alpha-carotene and Diabetes-Mellitus--Type-2

In vitro, ex vivo and animal studies suggest palm-based tocotrienols and carotenes enhance vascular function, but limited data in humans exists. The aim was to examine the effects of palm-tocotrienols (TRF- 80) and palm-carotene (CC-60) supplementation on vascular function and cardiovascular disease (CVD) risk factors in adults at increased risk of impaired vascular function.. Plasma α- and β-carotene and α-, δ- and γ-tocotrienol concentrations increased in CC-60 and TRF-80 groups, respectively, compared to placebo (mean ± SE difference in total plasma carotene change between CC-60 and placebo: 1.5 ± 0.13 μg/ml, p < 0.0001; total plasma tocotrienol change between TRF-80 and placebo: 0.36 ± 0.05 μg/ml, p < 0.0001). Neither FMD (treatment x time effect for CC-60 vs. placebo, p = 0.71; TRF-80 vs. placebo, p = 0.80) nor any other vascular function and CVD outcomes were affected by treatments.. CC-60 and TRF-80 supplementation increased bioavailability of palm-based carotenes and tocotrienols but had no effects, superior or detrimental, on vascular function or CVD risk factors.

Topics: Adolescent; Adult; Aged; beta Carotene; Blood Glucose; Brachial Artery; Cardiovascular Diseases; Carotenoids; Diabetes Mellitus, Type 2; Dietary Supplements; Double-Blind Method; Female; Humans; Inflammation; Insulin; Male; Middle Aged; Oxidative Stress; Palm Oil; Risk Factors; Tocotrienols; Young Adult

Recent studies suggest increased cancer risk in patients with type 2 diabetes mellitus (T2DM) compared with healthy individuals. The present study aims to assess whether T2DM is associated with increased genome instability and whether a healthy diet with natural foods can improve genome stability in peripheral blood lymphocytes (PBLs). Seventy-six diabetic and 21 non-diabetic individuals were randomly assigned to either an 'intervention' or an 'information only' group. All participants received information about the beneficial effects of a healthy diet, while subjects of the intervention group received additionally 300g of vegetables and 25ml of plant oil rich in polyunsaturated fatty acids per day for 8 weeks. Chromosomal damage was assessed using the cytokinesis-block micronucleus (MN) cytome assay. Levels of chromosomal damage did not differ between diabetic and non-diabetic individuals. However, diabetic individuals with MN frequency above the high 50th percentile had significantly higher levels of fasting plasma glucose, glycosylated haemoglobin and were at higher risk for cardiovascular disease (CVD), assessed by the Framingham general cardiovascular risk score. Non-diabetic individuals with MN frequency above the 50th percentile had significantly lower vitamin B12 levels. The intervention with vegetables and plant oil led to significant increases in folate, γ-tocopherol, α- and β-carotene while vitamin B12 was significantly reduced. Levels of chromosomal damage were not altered, only apoptosis was slightly increased. The results suggest interactions between glycaemic control, CVD risk and genome stability in individuals with T2DM. However, a healthy diet does not improve genome damage in PBLs.

Topics: Aged; Anthropometry; beta Carotene; Blood Glucose; Blood Pressure; Cardiovascular Diseases; Carotenoids; Chromosome Aberrations; Diabetes Mellitus, Type 2; DNA Damage; Fatty Acids, Unsaturated; Female; Folic Acid; gamma-Tocopherol; Genome, Human; Genomic Instability; Glycated Hemoglobin; Humans; Lymphocytes; Male; Micronucleus Tests; Middle Aged; Plant Oils; Risk Factors; Vegetables; Vitamin B 12

Diabetic retinopathy (DR) is one of the leading causes of blindness. Carotenoids are plant-derived pigments required for general health and particularly for vision. In this study, we evaluated the dietary intake and blood carotenoid levels of type 2 diabetes (T2D) patients with and without DR. A cross-sectional case-control study was conducted among 151 age-matched controls and 344 T2D patients, of which 194 had DR and 150 had no DR (NDR). After a complete ophthalmic examination, the demographic, anthropometric and clinical profiles were obtained. Carotenoids in the plasma were measured by HPLC and dietary intakes were obtained using a food frequency questionnaire. The mean plasma levels of carotenoids (except γ-carotene) were significantly lower in the DR group compared to the Control and NDR groups. The dietary intakes of zeaxanthin, lycopene, α-carotene and β-carotene were significantly lower in the NDR group compared to the Control group, and were further lower in the DR group compared to the NDR group. Plasma carotenoid levels were significantly inversely associated with the duration of diabetes, RBS and HbA1c but positively associated with HDL. This study demonstrated decreased plasma levels and lower dietary intakes of carotenoids in DR subjects.

Topics: beta Carotene; Carotenoids; Case-Control Studies; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Eating; Female; Glycated Hemoglobin; Humans; Lycopene; Male; Middle Aged; Pilot Projects; Retinal Diseases; Surveys and Questionnaires; Zeaxanthins

Few food frequency questionnaires (FFQs) have been developed to assess diet in diabetes patients. This cross-sectional study examined the validity of a 45-item FFQ assessing the intake of macronutrients against three 24-h dietary recalls (24-HDRs) in Taiwan, and compared vegetable and fruit intakes with carotenoid biomarkers. We recruited 126 adults with type 2 diabetes who completed the FFQ and three 24-HDRs administered by a registered dietitian. We measured plasma carotenoids (α-carotene, β-carotene and lutein) in 71 subjects. Partial Pearson correlation coefficients derived from the FFQs and three 24-HDRs and adjusted for energy were of 0.651, 0.587, 0.639 and 0.664 for protein, fat, carbohydrate and fiber, respectively. Cross-classification analysis revealed that 71.5⁻81% of the macronutrients and fiber were categorized into the same or adjacent quartiles by the FFQ and 24-HDRs. Bland⁻Altman plots revealed good agreement for energy/macronutrients/fiber across the range of intakes. Multiple linear regression of backward elimination revealed that tertile levels of dark- or light-colored vegetables obtained by the FFQ were significantly associated with plasma α-carotene and β-carotene, but not lutein. Fruit consumption did not correlate with carotenoid biomarkers. In conclusion, this short FFQ provided a valid assessment of macronutrients and fiber intake in type 2 diabetes patients. Vegetable consumption estimated by the FFQ corresponded to plasma α-carotene and β-carotene concentrations.

Topics: Adult; beta Carotene; Biomarkers; Carotenoids; Cross-Sectional Studies; Diabetes Mellitus, Type 2; Dietary Fiber; Feeding Behavior; Female; Fruit; Humans; Male; Mental Recall; Middle Aged; Nutrients; Surveys and Questionnaires; Taiwan; Vegetables

Carotenoids may reduce diabetes risk, due to their antioxidant properties. However, the association between dietary carotenoids intake and type 2 diabetes risk is still unclear. Therefore, the objective of this study was to examine whether higher dietary carotenoid intakes associate with reduced type 2 diabetes risk.. Data from 37,846 participants of the European Prospective Investigation into Cancer and Nutrition- Netherlands study were analyzed. Dietary intakes of β-carotene, α-carotene, β-cryptoxanthin, lycopene, lutein & zeaxanthin and the sum of these carotenoids were assessed using a validated food frequency questionnaire. Incident type 2 diabetes was mainly self-reported, and verified against general practitioner information. Mean ±SD total carotenoid intake was 10 ± 4 mg/day. During a mean ±SD follow-up of 10 ± 2 years, 915 incident cases of type 2 diabetes were ascertained. After adjustment for age, sex, diabetes risk factors, dietary intake, waist circumference and BMI, higher β-carotene intakes associated inversely with diabetes risk [Hazard Ratio quartile 4 versus quartile 1 (HR(Q4)): 0.78 (95%CI:0.64,0.95), P-linear trend 0.01]. For α-carotene, a borderline significant reduced risk was observed, with a HR(Q4) of 0.85 (95%CI:0.70,1.03), and P-linear trend 0.05. β-cryptoxanthin, lycopene, lutein & zeaxanthin, and the sum of all carotenoids did not associate with diabetes risk.. This study shows that diets high in β-carotene and α-carotene are associated with reduced type 2 diabetes in generally healthy men and women.

Topics: Aged; Antioxidants; beta Carotene; Carotenoids; Cryptoxanthins; Diabetes Mellitus, Type 2; Energy Metabolism; Female; Follow-Up Studies; Humans; Incidence; Lutein; Lycopene; Male; Middle Aged; Netherlands; Nutrition Assessment; Prospective Studies; Risk Factors; Surveys and Questionnaires; Zeaxanthins

Diabetic retinopathy increases with duration of diabetes and may be associated with carotenoid status. Carotenoids alter the pro-oxidation/antioxidation balance, and circulating levels depend largely on dietary intake. Lower levels have been reported in diabetes and age-related macular degeneration; however, little is known of the relationship between carotenoids and diabetic complications. Consequently, the purpose of the present study was to evaluate the relationship between plasma carotenoids and diabetic retinopathy. We assessed the carotenoid-retinopathy relationship in 111 individuals with type 2 diabetes in a community-based, cross-sectional study. We photodocumented retinal status and used HPLC to measure plasma carotenoid concentrations. Data for clinical and demographic variables and risk factors for diabetic retinopathy were obtained from 24 h urine and fasting blood samples, and an interviewer-assisted lifestyle questionnaire. We found that the combined lycopene and lutein/zeaxanthin (non-pro-vitamin A (non-PVA) carotenoid) concentration when compared with the pro-vitamin A (PVA) carotenoids (alpha-carotene, beta-carotene and beta-cryptoxanthin) was significantly lower in the retinopathy than non-retinopathy group (OR 1.2 (95% CI 1.0, 1.4) v. 1.6 (95% CI 1.4, 1.7), respectively; P=0.009). A higher non-PVA:PVA ratio also predicted a lower risk of diabetic retinopathy, after adjustment for potential confounders (OR 0.33 (95% CI 0.12, 0.95); P=0.039). Finally, a higher concentration of PVA carotenoids was associated with greater odds of diabetic retinopathy, after adjustment for risk factors (P=0.049). We suggest synergies between carotenoids are implicated in diabetic retinopathy, independent of established risk factors. Importantly, our observations indicate dietary modulation of retinopathy risk may be possible by increasing intakes of lutein- and lycopene-rich foods.

Topics: Adult; Aged; Antioxidants; beta Carotene; Biomarkers; Blood Glucose; Carotenoids; Chi-Square Distribution; Cross-Sectional Studies; Cryptoxanthins; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Female; Humans; Lutein; Lycopene; Male; Middle Aged; Risk; Xanthophylls; Zeaxanthins

The authors conducted a nested case-control study from 1992 to 2003 among US women aged 45 years or older and free from cardiovascular disease and cancer to examine the prospective association among plasma lycopene, other carotenoids, and the risk of developing type 2 diabetes. During 10 years of follow-up, 470 cases of incident type 2 diabetes were selected and individually matched on age (+/- 1 year) and follow-up time to 470 nondiabetic controls. Baseline plasma levels of lycopene, alpha-carotene, beta-carotene, beta-cryptoxanthin, and lutein/zeaxanthin were similar in cases and controls (all p > 0.05). A possible crude inverse association between plasma lycopene and risk of type 2 diabetes was attenuated upon multivariate adjustment. After control for plasma total cholesterol and known diabetes risk factors, the multivariate odds ratios of type 2 diabetes in the highest versus the lowest quartile of plasma carotenoids were 1.13 (95% confidence interval (CI): 0.60, 2.13) for lycopene, 1.27 (95% CI: 0.63, 2.57) for alpha-carotene, 1.10 (95% CI: 0.57, 2.13) for beta-carotene, 0.91 (95% CI: 0.46, 1.81) for beta-cryptoxanthin, and 1.35 (95% CI: 0.68, 2.69) for lutein/zeaxanthin. There was no prospective association between baseline plasma carotenoids and the risk of type 2 diabetes in middle-aged and older women.

Topics: Aged; Aspirin; beta Carotene; Carotenoids; Case-Control Studies; Cryptoxanthins; Diabetes Mellitus, Type 2; Double-Blind Method; Female; Humans; Incidence; Logistic Models; Lutein; Lycopene; Middle Aged; Prospective Studies; Randomized Controlled Trials as Topic; Risk Factors; Surveys and Questionnaires; United States; Xanthophylls; Zeaxanthins