; Cardiovascular Diseases; Carotenoids; Cholesterol; Cholesterol, LDL; Diet; Female; Humans; Lipids; Lycopene; Male; Middle Aged; Oxidation-Reduction; Solanum lycopersicum; Vitamin E

Diabetes mellitus is one of the most common metabolic disorders that causes micro- and macro-vascular complications. Because of additive effects of hyperglycaemia and hyperlipidaemia for cardiovascular diseases, lipid abnormalities should be evaluated in diabetes. As vitamin C is known for its beneficial effects on serum lipids and glycated haemoglobin (HbA1c), we evaluated the effect of different doses of vitamin C on blood glucose, serum lipids and serum insulin in individuals with type 2 diabetes mellitus.. A total of 84 patients with type 2 diabetes referred to Yazd Diabetes Research Center, Iran, were included in the study. They received randomly either 500 mg or 1000 mg daily of vitamin C for six weeks. Fasting blood sugar (FBS), triglyceride (TG), total cholesterol (TC), low and high density lipoprotein (LDL, HDL), glycated haemoglobin HbA(Ic) and serum insulin were measured before and after vitamin C consumption and the results were analyzed.. A significant decrease in FBS, TG, LDL, HbA1c and serum insulin was seen in the group supplemented with 1000 mg vitamin C. The dose of 500 mg vitamin C, however, did not produce any significant change in any of the parameters studied.. Our results indicate that daily consumption of 1000 mg supplementary vitamin C may be beneficial in decreasing blood glucose and lipids in patients with type 2 diabetes and thus reducing the risk of complications.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Blood Glucose; Cardiovascular Diseases; Diabetes Complications; Diabetes Mellitus, Type 2; Female; Glycated Hemoglobin; Humans; Insulin; Lipids; Lipoproteins, LDL; Male; Middle Aged

Recent studies have demonstrated that oxidative modification of low-density lipoprotein (LDL) involving the formation of lipid peroxides (MDA), exerts several biological effects that may contribute to the onset and progression of cardiovascular diseases in postmenopausal women with Type 2 diabetes (DPMW). Therefore, the aim of our study was to evaluate the effect of hormone replacement therapy (HRT), vitamin C and E (VCE) treatments on lipid profiles, glucose and MDA levels as well as antioxidant vitamins and enzymes in plasma and red blood cells (RBC) in diabetic or non-diabetic postmenopausal women (PMW).. Oral HRT and VCE supplementation for 6 weeks were compared with HRT treatment in 40 non-diabetic PMW and 40 DPMW.. In the 40 postmenopausal women (PMW) and 20 postmenopausal women with DPMW who received oral HRT and 20 DPMW who received HRT plus VCE, there was a significant fall in MDA, total cholesterol, LDL-cholesterol and triglyceride values. Glycated haemoglobin (HbA1c) in the DPMW was significantly improved with oral HRT and VCE although no significant change in white blood cell counts, vitamin A and HDL values occurred. Additionally, a fall in plasma glucose, HbA1c and platelet values also occurred in the PMW and DPMW groups by oral HRT and VCE treatments. There was a significant increase in plasma vitamin E and beta-carotene concentrations, catalase, glutathione peroxidase and reduced glutathione levels in RBC and plasma in DPMW by treatments with HRT and/or VCE.. Daily VCE and HRT administrations both in PMW and DPMW seem to produce significant improvement in antioxidants concentrations, and the metabolic control of lipids and glucose. The HRT and VCE supplementations may strengthen the antioxidant defense system due to reducing blood glucose and lipid metabolites, and they may play a role in preventing cardiovascular diseases in postmenopausal women with Type 2 diabetes.

Topics: Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Erythrocytes; Female; Glycated Hemoglobin; Hormone Replacement Therapy; Humans; Lipid Peroxides; Lipids; Middle Aged; Postmenopause; Vitamin E

We have investigated the effect of modest supplementation with alpha-tocopherol (100 mg/day), beta-carotene (6 mg/day), vitamin C (100 mg/day) and selenium (50 microg/day) on oxidative stress and chromosomal damage, and the influence of methylenetetrahydrofolate reductase (MTHFR) genotype on these end-points. Subjects were two groups of middle-aged men differing in cardiovascular risk; 46 survivors of myocardial infarction before age 50 and 60 healthy controls. They were randomly divided into equal groups to receive antioxidants or placebo for 12 weeks. Twenty-eight patients and 58 controls completed the intervention. Micronucleus levels in peripheral lymphocytes and changes seen after intervention were studied in relation to the MTHFR C677T genotype, basal homocysteine and plasma folate levels. Ferric reducing ability of plasma and concentration of malondialdehyde were measured to assess the antioxidant effect of supplementation. There was no association of micronuclei with folate, homocysteine or malondialdehyde levels before supplementation. Micronucleus frequencies and plasma folate levels did not vary significantly with MTHFR genotype. Homocysteine levels in subjects with the TT variant genotype were significantly higher compared with CT or CC (P = 0.001), especially in subjects with low folate (P = 0.012). In the placebo control group an increase in micronuclei (P = 0.04) was detected at the end of the intervention period. This effect was not seen in the supplemented group. In antioxidant-supplemented myocardial infarction survivors we found an increase in the ferric reducing ability of plasma (P < 0.001) and a decrease in malondialdehyde (P = 0.001). Micronucleus frequency showed a decrease, strongest in subjects with normal folate levels (P = 0.015). In subjects with low folate levels, a high correlation was found between micronuclei after supplementation and homocysteine, both before (r = 0.979, P = 0.002) and after supplementation (r = 0.922, P = 0.009). Thus, folate deficiency may amplify the effect of other risk factors such as elevated homocysteine levels or variant MTHFR genotype, as well as influencing the ability of antioxidant supplementation to protect against genetic damage.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Dietary Supplements; DNA Damage; Folic Acid; Folic Acid Deficiency; Genotype; Humans; Male; Methylenetetrahydrofolate Reductase (NADPH2); Micronucleus Tests; Middle Aged; Myocardial Infarction; Oxidative Stress; Selenium

Insulin therapy may influence cardiovascular disease (CVD) and lipid metabolism in type 2 diabetes (T2D). Exaggerated postprandial lipaemia (PPL) is a feature of diabetic dyslipidaemia affecting CVD via enhanced oxidative stress (OS) and endothelial dysfunction. We assessed endothelial function and OS during PPL following insulin and vitamin C. Twenty (17 M) T2D patients were studied (mean Hba1c 8.4%) at baseline, following 6 weeks of insulin lispro (0.2 Iu kg-1) and vitamin C 1-g daily. Eight-h lipid and glucose profiles were measured following a fatty meal. Endothelial function (flow-mediated vasodilatation: FMD) and OS were measured at fasting, 4 h and 8 h.. Glucose, body mass index, and total and LDL cholesterol remained unchanged. FMD improved. Placebo group: fasting, 1.1 +/- 1.2 to 4.2 +/- 1.1% (P < 0.001); 4-h, 0.3 +/- 1.2 to 3.1 +/- 0.9% (P < 0.01); 8-h, 0.7 +/- 1.1 to 3.76 +/- 1.1% (P < 0.001). Vitamin C group: fasting, 0.9 +/- 1.1 to 6.1 +/- 1.3% (P < 0.001); 4-h, 0.7 +/- 1.5 to 4.9 +/- 2.1% (P < 0.001); 8-h, 0.8 +/- 0.9 to 5.8 +/- 0.6% (P < 0.01). Post-prandial lipaemia was attenuated: TG area-under-curve (mmol L-1 8 h-1), 52.6 +/- 11 to 39.1 +/- 12.5 (placebo group), P < 0.02; and 56.9 +/- 8 to 40.1 +/- 10.3 (vitamin C group), P < 0.02. Oxidative stress was reduced, with greater changes in the vitamin C group.. Insulin may thus exert vascular benefits in T2D, by modifying fasting and postprandial lipid metabolism resulting in reduced OS and improved EF. Vitamin C therapy may augment the vascular benefits of insulin in T2D through additional effects on OS and EF.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Endothelium, Vascular; Female; Humans; Hyperlipidemias; Hypoglycemic Agents; Insulin; Insulin Lispro; Male; Middle Aged; Oxidative Stress; Postprandial Period

At 60 patients with coronary artery disease and high blood pressure studied effects of a diet with low lipid and flavons. The application of a diet and flavons promoted positive dynamics (changes) of clinical manifestations of disease, lipid spectrum and antioxidants.

Topics: Adult; Aged; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Diet; Electrocardiography; Flavonoids; Humans; Hypertension; Lipid Peroxidation; Malondialdehyde; Middle Aged; Myocardial Ischemia; Obesity

Older persons are at risk of both poor nutrition and increased oxidative stress. Plasma ascorbate concentrations fall with increasing age, and concentrations of other antioxidants may also be reduced.. The goal was to examine the association between antioxidants and mortality in older persons.. We randomly selected persons aged 75-84 y from the lists of 51 British family practitioners taking part in a randomized trial of assessment of older persons. A total of 1214 participants provided a blood sample and were interviewed about their usual diet with the use of a food-frequency questionnaire. Statistical analyses were based on deaths after a median of 4.4 y of follow-up, and hazard ratios were estimated for quintiles of dietary or blood antioxidants.. We found strong inverse trends for blood ascorbate concentrations with all-cause and cardiovascular disease mortality, which were only marginally reduced after adjustment for confounders or supplement use. Those in the lowest fifth (< 17 micromol/L) had the highest mortality, whereas those in the highest fifth (> 66 micromol/L) had a mortality risk nearly half that (hazard ratio = 0.54; 95% CI: 0.34, 0.84). Similar results were found after the exclusion of those subjects with cardiovascular disease or cancer at baseline (hazard ratio = 0.51; 0.28, 0.93). In fully adjusted models, there was no evidence for an influence of alpha-tocopherol, beta-carotene, or retinol on total mortality. Dietary antioxidants measured by the food-frequency questionnaire were not associated with all-cause or cardiovascular disease mortality.. Low blood vitamin C concentrations in the older British population are strongly predictive of mortality.

Topics: Aged; Aged, 80 and over; Aging; alpha-Tocopherol; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Diet; Diet Records; Dietary Supplements; Female; Humans; Male; Mortality; Nutrition Assessment; Nutritional Physiological Phenomena; Proportional Hazards Models; Risk Factors; Surveys and Questionnaires; Vitamin A; Vitamins

It has been suggested that increased intake of various antioxidant vitamins reduces the incidence rates of vascular disease, cancer, and other adverse outcomes.. 20,536 UK adults (aged 40-80) with coronary disease, other occlusive arterial disease, or diabetes were randomly allocated to receive antioxidant vitamin supplementation (600 mg vitamin E, 250 mg vitamin C, and 20 mg beta-carotene daily) or matching placebo. Intention-to-treat comparisons of outcome were conducted between all vitamin-allocated and all placebo-allocated participants. An average of 83% of participants in each treatment group remained compliant during the scheduled 5-year treatment period. Allocation to this vitamin regimen approximately doubled the plasma concentration of alpha-tocopherol, increased that of vitamin C by one-third, and quadrupled that of beta-carotene. Primary outcomes were major coronary events (for overall analyses) and fatal or non-fatal vascular events (for subcategory analyses), with subsidiary assessments of cancer and of other major morbidity.. There were no significant differences in all-cause mortality (1446 [14.1%] vitamin-allocated vs 1389 [13.5%] placebo-allocated), or in deaths due to vascular (878 [8.6%] vs 840 [8.2%]) or non-vascular (568 [5.5%] vs 549 [5.3%]) causes. Nor were there any significant differences in the numbers of participants having non-fatal myocardial infarction or coronary death (1063 [10.4%] vs 1047 [10.2%]), non-fatal or fatal stroke (511 [5.0%] vs 518 [5.0%]), or coronary or non-coronary revascularisation (1058 [10.3%] vs 1086 [10.6%]). For the first occurrence of any of these "major vascular events", there were no material differences either overall (2306 [22.5%] vs 2312 [22.5%]; event rate ratio 1.00 [95% CI 0.94-1.06]) or in any of the various subcategories considered. There were no significant effects on cancer incidence or on hospitalisation for any other non-vascular cause.. Among the high-risk individuals that were studied, these antioxidant vitamins appeared to be safe. But, although this regimen increased blood vitamin concentrations substantially, it did not produce any significant reductions in the 5-year mortality from, or incidence of, any type of vascular disease, cancer, or other major outcome.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cause of Death; Cholesterol; Coronary Disease; Diabetes Mellitus; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms; Severity of Illness Index; Stroke; United Kingdom; Vitamin E

The high incidence of cardiovascular disease in hemodialyzed (HD) patients is well established and oxidative stress has been involved in this phenomenon. The aim of our study was to evaluate if a vitamin E-coated dialyzer could offer protection to HD patients against oxidative stress. Sixteen HD patients were successively assessed for one month (i) on a high biocompatible synthetic dialyzer (AN) and (ii) on a vitamin E-coated dialyzer (VE). Blood samples were taken before and after the dialysis session at the end of each treatment period. HD session conducted with the AN dialyzer was responsible for acute oxidative stress, significantly assessed after HD by a decreased plasma vitamin C level and an increased ascorbyl free radical (AFR)/vitamin C ratio used as an index of oxidative stress. Plasma elastase activity, reflecting neutrophil activation, was also increased; soluble P-selectin, reflecting platelet activation, did not show any variation. The use of the VE dialyzer was associated with a less extended oxidative stress compared with the AN membrane: basal vitamin C level was higher, and after the HD session AFR/vitamin C ratio and elastase activity were not significantly increased. Plasma vitamin E levels were not affected. Our study demonstrates that HD is associated with oxidative stress, which can be partially prevented by the use of a vitamin E-coated dialyzer. Our data suggest that this dialyzer may exert a site-specific scavenging effect on free radical species in synergy with a reduced activation of neutrophils.

Topics: Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cross-Over Studies; Female; Free Radicals; Humans; Kidneys, Artificial; Male; Middle Aged; Oxidative Stress; Pancreatic Elastase; Prospective Studies; Renal Dialysis; Vitamin E

Endothelial function is impaired in coronary artery disease and may contribute to its clinical manifestations. Increased oxidative stress has been linked to impaired endothelial function in atherosclerosis and may play a role in the pathogenesis of cardiovascular events. This study was designed to determine whether endothelial dysfunction and vascular oxidative stress have prognostic impact on cardiovascular event rates in patients with coronary artery disease.. Endothelium-dependent and -independent vasodilation was determined in 281 patients with documented coronary artery disease by measuring forearm blood flow responses to acetylcholine and sodium nitroprusside using venous occlusion plethysmography. The effect of the coadministration of vitamin C (24 mg/min) was assessed in a subgroup of 179 patients. Cardiovascular events, including death from cardiovascular causes, myocardial infarction, ischemic stroke, coronary angioplasty, and coronary or peripheral bypass operation, were studied during a mean follow-up period of 4.5 years. Patients experiencing cardiovascular events (n=91) had lower vasodilator responses to acetylcholine (P<0.001) and sodium nitroprusside (P<0.05), but greater benefit from vitamin C (P<0.01). The Cox proportional regression analysis for conventional risk factors demonstrated that blunted acetylcholine-induced vasodilation (P=0.001), the effect of vitamin C (P=0.001), and age (P=0.016) remained independent predictors of cardiovascular events.. Endothelial dysfunction and increased vascular oxidative stress predict the risk of cardiovascular events in patients with coronary artery disease. These data support the concept that oxidative stress may contribute not only to endothelial dysfunction but also to coronary artery disease activity.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Coronary Artery Disease; Disease Progression; Dose-Response Relationship, Drug; Endothelium, Vascular; Female; Follow-Up Studies; Forearm; Humans; Male; Middle Aged; Oxidative Stress; Plethysmography; Predictive Value of Tests; Prognosis; Proportional Hazards Models; Prospective Studies; Regional Blood Flow; Risk Assessment; Survival Rate; Vasodilation; Vasodilator Agents

Both lipid-modifying therapy and antioxidant vitamins are thought to have benefit in patients with coronary disease. We studied simvastatin-niacin and antioxidant-vitamin therapy, alone and together, for cardiovascular protection in patients with coronary disease and low plasma levels of HDL.. In a three-year, double-blind trial, 160 patients with coronary disease, low HDL cholesterol levels and normal LDL cholesterol levels were randomly assigned to receive one of four regimens: simvastatin plus niacin, vitamins, simvastatin-niacin plus antioxidants; or placebos. The end points were arteriographic evidence of a change in coronary stenosis and the occurrence of a first cardiovascular event (death, myocardial infarction, stroke, or revascularization).. The mean levels of LDL and HDL cholesterol were unaltered in the antioxidant group and the placebo group; these levels changed substantially (by -42 percent and +26 percent, respectively) in the simvastatin-niacin group. The protective increase in HDL2 with simvastatin plus niacin was attenuated by concurrent therapy with antioxidants. The average stenosis progressed by 3.9 percent with placebos, 1.8 percent with antioxidants (P=0.16 for the comparison with the placebo group), and 0.7 percent with simvastatin-niacin plus antioxidants (P=0.004) and regressed by 0.4 percent with simvastatin-niacin alone (P<0.001). The frequency of the clinical end point was 24 percent with placebos; 3 percent with simvastatin-niacin alone; 21 percent in the antioxidant-therapy group; and 14 percent in the simvastatin-niacin-plus-antioxidants group.. Simvastatin plus niacin provides marked clinical and angiographically measurable benefits in patients with coronary disease and low HDL levels. The use of antioxidant vitamins in this setting must be questioned.

Topics: alpha-Tocopherol; Antioxidants; Apolipoproteins; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Coronary Angiography; Coronary Disease; Coronary Stenosis; Double-Blind Method; Drug Interactions; Drug Therapy, Combination; Female; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypolipidemic Agents; Lipids; Male; Middle Aged; Niacin; Selenium; Simvastatin; Vitamin E

To assess the balance of benefits and risks of supplementation with beta-carotene, vitamin E, vitamin C, and multivitamins on cancer, cardiovascular (CVD), and eye diseases.. Physicians' Health Study II (PHS II) is a randomized, double-blind, placebo-controlled trial enrolling 15,000 willing and eligible physicians aged 55 years and older. PHS II will utilize a 2 x 2 x 2 x 2 factorial design to test alternate day beta-carotene, alternate day vitamin E, daily vitamin C, and a daily multivitamin, in the prevention of total and prostate cancer, CVD, and the age-related eye diseases, cataract and macular degeneration. PRIOR RESULTS: The final results of the recently completed Physicians' Health Study I (PHS I), a randomized, double-blind, placebo-controlled trial in 22,071 healthy US male physicians, indicated that beta-carotene supplementation (50 mg on alternate days) had no significant benefit or harm on cancer or CVD during more than 12 years of treatment and follow-up. In regards to cancer, there were possible benefits on total and prostate cancer in those with low baseline levels assigned to beta-carotene, a finding compatible with the Chinese Cancer Prevention Study for combined treatment with beta-carotene, vitamin E, and selenium in a poorly nourished population. Further, with respect to CVD, there were apparent benefits of beta-carotene supplementation on subsequent vascular events among a small subgroup of 333 men with prior angina or revascularization. The currently available data from randomized trials of primary prevention are sparse and inconsistent for vitamin E and non-existent for vitamin C and multivitamins. For eye diseases, namely cataract and age-related macular degeneration, there are no completed large-scale randomized trials of antioxidant vitamins.. PHS II is unique in several respects. PHS II is the only primary prevention trial in apparently healthy men testing the balance of benefits and risks of vitamin E on cancer and CVD. In addition, PHS II is the only primary prevention trial in apparently healthy men to test the balance of benefits and risks of vitamin C, multivitamins, as well as any single antioxidant vitamin, alone and in combination, on cancer, CVD, and eye diseases. Finally, PHS II is the only trial testing a priori the hypotheses that beta-carotene and vitamin E may reduce the risks of prostate cancer. Thus, PHS II will add unique as well as importantly relevant and complementary information to the totality of evidence from other completed and ongoing large-scale randomized trials on the balance of benefits and risks of beta-carotene, vitamin E, vitamin C, and multivitamins alone and in combination on prevention of cancer, CVD and eye diseases.

Topics: Aged; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cataract; Double-Blind Method; Female; Follow-Up Studies; Humans; Macular Degeneration; Male; Middle Aged; Neoplasms; Sample Size; Vitamin E

Increased levels of homocysteine are associated with risk of cardiovascular disease. Homocysteine may cause this risk by impairing endothelial cell function.. To evaluate the effect of acute hyperhomocysteinemia with and without antioxidant vitamin pretreatment on cardiovascular risk factors and endothelial functions.. Observer-blinded, randomized crossover study conducted at a university hospital in Italy.. Twenty healthy hospital staff volunteers (10 men, 10 women) aged 25 to 45 years.. Subjects were given each of 3 loads in random order at 1-week intervals: oral methionine, 100 mg/kg in fruit juice; the same methionine load immediately following ingestion of antioxidant vitamin E, 800 IU, and ascorbic acid, 1000 mg; and methionine-free fruit juice (placebo). Ten of the 20 subjects also ingested a placebo load with vitamins.. Lipid, coagulation, glucose, and circulating adhesion molecule parameters, blood pressure, and endothelial functions as assessed by hemodynamic and rheologic responses to L-arginine, evaluated at baseline and 4 hours following ingestion of the loads.. The oral methionine load increased mean (SD) plasma homocysteine level from 10.5 (3.8) micromol/L at baseline to 27.1 (6.7) micromol/L at 4 hours (P<.001). A similar increase was observed with the same load plus vitamins (10.0 [4.0] to 22.7 [7.8] micromol/L; P<.001) but no significant increase was observed with placebo (10.1 [3.7] to 10.4 [3.2] micromol/L; P=.75). Coagulation and circulating adhesion molecule levels significantly increased after methionine ingestion alone (P<.05) but not after placebo or methionine ingestion with vitamins. While the mean (SD) blood pressure (-7.0% [2.7%]; P<.001), platelet aggregation response to adenosine diphosphate (-11.4% [4.5%]; P=.009) and blood viscosity (-3.0% [1.2%]; P=.04) declined in these parameters 10 minutes after an L-arginine load (3 g) following placebo, the increase after methionine alone (-2.3% [1.5%], 4.0% [3.0%], and 1.5% [1.0%], respectively; P<.05), did not occur following methionine load with vitamin pretreatment (-6.3% [2.5%], -7.9% [3.5%], and -1.5% [1.0%], respectively; P=.24).. Our data suggest that mild to moderate elevations of plasma homocysteine levels in healthy subjects activate coagulation, modify the adhesive properties of endothelium, and impair the vascular responses to L-arginine. Pretreatment with antioxidant vitamin E and ascorbic acid blocks the effects of hyperhomocysteinemia, suggesting an oxidative mechanism.

Topics: Acute Disease; Adult; Antioxidants; Arginine; Ascorbic Acid; Blood Coagulation; Blood Viscosity; Cardiovascular Diseases; Cross-Over Studies; Endothelium, Vascular; Female; Hemodynamics; Homocysteine; Humans; Male; Methionine; Platelet Aggregation; Risk Factors; Single-Blind Method; Vitamin E

Evidence from observational epidemiologic studies has indicated that antioxidants consumed through the diet or as dietary supplements lower the risk of developing atherosclerotic cardiovascular disease. Evidence suggesting that the major mechanism for the protective effect of antioxidants is mediated through decreased oxidation of lipids, particularly low-density lipoprotein (LDL) cholesterol is accumulating. Other evidence, however, suggests that antioxidants may influence traditional modifiable cardiovascular risk factors such as the blood pressure and serum lipids favorably. The purpose of this study was to determine the effect of antioxidant vitamin supplementation on modifiable risk factors for atherosclerotic cardiovascular disease.. A randomized, placebo-controlled, clinical trial of antioxidant vitamin supplementation, conducted at a single community-based clinical research center.. We assigned 297 retired teachers who were members of the Maryland Retired Teachers Association randomly to 2-4 months of dietary supplementation with placebo or combined antioxidant vitamin capsules providing 400 IU/day vitamin E, 500 mg/day vitamin C, and 6 mg/day beta-carotene. The outcome measures were the blood pressure, fasting serum total cholesterol, high-density lipoprotein cholesterol, LDL cholesterol, and fasting glucose.. After 2-4 months of supplementation the combined antioxidant supplement had had no significant effect on the systolic and diastolic blood pressures, fasting serum lipids (total cholesterol, high-density lipoprotein cholesterol, and LDL cholesterol) and fasting glucose, with unadjusted and adjusted analyses.. Data from this trial suggest that the protective effect from antioxidant vitamin supplementation, if there is one, likely results from mechanisms other than modification of traditionally modifiable cardiovascular risk factors.

Topics: Antioxidants; Arteriosclerosis; Ascorbic Acid; beta Carotene; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Double-Blind Method; Female; Humans; Lipids; Male; Middle Aged; Pilot Projects; Risk Factors; Time Factors; Vitamin E

To determine the plasma ascorbic acid concentrations among men in North Karelia (Finland) and in Pitkäranta (Republic of Karelia) and to test how a short intervention would affect the plasma concentrations.. The baseline survey was done as a cross-sectional population survey. A subsample was selected to the intervention study and randomised to treatment and control groups.. North Karelia province in Finland and the Pitkäranta area in the Republic of Karelia.. In the cross-section population survey the stratified random sample of men between 25 and 64 years of age was 1000 in North Karelia and 500 in Pitkäranta. Participation rates were 68% and 77%, respectively. Plasma ascorbic acid measurements were made in one-third of the sample. In Pitkäranta 60 men, having very low plasma ascorbic acid concentrations, were invited to the intervention study.. A controlled intervention study was made with blackcurrant-strawberry nectar in which vitamin C content was approximately 70 mg/100 g. The treatment group drank two times daily 200 ml nectar for 4-5 weeks. After intervention plasma ascorbic acid concentration was measured from both treatment and control groups.. Plasma ascorbic acid concentrations were very different in the two areas. In Pitkäranta 93% of the men and in North Karelia only 2% of the men had plasma levels suggesting severe vitamin C deficiency. After intervention 46% of the men in the experimental group compared with 5% in the control group had plasma ascorbic acid concentrations exceeding 23 mumol/l (4.0 mg/l).. In addition to a high smoking prevalence the very low ascorbic acid concentration among men in the Republic Karelia can have an effect on the high cardiovascular disease mortality.

Topics: Administration, Oral; Adult; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Cross-Sectional Studies; Finland; Humans; Male; Middle Aged; Prevalence; Russia; Smoking

The evidence for a potential benefit of antioxidant vitamins in the prevention and therapy of atherosclerotic disease is derived from laboratory, clinical, and observational epidemiologic studies but remains inconclusive. Data from randomized clinical trials are sparse, particularly for women. Therefore, it is both timely and important to conduct large-scale primary and secondary prevention trials of antioxidants and cardiovascular disease (CVD). The Women's Antioxidant and Cardiovascular Study (WACS) is a randomized, double-blind, placebo-controlled secondary prevention trial of the balance of benefits and risks of antioxidant vitamins (vitamins E and C, and beta-carotene) among 8000 women with preexisting CVD. This secondary prevention trial will be conducted as a companion to the recently started Women's Health Study, a primary prevention trial of vitamin E and beta-carotene, as well as aspirin. In the WACS, US female health professionals aged 40 years and older with a history of myocardial infarction, angina pectoris, coronary revascularization, stroke, transient cerebral ischemia, carotid endarterectomy, or peripheral artery surgery will be randomly assigned, utilizing a 2 x 2 x 2 factorial design, to receive vitamin E, vitamin C, beta-carotene, and/or placebo. Cardiovascular end points include nonfatal myocardial infarction, nonfatal stroke, coronary revascularization procedures, and total CVD mortality. The present article describes the rationale, design, and methods of the trial.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Double-Blind Method; Female; Humans; Middle Aged; Research Design; Risk Factors; United States; Vitamin E

Topics: Adult; Antioxidants; Ascorbic Acid; Blood Pressure; Cardiovascular Diseases; Female; Free Radicals; Heart Rate; Humans; Hypertension; Male; Middle Aged; Reactive Oxygen Species; Smoking

In vitro data suggest that vitamin C alters numerous parameters of immune function and might have potential as an agent which prevents infection. When an uncontrolled Japanese trial claimed efficacy of vitamin C in preventing posttransfusion hepatitis, a randomized double-blind controlled trial was initiated to determine if this claim of vitamin C efficacy could be confirmed. For 2 days before surgery and 2 wk after operation, cardiac surgery patients received orally either a lactose placebo or 800 mg of vitamin C four times daily. One hundred seventy-five patients completed the study. Highly significant elevations of plasma vitamin C were seen in the vitamin C treatment group as compared to the placebo group (p < 0.0005), but no significant difference in the incidence of posttransfusion hepatitis (p < 0.50) or the clinical course of hepatitis was seen between the two treatment groups.

Topics: Alanine Transaminase; Ascorbic Acid; Aspartate Aminotransferases; Cardiovascular Diseases; Double-Blind Method; Female; Hepatitis; Hepatitis B Surface Antigens; Humans; Male; Middle Aged; Placebos; Transfusion Reaction

Topics: Aged; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Female; Humans; Male; Placebos; Thrombosis

The relationship between dietary total antioxidant capacity (DTAC) and death risk among CKD populations remains unclear.. Our results showed L-shaped associations of DTAC with all-cause mortality among individuals with CKD stages 1-2 in both cohorts. Compared to the lowest quartile, higher dietary total antioxidant intake was associated with lower all-cause mortality risks among CKD stages 1-2 after adjustment for covariates, with HRs (95%CI) of 1.00, 0.91 (0.71,1.17), 0.69 (0.53,0.90), and 0.70 (0.54,0.91) in VCEAC, and similar respective estimate trends in CDAI. After sensitivity and subgroup analyses, there were no benefits for patients with stage 3-5 CKD or albuminuria. Mediation analysis revealed that the proportions mediated in both cohorts were less consistent.. Moderate dietary total antioxidants intake has potential benefits for early-stage CKD patients. However, further evidence is needed to confirm whether patients with worsening CKD can benefit in the long term.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Mortality; Nutrition Surveys; Renal Insufficiency, Chronic; Retrospective Studies

Cardiovascular diseases remain a major cause of death globally. Cardiac cells once damaged, cannot resume the normal functioning of the heart. Bone marrow derived mesenchymal stem cells (BM-MSCs) have shown the potential to differentiate into cardiac cells. Epigenetic modifications determine cell identity during embryo development via regulation of tissue specific gene expression. The major epigenetic mechanisms that control cell fate and biological functions are DNA methylation and histone modifications. However, epigenetic modifiers alone are not sufficient to generate mature cardiac cells. Various small molecules such as ascorbic acid (AA) and salvianolic acid B (SA) are known for their cardiomyogenic potential. Therefore, this study is aimed to examine the synergistic effects of epigenetic modifiers, valproic acid (VPA) and 5-azacytidine (5-aza) with cardiomyogenic molecules, AA and SA in the cardiac differentiation of MSCs.. BM-MSCs were isolated, propagated, characterized, and then treated with an optimized dose of VPA or 5-aza for 24 h. MSCs were maintained in a medium containing AA and SA for 21 days. All groups were assessed for the expression of cardiac genes and proteins through q-PCR and immunocytochemistry, respectively. Results show that epigenetic modifiers VPA or 5-aza in combination with AA and SA significantly upregulate the expression of cardiac genes MEF2C, Nkx2.5, cMHC, Tbx20, and GATA-4. In addition, VPA or 5-aza pretreatment along with AA and SA enhanced the expression of the cardiac proteins connexin-43, GATA-4, cTnI, and Nkx2.5.. These findings suggest that epigenetic modifiers valproic acid and 5-azacytidine in combination with ascorbic acid and salvianolic acid B promote cardiac differentiation of MSCs. This pretreatment strategy can be exploited for designing future stem cell based therapeutic strategies for cardiovascular diseases.

Topics: Ascorbic Acid; Azacitidine; Cardiovascular Diseases; Cell Differentiation; Cells, Cultured; Humans; Mesenchymal Stem Cells; Myocytes, Cardiac; Valproic Acid

We aimed to investigate the familial resemblance of dietary intakes, including energy and nutrients, and the family-based heritability of dietary intake in different age-sex dyads of the Tehran cardiometabolic genetic study.. This cross-sectional study was conducted on 9,798 participants, aged ≥ 18 years, with complete data in each of the third, fourth, fifth, and sixth surveys of the Tehran Cardiometabolic Genetic study, who were eligible to enter the current study based on inclusion and exclusion criteria. Nutrient intake was determined using a valid and reliable food frequency questionnaire (FFQ). FCOR command of the S.A.G.E. software was used to estimate the intra-class correlation coefficients of all relative pairs to verify the family resemblance of dietary nutrient intakes. Classical likelihood-based is used to assess the family-based heritability of dietary nutrient traits.. There were 4338 families with a mean family size of 3.20 ± 2.89, including 1 to 32 members (2567 constituent pedigrees and 1572 singletons) and 3627 sibships. The mean ± SD age of participants was 42.0 ± 15.2 years, and 44.5% were males. The heritability of nutrient intake ranged from 3 to 21%. The resemblance degree of energy intake and most nutrients between spouses or between parents and children is weak to moderate; however, a high resemblance of intake was observed for some food components, especially among spouses, including trans fatty acids (TFAs) (r:0.70), chromium (r:0.44), fiber(r:0.35), pantothenic acid (r:0.31), and vitamin C(r:0.31). Based on our findings, the resemblance of nutrient intake in spouses was greater than in parent-offspring. The similarity in parent-offspring nutrient intake was different, and the correlation in mother-girls nutrient intakes was greater than other parent-child correlations. Also, the lowest resemblance in nutrient intake was observed among siblings.. Our findings suggested a weak-to-moderate similarity between the nutrient intakes of parents and offspring. The resemblance degree in nutrient intake varied between different family pairs; the strongest correlation of nutrients was observed between spouses, which includes TFAs, chromium, fiber, pantothenic acid, and vitamin C. The lowest correlation of nutrients was between siblings, such as carbohydrates, thiamine, niacin, and vitamin K. An individual's nutrient intake can somewhat be influenced by genetics, family relationships, and the effects of parents, although the significant influence of environmental factors should not be ignored.

Topics: Ascorbic Acid; Cardiovascular Diseases; Chromium; Cross-Sectional Studies; Eating; Energy Intake; Female; Humans; Iran; Likelihood Functions; Male; Nutrients; Pantothenic Acid; Vitamins

Cardiovascular disease (CVD) is the leading cause of mortality, and vascular calcification has been highly correlated with CVD events. Abdominal aortic calcification (AAC) has been shown to predict subclinical CVD and incident CVD events. However, the relationship between vitamin C and abdominal aortic calcification remains unclear.. To investigate the relationship of dietary vitamin C with AAC among the adult population in the US.. The National Health and Nutrition Examination Survey (NHANES) 2013-2014 provided the data for the cross-sectional study. 2297 subjects (1089 males) were included in the study. Two scoring systems, AAC 24-point scale (Kauppila) and AAC 8-point scale (Schousboe), were used for the measurement of AAC score. Dietary vitamin C intake was calculated as the average of two rounds of 24-h interview recall data and classified in tertiles for analysis. We applied weighted multiple regression analyses to assess the relationship of dietary vitamin C with AAC score and the risk of having AAC. To ensure the robustness of the findings, subgroup and sensitivity analyses were performed. Additionally, smooth curve fittings, using generalized additive models (GAM) were employed to visualize potential nonlinear relationships. Furthermore, an exploratory analysis on the relationship of vitamin C supplements with AAC was also conducted.. The results showed that higher dietary vitamin C intake was related to a reduction in AAC score (AAC-24: β = -0.338, 95% confidence interval [CI] -0.565, -0.111, P = 0.004; AAC-8: β = -0.132, 95%CI -0.217, -0.047, P = 0.002), and lower risk of AAC (odds ratio [OR] = 0.807, 95%CI 0.659, 0.989, P = 0.038). However, the relationship of vitamin C supplements with AAC was not identified.. The study revealed that higher intake of dietary vitamin C rather than vitamin C supplements was related to reduced AAC score and lower risk of AAC, indicating that diets rich in vitamin C are recommended due to its potential benefits for protecting against vascular calcification and CVD among the adult population in the US.

Topics: Adult; Aorta, Abdominal; Aortic Diseases; Ascorbic Acid; Cardiovascular Diseases; Cross-Sectional Studies; Diet; Humans; Male; Nutrition Surveys; Risk Factors; Vascular Calcification; Vitamins

To evaluate the relations of dietary total antioxidant capacity (DTAC) with mortality outcomes in a Chinese population.. The study included 62,063 participants from the Singapore Chinese Health Study. The participants were 45-74 years at baseline (1993-1998) when dietary data were collected with a validated 165-item food frequency questionnaire. The DTAC was derived using two widely adopted scores of integrated dietary consumption of antioxidant nutrients, i.e., the Comprehensive Dietary Antioxidant Index (CDAI) and Vitamin C Equivalent Antioxidant Capacity (VCEAC). We used Cox proportional hazard model to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations with adjustment for potential confounders.. During 1,212,318 person-years of follow-up, 23,397 deaths [cardiovascular diseases (CVD): 7523; respiratory diseases: 4696; and cancer: 7713] occurred. In multivariable models, the HR (95% CI) comparing participants in the highest vs. lowest quartile of CDAI was 0.85 (0.82, 0.88) for all-cause mortality, 0.82 (0.76, 0.88) for CVD mortality, 0.76 (0.70, 0.83) for respiratory disease mortality (all P-trend < 0.001), and 0.94 (0.88, 1.00) for cancer mortality (P-trend = 0.16). Similar associations were found with the VCEAC index. Higher intakes of the DTAC components, i.e., vitamin C, vitamin E, carotenoids, and flavonoids, were all associated with lower mortality risk.. Diet with a higher antioxidant capacity in midlife was associated with a lower risk of all-cause, cardiovascular and respiratory disease mortality in the Singapore Chinese population, supporting the public health recommendation of consuming more plant-based foods that are rich in antioxidant nutrients.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; China; Diet; Humans; Neoplasms; Proportional Hazards Models; Prospective Studies; Risk Factors; Singapore; Vitamins

Background: to evaluate the prevalence and predictors of insufficient plasma vitamin C among adults in a subtropical region and its associations with cardiovascular disease risk factors including dyslipidemia and lipid-independent markers, namely homocysteine, high-sensitivity C-reactive protein (hs-CRP) and lipoprotein(a). Methods: Data of this retrospective cross-sectional study were extracted from electronic medical database of a Medical Center. Based on plasma vitamin C status, subjects were split into two groups—subjects with sufficient and insufficient plasma vitamin C levels (<50 µmol/L, ≤8.8 mg/L). Results: Prevalence of insufficient plasma vitamin C in 3899 adults was 39%. Multivariate logistic regression identified male gender, high body mass index, age 20−39, and winter/spring as independent predictors of insufficient vitamin C among all subjects. Greater proportions of subjects with insufficient plasma vitamin C had lower high-density lipoprotein cholesterol levels and elevated levels of triglyceride, homocysteine and hs-CRP (all p < 0.001). There were no differences in total cholesterol, low-density lipoprotein cholesterol and lipoprotein(a) between groups. Conclusions: There was a high prevalence of insufficient plasma vitamin C in the subtropical region, which indicates that insufficient plasma vitamin C remains a public health issue. Further study is needed to confirm these findings and to determine the underlying mechanisms.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Cross-Sectional Studies; Humans; Male; Prevalence; Retrospective Studies; Risk Factors; Young Adult

Topics: Ascorbic Acid; Cardiovascular Diseases; Genetic Predisposition to Disease; Humans; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Vitamins

The association between levels of circulating vitamin C and mortality remains controversial. The aim of this study was to explore the non-linear association between serum vitamin C levels and all-cause or cause-specific mortality.. We included 9902 US adults with their serum vitamin C levels from the National Health and Nutrition Examination Survey (NHANES 2003-2006). Their survival information was retrieved from baseline until 2015 using the national death index. Multivariable Cox proportional hazards models were used to show the risk for all-cause or cause-specific death according to baseline serum vitamin C levels. Smooth curve fitting and threshold effect analyses were used to clarify potential nonlinearity.. During a median follow-up of 10.6 y, there were 1558 all-cause deaths, including 320 from cancer, 374 from cardiovascular disease (CVD), and 120 from respiratory diseases. Serum vitamin C levels had a U-shaped relationship with all-cause or CVD-associated mortality. Interestingly, serum vitamin C levels lower than the threshold value (1.06 mg/dL) were negatively associated with all-cause (fully adjusted hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.59-0.86) and CVD (fully adjusted HR, 0.70; 95% CI, 0.47-1.03) mortality. In contrast, serum vitamin C levels higher than the threshold value (1.06 mg/dL) were positively associated with all-cause (fully adjusted HR, 1.33; 95% CI, 1.15-1.54) and CVD (fully adjusted HR, 1.60, 95% CI, 1.23-2.10) mortality, respectively.. Serum vitamin C levels showed a U-shaped relationship with all-cause and CVD-associated deaths among US adults using the NHANES data.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Cause of Death; Humans; Nutrition Surveys; Proportional Hazards Models; Risk Factors; Vitamins

We conducted a two-sample Mendelian randomization (MR) study to assess the associations of genetically predicted circulating vitamin C levels with cardiovascular diseases (CVDs).. Ten lead single-nucleotide polymorphisms associated with plasma vitamin C levels at the genome-wide significance level were used as instrumental variables. Summary-level data for 15 CVDs were obtained from corresponding genetic consortia, the UK Biobank study, and the FinnGen consortium. The inverse-variance-weighted method was the primary analysis method, supplemented by the weighted median and MR-Egger methods. Estimates for each CVD from different sources were combined. Genetically predicted vitamin C levels were not associated with any CVD after accounting for multiple testing. However, there were suggestive associations of higher genetically predicted vitamin C levels (per 1 standard deviation increase) with lower risk of cardioembolic stroke [odds ratio, 0.79; 95% confidence interval (CI), 0.64, 0.99; P = 0.038] and higher risk of atrial fibrillation (odds ratio, 1.09; 95% CI, 1.00, 1.18; P = 0.049) in the inverse-variance-weighted method and with lower risk of peripheral artery disease (odds ratio, 0.76, 95% CI, 0.62, 0.93; P = 0.009) in the weighted median method.. We found limited evidence with MR techniques for an overall protective role of vitamin C in the primary prevention of CVD. The associations of vitamin C levels with cardioembolic stroke, atrial fibrillation, and peripheral artery disease need further study.

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Risk Factors; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Genetic Predisposition to Disease; Humans; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Primary Prevention

Previous observational studies have reported associations between plasma vitamin C levels, and cardiovascular diseases (CVDs) and Alzheimer's disease (AD); however, no conclusive results have been obtained. We conducted a Mendelian randomization (MR) study to investigate the causality of vitamin C on the risk of nine CVDs [including coronary artery disease (CAD), myocardial infarction (MI), atrial fibrillation (AF), heart failure (HF), stroke, ischemic stroke (IS), and IS subtypes] and Alzheimer's disease.. Eleven single-nucleotide polymorphisms (SNPs) identified in a recent genome-wide meta-analysis (N = 52,018) were used as the instrumental variables for plasma vitamin C levels. The summary-level data for CVDs and AD were extracted from consortia and genome-wide association studies (GWAS). We performed MR analyses using the fixed-effects inverse-variance-weighted (IVW) method, weighted median, and MR-Egger approaches.. This MR study found suggestive evidence that genetic liability to higher vitamin C levels was associated with a lower risk of cardioembolic stroke [odds ratio (OR, presented per 1 standard deviation increase in plasma vitamin C levels) = 0.773; 95% confidence interval (CI), 0.623-0.959; P = 0.020] and AD (OR = 0.968; 95% CI, 0.946-0.991; P = 0.007) using the fixed-effects IVW method. Sensitivity analysis yielded directionally similar results. A null-association was observed between vitamin C and the other CVDs.. Our MR study provided suggestive evidence that higher vitamin C levels were casually associated with a decreased risk of cardioembolic stroke and AD. No evidence was observed to suggest that vitamin C affected the risk of CAD, MI, AF, HF, stroke, IS, large artery stroke, or small vessel stroke. However, well-designed studies are warranted to confirm these results and determine the underlying mechanisms of the causal links.

Topics: Alzheimer Disease; Ascorbic Acid; Cardiovascular Diseases; Humans; Mendelian Randomization Analysis; Polymorphism, Single Nucleotide; Protective Factors; Risk

The impact of vitamin C supplementation on the risk of cardiovascular diseases (CVDs) remains uncertain with inconsistent evidence obtained from observational studies and randomized clinical trials (RCTs). We aimed to assess possible causal associations of vitamin C with major CVD events as well as their risk factors using Mendelian randomization (MR) design.. Nine genetic variants associated with vitamin C at genome-wide significance (p < 5 × 10. This MR study does not support a causal protective role to circulate vitamin C levels on various types of CVD events. In combination with previous RCT results, our findings suggest that vitamin C supplementation to increase circulating vitamin C levels may not help in CVD prevention.

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Blood Pressure; Body Composition; Cardiovascular Diseases; Genetic Predisposition to Disease; Heart Disease Risk Factors; Humans; Lipids; Mendelian Randomization Analysis; Phenotype; Polymorphism, Single Nucleotide; Risk Assessment

In this paper, we hypothesized that the gap between estimated cardiovascular age (eCV-age) and chronological age had a gender-wise correlation with the Korean Healthy Eating Index (KHEI). We tested the hypothesis in adults aged 20-64 years old using the KNHANES 2013-2017 data. eCV-age was estimated based on the designated risk factors of cardiovascular disease (CVD) and age-gap was calculated by subtracting the eCV-age from the chronological age in 12,317 adults. Adjusted odds ratios for the age-gap were measured according to KHEI, while controlling for covariates to influence risk factors of CVD, using logistic regression analysis with the complex sample survey design. Age-gaps were divided into four groups: >4 (High), 0-4 (Moderate), -4-0 (Mild), and <-4 years (Low). The higher the age-gap, the lower the cardiovascular risk. Persons included in the following categories belonged to the high and moderate age-gap groups: young (<40 years), women, urban living, better than high school education, higher income, lean, mild drinking, and exercising regularly. KHEI scores were overall higher in women than men (

Topics: Adult; Age Factors; Ascorbic Acid; Breakfast; Cardiovascular Diseases; Cardiovascular Physiological Phenomena; Cardiovascular System; Diet, Healthy; Dietary Fiber; Energy Intake; Feeding Behavior; Female; Humans; Income; Logistic Models; Male; Middle Aged; Nutrition Surveys; Obesity; Regression Analysis; Risk Factors; Socioeconomic Factors; Surveys and Questionnaires; Young Adult

One of the major issues in cell therapy of myocardial infarction (MI) is early death of engrafted cells in a harsh oxidative stress environment, which limits the potential therapeutic utility of this strategy in the clinical setting. Increasing evidence implicates beneficial effects of omega-3 fatty acids including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and ascorbic acid (AA) in cardiovascular diseases, in particular their role in ameliorating fibrosis. In the current study, we aim to assess the cytoprotective role of EPA + DHA and AA in protecting embryonic stem cell (ESC)-derived cardiac lineage cells and amelioration of fibrosis. Herein, we have shown that preincubation of the cells with EPA + DHA + AA prior to H

Topics: Animals; Ascorbic Acid; Biomarkers; Blotting, Western; Cardiovascular Diseases; Cell Differentiation; Cell Survival; Docosahexaenoic Acids; Echocardiography; Eicosapentaenoic Acid; Embryonic Stem Cells; Fatty Acids, Omega-3; Heme Oxygenase-1; Humans; Hydrogen Peroxide; Male; Myocardial Infarction; Oxidative Stress; Rats; Rats, Wistar; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction

Vitamin C insufficiency occurs across many countries and has been hypothesised to increase risk of various diseases. Few prospective studies with measured circulating vitamin C have related deficiency to disease mortality, particularly in low-income and middle-income countries.. We randomly selected 948 subjects (473 males and 475 females) aged 53-84 years from a Chinese cohort and measured meta-phosphoric acid-preserved vitamin C concentrations in plasma samples collected in 1999-2000. A total of 551 deaths were accrued from sample collection through 2016, including 141 from cancer, 170 from stroke and 174 from heart diseases. Vitamin C was analysed using season-specific quartiles, as a continuous variable and as a dichotomous variable based on sufficiency status (normal >28 µmol/L vs low ≤28 µmol/L). HRs and 95% CIs were estimated using Cox proportional hazards models.. We found significant inverse associations between higher plasma vitamin C concentrations and total mortality in quartile (HR. In this long-term prospective Chinese cohort study, higher plasma vitamin C concentration was associated with lower total mortality, heart disease mortality and cancer mortality. Our results corroborate the importance of adequate vitamin C to human health.

Topics: Aged; Aged, 80 and over; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Cause of Death; China; Female; Humans; Male; Middle Aged; Mortality; Neoplasms; Prospective Studies; Seasons

Topics: Ascorbic Acid; Cardiovascular Diseases; China; Diet; Humans; Neoplasms; Seasons

Pan Masala containing Tobacco (PMT) use contributes significantly to the overall world tobacco burden especially in south Asian country like Nepal. Oxidative stress caused by it may leads to cardiovascular disease, peripheral vascular disease, hypertension, etc. Therefore, this work proposes to study the antioxidant and oxidative stress along with cardiovascular morbidity in PMT users.. Hundred PMT users and 80 non-user controls with age and sex matched were enrolled. There was a significant difference in blood pressure, albumin, uric acid, vitamin C, vitamin E, malondialdehyde (MDA), total cholesterol, triglycerides, low density lipoprotein cholesterol between the two groups (p < 0.001). We observed statistically significant (p < 0.001) decrease in antioxidant and increase oxidative stress in PMT users. Duration and quantity of PMT user were significantly associated with the MDA level.

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cross-Sectional Studies; Female; Humans; Male; Malondialdehyde; Middle Aged; Nepal; Oxidative Stress; Tobacco, Smokeless; Vitamin E

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Asian People; Blood Glucose; Body Mass Index; Cardiovascular Diseases; Cardiovascular System; Cholesterol; Diet; Dietary Fiber; Female; Follow-Up Studies; Hong Kong; Humans; Male; Middle Aged; Potassium; Prevalence; Proportional Hazards Models; Prospective Studies; Risk Factors; Sodium; Triglycerides; Vitamin A; Vitamin E; Waist Circumference

A family of 12 members of Naphthalene-2-ol-indolin-2-one-thiocarbamides (5a-l) with pharmacological potentials of cardiovascular modulator were efficiently synthesized and evaluated. These compounds show inhibitory activity on angiotensin-converting enzyme (ACE), which is a principal constituent of the renin-angiotensin system and causative source for hypertension (HTN) (elevated blood pressure) and congestive heart failure (CHF), a parameter that was tested in this report. Prior to this, to get more insight into the binding mode and inhibition of human ACE C-domain (PDB ID: 2XY9) and N-domain (PDB ID: 3NXQ) compounds 5a-l was docked into the active site of them. The established inhibitory constant (Ki) (range 40-500 nM) and least binding affinities (-18.52 to -30.57 kcal/mol) indicated the therapeutic selectivity of compounds 5a-l towards ACE C-domain inhibition over ACE N-domain. The cytotoxicity effect of most potent compounds among 5a-l were tested in normal breast cells and MCF-7 cell lines. Simultaneously, H

Topics: Angiotensin-Converting Enzyme Inhibitors; Cardiovascular Diseases; Cell Line; Cell Survival; Dose-Response Relationship, Drug; Heart Failure; Humans; Hypertension; Indoles; Models, Molecular; Molecular Structure; Structure-Activity Relationship; Thrombolytic Therapy

Observational studies have found a protective effect of vitamin C on cardiovascular health. However, results are inconsistent, and residual confounding by fiber might be present. The aim of this study was to assess the association of vitamin C with the incidence of cardiovascular disease (CVD) and cardiovascular mortality (CVM) while accounting for fiber intake and adherence to the Mediterranean dietary pattern. We followed up 13,421 participants in the Seguimiento Universidad de Navarra (University of Navarra follow-up) (SUN) cohort for a mean time of 11 years. Information was collected at baseline and every two years through mailed questionnaires. Diet was assessed with a validated semi-quantitative food frequency questionnaire. Incident CVD was defined as incident fatal or non-fatal myocardial infarction, fatal or non-fatal stroke, or death due to any cardiovascular cause. CVM was defined as death due to cardiovascular causes. Events were confirmed by physicians in the study team after revision of medical records. Cox proportional hazard models were fitted to assess the associations of (a) energy-adjusted and (b) fiber-adjusted vitamin C intake with CVD and CVM. We found energy-adjusted vitamin C was inversely associated with CVD and CVM after adjusting for several confounding factors, including fiber from foods other than fruits and vegetables, and adherence to the Mediterranean dietary pattern. On the other hand, when vitamin C was adjusted for total fiber intake using the residuals method, we found a significant inverse association with CVM (HR (95% confidence interval (CI)) for the third tertile compared to the first tertile, 0.30 (0.12-0.72), but not with CVD in the fully adjusted model.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Cohort Studies; Diet Surveys; Female; Food Analysis; Humans; Male; Middle Aged; Nutritional Status; Risk Factors; Spain; Surveys and Questionnaires

The cardiovascular benefit of increasing fruit and vegetable (F&V) intake following diagnosis of diabetes remains unknown. We aimed to describe how quantity and variety of F&V intake, and plasma vitamin C, change after diagnosis of type 2 diabetes and examine whether these changes are associated with improvements in cardiovascular risk factors.. A total of 401 individuals with screen-detected diabetes from the ADDITION-Cambridge study were followed up over 5 years. F&V intake was assessed by food frequency questionnaire and plasma vitamin C at baseline, at 1 year and at 5 years. Linear mixed models were used to estimate associations of changes in quantity and variety of F&V intake, and plasma vitamin C, with cardiovascular risk factors and a clustered cardiometabolic risk score (CCMR), where a higher score indicates higher risk.. Increases in F&V quantity following diagnosis of diabetes are associated with lower cardiovascular risk factors. Health promotion interventions might highlight the importance of increasing, and maintaining increases in, F&V intake for improved cardiometabolic health in patients with diabetes.

Topics: Adult; Aged; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Diet; Diet Surveys; Eating; Female; Follow-Up Studies; Fruit; Glycated Hemoglobin; Humans; Linear Models; Lipoproteins, HDL; Male; Middle Aged; Risk Assessment; Risk Factors; United Kingdom; Vegetables; Waist Circumference

Few studies have evaluated dietary antioxidant vitamins intake in relation to risk of mortality in Asia.. We examined the associations between total carotene, vitamin C, and vitamin E from diet and risk of mortality from all causes, cancer, and cardiovascular disease in 134,358 participants (59,739 men and 74,619 women) from the Shanghai Men's Health Study and Shanghai Women's Health Study, two prospective cohort studies of middle-aged and elderly Chinese adults in urban Shanghai. Participants were followed up for a median period of 8.3 and 14.2 years for men and women, respectively. Hazard ratios (HRs) and 95% confidence interval (CIs) were estimated using Cox proportional hazards regression models.. During the 495,332 and 1,029,198 person-years of follow-up for men and women, respectively, there were 10,079 deaths (4170 men and 5909 women). For men, compared with the lowest quintiles, the multivariable-adjusted risk reductions in the highest categories were 17% (HR 0.83; 95% CI, 0.76-0.92) for dietary total carotene and 17% (HR 0.83; 95% CI, 0.75-0.91) for dietary vitamin C. Associations were weaker in women than in men, though they were still statistically significant (highest versus lowest quintiles of dietary total carotene, HR 0.87; 95% CI, 0.80-0.95; dietary vitamin C: HR 0.83; 95% CI, 0.77-0.91). Significant inverse associations were observed between dietary total carotene, vitamin C, and risk of cardiovascular disease mortality but not cancer mortality.. This study suggests that total carotene and vitamin C intake from diet were inversely associated with deaths from all causes and cardiovascular disease in middle-aged or elderly people in China.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Asian People; Cardiovascular Diseases; Carotenoids; Cause of Death; China; Cohort Studies; Diet; Dietary Supplements; Dose-Response Relationship, Drug; Female; Humans; Male; Neoplasms; Proportional Hazards Models; Prospective Studies; Risk Factors; Socioeconomic Factors; Surveys and Questionnaires; Vitamin E; Vitamins

Chronic kidney disease (CKD) is a group of heterogeneous abnormalities affecting the function and structure of the kidney and mostly further proceeds to cardiovascular damage prior to end stage renal disease (ESRD). The oxidative insult and inflammatory mediators have some undefined role in CKD and cardiovascular complications. It is therefore, aimed at to pin point the predictive factors in the development of cardiovascular disorder in patients with chronic kidney disease.. Fifty patients of CKD experiencing cardiovascular distress and twenty normal individuals having same age and sex acted as control during these observations. Blood samples (Each 5 ml) were drawn and subjected to centrifugation for 10-15 minutes to separate the serum at 4000-5000rpm. The levels of MDA, GSH, SOD, CAT, VIT C, VIT E, IL-1, TNF-alpha, nitric oxide (NO) and advanced oxidation protein products (AOPPs) were estimated and analyzed.. The nitric oxide levels in the CKD patients decreased significantly (13.26±1.25 ng/ml) compared to controls (42.15±5.26 ng/ml). The serum vitamin E and C levels in these patients recorded 2.15±0.25 μg/ml and 0.97±0.09 μg/ml respectively as against their assigned controls which read 6.35±1.22 μg/ml and 3.29±0.25 μg/ml. Furthermore, a significantly higher level of Malondialdehyde (MDA) as1.25±0.07 nmol/ml was observed in CKD patients viz-a-viz relevant control. However, the serum SOD, catalase (CAT) and GSH levels in the same patients registered a significant decline as evident from respective figures 0.07±0.002 μg/dl, 1.22±0.012 μmol/mol, and 3.25±1.05 μg/dl. The control for these was observed as0.99±0.06 μg/dl, 3.19±0.05 μmol/mol, and 8.64±0.03 μg/dL. On the other hand, the IL-1 levels in the CKD patients found quite higher (402.5±18.26 pg/ml). This clearly points to substantial increase in oxidative insult and reduced NO levels leading to the renal and cardiovascular damage.. Observations support the fact that the decrease in anti-oxidative capacity accompanied by higher inflammatory mediators in CKD is indicative of oxidative stress, consequently leading to CKD progression, in all probability to cardiovascular insult. The outcome reiterates that strategies be designed afresh to contain CKD progression to cardiovascular complications and ESRD. One way could be to focus on early detection of stress related to the disease. It requires analyzing the factors related to stress, such as the one reported here. Linking these factors with the symptoms could be a crucial step forward. And further, the disease could be monitored in a more disciplined manner.

Topics: Advanced Oxidation Protein Products; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Case-Control Studies; Cytokines; Female; Humans; Inflammation Mediators; Male; Malondialdehyde; Nitric Oxide; Oxidation-Reduction; Oxidative Stress; Renal Insufficiency, Chronic; Superoxide Dismutase; Vitamin E

The aim of the study was to assess the relationships between individual-level dietary intakes of antioxidant vitamins C, E and beta-carotene with all-cause and cause-specific mortality in three Central and Eastern European (CEE) populations.. Data from the Health, Alcohol and Psychosocial factors in Eastern Europe cohort study were used. At the baseline survey, between 2002 and 2005, 28,945 men and women aged 45-69 years were examined in Novosibirsk (Russia), Krakow (Poland) and seven Czech towns. Deaths in the cohorts were identified through mortality registers. Cox regression was used to estimate the association between vitamin consumption and all-cause, cardiovascular (CVD) disease and cancer mortality.. In multivariable-adjusted analyses, there were no clear inverse associations between antioxidant vitamin intakes and mortality, although in some groups, several hazard ratios (HRs) were significant. For example, in men, compared with the lowest quintile of vitamin C intake, all-cause mortality in the third and fourth quintiles was lower by 28 % (HR 0.72; 95 % CI 0.61-0.85) and by 20 % (HR 0.80; 95 % CI 0.68-0.95), respectively. CVD mortality was lower by 35 % (HR 0.65; 95 % CI 0.50-0.84) and by 23 % (HR 0.77; 95 % CI 0.59-0.99) in third and fourth quintile of vitamin C intake, respectively. In women, the third and fourth quintiles of dietary intake of vitamin E were associated with reduced risk of all-cause death by 33 % (HR 0.67; 95 % CI 0.53-0.84) and by 23 % (HR 0.77; 95 % CI 0.61-0.97), respectively. Consumption of vitamin C, vitamin E and beta-carotene was not related to CVD mortality in women and to cancer mortality in either gender.. This large prospective cohort study in CEE populations with low prevalence of vitamin supplementation did not find a strong, dose-response evidence for protective effects of antioxidant vitamin intake.

Topics: Aged; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cause of Death; Czech Republic; Dietary Supplements; Female; Follow-Up Studies; Humans; Male; Middle Aged; Neoplasms; Poland; Proportional Hazards Models; Prospective Studies; Risk Factors; Russia; Socioeconomic Factors; Surveys and Questionnaires; Urban Population; Vitamin E; Vitamins

The interaction between genetics and diet may explain the present disagreement in the protective role of vitamin intake on cardiovascular disease. We cross-sectionally assessed the interaction of habitual dietary intake of β-carotene, vitamin C, folate, and vitamin E with single nucleotide polymorphisms (SNPs) on brachial-ankle pulse wave velocity (baPWV), a measure of arterial stiffness.. Dietary intakes of β-carotene, vitamin C, folate, and vitamin E were quantified by a food frequency questionnaire in 3198 healthy men and women (≥ 40 years) from the Korea Multi-Rural communities Cohort study. baPWV was measured, and 19 SNPs were genotyped. The associations and interactions between dietary vitamin intake, SNP genotype, and baPWV were assessed using general linear models.. In both men and women, dietary intake of β-carotene, vitamin C, folate, or vitamin E and baPWV were not directly associated. Vitamin C, folate, and vitamin E intake had an interaction with rs4961 (ADD1) genotype on baPWV in men. rs4961 also interacted with folate intake on baPWV in women. In women, rs10817542 (ZNF618) and rs719856 (CD2AP) had an interaction with β-carotene and folate intake and rs5443 (GNB3) had an interaction with vitamin E intake on baPWV. In general, minor allele homozygotes with low vitamin intake had higher baPWV than other subgroups. Results were similar when supplement users were excluded.. Higher intake of dietary vitamin C, folate, and vitamin E may be related to high baPWV in healthy Korean men who are minor allele homozygotes of rs4961. In healthy Korean women, dietary folate, β-carotene, and vitamin E intake may affect baPWV differently according to rs4961, rs10817542, rs719856, or rs5443 genotype. Greater dietary intake of these nutrients may protect those that are genetically vulnerable to stiffening of the arteries.

Topics: Alleles; Ankle Brachial Index; Ascorbic Acid; beta Carotene; Body Mass Index; Cardiovascular Diseases; Cohort Studies; Cross-Sectional Studies; Diet; Female; Folic Acid; Gene-Environment Interaction; Genotype; Humans; Male; Middle Aged; Nutrition Assessment; Polymorphism, Single Nucleotide; Republic of Korea; Risk Factors; Rural Population; Vascular Stiffness; Vitamin E

Particulate matter (PM) from traffic and other sources has been associated with adverse health effects. One unifying theory is that PM, whatever its source, acts on the human body via its capacity to cause damaging oxidation reactions related to its content of pro-oxidants components. Few epidemiological studies have investigated particle oxidative potential (OP) and health. We conducted a time series analysis to assess associations between daily particle OP measures and numbers of deaths and hospital admissions for cardiovascular and respiratory diseases.. During 2011 and 2012 particles with an aerodynamic diameter less than 2.5 and 10μm (PM2.5 and PM10 respectively) were collected daily on Partisol filters located at an urban background monitoring station in Central London. Particulate OP was assessed based on the capacity of the particles to oxidize ascorbate (OP(AA)) and glutathione (OP(GSH)) from a simple chemical model reflecting the antioxidant composition of human respiratory tract lining fluid. Particulate OP, expressed as % loss of antioxidant per μg of PM, was then multiplied by the daily concentrations of PM to derive the daily OP of PM mass concentrations (% loss per m(3)). Daily numbers of deaths and age- and cause-specific hospital admissions in London were obtained from national registries. Poisson regression accounting for seasonality and meteorology was used to estimate the percentage change in risk of death or admission associated with an interquartile increment in particle OP.. We found little evidence for adverse associations between OP(AA) and OP(GSH) and mortality. Associations with cardiovascular admissions were generally positive in younger adults and negative in older adults with confidence intervals including 0%. For respiratory admissions there was a trend, from positive to negative associations, with increasing age although confidence intervals generally included 0%.. Our study, the first to analyse daily particle OP measures and mortality and admissions in a large population over two years, found little evidence to support the hypothesis that short-term exposure to particle OP is associated with adverse health effects. Further studies with improved exposure assessment and longer time series are required to confirm or reject the role of particle OP in triggering exacerbations of disease.

Topics: Adolescent; Adult; Aged; Air Pollutants; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Child; Child, Preschool; Environmental Monitoring; Glutathione; Hospitalization; Humans; Infant; Infant, Newborn; London; Middle Aged; Nitrogen Dioxide; Oxidation-Reduction; Ozone; Particulate Matter; Respiratory Tract Diseases; Sulfur Dioxide; Young Adult

Observational studies are prone to (unmeasured) confounding. Sensitivity analysis of unmeasured confounding typically focuses on a single unmeasured confounder. The purpose of this study was to assess the impact of multiple (possibly weak) unmeasured confounders.. Simulation studies were performed based on parameters estimated from the British Women's Heart and Health Study, including 28 measured confounders and assuming no effect of ascorbic acid intake on mortality. In addition, 25, 50, or 100 unmeasured confounders were simulated, with various mutual correlations and correlations with measured confounders.. The correlated unmeasured confounders did not need to be strongly associated with exposure and outcome to substantially bias the exposure-outcome association at interest, provided that there are sufficiently many unmeasured confounders. Correlations between unmeasured confounders, in addition to the strength of their relationship with exposure and outcome, are key drivers of the magnitude of unmeasured confounding and should be considered in sensitivity analyses. However, if the unmeasured confounders are correlated with measured confounders, the bias yielded by unmeasured confounders is partly removed through adjustment for the measured confounders.. Discussions of the potential impact of unmeasured confounding in observational studies, and sensitivity analyses to examine this, should focus on the potential for the joint effect of multiple unmeasured confounders to bias results.

Topics: Ascorbic Acid; Cardiovascular Diseases; Confounding Factors, Epidemiologic; Epidemiologic Methods; Female; Humans; Mortality; Research Design; Sensitivity and Specificity; Women's Health

In our previous studies, veratric acid (VA) shows beneficial effect on hypertension and its associated dyslipidaemia. In continuation, this study was designed to investigate the effect of VA, one of the major benzoic acid derivatives from vegetables and fruits, on cardiovascular remodelling in hypertensive rats, primarily assessed by functional studies using Langendorff isolated heart system and organ bath system. Hypertension was induced in male albino Wistar rats by oral administration of N ω -nitro-l-arginine methyl ester hydrochloride (l-NAME) (40 mg/kg body weight (b.w.)) in drinking water for 4 weeks. VA was orally administered at a dose of 40 mg/kg b.w. l-NAME-treated rats showed impaired cardiac ventricular and vascular function, evaluated by Langendorff isolated heart system and organ bath studies, respectively; a significant increase in the lipid peroxidation products such as thiobarbituric acid-reactive substances and lipid hydroperoxides in aorta; and a significant decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase and levels of GSH, vitamin C and vitamin E in aorta. Fibrotic remodelling of the aorta and heart were assessed by Masson's Trichrome staining and Van Gieson's staining, respectively. In addition, l-NAME rats showed increased heart fibronectin expression assessed by immunohistochemical analysis. VA supplementation throughout the experimental period significantly normalised cardiovascular function, oxidative stress, antioxidant status and fibrotic remodelling of tissues. These results of the present study conclude that VA acts as a protective agent against hypertension-associated cardiovascular remodelling.

Topics: Administration, Oral; Animals; Antioxidants; Aorta; Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Catalase; Disease Models, Animal; Dose-Response Relationship, Drug; Fruit; Glutathione; Glutathione Peroxidase; Hypertension; Lipid Peroxidation; Lipid Peroxides; Male; NG-Nitroarginine Methyl Ester; Oxidative Stress; Rats; Rats, Wistar; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances; Vanillic Acid; Vascular Remodeling; Vegetables; Vitamin E

Topics: Ascorbic Acid; Cardiovascular Diseases; Diet; Fruit; Heart Diseases; Humans; Vegetables

Combined lipid and glucose point-of-care testing (POCT) devices could facilitate widespread population screening for cardiovascular disease (CVD) and diabetes as part of the NHS Vascular Risk Assessment and Management Program (NHS Health Checks). An evaluation of the Cholestech LDX and CardioChek PA POCT analysers was performed in collaboration with the Wolverhampton City Primary Care Trust (PCT).. Intra-/inter-batch imprecision, between-analyser variation and the effect of haematocrit and ascorbic acid assay interference were investigated. Accuracy of the POCT capillary whole blood total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-C) and glucose measurements was estimated by comparison with those from the laboratory analysis of paired venous samples. POCT usability and clinical governance were also assessed.. The LDX exhibited lower intra- and inter-batch imprecision and external quality assessment (EQA) scheme between-analyser variation for the measurement of TC, HDL-C and glucose when compared to the CardioChek. Ascorbic acid negatively interfered in all three assays on both POCT analysers and results reported by the CardioChek were influenced by the specimen haematocrit. The LDX displayed closer agreement with the laboratory methods for the measurement of TC and HDL-C but both the LDX and the CardioChek displayed positive bias for the measurement of glucose.. POCT has clear advantages for delivering NHS Health Checks over the laboratory-based approach although device performance does differ. Users should also be aware of the potential clinical governance and interference issues associated with these devices.

Topics: Ascorbic Acid; Blood Glucose; Cardiovascular Diseases; Cholesterol, HDL; Hematologic Tests; Humans; Point-of-Care Systems; Risk Assessment

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dexamethasone; Male; Vitamin E; Vitamins

The use of cardiopulmonary bypass (CPB) is suggested to induce oxidative stress, reflected by an imbalance between prooxidant and antioxidant substances. The majority of studies published have either focused on only one aspect (prooxidant or antioxidant side) or covered only a short observation period. Therefore, the aim of this study was to investigate the long-term effects of CPB on the balance of prooxidative markers and antioxidant substances in one single group of patients, being able to estimate the degree of oxidative stress.. Blood samples were taken from 29 patients undergoing cardiovascular surgery beginning the day before surgery through postoperative day 6 (discharge). Plasma concentrations of vitamins C (total ascorbic acid) and E and malondialdehyde were measured by high-performance liquid chromatography. Plasma levels of ascorbyl free radical were determined using electron paramagnetic resonance spectroscopy.. The study showed a significant decrease in vitamin C plasma levels during CPB without any recovery of vitamin C up to the time of discharge. Furthermore, CPB induced a significant increase in malondialdehyde plasma concentrations immediately after unclamping, accompanied by a significant increase in the ascorbyl free radical to total ascorbic acid ratio. The latter stayed elevated until the end of observation.. Our findings indicate that the oxidative stress event after CPB can be divided into two phases: Immediately after reperfusion, a massive oxidative stress occurs, reflected by the increase in malondialdehyde. During convalescence, there must be an ongoing situation of oxidative stress, especially in the water-soluble compartment, leading to the consumption of vitamin C. Because the main antioxidant substance, vitamin C, did not increase again over the entire observation period, supplementation should be given consideration.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Cardiopulmonary Bypass; Cardiovascular Diseases; Chromatography, High Pressure Liquid; Dehydroascorbic Acid; Electron Spin Resonance Spectroscopy; Female; Humans; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Reactive Oxygen Species; Time Factors; Vitamin E

Antiproliferative drugs such as paclitaxel and sirolimus are delivered from stents to inhibit the growth of smooth muscle cells (SMCs) for preventing neointimal hyperplasia. However, these drugs delay the growth of endothelial cells (ECs) as well and cause late stent thrombosis. We recently demonstrated the use of Vitamin-C (l-ascorbic acid, l-AA) over paclitaxel and sirolimus for inhibiting SMCs growth and promoting EC growth simultaneously. In this study, we have investigated the delivery of l-AA from CoCr alloy surfaces for potential use in stents. A polymer-free phosphoric acid (PA) platform and a polymer-based poly(lactic-co-glycolic acid) (PLGA) platform were used for coating l-AA onto CoCr surfaces. For the PA platform, FTIR confirmed that the PA was coated on CoCr, while the AFM showed that the PA coating on the CoCr surface was homogeneous. The successful deposition of l-AA on PA-coated CoCr was also confirmed by FTIR. The uniform distribution of l-AA crystals on PA-coated CoCr was shown by SEM, optical profilometer, and AFM. The drug release studies showed that l-AA (276 μg/cm(2)) was burst released from the PA platform by 1 h. For the PLGA platform, SEM showed that the l-AA incorporated polymer films were smoothly and uniformly coated on CoCr. FTIR showed that l-AA was incorporated into the bulk of the PLGA film. DSC showed that the l-AA was present in an amorphous form and formed an intermolecular bonding interaction with PLGA. The drug release studies showed that l-AA was sustained released from the PLGA coated CoCr for up to 24 h. The SEM, FTIR, and DSC characterizations of samples collected post drug release shed light on the mechanism of l-AA release from PLGA coated CoCr. Thus, this study demonstrated the delivery of l-AA from biomaterial surfaces for potential applications in stents and other implantable medical devices.

Topics: Alloys; Ascorbic Acid; Biocompatible Materials; Calorimetry, Differential Scanning; Cardiovascular Diseases; Chromium Alloys; Drug Carriers; Drug-Eluting Stents; Humans; Lactic Acid; Materials Testing; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Phosphoric Acids; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Polymers; Prosthesis Design; Prosthesis Failure; Spectroscopy, Fourier Transform Infrared; Thrombosis; Time Factors

Vitamin D is associated with many health conditions, but optimal blood concentrations are still uncertain.. We examined the prospective relation between serum 25-hydroxyvitamin D [25(OH)D] concentrations [which comprised 25(OH)D3 and 25(OH)D2] and subsequent mortality by the cause and incident diseases in a prospective population study.. Serum vitamin D concentrations were measured in 14,641 men and women aged 42-82 y in 1997-2000 who were living in Norfolk, United Kingdom, and were followed up to 2012. Participants were categorized into 5 groups according to baseline serum concentrations of total 25(OH)D <30, 30 to <50, 50 to <70, 70 to <90, and ≥ 90 nmol/L.. The mean serum total 25(OH)D was 56.6 nmol/L, which consisted predominantly of 25(OH)D3 (mean: 56.2 nmol/L; 99% of total). The age-, sex-, and month-adjusted HRs (95% CIs) for all-cause mortality (2776 deaths) for men and women by increasing vitamin D category were 1, 0.84 (0.74, 0.94), 0.72 (0.63, 0.81), 0.71 (0.62, 0.82), and 0.66 (0.55, 0.79) (P-trend < 0.0001). When analyzed as a continuous variable and with additional adjustment for body mass index, smoking, social class, education, physical activity, alcohol intake, plasma vitamin C, history of cardiovascular disease, diabetes, or cancer, HRs for a 20-nmol/L increase in 25(OH)D were 0.92 (0.88, 0.96) (P < 0.001) for total mortality, 0.96 (0.93, 0.99) (P = 0.014) (4469 events) for cardiovascular disease, 0.89 (0.85, 0.93) (P < 0.0001) (2132 events) for respiratory disease, 0.89 (0.81, 0.98) (P = 0.012) (563 events) for fractures, and 1.02 (0.99, 1.06) (P = 0.21) (3121 events) for incident total cancers.. Plasma 25(OH)D concentrations predict subsequent lower 13-y total mortality and incident cardiovascular disease, respiratory disease, and fractures but not total incident cancers. For mortality, lowest risks were in subjects with concentrations >90 nmol/L, and there was no evidence of increased mortality at high concentrations, suggesting that a moderate increase in population mean concentrations may have potential health benefit, but <1% of the population had concentrations >120 nmol/L.

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Body Mass Index; Cardiovascular Diseases; Female; Fractures, Bone; Humans; Incidence; Male; Middle Aged; Motor Activity; Multivariate Analysis; Proportional Hazards Models; Prospective Studies; Respiratory Tract Diseases; Socioeconomic Factors; United Kingdom; Vitamin D; Vitamin D Deficiency

Fetal hypoxia is common and in vitro evidence supports its role in the programming of adult cardiovascular dysfunction through the generation of oxidative stress. Whether fetal chronic hypoxia programmes alterations in cardiovascular control in vivo, and if these alterations can be prevented by antioxidant treatment, is unknown. This study investigated the effects of prenatal fetal hypoxia, with and without maternal supplementation with vitamin C, on basal and stimulated cardiovascular function in vivo in the adult offspring at 4 months of age in the rat.. From days 6 to 20 of pregnancy, Wistar rats were subjected to Normoxia, Hypoxia (13% O2), Hypoxia+Vitamin C (5mg/ml in drinking water) or Normoxia+Vitamin C. At 4 months, male offspring were instrumented under urethane anaesthesia. Basal mean arterial blood pressure, heart rate and heart rate variability (HRV) were assessed, and stimulated baroreflex curves were generated with phenylephrine and sodium nitroprusside. Chronic fetal hypoxia increased the LF/HF HRV ratio and baroreflex gain, effects prevented by vitamin C administration during pregnancy.. Chronic intrauterine hypoxia programmes cardiovascular dysfunction in vivo in adult rat offspring; effects ameliorated by maternal treatment with vitamin C. The data support a role for fetal chronic hypoxia programming cardiovascular dysfunction in the adult rat offspring in vivo through the generation of oxidative stress in utero. 

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Female; Fetal Hypoxia; Hypoxia; Male; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Time Factors

Observational studies have suggested that antioxidant nutrients may reduce cancer and overall mortality risks. However, most randomized trials have failed to show survival benefits. Examining nonlinear associations between antioxidant levels and health outcomes may help to explain these discrepant findings.. We evaluated all-cause, cancer, and cardiovascular mortality risks associated with quintiles (Q1-Q5) of serum antioxidant (vitamins C and E, β-carotene, and selenium) and vitamin A levels, in 16,008 adult participants of The Third National Health and Nutrition Examination Survey (NHANES III; 1988-1994).. Over a median follow-up period of 14.2 years, there were 4,225 deaths, including 891 from cancer and 1,891 from cardiovascular disease. We observed a dose-response decrease in cancer and overall mortality risks with higher vitamin C levels. In contrast, for vitamin A, risk of cancer death decreased from Q1-Q2, with no further decline in risk at higher levels. For vitamin E, having levels in Q4 was associated with the lowest cancer mortality risk. Both vitamin A and E had U-shaped associations with all-cause mortality. Cancer mortality risks decreased from Q1-Q2 for β-carotene and from Q1-Q4 for selenium. However, for β-carotene and selenium, overall mortality risks decreased from Q1-Q2 but then did not change significantly with higher levels.. Antioxidant supplement use should be studied in the context of overall mortality and other competing mortality risks.. These data suggest the need for novel intervention studies where doses of these agents are individualized based on their serum levels, and possibly, markers of oxidative stress and systemic inflammatory response.

Topics: Adult; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Female; Follow-Up Studies; Humans; Male; Neoplasms; Nutrition Surveys; Selenium; United States; Vitamin A; Young Adult

Glucocorticoids are widely used to treat chronic lung disease in premature infants but their longer-term adverse effects on the cardiovascular system raise concerns. We reported that neonatal dexamethasone treatment in rats induced in the short term molecular indices of cardiac oxidative stress and cardiovascular tissue remodelling at weaning, and that neonatal combined antioxidant and dexamethasone treatment was protective at this time. In this study, we investigated whether such effects of neonatal dexamethasone have adverse consequences for NO bioavailability and cardiovascular function at adulthood, and whether neonatal combined antioxidant and dexamethasone treatment is protective in the adult. Newborn rat pups received daily i.p. injections of a human-relevant tapering dose of dexamethasone (D; n = 8; 0.5, 0.3, 0.1 μg g(-1)) or D with vitamins C and E (DCE; n = 8; 200 and 100 mg kg(-1), respectively) on postnatal days 1-3 (P1-3); vitamins were continued from P4 to P6. Controls received equal volumes of vehicle from P1 to P6 (C; n = 8). A fourth group received vitamins alone (CCE; n = 8). At P100, plasma NO metabolites (NOx) was measured and isolated hearts were assessed under both Working and Langendorff preparations. Relative to controls, neonatal dexamethasone therapy increased mortality by 18% (P < 0.05). Surviving D pups at adulthood had lower plasma NOx concentrations (10.6 ± 0.8 vs. 28.0 ± 1.5 μM), an increased relative left ventricular (LV) mass (70 ± 2 vs. 63 ± 1%), enhanced LV end-diastolic pressure (14 ± 2 vs. 8 ± 1 mmHg) and these hearts failed to adapt output with increased preload (cardiac output: 2.9 ± 2.0 vs. 10.6 ± 1.2 ml min(-1)) or afterload (cardiac output: -5.3 ± 2.0 vs.1.4 ± 1.2 ml min(-1)); all P < 0.05. Combined neonatal dexamethasone with antioxidant vitamins improved postnatal survival, restored plasma NOx and protected against cardiac dysfunction at adulthood. In conclusion, neonatal dexamethasone therapy promotes cardiac dysfunction at adulthood. Combined neonatal treatment with antioxidant vitamins is an effective intervention.

Topics: Age Factors; Animals; Animals, Newborn; Antioxidants; Ascorbic Acid; Cardiac Output; Cardiovascular Diseases; Dexamethasone; Heart Rate; Male; Nitric Oxide; Oxidative Stress; Rats; Rats, Wistar; Ventricular Remodeling; Vitamin E; Vitamins

Topics: Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Female; Humans; Male; Neoplasms; Selenium; Vitamin A

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dexamethasone; Male; Vitamin E; Vitamins

Chronic renal failure patients undergoing peritoneal dialysis (PD) are characterized by increased oxidative stress (OS), which is associated with enhanced cardiovascular risk. Moreover, oxidative stress also contributes to peritoneal membrane changes and ultrafiltration failure. The aim of this study was to evaluate OS in PD patients and the effect of treatment with ascorbic acid and α-tocopherol.. Plasma, erythrocyte, urine, and peritoneal effluent samples from 20 patients on PD were evaluated for glutathione peroxidase and superoxide dismutase activity, total antioxidant capacity (TAC) and malondialdehyde (MDA) levels, as well as protein carbonyl formation, before and after administration of vitamin C, alone or in combination with vitamin E, in comparison with 10 apparently healthy control individuals.. All studied markers showed enhanced OS in the PD group, compared to controls. The supplementation of vitamin C and E resulted in improvements of all the OS markers, as indicated by increased erythrocyte antioxidant enzymes activity and TAC levels, as well as decreased MDA concentration and carbonyl compound formation.. The oral supplementation of antioxidant vitamins C and E, in combination, can lead to decreased OS, thus providing a useful and cost-effective therapeutic option in PD patients.

Topics: Aged; Analysis of Variance; Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Dietary Supplements; Female; Follow-Up Studies; Glutathione Peroxidase; Humans; Kidney Failure, Chronic; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Peritoneal Dialysis, Continuous Ambulatory; Reference Values; Retrospective Studies; Risk Assessment; Superoxide Dismutase; Treatment Outcome; Vitamin E

Deficiencies of essential nutrients have been responsible for many epidemic outbreaks of deficiency diseases in the past. Large observational studies point at possible links between nutrition and chronic diseases. Low intake of antioxidant vitamins e. g. have been correlated to increased risk of cardiovascular diseases or cancer. The main results of these studies are indications that an intake below the recommendation could be one of the risk factors for chronic diseases. There was hardly any evidence that amounts above the RDA could be of additional benefit. Since observational studies cannot prove causality, the scientific community has been asking for placebo-controlled, randomized intervention trials (RCTs). Thus, the consequences of the epidemiological studies would have been to select volunteers whose baseline vitamin levels were below the recommended values. The hypothesis of the trial should be that correcting this risk factor up to RDA levels lowers the risk of a disease like CVD by 20 - 30 %. However, none of the RCTs of western countries was designed to correct a chronic marginal deficiency, but they rather tested whether an additional supplement on top of the recommended values would be beneficial in reducing a disease risk or its prognosis. It was, therefore, not surprising that the results were disappointing. As a matter of fact, the results confirmed the findings of the observational studies: chronic diseases are the product of several risk factors, among them most probably a chronic vitamin deficiency. Vitamin supplements could only correct the part of the overall risk that is due to the insufficient vitamin intake.

Topics: Antioxidants; Ascorbic Acid; Avitaminosis; beta Carotene; Cardiovascular Diseases; Chronic Disease; Dietary Supplements; Dose-Response Relationship, Drug; Female; Humans; Male; Nutrition Policy; Prognosis; Randomized Controlled Trials as Topic; Risk Factors; Vitamin E; Vitamins

We explored the characteristics of the vitamin status in 471 patients with cardiovascular diseases, according to sex, and BMI values. All patients underwent examination of the system Nutritest-IP: studying their actual meals at home, determined anthropometric measurement, body composition, using biochemical methods evaluated the state of the protein, lipid and carbohydrate metabolism, the functional state of liver and biliary tract, hemostasis, vitamin provision. The results suggest a lack of availability of patients with vitamins C and B group. The number of patients with deficient serum beta-carotene increased proportional to body mass index. The concentration of beta-carotene decreased and vitamin E - increased in blood serum proportionally to increase the degree of obesity. Thus the availability of vitamins in the blood serum depends from sex and body mass index values of the patients. These data suggest that the rate of supply of vitamins are reliable markers to assess the adequacy of the diet consumed by the content of vitamins in people with normal body weight. Appraisingly the content of beta-carotene and vitamin E in the serum of patients it should be taken into account that they have overweight or obese, and abnormality of lipid spectrum of blood serum.

Topics: Aged; Ascorbic Acid; beta Carotene; Body Mass Index; Cardiovascular Diseases; Diet; Female; Humans; Male; Meals; Middle Aged; Obesity; Riboflavin; Sex Factors; Vitamin B 6; Vitamin E; Vitamins

Approximately 30% of the adult Czech population smokes. Previous studies of smokers have documented diet sufficient in energy, but inadequate intake of dietary fibre, vitamins A, E, calcium and proteins.. Nutrition was assessed between the groups of the probands (over 18 years aged, 667 smokers, 1044 nonsmokers, 428 past smokers) from 1% random sample of the Czech population. All volunteers completed a one day dietary recall after instruction from a nutrition expert. The dietary recall calculated energy, proteins, fats, vitamins C and E, cholesterol, fibre, calcium and iron intake using the Nutridan programme.. Smokers had higher consumption of animal (p=0.0034), and total fat (p=0.0315), cholesterol (p=0.005), and lower intake of vitamin E (p=0.004) than nonsmokers. No other differences were found. The differences between past smokers and other groups were insignificant.. The smokers consumed more total and animal fat, cholesterol and less of vitamin E than nonsmokers.

Topics: Adult; Ascorbic Acid; Calcium, Dietary; Cardiovascular Diseases; Czech Republic; Dietary Fats; Dietary Proteins; Feeding Behavior; Female; Humans; Iron, Dietary; Male; Middle Aged; Neoplasms; Nutrition Surveys; Risk Factors; Smoking; Vitamin E

Consumption of 100% orange juice (OJ) has been positively associated with nutrient adequacy and diet quality, with no increased risk of overweight/obesity in children; however, no one has examined these factors in adults. The purpose of this study was to examine the association of 100% OJ consumption with nutrient adequacy, diet quality, and risk factors for metabolic syndrome (MetS) in a nationally representative sample of adults.. Data from adults 19+ years of age (n = 8,861) participating in the National Health and Nutrition Examination Survey 2003-2006 were used. The National Cancer Institute method was used to estimate the usual intake (UI) of 100% OJ consumption, selected nutrients, and food groups. Percentages of the population below the Estimated Average Requirement (EAR) or above the Adequate Intake (AI) were determined. Diet quality was measured by the Healthy Eating Index-2005 (HEI-2005). Covariate adjusted logistic regression was used to determine if consumers had a lower odds ratio of being overweight or obese or having risk factors of MetS or MetS.. Usual per capita intake of 100% OJ was 50.3 ml/d. Among consumers (n = 2,310; 23.8%), UI was 210.0 ml/d. Compared to non-consumers, consumers had a higher (p < 0.05) percentage (% ± SE) of the population meeting the EAR for vitamin A (39.7 ± 2.5 vs 54.0 ± 1.2), vitamin C (0.0 ± 0.0 vs 59.0 ± 1.4), folate (5.8 ± 0.7 vs 15.1 ± 0.9), and magnesium (51.6 ± 1.6 vs 63.7 ± 1.2). Consumers were also more likely to be above the AI for potassium (4.1 ± 0.8 vs 1.8 ± 0.2). HEI-2005 was significantly (p < 0.05) higher in consumers (55.0 ± 0.4 vs 49.7 ± 0.3). Consumers also had higher intakes of total fruit, fruit juice, whole fruit, and whole grain. Consumers had a lower (p < 0.05) mean body mass index (27.6 ± 0.2 vs 28.5 ± 0.1), total cholesterol levels (197.6 ± 1.2 vs 200.8 ± 0.75 mg/dL), and low density lipoprotein-cholesterol levels (112.5 ± 1.4 vs 116.7 ± 0.93 mg/dL). Finally, compared to non-consumers of 100% OJ, consumers were 21% less likely to be obese and male consumers were 36% less likely to have MetS.. The results suggest that moderate consumption of 100% OJ should be encouraged to help individuals meet the USDA daily recommendation for fruit intake and as a component of a healthy diet.

Topics: Adult; Ascorbic Acid; Beverages; Biomarkers; Body Mass Index; Cardiovascular Diseases; Cholesterol; Citrus sinensis; Diet; Edible Grain; Female; Folic Acid; Fruit; Humans; Magnesium; Male; Metabolic Syndrome; Motor Activity; Nutrition Surveys; Nutritional Status; Obesity; Potassium, Dietary; Regression Analysis; Risk Factors; Socioeconomic Factors; Surveys and Questionnaires; Vitamin A

To determine whether frequent vitamin C supplement use is associated with healthier behaviours, and a history of cancer and other illnesses in UK women.. The present cross-sectional analysis examines the odds of taking supplements containing vitamin C as recorded in 4 d food diaries, based on lifestyle characteristics and morbidity history self-reported by questionnaire.. A large national UK cohort study.. A total of 12,453 women aged between 37 and 79 years.. Women frequently taking supplements containing vitamin C, compared to those who did not, had healthier behaviours, including higher consumption of fruit and vegetables. Frequent high-dose vitamin C users (≥1000 mg) had a higher socio-economic status, visited alternative practitioners more often than family or private doctors, and were more likely to be ex-smokers and to drink little or no alcohol. Women who self-reported having had cancer (OR = 1·33, 95% CI 1·00, 1·76) or specifically breast cancer (OR = 1·70, 95% CI 1·14, 2·55), or reported a family history of cancer (OR = 1·16, 95% CI 0·95, 1·41) or breast cancer (OR = 1·26, 95% CI 1·01, 1·58) had increased odds of being frequent high-dose users after adjusting for sociodemographic and health behaviours. Women with personal or family histories of some cardiovascular or intestinal disorders were more likely to take supplements containing vitamin C, though not necessarily at high doses.. High-dose vitamin C intake by UK women was associated with healthier behaviours and a history of breast cancer, total cancer and other illnesses. Consequences of high-dose vitamin C supplement intake are not clear at the population level.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Breast Neoplasms; Cardiovascular Diseases; Cohort Studies; Cross-Sectional Studies; Diet Records; Dietary Supplements; Dose-Response Relationship, Drug; Female; Health Behavior; Humans; Life Style; Middle Aged; Odds Ratio; Socioeconomic Factors; United Kingdom

Pulmonary toxicity induced by asbestos is thought to be mediated through redox-cycling of fiber-bound and bioavailable iron (Fe). We hypothesized that Libby amphibole (LA)-induced cute lung injury will be exacerbated in rat models of cardiovascular disease (CVD)-associated Fe-overload and oxidative stress. Healthy male Wistar Kyoto (WKY), spontaneously hypertensive (SH) and SH heart failure (SHHF) rats were intratracheally instilled with 0.0, 0.25 or 1.0  mg/rat LA and examined at 1 day, 1 week or 1 month. Although histologically it was not possible to distinguish severity differences between strains in LA-induced initial inflammation and later fibrosis, quantitative assessment of biomarkers showed strain-related differences. LA-induced neutrophilic inflammation was reversible in WKY but persisted more in SH and SHHF. Lung MIP-2 mRNA increased only in WKY at 1 day in response to LA but not in SH and SHHF. Bronchoalveolar lavage fluid (BALF) protein increased in SH but not WKY at 1 week and 1 month, while γ-glutamyltransferase and N-acetyl-β-D-glucosaminidase activities increased in all strains (WKY>SH=SHHF). BALF ferritin levels were high at baseline and increased following LA exposure only in SH and SHHF. Ferritin heavy chain mRNA increased only in SHHF at 1 day. At 1 month ferritin light chain mRNA declined from already high baseline levels in SHHF but increased in WKY and SH suggesting its differential involvement in LA-induced injury in Fe-overload. Unlike WKY, both SHHF and SH failed to increase the lung lining antioxidant, ascorbate, in response to LA. We conclude that underlying CVD-associated Fe-overload is likely linked to persistent lung injury, inflammation and antioxidant decompensation following LA exposure in rats.

Topics: Animals; Asbestos, Amphibole; Asbestosis; Ascorbic Acid; Biomarkers; Bronchoalveolar Lavage Fluid; Cardiovascular Diseases; Chemokine CXCL2; Dose-Response Relationship, Drug; Ferritins; Gene Expression Regulation; Iron Overload; Lung; Male; Neutrophil Infiltration; Neutrophils; Oxidative Stress; Particulate Matter; Pneumonia; Rats; RNA, Messenger; Severity of Illness Index

Reactive oxygen species (ROS) play a role in cardiovascular diseases such as hypertension and heart failure. The objective of the present study was to investigate the role of endogenous ROS in atrial hemodynamics and ANP secretion in isolated perfused beating rat atria. Pyrogallol (a generator of superoxide anion, 0.1, 1mM) or hydrogen peroxide (0.1, 1, 10, 30mM) was perfused into atria paced at 1.2Hz. Pyrogallol and hydrogen peroxide stimulated ANP secretion and concentration in a dose-dependent manner and dramatically decreased atrial contractility and translocation of extracellular fluid. The stimulatory effect of pyrogallol and hydrogen peroxide on ANP secretion was attenuated by the pretreatment with ascorbic acid (an antioxidant; 1mM) and cariporide (an inhibitor of the Na(+)/H(+) exchanger; 1μM) but negative inotropic effect was not changed. U120 (a MAPK(erk) pathway inhibitor; 10μM) attenuated the stimulatory effect of hydrogen peroxide on ANP secretion. However, U120 augmented negative inotropic effect and stimulatory effect of ANP concentration induced by pyrogallol. Antioxidant such as N-acetyl cystein, gallate, propyl gallate, or ellagic acid did not cause any significant changes in atrial parameters. These results suggest that intracellular - formed ROS stimulates ANP secretion partly through activation of MAPK(erk) pathway and Na(+)/H(+) exchanger.

Topics: Acetylcysteine; Animals; Ascorbic Acid; Atrial Natriuretic Factor; Cardiovascular Diseases; Extracellular Fluid; Guanidines; Heart Atria; Hemodynamics; Hydrogen Peroxide; Male; Mitogen-Activated Protein Kinase Kinases; Myocardial Contraction; Organ Culture Techniques; Oxidative Stress; Propyl Gallate; Pyrogallol; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Sodium-Hydrogen Exchangers; Sulfones

Trans-resveratrol is a nutraceutical with known antioxidant, anti-inflammatory, cardioprotective, and anti-apoptotic properties. The aim of this study was to evaluate the effects of resveratrol on heart mitochondria. Resveratrol significantly decreased Fe(2+) + ascorbate oxidant system-induced lipid peroxide levels, preserved physiological levels of glutathione, and increased nitric oxide (NO) levels in mitochondria. Under calcium-mediated stress, there was a 2.7-fold increase in the NO levels, and a mild decoupling in the mitochondrial respiratory chain. These results provide a mechanism for and support the beneficial effects of resveratrol under pathological conditions induced by oxidative stress and calcium overload. In addition, these findings underscore the usefulness of resveratrol in the prevention of cardiovascular diseases.

Topics: Animals; Antioxidants; Ascorbic Acid; Calcium; Cardiovascular Diseases; Glutathione; Iron; Male; Mitochondria, Heart; Nitric Oxide; Oxidative Stress; Rats; Rats, Wistar; Resveratrol; Stilbenes

The purpose of this study was to evaluate the overall diet quality effects, mainly on antioxidant nutritional status and some cytokines related to the cellular immune response as well as oxidative stress in a healthy Italian population group.. An observational study was conducted on 131 healthy free-living subjects. Dietary intake was assessed by dietary diary. Standardised procedures were used to make anthropometric measurements. On blood samples (serum, plasma and whole blood) were evaluated: antioxidant status by vitamin A, vitamin E, carotenoids, vitamin C, uric acid, SH groups, SOD and GPx activities; lipid blood profile by total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides; total antioxidant capacity by FRAP and TRAP; the immune status by TNF-α, and IL-10 cytokines; the levels of malondialdehyde in the erythrocytes as marker of lipid peroxidation.. The daily macronutrients intake (g/day) have shown a high lipids consumption and significant differences between the sexes with regard to daily micronutrients intake. On total sample mean Mediterranean Diet Score (MDS) was 4.5 ± 1.6 and no significant differences between the sexes were present. A greater adherence to a Mediterranean dietary pattern increases the circulating plasma levels of carotenoids (lutein plus zeaxanthin, cryptoxanthin, α and β-carotene), vitamin A and vitamin E. The levels of endogenous antioxidants were also improved. We observed higher levels in anti-inflammatory effect cytokines (IL-10) in subjects with MDS ≥ 6, by contrast, subjects with MDS ≤ 3 show higher levels in sense of proinflammatory (TNF α P < 0.05). Lower levels of MDA were associated with MDS > 4. Our data suggest a protective role of vitamin A against chronic inflammatory conditions especially in subjects with the highest adherence to the Mediterranean-type dietary pattern.. Mediterranean dietary pattern is associated with significant amelioration of multiple risk factors, including a better cardiovascular risk profile, reduced oxidative stress and modulation of inflammation.

Topics: Adult; Antioxidants; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Carotenoids; Cholesterol; Diet, Mediterranean; Feeding Behavior; Female; Humans; Interleukin-10; Interviews as Topic; Italy; Lipid Peroxidation; Male; Malondialdehyde; Nutritional Status; Oxidative Stress; Risk Factors; Surveys and Questionnaires; Triglycerides; Tumor Necrosis Factor-alpha; Vitamin A; Vitamin E; Vitamins; Young Adult

Some studies have hypothesized the protective role of vitamin C against cardiovascular disorders (CVD) in patients with end-stage renal disease (ESRD). This study was designed to assess plasma vitamin C concentration and its relationship to hemodialysis (HD) patients' morbidity and mortality.. Plasma vitamin C concentrations were assessed in HD patients using spectrophotometry and subjects were prospectively followed for up eighteen months for all-cause mortality. Any association between vitamin C concentration and patients' demographic data, co-morbidities, or the cause of ESRD were investigated using the Chi-square test.. Ninety-one patients with a mean age of 56.7 ± 15.7 years were included in this study. The most frequent cause of ESRD was simultaneous hypertension and diabetes in 30 % of patients, followed by hypertension in 25.6 %, and diabetes in 11.1 %, respectively. About 34 % of patients had CVD as the most prevalent co-morbidity. Forty-nine patients (53.8 %) had low levels of vitamin C concentration. There was a significant relationship between vitamin C insufficiency and presence of any co-morbidity in HD patients (p < 0.05). There was a significant difference in vitamin C concentrations between patients without co-morbidities and those with cardiovascular ones (F[2,88]=3.447, p = 0.036). Twenty-two (24.2 %) patients died over a median duration of 227 days. There was a significant difference in time to death of patients with and without low levels of vitamin C concentration (p = 0.04).. The results showed lower plasma vitamin C levels in HD patients who suffered any co-morbidity and sooner time to death in these patients.

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Diabetic Nephropathies; Female; Follow-Up Studies; Hospitals, University; Humans; Hypertension; Iran; Kidney Failure, Chronic; Male; Middle Aged; Morbidity; Mortality; Prospective Studies; Renal Dialysis; Survival Analysis; Young Adult

In premature infants, glucocorticoids ameliorate chronic lung disease, but have adverse effects on growth and the cardiovascular system. Glucocorticoid excess promotes free radical overproduction and vascular dysfunction.. We hypothesized that the adverse effects of postnatal glucocorticoid therapy are secondary to oxidative stress and that antioxidant treatment would diminish unwanted effects.. Male rat pups received a clinically relevant course of dexamethasone (Dex), or Dex with vitamins C and E (DexCE), on postnatal days 1-6 (P1-6). Controls received saline (Ctrl) or saline with vitamins (CtrlCE).. At P21, Dex reduced survival (Ctrl: 96 vs. Dex: 70%) and promoted asymmetric growth restriction (ponderal index, Ctrl: 6.3 +/- 0.1 g . mm(-3) x 10(-5) vs. Dex: 7.4 +/- 0.2 g . mm(-3) x 10(-5)), both p < 0.05. Dex increased cardiac oxidative stress (protein expression: 4-HNE +20%, Hsp90 -42% and eNOS -54%), induced left ventricle (LV) wall thinning (LV wall volume: Ctrl: 47.2 +/- 1.2 mm(3) vs. Dex: 38.9 +/- 1.7 mm(3)) and decreased the ratio of the aortic lumen:total vessel area (Ctrl: 0.74 +/- 0.01 vs. Dex: 0.66 +/- 0.02), all p < 0.05. DexCE restored towards control values survival, growth symmetry the aortic lumen:total vessel area, and increased the cardiac expression of Hsp90 relative to Dex. In addition, relative to controls, the decrease in the cardiac expression of eNOS was no longer significant in DexCE animals (-20.3 +/- 14.4%, p > 0.05). However, DexCE did not prevent growth retardation, cardiac 4-HNE upregulation (DexCE: +29%) or LV thinning (DexCE: 40.1 +/- 1.1 mm(3)). Treatment of neonates with vitamins alone affected somatic growth and promoted thinner LV walls (CtrlCE: 39.9 +/- 0.5 mm(3), p < 0.05).. Combined glucocorticoid and antioxidant therapy in premature infants may be safer than glucocorticoids alone in the treatment of chronic lung disease. However, antioxidant therapy in healthy offspring is not recommended.

Topics: Aldehydes; Animals; Animals, Newborn; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Chronic Disease; Dexamethasone; Drug Therapy, Combination; Glucocorticoids; Heart; HSP90 Heat-Shock Proteins; Lung Diseases; Male; Nitric Oxide Synthase Type III; Oxidative Stress; Rats; Vitamin E

Postnatal glucocorticoid therapy in premature infants diminishes chronic lung disease, but it also increases the risk of hypertension in adulthood. Since glucocorticoid excess leads to overproduction of free radicals and endothelial dysfunction, this study tested the hypothesis that adverse effects on cardiovascular function of postnatal glucocorticoids are secondary to oxidative stress. Therefore, combined postnatal treatment of glucocorticoids with antioxidants may diminish unwanted effects.. Male rat pups received a course of dexamethasone (Dex), or Dex with vitamins C and E (DexCE), on postnatal days 1-6 (P1-6). Controls received vehicle (Ctrl) or vehicle with vitamins (CtrlCE). At P21, femoral vascular reactivity was determined via wire myography. Dex, but not DexCE or CtrlCE, increased mortality relative to Ctrl (81.3 versus 96.9 versus 90.6 versus 100% survival, respectively; P<0.05). Constrictor responses to phenylephrine (PE) and thromboxane were enhanced in Dex relative to Ctrl (84.7+/-4.8 versus 67.5+/-5.7 and 132.7+/-4.9 versus 107.0+/-4.9% Kmax, respectively; P<0.05); effects that were diminished in DexCE (58.3+/-7.5 and 121.1+/-4.3% Kmax, respectively; P<0.05). Endothelium-dependent dilatation was depressed in Dex relative to Ctrl (115.3+/-11.9 versus 216.9+/-18.9, AUC; P<0.05); however, this effect was not restored in DexCE (68.3+/-8.3, AUC). Relative to Ctrl, CtrlCE alone diminished PE-induced constriction (43.4+/-3.7% Kmax) and the endothelium-dependent dilatation (74.7+/-8.7 AUC; P<0.05).. Treatment of newborn rats with dexamethasone has detrimental effects on survival and peripheral vasoconstrictor function. Coadministration of dexamethasone with antioxidant vitamins improves survival and partially restores vascular dysfunction. Antioxidant vitamins alone affect peripheral vascular function.

Topics: Animals; Animals, Newborn; Antioxidants; Ascorbic Acid; Body Weight; Cardiovascular Diseases; Dexamethasone; Dose-Response Relationship, Drug; Female; Femoral Artery; Glucocorticoids; In Vitro Techniques; Male; Nitric Oxide Donors; Nitroprusside; Peritonitis; Potassium; Random Allocation; Rats; Rats, Wistar; Survival Rate; Time Factors; Vasoconstriction; Vitamin E

Underlying cardiovascular disease (CVD) is a risk factor for the exacerbation of air pollution health effects. Pulmonary oxidative stress, inflammation, and altered iron (Fe) homeostasis secondary to CVD may influence mammalian susceptibility to air pollutants. Rodent models of CVD are increasingly used to examine mechanisms of variation in susceptibility. Baseline cardiac and pulmonary disease was characterized in healthy normotensive Wistar Kyoto (WKY) rats, cardiovascular compromised spontaneously hypertensive rats (SHR), and spontaneously hypertensive heart failure (SHHF) rats. Blood pressure, heart rate, and breathing frequencies were measured in rats 11 to 12 wk of age, followed by necropsy at 14 to 15 wk of age. Blood pressure and heart rate were increased in SHR and SHHF relative to WKY rats (SHR > SHHF > WKY). Increased breathing frequency in SHHF and SHR (SHR > SHHF > WKY) resulted in greater minute volume relative to WKY. Bronchoalveolar lavage fluid (BALF) protein and neutrophils were higher in SHHF and SHR relative to WKY (SHHF >> SHR > WKY). Lung ascorbate and glutathione levels were low in SHHF rats. BALF Fe-binding capacity was decreased in SHHF relative to WKY rats and was associated with increased transferrin (Trf) and ferritin. However, lung ferritin was lower and Trf was higher in SHHF relative to WKY or SHR rats. mRNA for markers of inflammation and oxidative stress (macrophage inflammatory protein [MIP]-2, interleukin [IL]-1alpha, and heme oxygenase [HO]-1) were greater in SHHF and SHR relative to WKY rats. Trf mRNA rose in SHR but not SHHF relative to WKY rats, whereas transferrin receptors 1 and 2 mRNA was lower in SHHF rats. Four of 12 WKY rats exhibited cardiac hypertrophy despite normal blood pressure, while demonstrating some of the pulmonary complications noted earlier. This study demonstrates that SHHF rats display greater underlying pulmonary complications such as oxidative stress, inflammation, and impaired Fe homeostasis than WKY or SHR rats, which may play a role in SHHF rats' increased susceptibility to air pollution.

Topics: Animals; Ascorbic Acid; Biomarkers; Bronchoalveolar Lavage Fluid; Cardiovascular Diseases; Disease Models, Animal; Ferritins; Gene Expression; Glutathione; Heart Failure; Hemodynamics; Homeostasis; Hypertension; Inflammation; Iron; Lung; Lung Diseases; Male; Obesity; Oxidative Stress; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Respiratory Function Tests; Stroke; Transferrin

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Humans; Myocardial Infarction; Vitamin B Complex; Vitamin E

The factors influencing total plasma homocysteine levels (tHcy) are of special interest in the attempt to reduce cardiovascular risk.. This investigation aimed to assess the independent effects of antioxidant vitamins on tHcy in elderly people.. Our cross-sectional analysis included data of 184 subjects (≥60 years) from the longitudinal study in an aging population in Giessen (GISELA), Germany. We examined the effects of plasma levels, intake and supplementation of vitamin C, vitamin E, and β-carotene on tHcy.. The mean tHcy was within the normal range in this population. Serum folate, the estimated glomerular filtration rate (eGFR), and plasma vitamin C showed a negative association with tHcy in simple regression analysis. In a subsequent multiple regression analysis, eGFR, serum folate, and plasma vitamin C were the relevant independent predictors of tHcy. Intake and supplementation of vitamin C, as well as plasma levels, intake and supplementation of vitamin E, and β-carotene were not associated with tHcy.. Vitamin C may be an independent predictor of tHcy in free-living elderly people and, therefore, should be considered in attempts to reduce tHcy.

Topics: Aged; Aging; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Cross-Sectional Studies; Female; Folic Acid; Germany; Glomerular Filtration Rate; Homocysteine; Humans; Longitudinal Studies; Male; Vitamin E; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Male; Randomized Controlled Trials as Topic; Vitamin E

Topics: Aged; Ascorbic Acid; Cardiovascular Diseases; Clinical Protocols; Clinical Trials as Topic; Data Interpretation, Statistical; Humans; Male; Middle Aged; Neoplasms; Oxidative Stress; Patient Compliance; Prostatic Neoplasms; Vitamin E

Paraoxonase 1 (PON1) is a cardioprotective enzyme associated with high-density lipoprotein (HDL). We tested the hypothesis that vitamin C protects HDL and PON1 from deleterious effects of hypochlorous acid, a proinflammatory oxidant. In our experiments, HDL (from human plasma) or diluted human plasma was incubated with hypochlorite in either the absence (control) or presence of vitamin C before measuring chemical modification and PON1 activities. Vitamin C minimized chemical modification of HDL, as assessed by lysine modification and accumulation of chloramines. In the absence of vitamin C, chloramines accumulated to 114 +/- 4 micromol/L in HDL incubated with a 200-fold molar excess of hypochlorite; but addition of vitamin C (200 micromol/L) limited formation to 36 +/- 6 micromol/L (P < .001). In plasma exposed to hypochlorite, IC(50) values of 1.2 +/- 0.1, 9.5 +/- 1.0, and 5.0 +/- 0.6 mmol/L were determined for PON1's phosphotriesterase, arylesterase, and (physiologic) lactonase activities, respectively. Vitamin C lessened this inhibitory effect of hypochlorite on PON1 activities. In plasma supplemented with vitamin C (400 micromol/L), PON1 phosphotriesterase activity was 72% +/- 17% of normal after incubation with hypochlorite (2 mmol/L), compared with 42% +/- 6% for unsupplemented plasma (P < .05). Similar effects were seen for other PON1 activities. In some experiments, vitamin C also appeared to reverse hypochlorite-mediated loss of PON1 phosphotriesterase activity; but this effect was not observed for the other PON1 activities. In conclusion, vitamin C attenuated hypochlorite-mediated loss of PON1 activity in vitro and may, therefore, preserve cardioprotective properties of HDL during inflammation.

Topics: Antioxidants; Aryldialkylphosphatase; Ascorbic Acid; Carboxylic Ester Hydrolases; Cardiovascular Diseases; Humans; Hypochlorous Acid; Lipoproteins, HDL; Lipoproteins, LDL; Phosphoric Triester Hydrolases

Topics: Antioxidants; Ascorbic Acid; Biological Availability; Cardiovascular Diseases; Dietary Supplements; Humans; Male; Vitamin E; Vitamins

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Drug Interactions; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Male; Vitamin E; Vitamins

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Dietary Supplements; Humans; Male; Vitamins

In this cohort study, the authors evaluated how supplemental use of multivitamins, vitamin C, and vitamin E over a 10-year period was related to 5-year total mortality, cancer mortality, and cardiovascular disease (CVD) mortality. Participants (n = 77,719) were Washington State residents aged 50-76 years who completed a mailed self-administered questionnaire in 2000-2002. Adjusted hazard ratios and 95% confidence intervals were computed using Cox regression. Multivitamin use was not related to total mortality. However, vitamin C and vitamin E use were associated with small decreases in risk. In cause-specific analyses, use of multivitamins and use of vitamin E were associated with decreased risks of CVD mortality. The hazard ratio comparing persons who had a 10-year average frequency of multivitamin use of 6-7 days per week with nonusers was 0.84 (95% confidence interval: 0.70, 0.99); and the hazard ratio comparing persons who had a 10-year average daily dose of vitamin E greater than 215 mg with nonusers was 0.72 (95% confidence interval: 0.59, 0.88). In contrast, vitamin C use was not associated with CVD mortality. Multivitamin and vitamin E use were not associated with cancer mortality. Some of the associations we observed were small and may have been due to unmeasured healthy behaviors that were more common in supplement users.

Topics: Aged; Ascorbic Acid; Cardiovascular Diseases; Cohort Studies; Dietary Supplements; Follow-Up Studies; Humans; Middle Aged; Mortality; Neoplasms; Proportional Hazards Models; Vitamin E; Vitamins; Washington

Growing evidence has demonstrated that oxidative stress and increased altered oxygen utilization contribute to atherogenesis and cardiovascular disease (CVD) progression. Antioxidants protect the body from damage caused by free radicals. The objective of this study was to determine antioxidants status in CVD patients. This cross-sectional study was performed on 71 patients clinically diagnosed with CVD and 63 healthy individuals. Plasma malondialdehyde (MDA) level was measured for lipid peroxidation product and erythrocyte SOD and GPx activities as enzymatic antioxidants. The serum levels of vitamins A and E were assayed using HPLC and vitamin C by the photometric method. Total antioxidant capacity (TAC) was measured using the ferric reducing ability of plasma (FRAP) method. The results showed a significant reduction in antioxidant status (enzymatic and non-enzymatic) with a concomitant increase in the concentrations of lipid peroxidation products in CVD patients. There was a significant inverse correlation among TAC, SOD, GPx and vitamin C with MDA. It can be concluded that the antioxidant defense system plays an important role in preventing the development and progression of CVD with the ability to control oxidative stress.

Topics: Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Chromatography, High Pressure Liquid; Cross-Sectional Studies; Erythrocytes; Female; Glutathione Peroxidase; Humans; Iran; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Photometry; Superoxide Dismutase; Vitamins

Cardiovascular disease (CVD) is the most important adult health problem in the world. Epidemiological studies and laboratory experiments have shown that fruit and vegetable consumption has protective effects against CVD. The purpose of the study was to investigate the effects of consumption of two kiwifruit per day on the lipid profile, antioxidants and markers of lipid peroxidation in hyperlipidemic adult men and women in Taiwan. Forty-three subjects who had hyperlipidemia, including 13 males and 30 females, participated in this study. They were asked to consume two kiwifruit per day for 8 weeks. Anthropometric measurements were made. Before the intervention and at 4 and 8 weeks of the intervention, fasting blood samples were analyzed for total cholesterol, triacylglycerol, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein cholesterol (HDL-C). Additionally vitamin E and vitamin C, the malondialdehyde + 4-hydroxy-2(E)-nonenal concentration, and the lag time of LDL oxidation were determined. No significant differences from baseline to 8 weeks of the intervention were detected for triacylglycerol, total cholesterol, or LDL cholesterol. However, after 8 weeks of consumption of kiwifruit, the HDL-C concentration was significantly increased and the LDL cholesterol/HDL-C ratio and total cholesterol/HDL-C ratio were significantly decreased. Vitamin C and vitamin E also increased significantly. In addition, the lag time of LDL oxidation and malondialdehyde + 4-hydroxy-2(E)-nonenal had significantly changed at 4 and 8 weeks during the kiwifruit intervention. Regular consumption of kiwifruit might exert beneficial effects on the antioxidative status and the risk factors for CVD in hyperlipidemic subjects.

Topics: Actinidia; Adult; Aged; Aldehydes; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Female; Fruit; Humans; Hyperlipidemias; Lipid Peroxidation; Lipids; Lipoproteins; Lipoproteins, LDL; Male; Middle Aged; Oxidation-Reduction; Risk Factors; Time Factors; Vitamin E; Young Adult

Since it is well known that estrogen deficiency or ovariectomy (OVX) results in a reduction of sexual steroids and increased prevalence of cardiovascular diseases (CVD), it was aimed to assess the benefits of hormone replacement therapy (HRT) alone or together with antioxidant vitamins (E and C) for the protection against CVD and oxidative stress.. The effect of ovariectomy and HRT alone or combined with antioxidants (Antiox) on lipid metabolism, insulin sensitivity, oxidative stress, antioxidant and markers of CVD was examined in four groups of female Wistar rats of 10 animals each: Group 1 (sham operated); Group 2 (OVX); Group 3 (OVX + HRT); Group 4 (OVX + HRT + Antiox). After four weeks of treatment total cholesterol, HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C), triglycerides (TG), Apo B lipoprotein, glucose and insulin as well as malondialdehyde (MDA; as index of lipid peroxidation), oxidized LDL (ox-LDL), homocysteine level, oxidized and reduced glutathione were determined in plasma.. The lipid pattern of OVX rats showed a deviation from sham group in all lipid fractions and atherogenic indexes; LDL/HDL and TC/HDL. HRT group showed partial correction of these abnormalities and the antioxidant adjunct treatment significantly improved the lipid profile. OVX rats had significantly higher insulin and glucose levels compared to the sham group which was abolished by HRT and completely normalized by adjunct antioxidant treatment. HOMA was significantly decreased by HRT and showed normal value with adjunct antioxidant treatment. The oxidative stress parameters; MDA, ox-LDL and GSSG levels were increased, also homocysteine was greatly elevated in OVX rats. The HRT significantly corrected the levels of MDA, ox-LDL and GSSG while it had no effect on homocysteine and GSH. The adjunct antioxidant treatment potentiated the HRT and showed a significant correction of homocysteine and GSH levels.. Our data suggested that adjunct antioxidant treatment together with HRT may ameliorate the cardiovascular protection and improve metabolic syndrome as well as insulin resistance in OVX rats. Further studies are warranted to elucidate the beneficial role of antioxidant treatment on cardiovascular protection of menopause women.

Topics: Adjuvants, Pharmaceutic; Animals; Antioxidants; Ascorbic Acid; Blood Glucose; Cardiovascular Diseases; Estrogen Replacement Therapy; Female; Insulin; Insulin Resistance; Ovariectomy; Oxidative Stress; Rats; Rats, Wistar; Vitamin E

High serum levels of homocysteine and cortisol are independent risk factors for several pathologies and their levels can be regulated by some vitamins. Since the relationship between serum concentrations of homocysteine, cortisol and ascorbate has not been assessed in healthy individuals to date, it was the topic of the present work.. The study group was composed of 20 men and 40 women aged >50 years. Blood samples were collected and serum concentrations of the analytes were quantified.. Serum homocysteine levels correlate positively with cortisol (r = 0.36, p <0.01) and age (r = 0.49, p < 0.001), and negatively with ascorbate (r = -0.30, p < 0.05) and folate (r = -0.31, p < 0.05). A negative correlation between serum levels of cortisol and ascorbate (r = -0.30, p < 0.05) was also observed. Multiple linear regression analysis showed that the best independent predictors of serum homocysteine concentration were cortisol (beta = 0.319, p < 0.003), age (beta = 0.529, p < 0.001) and folate (beta = -0.338, p < 0.001). When subjects were divided into tertiles according to their homocysteine concentration, the highest tertile of homocysteine concentration has also higher cortisol (p < 0.005) and lower ascorbate (p < 0.05) concentrations compared with the lowest tertile of homocysteine concentration.. The association between serum concentrations of homocysteine, cortisol and ascorbate suggests interaction between circulating levels of these molecules.

Topics: Aging; Ascorbic Acid; Cardiovascular Diseases; Female; Folic Acid; Health Status; Homocysteine; Humans; Hydrocortisone; Linear Models; Male; Middle Aged; Nutritional Status; Risk Factors

Comparative analysis of vitamin C, B2 and A sufficiency evaluation of the patients suffering from obesity and cardiovascular diseases has been done by means of rated vitamin intake on the basis of foodstuff consumption frequency and blood serum level detection. According to both methods the surveyed had optimal sufficiency with vitamin C. At lowered in comparison with recommended receipt of these vitamins with a diet in 56-94% of patients retinol blood serum concentration was within the limits of norm, while only 15% of patients had lowered concerning the bottom border of norm riboflavin blood serum level.

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Cardiovascular Diseases; Female; Humans; Male; Middle Aged; Obesity; Riboflavin; Vitamin A

Lower body fat percentage is positively associated with climbing performance. This may lead climbers to practice unhealthy diet restriction when no sport-specific nutrition information exists. This study examined whether prolonged diet restriction affects body composition, oxidative stress, or other potential health risks in outdoor rock climbers. Two healthy male climbers conducted a 5 week rock climbing trip with a limited food budget ($1 each per day). Subjects underwent an energy restriction of approximately 40%. Loss of body weight and fat mass at week 5 were 5.8% and 16.1%, respectively, and were accompanied by significant subcutaneous fat loss in the iliac crest and abdomen. Triacylglycerols (TG), free fatty acids and C-reactive protein (CRP) dramatically decreased from baseline to week 2, and then maintained the lower level until week 5. Plasma vitamin C was below the normal range, and F2-isoprostanes, a marker of oxidative stress, continuously increased to week 5. Superoxide dismutase and glutathione peroxidase increased to week 2, but had returned to baseline levels at week 5. These results indicate that prolonged reduced energy intake while climbing may have an impact on weight loss and fat mass loss, which may contribute to low circulating TG and CRP, indicating improvements in markers of cardiovascular risk, and may lead to increased oxidative stress and reduced circulating antioxidants. Further studies are warranted to determine whether antioxidant supplementation or increased energy intake reduce oxidative stress.

Topics: Adipose Tissue; Adult; Ascorbic Acid; Biomarkers; Body Weight; C-Reactive Protein; Cardiovascular Diseases; Catalase; Diet, Reducing; Energy Intake; Fatty Acids, Nonesterified; Glutathione Peroxidase; Humans; Isoprostanes; Lipid Peroxidation; Male; Oxidative Stress; Reference Values; Sports; Superoxide Dismutase; Triglycerides; Young Adult

During aging there is a tendency towards hyperlipidemia and changes in the distribution of lipoproteins. A decline in the functioning of the body's antioxidant defense system is also observed at this time. The objective of this study was to establish the relationship between serum concentrations of total cholesterol and fractions, triglycerides, and Vitamins C and E. 61 adults over 60 years of age were evaluated from January to March, 2006. Nutritional status was diagnosed by BMI (WHO); serum levels of triglycerides (TG), total cholesterol (TC) and fractions (HDL-c and LDL-c) were determined by enzyme method; Vitamin C (colorimetric method) and Vitamin E by HPLC. ATPIII values were used as a reference for risk of TG, TC, HDL, LDL-c, vitamin C: > 0.9 mg/dL (normal), < 0.9 mg/dL (deficit); vitamin E: = 1300 microg/dL (normal), 1300 = microg /dL (deficit). Consumption of vitamins C and E were estimated by the direct weighing method 3 days per week. According to BMI, 19.7% had nutritional deficit, 39.3% overweight, and 11.5% obesity. TG, TC, LDL-c levels were at risk in females, and HDL-c in both genders. Prevalence of risk for heart disease was: TG (45.2%), HDL-c (51.1%), and LDL-c (52.5%). Consumption and serum levels of vitamin E were low in both genders. There was no association between variables. A significant and positive correlation between TG, TC, LDL-C, serum vitamin E, and BMI was observed. The female group showed overweight, hypertriglyceridemia and hypercholesterolemia, HDL-c and LDL-c at risk, and vitamin E deficiency, all of which are important risk factors for cardiovascular disease in this age group.

Topics: Aged; Aged, 80 and over; Aging; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Epidemiologic Methods; Female; Humans; Lipids; Male; Middle Aged; Nutritional Status; Sex Distribution; Sex Factors; Triglycerides; Venezuela; Vitamin E

Topics: Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Confounding Factors, Epidemiologic; Evidence-Based Medicine; Food, Organic; Fruit; Humans; Stroke; Vegetables

The role of beta-carotene, alpha-tocopherol, and vitamin C in the prevention of cardiovascular diseases (CVD) is controversial. Prospective studies on gamma-tocopherol and carotenoids other than beta-carotene are sparse. We assessed relations between the intake of different carotenoids, alpha- and gamma-tocopherol, and vitamin C with 15-y CVD mortality in elderly men who participated in the Zutphen Elderly Study. Information on diet and potential confounding factors was collected in 1985, 1990, and 1995. In 1985, 559 men (mean age approximately 72 y) free of chronic diseases were included in the current analysis. After 15 y of follow-up, comprising 5744 person-years, 197 men had died from CVD. After adjustment for age, smoking, and other potential lifestyle and dietary confounders, relative risks (RR) (95% CI) of CVD death for a 1-SD increase in intake were 0.81 (0.66-0.99) for alpha-carotene and 0.80 (0.66-0.97) for beta-carotene. Carrots were the primary source of alpha- and beta-carotene and their consumption was related to a lower risk of death from CVD (adjusted RR, 0.83; 95% CI = 0.68-1.00). Intakes of carotenoids other than alpha- and beta-carotene were not associated with CVD mortality, nor were vitamin C and alpha- and gamma tocopherol. In conclusion, dietary intakes of alpha-carotene and beta-carotene are inversely associated with CVD mortality in elderly men. This study does not indicate an important role for other carotenoids, tocopherols, or vitamin C in lowering the risk of CVD death.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Cohort Studies; Diet; Feeding Behavior; Humans; Male; Netherlands; Tocopherols

Man, with other primates, lost the ability to synthesize vitamin C through an inactivating mutation of the gene encoding gulonolactone oxidase (GULO) millions of years ago. Though the consequences of this prehistoric loss must have been favorable (and thus selected for) at the population level, the inability to produce vitamin C may have serious health implications for modern humans, especially for those conditions in which antioxidants (like vitamin C) have been implicated as potential therapeutic agents. Two general types of recent findings regarding vitamin C have made re-evaluation of this important nutrient imperative. First, vitamin C is now known to be involved in several novel physiological phenomena including stem cell differentiation and respiratory development, which likely require pharmacological levels of vitamin C. Secondly, the growing recognition that many ageing-related diseases, including heart disease, neural degeneration and cancer, may have a contributing oxidative damage factor that might be reduced by dietary antioxidants such as vitamin C. In this paper, we hypothesize that high serum-level vitamin C provides important, broad-ranging therapeutic benefits in treating ageing-related degenerative diseases. This hypothesis can be readily tested using traditional and newly-developed genetically-engineered animal models.

Topics: Aging; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Humans; Models, Biological; Neoplasms; Nerve Degeneration

It has been suggested that a high dietary intake and high circulating concentrations of vitamin C may protect against ischemic heart disease.. The objective was to examine the associations between dietary and plasma vitamin C concentrations, fruit and vegetable intakes, and markers of inflammation and hemostasis associated with cardiovascular disease in older men free of cardiovascular disease.. This cross-sectional study examined 3258 men aged 60-79 y with no physician diagnosis of myocardial infarction, stroke, or diabetes and who were drawn from general practices in 24 British towns. Fruit and vegetable intakes and dietary vitamin C were assessed by using a food-frequency questionnaire.. Plasma vitamin C, fruit intake, and dietary vitamin C intake were significantly and inversely associated with mean concentrations of C-reactive protein, an acute phase reactant, and tissue plasminogen activator (t-PA) antigen, a marker of endothelial dysfunction, even after adjustment for confounders. Vegetable intake was correlated significantly (inversely) only with t-PA. For plasma vitamin C (highest versus lowest quartile), the adjusted odds of elevated C-reactive protein and t-PA (highest tertile versus lowest tertile) were 0.56 (95% CI: 0.44, 0.71) and 0.79 (0.62, 1.00); for fruit intake, the corresponding odds ratios were 0.76 (0.60, 0.95) and 0.76 (0.61, 0.95). Plasma (but not dietary) vitamin C also showed inverse associations with both fibrinogen concentrations and blood viscosity. No associations were seen with von Willebrand factor or factor VIII.. The findings suggest that vitamin C has antiinflammatory effects and is associated with lower endothelial dysfunction in men with no history of cardiovascular disease or diabetes.

Topics: Acute-Phase Proteins; Aged; Antioxidants; Ascorbic Acid; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Confidence Intervals; Cross-Sectional Studies; Endothelium, Vascular; Fruit; Hemostasis; Humans; Inflammation; Life Style; Male; Middle Aged; Odds Ratio; Surveys and Questionnaires; Tissue Plasminogen Activator; United Kingdom; Vegetables; von Willebrand Factor

Topics: Antioxidants; Ascorbic Acid; Atorvastatin; Calcinosis; Cardiovascular Diseases; Coronary Disease; Drug Therapy, Combination; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Pyrroles; Vitamin E

Accumulation of advanced glycation end-products (AGEs) has been implicated in the pathogenesis of chronic transplant dysfunction and cardiovascular disease in renal transplant recipients. We aimed to investigate which factors are associated with tissue AGE accumulation in renal transplant recipients.. The AGE accumulation was assessed using a validated skin-autofluorescence reader (AFR) in 285 consecutive renal transplant recipients (57% male, aged 50+/-12 years) visiting the outpatient clinic at a median (interquartile range) time of 73 (32-143) months after transplantation. Furthermore, various transplant- and recipient-related factors of interest were collected.. Average skin-autofluorescence of lower arm and leg was 2.7+/-0.8 a.u. Skin-autofluorescence was positively determined by recipient age, systolic blood pressure, smoking, high-sensitivity C-reactive protein, duration of pre-transplant dialysis, and negatively by plasma vitamin C levels, creatinine clearance at baseline, and change in creatinine clearance since one year after transplantation in linear multivariate regression analysis. Together, these factors explained 41% of the variance of skin-autofluorescence.. Skin-autofluorescence was associated with several risk factors for cardiovascular disease and chronic renal transplant dysfunction. These results are in line with the hypothesis that AGEs play a role in the pathogenesis of these conditions in renal transplant recipients. Prospective studies are required to investigate whether the AFR can be used as a simple, non-invasive tool to identify and monitor patients at risk for chronic renal transplant dysfunction and cardiovascular disease.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Ascorbic Acid; C-Reactive Protein; Cardiovascular Diseases; Comorbidity; Creatinine; Delayed Graft Function; Diabetes Complications; Female; Fluorometry; Forearm; Glycated Hemoglobin; Glycation End Products, Advanced; Histocompatibility; Humans; Hypercholesterolemia; Hypertension; Immunosuppressive Agents; Kidney; Kidney Failure, Chronic; Kidney Transplantation; Leg; Linear Models; Male; Middle Aged; Obesity; Risk Factors; Skin; Smoking; Vitamin E

Complementary and alternative medicine (CAM) use is common among patients with cardiovascular disorders and is generally underrecognized by physicians. The attitudes of these patients regarding these therapies and their perceptions of safety and efficacy have not been well defined.. A written survey was received from a cohort of outpatients seen at a large outpatient cardiovascular clinic in Texas. Over 75% of patients responded, with more than 90% of returned surveys adequate for analysis.. Of the 210 respondents 113 admitted to CAM use, with Vitamins E and C being the most frequently utilized agents. Women were significantly more likely to take CAM than men (69 vs. 46%, p = 0.002), particularly those taking hormone replacement therapy. Over half of patients surveyed stated their cardiologist was unaware of their use of CAM. Only 15% of patients felt that CAM was more efficacious than their traditional medications, but almost half felt it was significantly safer. A similar number were unaware of any interactions between CAM and their other medications.. Use of CAM is common in cardiology outpatients, and many patients remain unaware of potential health risks. Physicians should routinely question patients about use of CAM and attempt to educate users regarding potential health risks.

Topics: Aged; Ascorbic Acid; Cardiology; Cardiovascular Diseases; Cohort Studies; Complementary Therapies; Dietary Supplements; Estrogen Replacement Therapy; Female; Humans; Male; Outpatients; Patient Acceptance of Health Care; Phytotherapy; Plants, Medicinal; Surveys and Questionnaires; Texas; Vitamin E

Angiotensin II is a powerful vasoconstrictor and regulator of cardiovascular growth. Also, it increases formation of reactive oxygen species and contributes to vascular dysfunction. We investigated the role of oxidant stress in contraction of human resistance arteries to angiotensin II, in health and in the presence of cardiovascular disease.. Studies of isometric contraction to angiotensin II, using human resistance arteries from healthy volunteers and patients, undergoing cardiac revascularization surgery, were performed by the broad-spectrum antioxidant agent vitamin C and superoxide dismutase mimetic TEMPOL. In the presence of vitamin C, the potency and the maximum contractile response were reduced in both patients and healthy volunteers. Addition of TEMPOL caused a decrease in angiotensin II-induced contraction only in the patients' group.. Our studies provide evidence for the role of oxidant stress in the contractile response of human resistance arteries to angiotensin II. In patients with cardiovascular disease, the superoxide anion may be the major species involved. In healthy subjects, other reactive oxygen species and the redox-independent vasoconstrictor action of angiotensin II predominate.. Increased formation of reactive oxygen species, due to angiotensin II, contributes to vascular dysfunction. We determined the oxidative reactivity of human resistance arteries to angiotensin II in healthy subjects and patients, undergoing cardiac revascularization surgery, using the broad-spectrum antioxidant agent, vitamin C, and superoxide dismutase mimetic, TEMPOL. There was a large decrease in potency and maximum of angiotensin II-induced contractile response noted in both groups with the former, while the latter reduced contraction only in the patients' group. Superoxide anion may play a major role in angiotensin II contractions of human resistance arteries in the presence of cardiovascular disease. In healthy subjects, other reactive species and the redox-independent pathways predominate.

Topics: Aged; Angiotensin II; Antioxidants; Arteries; Ascorbic Acid; Cardiovascular Diseases; Cyclic N-Oxides; Dose-Response Relationship, Drug; Female; Humans; In Vitro Techniques; Male; Oxidative Stress; Reactive Oxygen Species; Reference Values; Spin Labels; Subcutaneous Fat; Vascular Resistance; Vasoconstriction; Vasoconstrictor Agents

Hemodialysis patients are prone to deficiency of vitamin C, which constitutes the most abundant nonenzymatic antioxidant in blood. Because antioxidants are involved in the pathogenesis of atherosclerosis, the authors examined the association of total vitamin C plasma level with cardiovascular outcomes in such patients. One hundred thirty-eight consecutive maintenance hemodialysis patients (median age 61 yr, 90 males) were enrolled in a single-center study. At baseline, routine laboratory parameters were recorded, and predialysis total vitamin C plasma levels were measured by high-pressure liquid chromatography. Patients were prospectively followed-up for the occurrence of a primary composite endpoint consisting of fatal and nonfatal major adverse cardiovascular events (MACE) and for all-cause and cardiovascular mortality. MACE occurred in 35 patients (25%) over a period of median 30 mo, and 42 patients (30%) died [29 cardiovascular deaths (21% of total)]. Using Cox proportional hazards modeling, adjusted hazard ratios for the occurrence of MACE were 3.90 (95% confidence interval [CI]: 1.42 to 10.67; P = 0.008) and 3.03 (95% CI: 1.03 to 8.92; P = 0.044) for patients in the lower (<32 micromol/L) and middle (32 to 60 micromol/L) tertile of total vitamin C levels, compared with patients in the upper tertile (>60 micromol/L). Hazard ratios for cardiovascular death were 3.79 (95% CI: 1.23 to 11.66; P = 0.020) and 2.89 (95% CI: 0.89 to 9.37; P = 0.076). Total vitamin C levels were not independently associated with all-cause mortality. This study concludes that low total vitamin C plasma levels predict adverse cardiovascular outcomes among maintenance hemodialysis patients. Future studies should address the potential protective effect of an adequate vitamin C supplementation.

Topics: Aged; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Prospective Studies; Renal Dialysis; Risk Factors

Traditional risk factors do not appear to explain fully the variation in the incidence of the cardiovascular diseases (CVD). Epidemiological studies have not been entirely consistent with regard to the relationship between antioxidant vitamin intake and CVD and there appears to be little data on this relationship in non-Caucasian populations. This study aimed to investigate the dietary intake of vitamin A, C, and vitamin E, and carotenoids, serum concentrations of vitamin E and A and indices of lipid peroxidation were measured in male Saudi patients with established CVD and age-matched controls. We assessed the dietary intakes of vitamins A, C, and E and carotenoids, by a food frequency questionnaire. Serum vitamins A and E concentrations were measured by HPLC, in 130 Saudi male subjects with established CVD, and 130 age-matched controls. We also determined serum lipid profiles (total cholesterol, triglycerides, HDL-C, LDL-C), lipoprotein (a), oxidized LDL, and serum lipid peroxide concentrations. Diabetes mellitus (P<0.0001), a positive smoking habit (P<0.0001) and hypertension (P<0.05) were more prevalent among CVD patients. Levels of dietary vitamin E and A were also significantly higher among cases. In conditional logistic regression analysis, the most significant characteristics differentiating CVD patients from controls were diabetes mellitus (Odds ratio 2.49, CI 1.42-4.37, P<0.001), total fat intake (Odds ratio 1.02, CI 1.01-1.03, P<0.01), serum vitamin A (Odds ratio 0.72, CI 0.53-0.99, P<0.05), and the vitamin A/total fat intake ratio (Odds ratio 1.04, CI 1.01-1.06, P<0.01). In a Saudi population, smoking habit and hypertension were significantly more common among patients with CVD. Multivariate analysis showed that dietary total fat and vitamin A and the presence of diabetes mellitus were independent coronary risk factors. This is the first report of a potentially deleterious effect of dietary vitamin A in a non-Caucasian population. However it is possible that unidentified residual confounding factors may account for this finding.

Topics: Antioxidants; Ascorbic Acid; Body Mass Index; Cardiovascular Diseases; Carotenoids; Case-Control Studies; Cholesterol; Chromatography, High Pressure Liquid; Diabetes Mellitus; Dietary Fats; Humans; Hypertension; Lipid Peroxidation; Logistic Models; Male; Middle Aged; Multivariate Analysis; Prevalence; Risk Factors; Saudi Arabia; Smoking; Surveys and Questionnaires; Vitamin A; Vitamin E

Dietary patterns are useful in nutritional epidemiology, providing a comprehensive alternative to the traditional approach based on single nutrients. The Cardiovascular Risk in Young Finns Study is a prospective cohort study with a 21-year follow-up. At baseline, detailed quantitative information on subjects' food consumption was obtained using a 48 h dietary recall method (n 1768, aged 3-18 years). The interviews were repeated after 6 and 21 years (n 1200 and n 1037, respectively). We conducted a principal component analysis to identify major dietary patterns at each study point. A set of two similar patterns was recognised throughout the study. Pattern 1 was positively correlated with consumption of traditional Finnish foods, such as rye, potatoes, milk, butter, sausages and coffee, and negatively correlated with fruit, berries and dairy products other than milk. Pattern 1 type of diet was more common among male subjects, smokers and those living in rural areas. Pattern 2, predominant among female subjects, non-smokers and in urban areas, was characterised by more health-conscious food choices such as vegetables, legumes and nuts, tea, rye, cheese and other dairy products, and also by consumption of alcoholic beverages. Tracking of the pattern scores was observed, particularly among subjects who were adolescents at baseline. Of those originally belonging to the uppermost quintile of pattern 1 and 2 scores, 41 and 38 % respectively, persisted in the same quintile 21 years later. Our results suggest that food behaviour and concrete food choices are established already in childhood or adolescence and may significantly track into adulthood.

Topics: Adolescent; Ascorbic Acid; Cardiovascular Diseases; Child; Child, Preschool; Dietary Carbohydrates; Dietary Fats; Dietary Supplements; Eating; Fatty Acids; Feeding Behavior; Female; Finland; Humans; Male; Mental Recall; Principal Component Analysis; Prospective Studies; Risk Factors

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Endothelium, Vascular; Humans; Lipid Peroxidation; Oxidative Stress; Reactive Oxygen Species; Research Design; Ubiquinone; Vitamin E

Topics: Antioxidants; Arthritis, Rheumatoid; Ascorbic Acid; Cardiovascular Diseases; Chronic Disease; Comorbidity; Diabetes Mellitus; Free Radicals; Gastritis; Inflammation; Oxidation-Reduction; Oxidative Stress; Pancreatitis

Vitamin C is considered to be a very efficient water-soluble antioxidant, for which several new cardiovascular properties were recently described. The aim of this study was to determine in vivo the effects of a severe depletion of vitamin C on cardiac and vascular variables and reperfusion arrhythmias. For this purpose, we used a mutant strain of Wistar rats, osteogenic disorder Shionogi (ODS). After 15 d of consuming a vitamin C-deficient diet, ODS rats had a 90% decrease in plasma and tissue levels of ascorbate compared with ODS vitamin C-supplemented rats and normal Wistar rats. However, plasma antioxidant capacity, proteins, alpha-tocopherol, urate, catecholamines, lipids, and nitrate were not influenced by the vitamin C deficiency in ODS rats. Moreover, there was no difference between ODS vitamin C-deficient and -supplemented rats in heart rate and arterial pressure. After 5 min of an in vivo regional myocardial ischemia, various severe arrhythmias were observed, but their intensities were not modified by vitamin C in vitamin C-deficient ODS rats. The vascular reactivity, measured in vitro on thoracic arteries, was not altered by ascorbate deficiency in ODS rats. These unexpected results suggest that unidentified compensatory mechanisms play a role in maintaining normal cardiac function and vascular reactivity in vitamin C-deficient rats.

Topics: Acetylcholine; alpha-Tocopherol; Animals; Aorta; Arrhythmias, Cardiac; Ascorbic Acid; Ascorbic Acid Deficiency; Blood Pressure; Bone Diseases; Cardiovascular Diseases; Diet; Epinephrine; Heart Rate; Male; Muscle Contraction; Myocardial Ischemia; Myocardial Reperfusion; Norepinephrine; Osteogenesis; Phenylephrine; Rats; Rats, Mutant Strains; Rats, Wistar

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Humans; Reproducibility of Results

Topics: Anthropometry; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Causality; Confounding Factors, Epidemiologic; Health Behavior; Humans; Life Style; Observation; Randomized Controlled Trials as Topic; Research Design; Socioeconomic Factors

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Endarterectomy; Humans; Oxidative Stress; Treatment Outcome; Vitamin E

It is often assumed that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases. Besides epidemiological observations, scientific evidences for their mechanism of action are scarce. In the present study, we investigated the mean term and post-prandial effects of lettuce ingestion on lipid metabolism and antioxidant protection in the rat.. Feeding rats a 20% lettuce diet for 3 weeks resulted in a decrease cholesterol LDL/HDL ratio and a marked decrease of liver cholesterol levels (-41%). Concurrently, fecal total steroid excretion increased (+44%) and apparent absorption of dietary cholesterol was significantly depressed (-37%) by the lettuce diet. Lettuce diet also displayed an improvement of vitamin E/TG ratio in plasma and limited lipid peroxidation in heart as evidenced by TBARS. In post-prandial experiment, lettuce intake significantly increased both ascorbic acid and alpha-tocopherol plasma levels which contribute to improve plasma antioxidant capacity within 2 h of consumption. Other lipid-soluble antioxidants (lutein and vitamin E) may also improve the plasma antioxidant capacity.. Lettuce consumption increases the total cholesterol end-products excretion and improves antioxidant status due to the richness in antioxidants (vitamins C, E and carotenoids). In our model, lettuce clearly shows a beneficial effect on lipid metabolism and on tissue oxidation. Therefore regular consumption of lettuce should contribute to improve protection against cardiovascular diseases.

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet; Feces; Lactuca; Lipid Peroxidation; Liver; Male; Postprandial Period; Random Allocation; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Vitamin E

The aim of this study was to prospectively assess the relation between red meat intake and incidence of type 2 diabetes.. Over an average of 8.8 years, we evaluated 37,309 participants in the Women's Health Study aged >/=45 years who were free of cardiovascular disease, cancer, and type 2 diabetes and completed validated semiquantitative food frequency questionnaires in 1993.. During 326,876 person-years of follow-up, we documented 1,558 incident cases of type 2 diabetes. After adjusting for age, BMI, total energy intake, exercise, alcohol intake, cigarette smoking, and family history of diabetes, we found positive associations between intakes of red meat and processed meat and risk of type 2 diabetes. Comparing women in the highest quintile with those in the lowest quintile, the multivariate-adjusted relative risks (RRs) of type 2 diabetes were 1.28 for red meat (95% CI 1.07-1.53, P < 0.001 for trend) and 1.23 for processed meat intake (1.05-1.45, P = 0.001 for trend). Furthermore, the significantly increased diabetes risk appeared to be most pronounced for frequent consumption of total processed meat (RR 1.43, 95% CI 1.17-1.75 for >/=5/week vs. <1/month, P < 0.001 for trend) and two major subtypes, which were bacon (1.21, 1.06-1.39 for >/=2/week vs. <1/week, P = 0.004 for trend) and hot dogs (1.28, 1.09-1.50 for >/=2/week vs. <1/week, P = 0.003 for trend). These results remained significant after further adjustment for intakes of dietary fiber, magnesium, glycemic load, and total fat. Intakes of total cholesterol, animal protein, and heme iron were also significantly associated with a higher risk of type 2 diabetes.. Our data indicate that higher consumption of total red meat, especially various processed meats, may increase risk of developing type 2 diabetes in women.

Topics: Ascorbic Acid; Aspirin; Cardiovascular Diseases; Diabetes Mellitus, Type 2; Energy Intake; Feeding Behavior; Female; Humans; Life Style; Male; Meat; Middle Aged; Neoplasms; Prospective Studies; Risk Assessment

Oxidative stress resulting from enhanced free-radical formation and/or a defect in antioxidant defenses has been implicated in the pathogenesis of experimental diabetic neuropathy. The objective of this study was to evaluate plasma levels of various biomarkers of oxidative stress in diabetic subjects in relation to the presence or absence of polyneuropathy (PN) and/or cardiovascular autonomic neuropathy (CAN).. Plasma 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), superoxide anion (O(2)(.-)) generation, lag phase to peroxidation by peroxynitrite (ONOO(-)), vitamin E-to-lipid ratio, and vitamin C were measured in nonsmoking diabetic patients without PN and CAN (PN(-)/CAN(-) group; n = 62), in a group with PN but without CAN (PN(+)/CAN(-) group; n = 105), in those with both PN and CAN (PN(+)/CAN(+) group; n = 22), and in healthy control subjects (n = 85).. All three markers of oxidative stress were significantly increased, and both markers of antioxidant defense were decreased in the PN(+)/CAN(-) group compared with the control group (all P < 0.05). PN(-)/CAN(-) subjects showed a significant increase compared with control subjects for 8-iso-PGF(2alpha), O(2)(.-), and ONOO(-) and a decrease for the vitamin E-to-lipid ratio (all P < 0.05). In the PN(+)/CAN(-) group, a significant increase compared with the PN(-)/CAN(-) group was noted for O(2)(.-), whereas the vitamin E-to-lipid ratio and vitamin C were reduced (all P < 0.05). No significant differences were noted between the PN(+)/CAN(-) and PN(+)/CAN(+) groups for each of the five markers of oxidative stress. In multivariate models, O(2)(.-) and ONOO(-) were independently associated with neuropathic deficits, but diabetes duration and triglyceride levels were also independent determinants.. Oxidative stress is enhanced in diabetic patients before the development of PN but to an even higher degree in those with PN, without further significant increase in relation to superimposed autonomic neuropathy. However, apart from oxidative stress, diabetes duration and triglyceride levels are also related to the severity of PN.

Topics: Adult; Antioxidants; Ascorbic Acid; Autonomic Nervous System Diseases; Cardiovascular Diseases; Diabetic Neuropathies; Dinoprost; Female; Humans; Male; Middle Aged; Oxidative Stress; Reference Values

We compared plasma biomarkers of antioxidant status, oxidative stress, inflammation, and risk for coronary heart disease in long-term vegetarians and age- and sex-matched omnivores.. Thirty vegetarians (mean age +/- standard deviation: 44.2 +/- 9.0 y) were recruited. The subjects had been vegetarian for 5 to 55 y (21.8 +/- 12.2 y). The control group comprised 30 adults selected by age-stratified sampling from a community health project (mean age: 44.0 +/- 9.2 y). Fasting plasma total antioxidant status (ferric-reducing antioxidant power), ascorbic acid (AA), alpha-tocopherol (total and lipid standardized), malondialdehyde, total cholesterol, triacylglycerol, uric acid (UA), and high-sensitivity C-reactive protein (hsCRP) were measured.. Plasma AA was significantly higher in the vegetarians than in the omnivores (90.5 +/- 21.0 and 61.8 +/- 17.0 microM; P < 0.001). The vegetarians had lower concentrations of triacylglycerol, UA, and hsCRP. Plasma total and lipid-standardized alpha-tocopherol concentrations were also lower in the vegetarians: 22.0 +/- 5.9 and 27.0 +/- 7.9 microM versus 3.76 +/- 0.57 and 4.23 +/- 0.58 microM per millimoles per liter of total cholesterol plus triacylglycerol, respectively. There was a significant inverse correlation between AA and UA (r = -0.343, P < 0.01; n = 60) and between AA and hsCRP (r = -0.306, P < 0.05; n = 55). Plasma ferric-reducing antioxidant power and malondialdehyde did not differ significantly between groups; however, the contribution of AA to the total antioxidant capacity of plasma was approximately 50% greater in the vegetarians.. A long-term vegetarian diet is associated with markedly higher fasting plasma AA concentrations and lower concentrations of TAG, UA, and hsCRP. Long-term vegetarians have a better antioxidant status and coronary heart disease risk profile than do apparently healthy omnivores. Plasma AA may act a useful marker of overall health status.

Topics: Adult; Antioxidants; Ascorbic Acid; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Case-Control Studies; Coronary Disease; Diet, Vegetarian; Female; Health Status; Humans; Male; Oxidative Stress; Risk Factors; Triglycerides; Uric Acid

Vitamin C acts as a potent antioxidant; however, it can also be a prooxidant and glycate protein under certain circumstances in vitro. These observations led us to hypothesize that a high intake of vitamin C in diabetic persons might promote atherosclerosis.. The objective was to examine the relation between vitamin C intake and mortality from cardiovascular disease.. We studied the relation between vitamin C intake and mortality from total cardiovascular disease (n = 281), coronary artery disease (n = 175), and stroke (n = 57) in 1923 postmenopausal women who reported being diabetic at baseline. Diet was assessed with a food-frequency questionnaire at baseline, and subjects initially free of coronary artery disease were prospectively followed for 15 y.. After adjustment for cardiovascular disease risk factors, type of diabetes medication used, duration of diabetes, and intakes of folate, vitamin E, and beta-carotene, the adjusted relative risks of total cardiovascular disease mortality were 1.0, 0.97, 1.11, 1.47, and 1.84 (P for trend < 0.01) across quintiles of total vitamin C intake from food and supplements. Adjusted relative risks of coronary artery disease were 1.0, 0.81, 0.99, 1.26, and 1.91 (P for trend = 0.01) and of stroke were 1.0, 0.52, 1.23, 2.22, and 2.57 (P for trend < 0.01). When dietary and supplemental vitamin C were analyzed separately, only supplemental vitamin C showed a positive association with mortality endpoints. Vitamin C intake was unrelated to mortality from cardiovascular disease in the nondiabetic subjects at baseline.. A high vitamin C intake from supplements is associated with an increased risk of cardiovascular disease mortality in postmenopausal women with diabetes.

Topics: Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus; Diet Surveys; Female; Humans; Iowa; Middle Aged; Postmenopause; Prospective Studies; Registries; Surveys and Questionnaires

Higher intake of fruits, vegetables, and antioxidants may help protect against oxidative damage, thus lowering cancer and cardiovascular disease risk. This Washington County, Maryland, prospective study examined the association of fruit, vegetable, and antioxidant intake with all-cause, cancer, and cardiovascular disease death. CLUE participants who donated a blood sample in 1974 and 1989 and completed a food frequency questionnaire in 1989 (N = 6,151) were included in the analysis. Participants were followed to date of death or January 1, 2002. Compared with those in the bottom fifth, participants in the highest fifth of fruit and vegetable intake had a lower risk of all-cause (cases = 910; hazard ratio (HR) = 0.63, 95% confidence interval (CI): 0.51, 0.78; p-trend = 0.0004), cancer (cases = 307; HR = 0.65, 95% CI: 0.45, 0.93; p-trend = 0.08), and cardiovascular disease (cases = 225; HR = 0.76, 95% CI: 0.54, 1.06; p-trend = 0.15) mortality. Higher intake of cruciferous vegetables was associated with lower risk of all-cause mortality (HR = 0.74, 95% CI: 0.60, 0.91; p-trend = 0.04). No statistically significant associations were observed between dietary vitamin C, vitamin E, and beta-carotene intake and mortality. Overall, greater intake of fruits and vegetables was associated with lower risk of all-cause, cancer, and cardiovascular disease death. These findings support the general health recommendation to consume multiple servings of fruits and vegetables (5-9/day).

Topics: Adult; Aged; Aged, 80 and over; alpha-Tocopherol; Antioxidants; Ascorbic Acid; beta Carotene; Body Mass Index; Cardiovascular Diseases; Cause of Death; Cohort Studies; Diet; Female; Fruit; Humans; Male; Maryland; Middle Aged; Neoplasms; Smoking; Vegetables

Topics: alpha-Tocopherol; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Carotid Artery Diseases; Clinical Trials as Topic; Drug Therapy, Combination; Endpoint Determination; Female; Humans; Male; Oxidative Stress; Vitamin E

Homocysteine, an atherogenic amino acid, promotes iron-dependent oxidation of low-density lipoprotein (LDL). We investigated whether vitamin C, a physiological antioxidant, could protect LDL from homocysteine-mediated oxidation. LDL (0.2 mg of protein/ml) was incubated at 37 degrees C with homocysteine (1000 microM) and ferric iron (10-100 microM) in either the absence (control) or presence of vitamin C (5-250 microM). Under these conditions, vitamin C protected LDL from oxidation as evidenced by an increased lag time preceding lipid diene formation (> or = 5 vs. 2.5 h for control), decreased thiobarbituric acid-reactive substances accumulation (< or = 19 +/- 1 nmol/mg when vitamin C > or = 10 microM vs. 32 +/- 3 nmol/mg for control, p <.01), and decreased lipoprotein anodic electrophoretic mobility. Near-maximal protection was observed at vitamin C concentrations similar to those in human blood (50-100 microM); also, some protection was observed even at low concentrations (5-10 microM). This effect resulted neither from altered iron redox chemistry nor enhanced recycling of vitamin E in LDL. Instead, similar to previous reports for copper-dependent LDL oxidation, we found that vitamin C protected LDL from homocysteine-mediated oxidation through covalent lipoprotein modification involving dehydroascorbic acid. Protection of LDL from homocysteine-mediated oxidation by vitamin C may have implications for the prevention of cardiovascular disease.

Topics: Ascorbic Acid; Cardiovascular Diseases; Copper; Dehydroascorbic Acid; Dose-Response Relationship, Drug; Free Radicals; Homocysteine; Humans; Iron; Lipoproteins; Lipoproteins, LDL; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxygen; Temperature; Thiobarbituric Acid Reactive Substances; Time Factors; Vitamin E

An improved antioxidant status (overthreshold plasma values of essential antioxidants) minimizes the oxidative damage. The levels of antioxidant vitamins C and E, ,,antioxidant" trace elements selenium, zinc, copper and iron were measured in two groups of adults with different nutritional habits--alternative (vegetarians; n=110) and traditional (mixed diet, control, n=101). The prevalence of iron and zinc deficiencies was found in the alternative group (20% vs 11%--iron, 13% vs 9%--zinc) as a consequence of higher intake of plant trace element absorption inhibitors. As opposed to the latter, the control group had higher findings of iron and copper levels over the optimal range (18% vs 8%--iron, 11% vs 2%--copper). The subjects on mixed diet was showed a significant negative linear correlation between serum zinc and iron levels. This favourable relationship means a decrease in Fenton reaction by indirect zinc effect. Average plasma values of vitamin C, vitamin C/vitamin E, vitamin E/ cholesterol (LDL protection), vitamin E/triacylglycerols (polyunsaturated fatty acid protection) in vegetarians are over the threshold with high number of individual overthreshold values (94% vs 17%--vitamin C, 100% vs 58%--vitamin C/vitamin E, 89% vs 68%--vitamin E/cholesterol, 100% vs 64%--vitamin E/triacylglycerols). Homocysteine levels in vegetarians (36% atherogenic levels) correlate significantly inversely to vitamin C levels, the fact of which means a positive vitamin C effect in free radical remove also in hyperhomocysteinemia. Plant food is a rich source of antioxidants. A correct vegetarian nutrition or optimized mixed diets with regular and frequent consumption of protective food commodities may be an effective contribution to the age-related chronic degenerative disease prevention. (Tab. 2, Fig. 2, Ref. 31.).

Topics: Adult; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diet; Diet, Vegetarian; Female; Free Radicals; Homocysteine; Humans; Male; Middle Aged; Random Allocation; Trace Elements; Vitamin E

The purpose of this study was to evaluate the relationship between body mass index (BMI), including low BMIs, and endothelial function.. Epidemiologic study has demonstrated that not only obesity but also a low BMI may be a risk factor for cardiovascular disease.. The forearm blood flow (FBF) response to acetylcholine (ACh) and isosorbide dinitrate (ISDN) was measured in 87 healthy young men (15 low BMI, 51 normal, 14 obese, and 7 extremely obese).. Plasma concentrations of 8-hydroxy-2'-deoxyguanosine and serum concentrations of malondialdehyde-modified low-density lipoprotein were higher in low BMI, obese, and extremely obese subjects than in normal subjects and were similar among the low BMI, obese, and extremely obese groups. The FBF response to ACh was greater in the normal group than in the other groups (p < 0.001), and was lower in the extremely obese group as compared with the other groups (p < 0.001). The ACh-stimulated vasodilation was similar between the low BMI group and the obese group. The ISDN-stimulated vasodilation was similar in all four groups. There were no significant differences in ACh-stimulated vasodilation between the four groups after the nitric oxide (NO) synthase inhibitor NG-monomethyl-L-arginine infusion. Co-infusion of vitamin C augmented the FBF response to ACh in low BMI, obese, and extremely obese groups--but not in normal BMI group.. These findings suggest that not only obesity but also a low BMI may be a risk factor for impaired endothelium-dependent vasodilation through the increased oxidative stress, leading to the reduced bioavailability of NO.

Topics: Acetylcholine; Adult; Analysis of Variance; Antioxidants; Ascorbic Acid; Blood Flow Velocity; Body Mass Index; Cardiovascular Diseases; Case-Control Studies; Endothelium, Vascular; Forearm; Humans; Isosorbide Dinitrate; Male; Nitric Oxide; Obesity; Oxidative Stress; Plethysmography; Risk Factors; Thinness; Vasodilation; Vasodilator Agents

Tooth loss has been associated with cardiovascular disease (CVD), but the mechanisms are unclear. We evaluated the association of total tooth loss with prevalent CVD in men and women; as well as with citrus fruit consumption, plasma vitamin C, and inflammatory and thrombotic variables.. We used an age-and sex-stratified population survey, of men and women aged 25-74 years, in North Glasgow.. Thirty-eight percent of women and 29% of men were edentulous. Total tooth loss was associated with prevalent CVD in both sexes. After adjustment for major potential confounders (age, sex, smoking, and social class), the odds ratio (95% CI) for prevalent CVD was 1.55 (1.13, 2.13) in the edentulous. Total tooth loss was also associated with low citrus fruit consumption and low plasma vitamin C levels, increased plasma C-reactive protein in men, and with increased plasma interleukin-6, fibrinogen, and factor VIII levels in women.. Prevalent CVD is associated with total tooth loss. Possible mechanisms include low intake of citrus fruit, and hence, low plasma vitamin C levels, and a predisposition to low-grade inflammation and thrombosis. It may be prudent to ensure adequate vitamin C intake in people with no teeth.

Topics: Adult; Age Distribution; Aged; Ascorbic Acid; Cardiovascular Diseases; Citrus; Diet; Female; Health Surveys; Humans; Male; Middle Aged; Mouth, Edentulous; Prevalence; Risk Factors; Scotland; Sex Distribution; Tooth Loss

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Coenzymes; Dietary Supplements; Humans; Ubiquinone; Vitamin E

Tobacco and alcohol consumption are strongly related to other cardiovascular and cancer risk factors. The aim of the present study was to analyse the association of nutrient intake, blood lipid variables and leisure-time physical activity with tobacco and alcohol consumption status. Participants were recruited in a cross-sectional population-based survey, including cardiovascular risk factor measurements and evaluation of physical activity and diet intake in a Mediterranean population (n 1748). Multiple linear regression analysis, adjusted for several confounders, showed a direct association of saturated fatty acids (g and % total energy intake), dietary cholesterol intakes and serum triacylglycerol with smoking. An inverse association was observed for smoking and unsaturated fatty acids (% energy intake), vitamin C, alpha-tocopherol and beta-carotene intakes, leisure-time physical activity and HDL-cholesterol. These associations were not observed for alcohol drinking. After adjusting for the confounders earlier mentioned, low dietary intakes of vitamin C and dietary fibre were more likely in heavy-smokers as compared with non-smokers (odds ratio 1.74 (95 % CI 1.07, 2.73) and 1.94 (95 % CI 1.29, 2.92) of low vitamin C (<60 mg/d) and dietary fibre intakes (<10 g/d) respectively). Alcohol consumption was directly associated with HDL-cholesterol and triacylglycerol, and attenuated the effects of smoking on HDL-cholesterol. These results suggest that the dietary intake of fibre and several antioxidant components of the Mediterranean diet is reduced in smokers, who also show an adverse lipid profile. However, the worst triacylglycerol levels are associated with the combination of heavy smoking and heavy alcohol drinking. Moderate alcohol consumption was not associated with an unhealthy diet pattern or adverse lipid profile. The health benefits of the Mediterranean diet appear to be strongly counteracted by smoking.

Topics: Adult; Aged; Alcohol Drinking; Ascorbic Acid; Cardiovascular Diseases; Cross-Sectional Studies; Dietary Fiber; Energy Intake; Exercise; Feeding Behavior; Female; Humans; Linear Models; Lipids; Male; Middle Aged; Neoplasms; Nutritional Status; Risk Factors; Smoking; Spain

Although basic research suggests that vitamins may have an important role in the prevention of cardiovascular diseases (CVD), the data from cohort studies and clinical trials are inconclusive.. This prospective cohort study was conducted among 83 639 male physicians residing in the United States who had no history of CVD or cancer. At baseline, data on use of vitamin E, ascorbic acid (vitamin C), and multivitamin supplements were provided by a self-administered questionnaire. Mortality from CVD and coronary heart disease (CHD) was assessed by death certificate review.. Use of supplements was reported by 29% of the participants. During a mean follow-up of 5.5 years, 1037 CVD deaths occurred, including 608 CHD deaths. After adjustment for several cardiovascular risk factors, supplement use was not significantly associated with total CVD or CHD mortality. For vitamin E use, the relative risks (RRs) were 0.92 (95% confidence interval [CI], 0.70-1.21) for total CVD mortality and 0.88 (95% CI, 0.61-1.27) for CHD mortality; for use of vitamin C, the RRs were 0.88 (95% CI, 0.70-1.12) for total CVD mortality and 0.86 (95% CI, 0.63-1.18) for CHD mortality; and for use of multivitamin supplements, the RRs were 1.07 (95% CI, 0.91-1.25) for total CVD mortality and 1.02 (95% CI, 0.83-1.25) for CHD mortality.. In this large cohort of apparently healthy US male physicians, self-selected supplementation with vitamin E, vitamin C, or multivitamins was not associated with a significant decrease in total CVD or CHD mortality. Data from ongoing large randomized trials will be necessary to definitely establish small potential benefits of vitamin supplements on subsequent cardiovascular risk.

Topics: Adult; Aged; Ascorbic Acid; Cardiovascular Diseases; Cohort Studies; Confidence Intervals; Dietary Supplements; Humans; Male; Middle Aged; Physicians; Prospective Studies; Risk; Surveys and Questionnaires; Treatment Outcome; United States; Vitamin E; Vitamins

The high cardiovascular mortality in patients receiving hemodialysis (HD) has been attributed, in part, to oxidative stress. Here we examined the effectiveness of antioxidants introduced by means of a novel hemolipodialysis (HLD) procedure in terms of reducing oxidative stress during ex vivo blood circulation. Oxidative stress was studied in a model HD system resembling the extracorporeal circulation of blood during clinical HD. Blood circulation produced an increase of up to 280% in free hemoglobin levels and an increase of 320% in electronegative LDL (LDL(-)) subfraction. A significant correlation between LDL(-) and free hemoglobin levels confirmed previous findings that LDL(-) formation during ex vivo circulation of blood can be mediated by the oxidative activity of free hemoglobin. These effects were significantly attenuated during HLD using a dialysis circuit containing vitamin E with or without vitamin C. By contrast, HLD with vitamin C alone had a marked pro-oxidant effect. TBARS, lipid hydroperoxides, vitamin E and beta-carotene content in LDL were not significantly altered by the HD procedure. These findings demonstrate the occurrence of oxidative stress in human plasma where lipoproteins are a target and indicate antioxidant-HLD treatment as a specific new approach to decreasing the adverse oxidative stress frequently associated with cardiovascular complications in high-risk populations of uremic patients.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Drug Therapy, Combination; Humans; Lipid Peroxidation; Lipoproteins, LDL; Oxidative Stress; Renal Dialysis; Thiobarbituric Acid Reactive Substances; Vitamin E

Ascorbic acid (vitamin C) might be protective for several chronic diseases. However, findings from prospective studies that relate ascorbic acid to cardiovascular disease or cancer are not consistent. We aimed to assess the relation between plasma ascorbic acid and subsequent mortality due to all causes, cardiovascular disease, ischaemic heart disease, and cancer.. We prospectively examined for 4 years the relation between plasma ascorbic acid concentrations and mortality due to all causes, and to cardiovascular disease, ischaemic heart disease, and cancer in 19 496 men and women aged 45-79 years. We recruited individuals by post using age-sex registers of general practices. Participants completed a health and lifestyle questionnaire and were examined at a clinic visit. They were followed-up for causes of death for about 4 years. Individuals were divided into sex-specific quintiles of plasma ascorbic acid. We used the Cox proportional hazard model to determine the effect of ascorbic acid and other risk factors on mortality.. Plasma ascorbic acid concentration was inversely related to mortality from all-causes, and from cardiovascular disease, and ischaemic heart disease in men and women. Risk of mortality in the top ascorbic acid quintile was about half the risk in the lowest quintile (p<0.0001). The relation with mortality was continuous through the whole distribution of ascorbic acid concentrations. 20 micromol/L rise in plasma ascorbic acid concentration, equivalent to about 50 g per day increase in fruit and vegetable intake, was associated with about a 20% reduction in risk of all-cause mortality (p<0.0001), independent of age, systolic blood pressure, blood cholesterol, cigarette smoking habit, diabetes, and supplement use. Ascorbic acid was inversely related to cancer mortality in men but not women.. Small increases in fruit and vegetable intake of about one serving daily has encouraging prospects for possible prevention of disease.

Topics: Age Distribution; Aged; Ascorbic Acid; Cardiovascular Diseases; Cause of Death; Female; Humans; Male; Middle Aged; Myocardial Ischemia; Neoplasms; Proportional Hazards Models; Prospective Studies; Registries; Risk Factors; Sex Distribution; Surveys and Questionnaires

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Lipid Peroxidation; Vitamin E

Topics: Ascorbic Acid; Cardiovascular Diseases; Female; Fruit; Humans; Male; Mortality; Vegetables

To examine the relation between serum ascorbic acid (SAA), a marker of dietary intake (including supplements), and cause-specific mortality.. We analyzed data from a probability sample of 8,453 Americans age > or = 30 years at baseline enrolled in the Second National Health and Nutrition Examination Survey (NHANES II), who were followed for mortality endpoints. We calculated relative hazard ratios as measures of disease association comparing the mortality rates in three biologically relevant SAA categories.. Participants with normal to high SAA levels had a marginally significant 21% to 25% decreased risk of fatal cardiovascular disease (CVD) (p for trend = 0.09) and a 25% to 29% decreased risk of all-cause mortality (p for trend <0.001) compared to participants with low levels. Because we determined that gender modified the association between SAA levels and cancer death, we analyzed these associations stratified by gender. Among men, normal to high SAA levels were associated with an approximately 30% decreased risk of cancer deaths, whereas such SAA levels were associated with an approximately two-fold increased risk of cancer deaths among women. This association among women persisted even after adjustment for baseline prevalent cancer and exclusion for early cancer death or exclusion for prevalent cancer.. Low SAA levels were marginally associated with an increased risk of fatal CVD and significantly associated with an increased risk for all-cause mortality. Low SAA levels were also a risk factor for cancer death in men, but unexpectedly were associated with a decreased risk of cancer death in women. If the association between low SAA levels and all-cause mortality is causal, increasing the consumption of ascorbic acid, and thereby SAA levels, could decrease the risk of death among Americans with low ascorbic acid intakes.

Topics: Adult; Aged; Ascorbic Acid; Cardiovascular Diseases; Cause of Death; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Neoplasms; Nutrition Surveys; Risk Factors; Sex Factors; United States

Topics: Ascorbic Acid; Biomarkers; C-Reactive Protein; Cardiovascular Diseases; Fibrinogen; Humans; Neoplasms; Risk Factors

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Neoplasms; Risk Factors

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Neoplasms; Risk Factors

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Neoplasms; Risk Factors

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Neoplasms; Risk Factors

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Drug Synergism; Humans; Vitamin E

Topics: Acetylcholine; Angiotensin-Converting Enzyme Inhibitors; Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Clinical Trials as Topic; Disease Progression; Endothelium, Vascular; Forearm; Humans; Nitric Oxide; Oxidative Stress; Predictive Value of Tests; Regional Blood Flow; Treatment Outcome; Vasodilation; Vitamin E

Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Cause of Death; Female; France; Humans; Male; Nutrition Surveys; Risk Factors

Various epidemiological studies suggested that individuals with high intake of antioxidant vitamins (E, A and C) have a better cardiovascular prognosis than subjects with relative deficiencies in such vitamins. However, placebo-controlled randomized clinical trials did not demonstrate that a specific supplementation in either alpha-tocopherol (vitamin E) or beta-carotene (vitamin A) allows to reduce the incidence of major cardiovascular events, in the general population or even in various subgroups at high risk, and there is no such controlled trials with vitamin C alone. Some studies suggested that combined supplements of several antioxidant vitamins might be more efficacious, and these observations led to initiate several large controlled studies. Thus, until now, there is no convincing arguments in the literature in favour of artificial supplements of antioxidant vitamins. It seems preferable to encourage a well-balanced healthy diet while awaiting the results of the large prospective ongoing trials with combined supplementation.

Topics: Ascorbic Acid; Cardiovascular Diseases; Evidence-Based Medicine; Humans; Preventive Medicine; Randomized Controlled Trials as Topic; Treatment Outcome; Vitamin A; Vitamin E

The hypothesis of the atherogenic role of oxidized. LDL lipoproteins and the observation of the longevity of individuals on a "mediterranean diet" led to the concept that antioxidant vitamins may exert cardiovascular protective effects. In this first article, we summarize the results of the main epidemiological studies which analyzed the influence of dietary intakes (or resulting plasma concentrations) in vitamin E (alpha-tocopherol), vitamin A (beta-carotene) or vitamin C (ascorbic acid). The three types of studies available in the literature provided quite heterogeneous results, in favour of a protective role of antioxidant vitamins as far as cross-cultural and most prospective observational studies were concerned, but rather negative when considering case-control studies. However, in general, epidemiological studies tended to support, a beneficial role of these antioxidant vitamins to prevent cardiovascular diseases, at least in some subgroups of individuals.

Topics: Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Cultural Characteristics; Epidemiologic Studies; Humans; Vitamin A; Vitamin E

Low vitamin C status may increase the risk of mortality from cancer and cardiovascular disease.. The objective was to test whether an association existed between serum ascorbate concentrations and mortality and whether the association was modified by cigarette smoking status or sex.. Serum ascorbate concentrations were measured in adults as part of the second National Health and Nutrition Examination Survey (1976-1980). Vital status was ascertained 12-16 y later.. The relative risk (RR) of death, adjusted for potential confounders, was estimated by using Cox proportional hazards models. Men in the lowest (<28.4 micromol/L) compared with the highest (>/=73.8 micromol/L) serum ascorbate quartile had a 57% higher risk of dying from any cause (RR: 1.57; 95% CI: 1.21, 2.03) and a 62% higher risk of dying from cancer (RR: 1.62; 95% CI: 1.01, 2.59). In contrast, there was no increased risk among men in the middle 2 quartiles for these outcomes and no increased risk of cardiovascular disease mortality in any quartile. There was no association between serum ascorbate quartile and mortality among women. These findings were consistent when analyses were limited to nonsmokers or further to adults who never smoked, suggesting that the observed relations were not due to cigarette smoking.. These data suggest that men with low serum ascorbate concentrations may have an increased risk of mortality, probably because of an increased risk of dying from cancer. In contrast, serum ascorbate concentrations were not related to mortality among women.

Topics: Adult; Aged; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Female; Humans; Male; Middle Aged; Neoplasms; Nutrition Surveys; Proportional Hazards Models; Prospective Studies; Risk Factors; Sex Factors; Smoking; United States

Free radicals have been implicated in over a hundred disease conditions in humans, including arthritis, hemorrhagic shock, atherosclerosis, advancing age, ischemia and reperfusion injury of many organs, Alzheimer and Parkinson's disease, gastrointestinal dysfunctions, tumor promotion and carcinogenesis, and AIDS. Antioxidants are potent scavengers of free radicals and serve as inhibitors of neoplastic processes. A large number of synthetic and natural antioxidants have been demonstrated to induce beneficial effects on human health and disease prevention. However, the structure-activity relationship, bioavailability and therapeutic efficacy of the antioxidants differ extensively. Oligomeric proanthocyanidins, naturally occurring antioxidants widely available in fruits, vegetables, nuts, seeds, flowers and bark, have been reported to possess a broad spectrum of biological, pharmacological and therapeutic activities against free radicals and oxidative stress. We have assessed the concentration- or dose-dependent free radical scavenging ability of a novel IH636 grape seed proanthocyanidin extract (GSPE) both in vitro and in vivo models, and compared the free radical scavenging ability of GSPE with vitamins C, E and beta-carotene. These experiments demonstrated that GSPE is highly bioavailable and provides significantly greater protection against free radicals and free radical-induced lipid peroxidation and DNA damage than vitamins C, E and beta-carotene. GSPE was also shown to demonstrate cytotoxicity towards human breast, lung and gastric adenocarcinoma cells, while enhancing the growth and viability of normal human gastric mucosal cells. The comparative protective effects of GSPE, vitamins C and E were examined on tobacco-induced oxidative stress and apoptotic cell death in human oral keratinocytes. Oxidative tissue damage was determined by lipid peroxidation and DNA fragmentation, while apoptotic cell death was assessed by flow cytometry. GSPE provided significantly better protection as compared to vitamins C and E, singly and in combination. GSPE also demonstrated excellent protection against acetaminophen overdose-induced liver and kidney damage by regulating bcl-X(L) gene, DNA damage and presumably by reducing oxidative stress. GSPE demonstrated excellent protection against myocardial ischemia-reperfusion injury and myocardial infarction in rats. GSPE was also shown to upregulate bcl(2) gene and downregulate the oncogene c-myc. Topical application of GS

Topics: Animals; Anthocyanins; Antioxidants; Apoptosis; Ascorbic Acid; beta Carotene; Biological Availability; Cardiovascular Diseases; Dose-Response Relationship, Drug; Flow Cytometry; Free Radical Scavengers; Free Radicals; Humans; Keratinocytes; Kidney Diseases; Liver Diseases; Neoplasms; Plant Extracts; Proanthocyanidins; Seeds; Vitamin E

The high incidence of cardiovascular diseases in chronic renal failure (CRF) and hemodialyzed (HD) patients is now well established and the involvement of oxidative stress has been hypothesized in these phenomena. The aim of our study was to evaluate the level of oxidative stress in healthy controls (CTL) compared with CRF and HD patients before (pre-HD) and after (post-HD) the dialysis session, carried out on a high biocompatible polyacrylonitrile membrane AN69.. Several indicators of the extracellular redox status were evaluated in plasma. The ascorbyl free radical (AFR) was directly measured using electron spin resonance spectroscopy (ESR) and expressed with respect to the vitamin C level to obtain a direct index of oxidative stress. Indirect plasma parameters such as vitamin E, thiol and uric acid levels were also quantified. The plasma antioxidant status (PAS) was evaluated by the allophycocyanin test. Nitric oxide (NO) stable-end metabolites: nitrites and nitrates (NO(x)), were measured in plasma.. In CRF patients, vitamin C and thiol levels were low, and the AFR/vitamin C ratio high compared with the CTL. On the other hand, PAS and uric acid levels were shown to be higher in CRF patients. After the dialysis session, vitamin C level decreased and AFR/vitamin C ratio increased. The thiol levels were shown to be increased, in return PAS and uric acid levels were significantly lower after the dialysis session. NO(x) levels rose during CRF, but were significantly decreased after the dialysis procedure. No differences in vitamin E status were observed between CTL, CRF and HD patients.. Our study demonstrates that profound disturbances in the extracellular redox system occur during the course of chronic renal failure and hemodialysis, and may provide an explanation for the cardiovascular complications in these patients.

Topics: Aged; Analysis of Variance; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Case-Control Studies; Cholesterol; Electron Spin Resonance Spectroscopy; Female; Free Radicals; Humans; Kidney Failure, Chronic; Male; Middle Aged; Nitrates; Nitric Oxide; Nitrites; Oxidative Stress; Renal Dialysis; Risk Factors; Sulfhydryl Compounds; Uric Acid; Vitamin E

Topics: Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Dietary Supplements; Female; Humans; Male; Sensitivity and Specificity; Vitamin B Complex; Vitamin E; Vitamins

Oxidative stress, which occurs when there is excessive free-radical production or low antioxidant levels, makes significant contributions to pathogenesis in many human diseases. Cardiovascular disease is the major cause of mortality in patients receiving hemodialysis. For these patients, oxidative stress and increased lipid peroxidation may contribute to increased risk of atherosclerosis. The aim of this study was to determine if hemodialysis patients were associated with disturbance of homeostasis of antioxidant status. In this experiment, total antioxidant status of serum is measured by its ability to inhibit generation of free radicals from 2,2'-amino-di-[3-ethylbenzthiazole sulphonate] by metmyoglobin and hydrogen peroxide. Status of radical scavengers, such as serum total protein, albumin, uric acid and total bilirubin, was also measured. Blood were collected from three different episodes of hemodialysis. In the first group (n = 29), blood were collected before and after hemodialysis. In the second group (n = 29), blood were collected after dialysis and before next hemodialysis. In the third group (n = 8), blood were collected before hemodialysis. After last hemodialysis, patients started ingesting vitamin C and blood were collected before next hemodialysis. There was a marked reduction of total antioxidant status after hemodialysis in the first group. There was a marked increase in total antioxidant status before next hemodialysis in the second group. High doses of vitamin C caused increase in total antioxidant status in the third group. In conclusion, disturbance of homeostasis of total antioxidant status were observed in patients receiving hemodialysis. This may play a role in the pathogenesis in these groups.

Topics: Adult; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Female; Free Radical Scavengers; Homeostasis; Humans; Male; Middle Aged; Oxidative Stress; Renal Dialysis; Risk

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Humans; Meta-Analysis as Topic; Randomized Controlled Trials as Topic

To examine the relation between serum ascorbic acid concentration, which reflects dietary and supplement intake, and the prevalence of cardiovascular disease.. We analyzed data from 7658 men and women enrolled in the Third National Health and Nutrition Examination Survey (NHANES III). We calculated odds ratios and 95% confidence intervals (CI) to estimate the relative prevalence of cardiovascular disease, defined as self-reported angina, myocardial infarction, or stroke. Because we detected an interaction between serum ascorbic acid concentration and alcohol intake, we performed analyses stratified by drinking status.. Among participants who reported no alcohol consumption, serum ascorbic acid concentrations were not independently associated with cardiovascular disease prevalence. Among participants who consumed alcohol, serum ascorbic acid concentrations consistent with tissue saturation (1.0-3.0 mg/dl) were associated with a decreased prevalence of angina (multivariate odds ratio (OR): 0.48; 95% CI: 0.23% to 1.03; p for trend = 0.06), but were not significantly associated with myocardial infarction or stroke prevalence.. These results suggest the possibility of a biologic interaction between ascorbic acid and alcohol and that higher intakes of ascorbic acid may be associated with a decreased risk of angina among drinkers.

Topics: Adult; Aged; Aged, 80 and over; Alcohol Drinking; Angina Pectoris; Ascorbic Acid; Cardiovascular Diseases; Female; Health Surveys; Humans; Male; Middle Aged; Prevalence; United States

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Clinical Trials as Topic; Humans; Vitamin E

To examine the relation between serum ascorbic acid level and the prevalence of cardiovascular disease, we analyzed data from 6,624 U.S. men and women enrolled in the Second National Health and Nutrition Examination Survey. We calculated odds ratios and 95% confidence intervals to estimate the relative prevalence of cardiovascular disease, defined as self-reported coronary heart disease or stroke, or a diagnosis of peripheral vascular disease based on physical examination. Serum ascorbic acid levels were independently associated with prevalence of coronary heart disease and stroke; a 0.5-mg per dl increase in serum ascorbic acid level was associated with an 11% reduction in coronary heart disease and stroke prevalence. We also analyzed the relation of ascorbic acid, grouped into low to marginal, normal, and saturation serum categories, to cardiovascular disease. Compared with participants with low to marginally low serum ascorbic acid levels, we found a 27% decreased prevalence of coronary heart disease (95% confidence interval = 10-41%) and a 26% decreased prevalence of stroke (95% confidence interval = 3-44%) among participants in the highest serum ascorbic acid category. Serum ascorbic acid levels were not consistently associated with prevalence of peripheral vascular disease. These results are consistent with the hypothesis that increased ascorbic acid intake may decrease the risk of coronary heart disease and stroke.

Topics: Adult; Aged; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Female; Health Surveys; Humans; Male; Middle Aged; Prevalence; United States

This study was undertaken to determine if African-American strict vegetarians (vegans) exhibit lower blood pressure (BP) and a more favorable serum lipid profile than their lacto-ovo vegetarian (LOV) counterparts, and if plasma ascorbic acid (AA) concentrations could explain any group differences in these cardiovascular disease (CVD) risk factors.. Habitual dietary intake, anthropometric characteristics, blood pressure, and blood lipids and ascorbic acid concentrations were determined in African-American study participants (male vegans, n = 14, age = 45.6 years; male LOV, n = 49, age = 49.8; female vegans, n = 31, age = 51.1, female LOV, n = 94, age = 52.1) recruited from Seventh-Day Adventist Churches in several cities in the northeastern United States.. Body mass index (BMI) was significantly lower in the vegans (24.7 +/- 1.9 kg/m2) compared to LOV (26.4 +/- 0.45 kg/m2). There were no diet or gender differences in BP. Serum total cholesterol (3.75 +/- 0.12 vs. 4.51 +/- 0.10 mmol/L), LDL-cholesterol (2.06 +/- 0.13 vs. 2.65 +/- 0.09 mmol/l), and triglycerides (0.94 +/- 0.07 vs. 1.17 +/- 0.04 mmol/L) were significantly (p < 0.05) lower in vegans compared to LOV, but there were no dietary group differences in HDL-C. The ratio of total to HDL-cholesterol was significantly lower in vegans than in LOV (3.0 +/- 0.13 vs. 3.7 +/- 0.13). There were no dietary group differences in plasma AA concentrations. However, in the entire sample, plasma AA was inversely associated with BP (SBP: r = -0.46, p < 0.001, DBP: r = -0.32, p < 0.001), but unrelated to the serum lipid concentrations.. African-American vegans exhibit a more favorable serum lipid profile than lacto-ovo-vegatarians and plasma AA is inversely related to BP in African-American vegetarians but does not explain any of the differences in CVD risk factors between vegans and lacto-ovo vegetarians.

Topics: Anthropometry; Ascorbic Acid; Black People; Blood Pressure; Body Constitution; Body Mass Index; Cardiovascular Diseases; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Diet, Vegetarian; Female; Humans; Lipids; Male; Malondialdehyde; Middle Aged; Risk Factors; Triglycerides; United States

Lipid profiles as well as vitamins A, C and E were determined in a sample of 90 men and 151 women with ages within 35 and 50 years old. Comparing the lipid profiles obtained in the study with the limits established by the National Cholesterol Education Program, resulted that a little more than 60% of the group had total cholesterol and LDL cholesterol levels in the desirable range, 20 to 30% had levels in the marginal range while 10 to 15% had levels in the high risk range. This distribution of the risk is more favorable than that observed in populations with a high risk of heart diseases such us the British or American populations, which show a substantially higher segment of the people in the high risk level. When the protective effect of the HDL cholesterol was included in the estimation of the risk by calculating the indexes: Total cholesterol/HDL chol., LDL Chol/HDL chol. or Total Chol-HDL chol. 65 to 80% of the population had values within the normal range and the first of these indexes, indicated that the men had a higher risk than the women. Integrating both methods of estimating the risk and considering that the risk of the individuals in the marginal range defined by the National Cholesterol Education Program is minimal unless they have two additional risk factors, it appears that an important segment (20-30%) of the studied population may benefit from programs aiming to reduce other risk factors such as smoking, high blood pressure, diabetes or overweight. The vitamin levels measured in this study indicated that the vast majority of the population had their levels in the safe range but an important segment had vitamin C serum levels indicative of poor consumption of this vitamin. Since vitamin C is high in fruits and vegetables we concluded that the studied population had a low consumption of these foods. Due to the existing evidence of a protective effect of fruits and vegetables in heart and other chronic diseases it was concluded that institutions such as the one studied here should engage in preventive campaigns emphasizing a reduction of both risk factors and the consumption of saturated fats. The results of this study also indicate that the consumption of fruits and vegetables should be encouraged.

Topics: Adult; Ascorbic Acid; Cardiovascular Diseases; Cholesterol, HDL; Cholesterol, LDL; Female; Humans; Lipids; Male; Middle Aged; Risk Factors; Triglycerides; Venezuela; Vitamin A; Vitamin E

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Chromatography, High Pressure Liquid; Cystic Fibrosis; Humans; Scurvy; Thiobarbituric Acid Reactive Substances

The purpose of this study was to investigate the association of health and dietary characteristics with the use of vitamin and mineral supplements in community-dwelling, cognitively intact elders aged in their 60s (n = 89), 80s (n = 92), and 100s (n = 76) who resided in Georgia in the southeastern United States. Elders who were physically active (p = 0.008), had stomach problems (p = 0.042), or used arthritis medication (p = 0.015) were more likely to take a nutritional supplement than elders without these characteristics. Physically active elders were more likely to take calcium (p = 0.004), vitamin E (p = 0.022), and vitamin C (p = 0.046) than non-physically active elders. Compared to non-users, supplement users were also more likely to comply with nutritional health seeking behaviors such as avoiding too much salt, fat, cholesterol, sugar, caffeine, and eating enough fiber, vitamins and minerals from food or supplements, and calcium in foods or supplements. The observation that the use of certain vitamin or mineral supplements is associated with dietary fat intakes, dietary protein intakes, and patterns of alcohol, decaffeinated coffee, and tea consumption suggests that supplement use is one of a cluster of health behaviors. Thus, it may be important that future investigations concerning the impact of supplement use on diseases, such as heart disease or cancer, control for the effects of dietary patterns and physical activity.

Topics: Aged; Aged, 80 and over; Aging; Alcohol Drinking; Ascorbic Acid; Caffeine; Calcium, Dietary; Cardiovascular Diseases; Cohort Studies; Diet; Dietary Fats; Dietary Proteins; Exercise; Female; Food, Fortified; Georgia; Health Status; Humans; Male; Minerals; Neoplasms; Risk Factors; Surveys and Questionnaires; Vitamin E; Vitamins

Coagulation factor activity (fibrinogen, VII, VIII and IX), coagulation inhibitor activity (antithrombin, protein C, protein S), and coagulation activation markers (prothrombin fragment F1, 2; thrombin-antithrombin complexes) were measured in 746 men and 816 women aged 25-74 years, randomly sampled from the north Glasgow population in the Third MONICA Survey. After age-adjustment, significant associations with cardiovascular risk factors were observed. Serum cholesterol and triglyceride were associated with increases in factors VII and IX, as well as antithrombin, protein C and protein S; and with increased fibrinogen and factor VIII in women. Apart from factor VIII (related to blood pressure in men, but not in women), similar associations were observed for blood pressure and body mass index. Smoking status and/or smoking markers were related to fibrinogen, factor IX, antithrombin and protein S. Alcohol intake was related to protein S, and inversely to fibrinogen and antithrombin in men. Low social class was associated with fibrinogen, factor VIII, factor IX, and with antithrombin, protein S, and low protein C in men. Serum vitamin C was associated inversely with coagulation factors and coagulation inhibitors. The only associations of activation markers were with low serum vitamin C, and with alcohol consumption and low social class in men. Prevalent cardiovascular disease was associated only with fibrinogen. These associations of coagulation factors and inhibitors with cardiovascular risk factors are plausibly relevant to thrombotic risk in cardiovascular disease. In general, 'worse' values of risk factors are associated with increased plasma levels of both coagulation factors and inhibitors, without significant increase in coagulation activation markers. However, the association of lower serum vitamin C with increased coagulation activation markers is of potential therapeutic interest.

Topics: Adult; Aged; Antithrombin III; Ascorbic Acid; Biomarkers; Blood Coagulation Factors; Blood Pressure; Body Mass Index; Cardiovascular Diseases; Cholesterol; Female; Health Surveys; Humans; Male; Middle Aged; Peptide Fragments; Peptide Hydrolases; Prevalence; Protein C; Protein Precursors; Protein S; Prothrombin; Risk Factors; Scotland; Sex Characteristics; Smoking; Social Class; Triglycerides

The present study was to investigate the levels of plasma lipid peroxide products including malondialdehyde (MDA) and conjugated dienes (CD), and antioxidants including enzyme superoxide dismutase, glutathione peroxidase, catalase, plasma vitamin E and vitamin C in diabetic patients. Fifty-eight diabetic subjects; 16 males and 42 females, aged 30-75 years, were recruited. Eighteen of them had diabetes and forty of them had diabetes with hyperlipidemia. Twenty-seven healthy subjects, 8 males and 19 females, aged 30-75 years, were used as the control group. The results showed that the concentrations of plasma MDA in diabetic patients with or without hyperlipidemia tended to be increased when compared to the controls but there were no significant differences. The CD values were increased significantly in both diabetic groups when compared with control subjects. Significantly elevated levels of plasma MDA and CD were found in diabetic patients with hypertriglyceridemia (> 150 mg%). This increment did not change the antioxidant status in both enzymes and vitamins except that the plasma vitamin E levels and the ratios of tocopherol: cholesterol were increased significantly. An increase of lipid peroxide in plasma may be one important factor in the development of vascular complication and atherosclerosis seen in diabetic patients.

Topics: Adult; Aged; Antioxidants; Arteriosclerosis; Ascorbic Acid; Cardiovascular Diseases; Catalase; Diabetes Mellitus; Female; Glutathione Peroxidase; Humans; Hyperlipidemias; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Superoxide Dismutase; Vitamin E

Reactive oxygen species are thought to be implicated in the pathogenesis of various human diseases. They are generated endogenously under physiological and pathological conditions but also upon exposure to exogenous challenge. The organism maintains defense systems against reactive oxygen species, including enzymes and low-molecular-weight antioxidants. Important antioxidants such as vitamins E and C and carotenoids are provided from the diet. Vitamin E, as the major chain-breaking antioxidant, inhibits lipid peroxidation, thus preventing membrane damage and modification of low-density lipoproteins. It is regenerated by the water-soluble vitamin C. Carotenoids efficiently scavenge singlet molecular oxygen and peroxyl radicals. There is increasing evidence from epidemiological studies, animal experiments, and in vitro investigations that an increased intake of antioxidants is associated with a diminished risk for several diseases.

Topics: Animals; Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Diabetic Nephropathies; Diabetic Retinopathy; Diet; Humans; Reactive Oxygen Species; Vitamin E

This study was undertaken to examine relationships among blood pressure, blood lipids, and plasma concentrations of ascorbic acid and malondialdehyde (MDA) equivalents (indicative of lipid peroxidation) in adult African-Americans. Subjects (n = 172, mean age = 48.0 y) were recruited from among the memberships of several Seventh-Day Adventist Churches. Plasma ascorbic acid and MDA equivalents were inversely correlated (r = -0.44, P < 0.0001). There were significant inverse correlations between plasma ascorbic acid levels and both systolic (r = -0.39, P < 0.0001) and diastolic blood pressure (r = -0.25, P < 0.03), and between plasma ascorbic acid and serum total cholesterol (r = -0.25, P < 0.03), LDL-cholesterol (LDL-C) (r = -0.33, P < 0.004), and the ratio of LDL-cholesterol to HDL-cholesterol (LDL-C/HDL-C) (r = -0.32, P < 0.004). Serum HDL-cholesterol was positively related to plasma ascorbic acid (r = 0.22, P < 0.05). The correlations for MDA equivalents and the blood pressure and blood lipid variables were of similar magnitude to those of plasma ascorbic acid, but were in the opposite direction. Multiple regression analysis revealed ascorbic acid to be a significant independent contributor to the prediction of blood pressure and LDL-C concentration. These data suggest that plasma concentrations of ascorbic acid and MDA equivalents are related to several cardiovascular risk indicators in black Americans.

Topics: Adult; Analysis of Variance; Ascorbic Acid; Black People; Blood Pressure; Cardiovascular Diseases; Cholesterol, LDL; Colorado; Female; Humans; Lipids; Male; Malondialdehyde; Middle Aged; Regression Analysis; Risk Factors; Texas

Serum vitamin E, vitamin E/cholesterol and physical activity and fitness were examined in a representative cross section (n = 1600) of the Northern Ireland population as part of the Northern Ireland health and activity survey. Serum vitamin E levels were measured by high-performance liquid chromatography, cholesterol by an enzymatic method, physical activity profile was recorded by computer assisted interview and physical fitness was determined by estimation of VO2 max. The levels of serum vitamin E and vitamin E/cholesterol ratio in the Northern Irish population were similar or higher than in other populations with lower incidences of coronary heart disease. The assessment of activity showed that 75% of the population fell below recommended activity levels likely to confer a cardioprotective effect. A significant relationship (P = 0.01) was found in males between serum vitamin E levels and lifetime participation in physical activity. Otherwise no relationship was found between serum vitamin E or vitamin E/cholesterol ratio and physical activity or fitness in the population.

Topics: Adolescent; Adult; Aged; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Cross-Sectional Studies; Exercise; Female; Humans; Linear Models; Lipids; Logistic Models; Male; Middle Aged; Northern Ireland; Physical Fitness; Population Surveillance; Risk Factors; Vitamin E

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Cardiovascular Diseases; Cataract; Copper; Diabetes Mellitus; Diet; Humans; Lens, Crystalline; Middle Aged; Oxidation-Reduction; Peptides; Reference Values; Regression Analysis; Tryptophan

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; Humans; Vitamin E

Topics: Acute-Phase Proteins; Ascorbic Acid; Cardiovascular Diseases; Factor VII; Fibrinogen; Humans

To examine the hypothesis that the increase in fibrinogen concentration and respiratory infections in winter is related to seasonal variations in vitamin C status (assessed with serum ascorbate concentration).. Longitudinal study of individuals seen at intervals of two months over one year.. Cambridge.. 96 men and women aged 65-74 years living in their own homes.. Haemostatic factors fibrinogen and factor VIIC; acute phase proteins; respiratory symptoms; respiratory function.. Mean dietary intake of vitamin C varied from about 65 mg/24 h in winter to 90 mg/24 h in summer; mean serum ascorbate concentration ranged from 50 mumol/l in winter to 60 mumol/l in summer. Serum ascorbate concentration was strongly inversely related to haemostatic factors fibrinogen and factor VIIC as well as to acute phase proteins but not to self reported respiratory symptoms or neutrophil count. Serum ascorbate concentration was also related positively to forced expiratory volume in one second. An increase in dietary vitamin C of 60 mg daily (about one orange) was associated with a decrease in fibrinogen concentrations of 0.15 g/l, equivalent (according to prospective studies) to a decline of approximately 10% in risk of ischaemic heart disease.. High intake of vitamin C has been suggested as being protective both for respiratory infection and for cardiovascular disease. These findings support the hypothesis that vitamin C may protect against cardiovascular disease through an effect on haemostatic factors at least partly through the response to infection; this may have implications both for our understanding of the pathogenetic mechanisms in respiratory and cardiovascular disease and for the prevention of such conditions.

Topics: Aged; Antioxidants; Ascorbic Acid; C-Reactive Protein; Cardiovascular Diseases; Common Cold; Factor VII; Female; Fibrinogen; Hemostasis; Humans; Longitudinal Studies; Male; Risk Factors; Seasons

Dietary antioxidants such as vitamin E, vitamin C, beta carotene and flavonoids may retard atherosclerosis by preventing low density lipoprotein oxidation. Observational epidemiological studies, including ecological correlations, case control and prospective studies, indicate that high vitamin E levels may be associated with decreased cardiovascular disease. Beta carotene may be protective among smokers and the elderly. Few studies have been able to show that vitamin C has a protective effect. A handful of intervention studies have examined the effects of vitamin E and beta carotene with mixed results. While few side effects of antioxidant supplementation are known, the results of current, large-scale studies in primary intervention must be awaited before recommendations can be made. Increased intake of fruits and vegetables that are rich in antioxidants is recommended.

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Case-Control Studies; Cohort Studies; Female; Humans; Male; Norway; Prospective Studies; Risk Factors; Vitamin E

Topics: Ascorbic Acid; Biomarkers; Cardiovascular Diseases; Female; Humans; Hypolipidemic Agents; Lipoprotein(a); Risk Factors

Topics: Aged; Aging; Animals; Antioxidants; Ascorbic Acid; beta Carotene; Cardiovascular Diseases; Carotenoids; DNA Damage; Female; Humans; Male; Middle Aged; Neoplasms; Reactive Oxygen Species; Selenium; Vitamin E

High plasma vitamin C may lower risk of cardiovascular disease as indicated by direct association with plasma high-density-lipoprotein (HDL) cholesterol and HDL2 cholesterol. Plasma lipids and vitamin C were determined in 316 women and 511 men (aged 19-95 y). After adjustment for age, sex, obesity, and smoking, plasma vitamin C was directly associated with HDL- (P = 0.01) and HDL2 cholesterol (P = 0.0002). When men and women with diseases that might affect lipids were excluded, associations between plasma vitamin C and HDL- and HDL2 cholesterol persisted, though the relationships were strongest in older men. Comparisons of diets in a subset (n = 485) who completed 7-d diet records were made. Total fat, saturated fatty acids, energy from fat, and cholesterol intakes were not associated with plasma vitamin C. Mean intakes of vitamin C were well above recommended dietary allowances. These findings suggest that high plasma concentrations of vitamin C may lower atherogenic risk.

Topics: Adult; Aged; Aged, 80 and over; Aging; Ascorbic Acid; Body Mass Index; Cardiovascular Diseases; Cholesterol, HDL; Diet Records; Female; Humans; Male; Middle Aged; Sex Factors; Smoking; Triglycerides

Complementary epidemiological studies consistently reveal a substantially increased risk of cardiovascular disease (CVD) at suboptimal plasma levels of essential antioxidants in comparison with optimum ranges of vitamin C (> 50 mumol/l), of lipid-standardized vitamin E (> 30 mumol/l or a tocopherol/cholesterol ratio > 5.2 mumol/mmol), beta-carotene (> 0.4 mumol/l). The poor level of any single essential antioxidant can increase the risk, and the combination of suboptimal levels has additive or even overmultiplicative effects on the risk for CVD. Suboptimal antioxidant levels are stronger predictors of the severalfold regional differences of CVD in Europe than classical risk factor such as hypercholesterolemia, hypertension, etc. Scotsmen and Fins tend to suboptimal levels of essential antioxidants, whereas German-speaking regions may mostly reveal a fair vitamin E status, but at least one out of four subjects can reveal suboptimal levels of vitamin C and carotene, particularly in smokers. This deficit can be avoided by 'prudent diets' rich in fruits and vegetables as practiced by Frenchmen, Italians and Spaniards. The simultaneous correction of all suboptimal antioxidant levels appears to be a promising new means for CVD prevention, particularly in the northern parts of Europe. In the USA the risk of CVD could substantially be reduced without dietary modifications by voluntary daily supplements as follows: vitamin C > 140 mg, vitamin E > 100 IU (100 mg d,l- or 74 mg d-alpha-tocopherylacetate), and in current smokers by gamma-carotene > 8.6 mg. Hence, these antioxidants may be crucial constituents of diets rich in fruits and vegetables, which are by consensus associated with a lower risk of premature death from CVD (and cancer as well).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Ethnicity; Europe; Humans; Predictive Value of Tests; Risk Factors; Vitamin E

There is accumulating evidence that free radicals may contribute to various diseases such as cancer or cardiovascular disease. Possible health hazards can to some extent be prevented by the body's multilevel defense system against free radicals, which comprises, besides others, antioxidant vitamins. The 12-year mortality follow-up of 2,974 participants of the Basal Study allowed to test the hypothesis that low antioxidant vitamin plasma concentrations (vitamin A, C, E and carotene) were associated with increased death from cancer of various sites and death from atherosclerosis such as ischemic heart disease and stroke, respectively. For the analysis 204 cancer cases, 132 fatalities from ischemic heart disease (IHD) and 31 deaths from cerebral vascular disease were available. Cancer mortality. Overall mortality from cancer was associated with low mean plasma levels of carotene adjusted for cholesterol (p less than 0.01) and of vitamin C (p less than 0.01). Bronchus and stomach cancers were associated with a low mean plasma carotene level (p less than 0.01). Subjects with subsequent stomach cancer had also lower mean vitamin C and lipid-adjusted vitamin A levels than survivors (p less than 0.05). Calculating the relative risk with exclusion of mortality during the first two years of follow-up, low plasma carotene was associated with an increased risk for bronchus cancer (RR 1.8, p less than 0.05), and the small number of stomach cancer cases (RR 2.95, p less than 0.05) low plasma levels of carotene and vitamin A with all cancer types (RR 2.47, p less than 0.01), and low plasma retinol in older subjects (greater than 60 years) with lung cancer (RR 2.17, p less than 0.05). Studies in other cohorts with a poor vitamin E status revealed an increased risk of subsequent cancer at low vitamin E levels as well. It is concluded that low plasma levels of all major essential antioxidants are associated with an increased risk of subsequent cancer mortality. Cardio-vascular mortality. Plasma carotene concentration below quartile 1 was associated with an increased risk for IHD (RR 1.53, p = 0.02). The same was true for low levels of both carotene and vitamin C (RR = 1.96, p = 0.022). The risk of cerebrovascular death was elevated in subjects with low carotene in the presence of low vitamin C plasma concentration (RR 4.17, p less than 0.01). These data confirm and extend recent findings on an inverse correlation of beta-carotene and vitamin C respectively to CVD.(ABSTRACT

Topics: Antioxidants; Ascorbic Acid; Cardiovascular Diseases; Carotenoids; Cerebrovascular Disorders; Cholesterol; Female; Follow-Up Studies; Free Radicals; Humans; Male; Myocardial Ischemia; Neoplasms; Prospective Studies; Risk Factors; Switzerland; Vitamin A; Vitamin E; Vitamins

Topics: Antioxidants; Ascorbic Acid; Brain Diseases; Cardiovascular Diseases; Cells; Free Radical Scavengers; Free Radicals; Humans; Ischemia; Phagocytes; Reactive Oxygen Species; Reperfusion Injury; Respiratory Tract Diseases; Superoxide Dismutase

As part of the Dutch Nutrition Surveillance System, cardiovascular risk factors and food consumption (24 h recall) as well as haematological, Fe and vitamin status (A, B6, C) were assessed in 126 Dutch boys aged 10-11 years (response 71%). Body mass index (BMI) and the sum of four skinfolds were strongly associated (r 0.85, P less than 0.01) and 8% of the boys were overweight (BMI greater than 20.1 kg/m2). Elevated serum total cholesterol levels (greater than 4.4 mmol/l) were observed in 38%; total cholesterol and low-density-lipoprotein-cholesterol levels were strongly associated (r 0.88, P less than 0.001). Intake of fat was high (38% of energy) and too much fat was saturated (polyunsaturated: saturated 0.44, guideline: 0.5-1.0), whereas intake of carbohydrate (49% of energy) and dietary fibre was low. About 12% of the boys had insufficient Fe stores (plasma ferritin less than 12.0 micrograms/l) and the mean Fe intake (9.0 mg/d) was below recommended daily allowance (10.0 mg/d). Plasma ferritin was, however, not associated with haematological indices and no frank anaemias were observed. No marginal values were observed for vitamins A, B6 and C status. In conclusion, the main nutritional risks in boys aged 10-11 years are cardiovascular risk factors and Fe nutrition.

Topics: Ascorbic Acid; Blood Pressure; Body Weight; Cardiovascular Diseases; Child; Cholesterol; Dietary Carbohydrates; Dietary Fats; Dietary Fiber; Energy Intake; Humans; Iron; Male; Netherlands; Nutritional Status; Pyridoxine; Risk Factors; Vitamin A

The concept that lipoprotein(a) [Lp(a)] is a surrogate for ascorbate is suggested by the fact that this lipoprotein is found generally in the blood of primates and the guinea pig, which have lost the ability to synthesize ascorbate, but only rarely in the blood of other animals. Properties of Lp(a) that are shared with ascorbate, in accordance with this hypothesis, are the acceleration of wound healing and other cell-repair mechanisms, the strengthening of the extracellular matrix (e.g., in blood vessels), and the prevention of lipid peroxidation. High plasma Lp(a) is associated with coronary heart disease and other forms of atherosclerosis in humans, and the incidence of cardiovascular disease is decreased by elevated ascorbate. Similar observations have been made in cancer and diabetes. We have formulated the hypothesis that Lp(a) is a surrogate for ascorbate in humans and other species and have marshaled the evidence bearing on this hypothesis.

Topics: Animals; Antioxidants; Arteriosclerosis; Ascorbic Acid; Biological Evolution; Cardiovascular Diseases; Diabetes Mellitus; Disease Models, Animal; Humans; Lipoprotein(a); Lipoproteins; Neoplasms; Wound Healing

Plasma oxalate has been measured in 125 patients maintained on continuous ambulatory peritoneal dialysis using an enzyme/bioluminescent assay. Values ranged between 6 and 134 mumol/l, with a positively skewed distribution. Multiple linear regression analysis with plasma oxalate as the dependent variable showed highly significant associations with the dose of ascorbic acid, dose of alfacalcidol, and plasma creatinine, and weaker associations with serum phosphate, serum calcium, and body weight. When the presence of other potential risk factors was taken into account, no significant relationship could be found between the presence of clinically evident cardiac or vascular disease and plasma oxalate.

Topics: Ascorbic Acid; Cardiovascular Diseases; Female; Humans; Male; Oxalates; Oxalic Acid; Peritoneal Dialysis, Continuous Ambulatory

Topics: Arteriosclerosis; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Chronic Disease; Czechoslovakia; Diet; Humans

Dietary intake as initially estimated by means of a 24-h recall has been related to the incidence of ischemic heart disease, stroke, and overall mortality during a 12-yr follow-up period in a prospective study of 1462 women representative of the general population. Energy intake was inversely correlated to the 12-yr incidence of myocardial infarction. The correlation was independent of age, indices of obesity, smoking habits, serum cholesterol, serum triglycerides, diabetes, systolic blood pressure, and physical activity. No correlation was found between dietary intake and incidence of stroke or overall mortality, nor was any correlation found between end-points and intake of fish, energy percentage of fat, protein, and carbohydrates. These observations suggest that suboptimal intake of nutrients may be an important factor in the pathogenesis of ischemic heart disease.

Topics: Adult; Animals; Ascorbic Acid; Cardiovascular Diseases; Cerebrovascular Disorders; Diet; Energy Intake; Female; Fishes; Humans; Middle Aged; Myocardial Infarction; Prospective Studies; Risk; Sweden

A steady fall in mortality rates from cardiovascular diseases (CVD) has been reported recently in the United States. This study tests the hypothesis that fruits and vegetables had a protective effect against cardiovascular mortality among the American population from 1964-78. Special attention was focused on more specific groups of fruits and vegetables, especially those rich in vitamin C, to examine the effect of consumption of these foods on cardiovascular mortality rates. These data showed that the consumption of fruits and vegetables, particularly those rich in vitamin C (based on content and consumption), may have offered a protective effect against deaths from CVD. Increased fruit and vegetable consumption appeared to contribute significantly to the reduction of CVD mortality in the American population in recent years.

Topics: Ascorbic Acid; Cardiovascular Diseases; Diet; Fruit; Humans; Vegetables

High but well-tolerated doses of the nutritional antioxidants selenium and vitamins E and C have significant immunostimulant, anti-inflammatory, and anti-carcinogenic effects which are well documented in the existing biomedical literature. In addition, these antioxidants help to protect the structural integrity of ischemic or hypoxic tissues, and may have useful anti-thrombotic actions as well. Supplementation with high-dose nutritional antioxidants may eventually gain a broad role in the prevention, treatment, or palliation of cancer, cardiovascular disease, infection, inflammatory disorders, and certain diabetic complications.

Topics: Adjuvants, Immunologic; Animals; Anti-Inflammatory Agents; Antioxidants; Arthritis; Ascorbic Acid; Cardiovascular Diseases; Diabetes Mellitus; Free Radicals; Humans; Hypoxia; Ischemia; Mice; Neoplasms; Rabbits; Rats; Selenium; Superoxides; Thrombosis; Vitamin E

Topics: Ascorbic Acid; Cardiovascular Diseases; Humans; Longevity; Neoplasms

Consideration of nine major factors predisposing to cerebral thrombosis, coronary thrombosis or thrombosis in the deep veins of the calf, reveals that these factors all have one thing in common. Estrogen administration, pregnancy, ageing, smoking, infection, trauma, surgery, soft water and winter season are all associated with a tendency towards decreased plasma ascorbic acid levels. Normally, ascorbic acid deficiency is thought of as causing a tendency towards hemorrhage rather than thrombosis, but it is here suggested that petechial hemorrhages under the endothelium of the blood vessels may precipitate thrombosis on the damaged endothelium. Is not blood coagulation the normal mechanism for the arrest of hemorrhage?

Topics: Age Factors; Ascorbic Acid; Cardiovascular Diseases; Communicable Diseases; Contraceptives, Oral; Female; Humans; Pregnancy; Seasons; Smoking; Surgical Procedures, Operative; Water Supply; Wounds and Injuries

Topics: Age Factors; Aged; Ascorbic Acid; Cardiovascular Diseases; Cholesterol; England; Female; Humans; Lipoproteins, HDL; Longitudinal Studies; Male; Risk; Sex Factors

Topics: Adolescent; Adult; Ascorbic Acid; Cardiovascular Diseases; Collagen Diseases; Electron Spin Resonance Spectroscopy; Flavonoids; Freeze Drying; Humans; Hypersensitivity; Middle Aged; Pneumonia

Topics: Ascorbic Acid; Cardiovascular Diseases; Cholesterol; Cholesterol, Dietary; Coronary Disease; Diet, Atherogenic; Dietary Carbohydrates; Dietary Fats; Finland; Humans; Male; Middle Aged; New York

Topics: Ascorbic Acid; Blood Circulation Time; Cardiac Catheterization; Cardiovascular Diseases; Coronary Circulation; Electrodes; Heart Septal Defects; Heart Valve Diseases; Humans; Hydrogen; Indicator Dilution Techniques; Methods; Oximetry; Regional Blood Flow

Topics: Aging; Alcohol Oxidoreductases; Ascorbic Acid; Ascorbic Acid Deficiency; Cardiovascular Diseases; Collagen; Humans; Liver; Neoplasms

Topics: Ascorbic Acid; Body Weight; Calcium; Calcium, Dietary; California; Cardiovascular Diseases; Diet; Dietary Carbohydrates; Dietary Fats; Dietary Proteins; Follow-Up Studies; Geriatrics; Humans; Iron; Morbidity; Mortality; Neoplasms; Nutrition Surveys; Vitamin A; Vitamin B Complex

Topics: Ascorbic Acid; Atrial Fibrillation; Cardiac Catheterization; Cardiovascular Diseases; Diagnosis; Endocardium; Heart Function Tests; Humans; Tricuspid Valve Insufficiency

Topics: Ascorbic Acid; Cardiovascular Diseases; Heart Defects, Congenital; Heart Function Tests; Humans; Indicator Dilution Techniques

Topics: Arteriosclerosis; Ascorbic Acid; Blood Chemical Analysis; Cardiovascular Diseases; Coronary Disease; Geriatrics; Heart Failure; Humans; Hypertension

Topics: Ascorbic Acid; Cardiovascular Diseases; Diagnostic Techniques, Cardiovascular; Indicator Dilution Techniques

Topics: Ascorbic Acid; Cardiovascular Diseases; Folic Acid; Humans; Occupational Medicine; Vitamin B Complex; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Cerebrovascular Disorders; Humans; Peripheral Vascular Diseases; Vascular Diseases; Vitamin D; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Humans; Metabolic Diseases; Vitamins

Topics: Ascorbic Acid; Blood Circulation; Cardiovascular Diseases; Disease; Hematologic Diseases; Humans; Physiological Phenomena; Vitamins

Topics: Ascorbic Acid; Cardiovascular Diseases; Cardiovascular System; Humans; Vitamins