11-octadecenoic-acid and palmitoleic-acid

trans Palmitoleic acid (t-16:1n-7, or 16:1 t9 in the δ nomenclature usually applied to trans fatty acids and used herein) arouses great scientific interest because it has been suggested to serve as a biomarker for lower risks of type 2 diabetes and coronary artery disease.. Although 16:1 t9 has been assumed to derive from dietary sources, we examined the hypothesis that 16:1 t9 might also be endogenously produced from its metabolic precursor vaccenic acid (t-18:1n-7 or 18:1 t11).. We reevaluated fatty acid data obtained from one human intervention study and one cellular model in both of which 18:1 t11 was supplemented. Both studies have already been published, but to our knowledge, 16:1 t9 has not yet been considered. This reanalysis of the datasets was reasonable because a new methodology for identifying 16:1 cis and trans isomers allowed us to address the subject presented in this article.. Data showed that the systemic or intracellular increase in 16:1 t9 was strongly correlated with the increase in 18:1 t11 after the dietary intake or cellular uptake of 18:1 t11. The conversion rate in humans was, on average, 17%.. Our findings suggest that endogenous 16:1 t9 is not, as has been assumed, exclusively diet derived but may also be produced by the partial β oxidation of dietary 18:1 t11.

Topics: Adult; Biomarkers; Cells, Cultured; Dairy Products; Dietary Fats; Double-Blind Method; Fatty Acids, Monounsaturated; Female; Flame Ionization; Humans; Kinetics; Leukocytes, Mononuclear; Male; Molecular Structure; Oleic Acids; Oxidation-Reduction; Stereoisomerism; Trans Fatty Acids

Polyunsaturated fatty acids of n-3 series (n-3 PUFA) were shown to increase basal fat oxidation in humans. The aim of the study was to compare the effect of n-3 PUFA added to a very low calorie diet (VLCD), with VLCD only during three-week inpatient weight reduction. Twenty severely obese women were randomly assigned to VLCD with n-3 PUFA or with placebo. Fatty acids in serum lipid fractions were quantified by gas chromatography. Differences between the groups were determined using ANOVA. Higher weight (7.55+/-1.77 vs. 6.07+/-2.16 kg, NS), BMI (2.82+/-0.62 vs. 2.22+/-0.74, p<0.05) and hip circumference losses (4.8+/-1.81 vs. 2.5+/-2.51 cm, p<0.05) were found in the n-3 group as compared to the control group. Significantly higher increase in beta-hydroxybutyrate was found in the n-3 group showing higher ketogenesis and possible higher fatty acid oxidation. The increase in beta-hydroxybutyrate significantly correlated with the increase in serum phospholipid arachidonic acid (20:4n-6; r = 0.91, p<0.001). In the n-3 group significantly higher increase was found in n-3 PUFA (eicosapentaenoic acid, 20:5n-3, docosahexaenoic acid, 22:6n-3) in triglycerides and phospholipids. The significant decrease of palmitoleic acid (16:1n-7) and vaccenic acid (18:1n-7) in triglycerides probably reflected lower lipogenesis. A significant negative correlation between BMI change and phospholipid docosahexaenoic acid change was found (r = -0.595, p<0.008). The results suggest that long chain n-3 PUFA enhance weight loss in obese females treated by VLCD. Docosahexaenoate (22:6n-3) seems to be the active component.

Topics: 3-Hydroxybutyric Acid; Caloric Restriction; Diet, Reducing; Dietary Supplements; Docosahexaenoic Acids; Eicosapentaenoic Acid; Fatty Acids, Monounsaturated; Fatty Acids, Omega-3; Female; Humans; Middle Aged; Obesity; Oleic Acids; Phospholipids; Triglycerides; Weight Loss

There has been controversial evidence regarding the relationship between isomers of circulating trans-fatty acids (TFAs) and mortality. This study aimed to ascertain the relationships between plasma TFAs and overall or cause-specific mortality of the general population in two independent subsets from the US National Health and Nutrition Examination Survey (1999-2000 and 2009-2010 cycles).. Plasma TFA isomers (C16:1n-7t, C18:1n-7t, C18:1n-9t and C18:2n-6,9t) in 3439 adults free of cancer or severe cardiovascular disease were analyzed by gas chromatography/mass spectrometry. Overall, 259 died among 1376 individuals over a median follow-up of 15.6 years in the 1999-2000 cycle, and 105 died in the latter subset of 2063 subjects during a median of 5.9 years. Cox proportional hazards regression was conducted to estimate the hazard ratios of mortality. The main isomer of industrially derived TFAs, elaidic acid (C18:1n-9t) was considerably associated with long-term total mortality in the 1999-2000 cycle after adjusting for confounders, with a 54% increase in the top tertile compared with the bottom one. However, the association disappeared with halving C18:1n-9t by 2009-2010. In contrast, neither of the ruminant-derived TFAs (C16:1n-7t and C18:1n-7t) suggested any inverse correlations with all-cause death, mortality due to heart disease, cancer or other causes.. The major isomer of industrial TFAs, the higher circulating C18:1n-9t might be associated with increased long-term mortality. The associations with death risk turned slight with the reduction of TFAs consumption by half. However, dietary guidelines should rigorously identify the healthy effect of animal TFAs consumption.

Topics: Adult; Cause of Death; Diet; Eating; Fatty Acids, Monounsaturated; Female; Follow-Up Studies; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Male; Middle Aged; Mortality; Nutrition Surveys; Oleic Acids; Proportional Hazards Models; Prospective Studies; Risk Factors; Time Factors; Trans Fatty Acids; United States

Determine whether plasma omega-7 vaccenic acid and palmitoleic acid levels are related to homeostasis model of insulin resistance scores and incident type II diabetes, and whether race/ethnicity modifies these associations.. Plasma phospholipid fatty acids were measured by gas chromatography with flame-ionization detection in Multi-Ethnic Study of Atherosclerosis participants. Linear regression determined associations of vaccenic acid and palmitoleic acid with log-transformed homeostasis model of insulin resistance scores (n=5689), and Cox regression determined associations with incident type II diabetes (n=5413, 660 cases). Race-interactions were tested.. Adjusting for typical risk factors, higher levels of plasma vaccenic acid were found to be inversely associated with insulin resistance scores across all four race/ethnicities, and a significant race-interaction was observed between Hispanics and Caucasians (P for interaction=0.03). Vaccenic acid was related to 17%, 32%, and 39% lower risks of incident type II diabetes in Black, Hispanic, and Chinese American participants, respectively. Differences in associations between races were detected (P for interactions<0.05). By contrast, higher levels of plasma palmitoleic acid were related to greater insulin resistance scores in Blacks (P<0.001) and Hispanics (P<0.001); significant race-based differences between associations were detected (P for interactions<0.05). Palmitoleic acid was correspondingly related to a 21% greater risk of incident type II diabetes in Black individuals.. Results suggest that plasma vaccenic acid and palmitoleic acid are markers of metabolic health and dysfunction, respectively. Coupled with previous evidence and the significant race-interactions, our findings have implications for future studies of the race-based differences in omega-7 fatty acids and their regulation in the context of deteriorating metabolic health.

Topics: Aged; Asian; Biomarkers; Black or African American; Diabetes Mellitus, Type 2; Fatty Acids, Monounsaturated; Female; Hispanic or Latino; Humans; Incidence; Insulin Resistance; Linear Models; Male; Metabolic Syndrome; Middle Aged; Oleic Acids; Proportional Hazards Models; White People

Trans-palmitoleic acid (trans-C16:1 n-7 or trans-Δ9-C16:1, TPA) is believed to improve several metabolic parameters according to epidemiological data. TPA may mainly come from direct intakes: however, data are inconsistent due to its very low amount in foods. Instead, TPA might arise from dietary trans-vaccenic acid (trans-C18:1 n-7, TVA), which is more abundant in foods. TVA chain-shortening would be involved, but formal proof of concept is still lacking to our knowledge. Therefore, the present study aimed at providing in vitro and in vivo evidence of TVA retroconversion to TPA. First, fresh rat hepatocytes cultured with growing doses of TVA were able to synthesize growing amounts of TPA, according to a 10% conversion rate. In addition, TPA was found in secreted triacylglycerols (TAG). Inhibiting peroxisomal β-oxidation significantly reduced TPA synthesis, whereas no effect was observed when mitochondrial β-oxidation was blocked. Second, pregnant female rats fed a TVA-supplemented diet free of TPA did metabolize dietary TVA, leading to detectable amounts of TPA in the liver. Apart from the brain, TPA was also found in all analyzed tissues, including the mammary gland. Hepatic peroxisomal β-oxidation of dietary TVA, combined with exportation of TPA under VLDL-TAG, may explain amounts of TPA in other tissues. In conclusion, dietary TVA undergoes peroxisomal β-oxidation and yields TPA. Thus, not only TPA circulating levels in humans can be explained by dietary TPA itself, but dietary TVA is also of importance.

Topics: Animals; Animals, Newborn; Cells, Cultured; Dietary Supplements; Dose-Response Relationship, Drug; Fatty Acids, Monounsaturated; Female; Hepatocytes; Lipoproteins, VLDL; Male; Oleic Acids; Peroxisomes; Pregnancy; Proof of Concept Study; Rats, Sprague-Dawley; Tissue Distribution; Triglycerides

Previous studies on health effects of trans fatty acids (TFA) have focused mainly on cardiovascular health. Little is known about the association of TFA with brain or mental health. In this study, we examined the associations of objectively-measured plasma TFA concentrations with depression in a large population-based cross-sectional study among U.S. adults.. We included 2136 non-pregnant participants aged 20 years or older from the National Health and Nutrition Examination Survey 2009-2010. Four major TFAs, including palmitelaidic acid (C16:1n-7t), elaidic acid (C18:1n-9t), vaccenic acid (C18:1n-7t), and linoelaidic acid (C18:2n-6t, 9t), were measured in fasting plasma using gas chromatography/mass spectrometry. Depressive symptoms were assessed using the validated Patient Health Questionnaire-9.. Participants with depressive symptoms had a higher plasma concentration of total TFA compared with those without depressive symptoms (6.6 vs 6.0 μmol/g lipids, P = 0.046). After adjustment for other major risk factors, the odds ratio (OR) of depressive symptoms comparing the highest with lowest tertile of TFAs was 1.44 (95% CI, 0.86-2.39) for total TFAs (P for trend 0.15). For each individual type of TFA, the corresponding OR was 1.78 (1.03-3.07) for elaidic acid (P for trend 0.049), 1.23 (0.76-2.00) for linoelaidic acid (P for trend 0.37), 1.19 (0.75-1.87) for palmitelaidic acid (P for trend 0.46), and 1.20 (0.75-1.94) for vaccenic acid (P for trend 0.43).. The cross-sectional study design limited causal inferences of the findings.. In a nationally representative population, plasma elaidic acid, a major trans fatty acid, was positively associated with depressive symptoms in adults. A positive but non-significant association of depressive symptoms was observed for total TFAs, linolelaidic acid, palmitelaidic acid, and vaccenic acid.

Topics: Adult; Aged; Cross-Sectional Studies; Depression; Fasting; Fatty Acids, Monounsaturated; Female; Gas Chromatography-Mass Spectrometry; Humans; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acids; Patient Health Questionnaire; Risk Factors; United States

Topics: Cadmium; Cell Line, Tumor; Chromatography, Gas; Dose-Response Relationship, Drug; Eicosanoic Acids; Fatty Acids; Fatty Acids, Monounsaturated; Humans; Macrophages; Oleic Acid; Oleic Acids

The effect of different individual TFA isomers on cardiovascular disease (CVD) has been a limited study, especially for stroke. We aimed to investigate the relationships between four major plasma TFA isomer (elaidic, vaccenic, palmitelaidic and linolelaidic acid) concentrations and the risk of CVD, stroke and non-stroke CVD. A cross-sectional study was conducted, utilising a nationally representative sample of US adults in the National Health and Nutrition Examination Survey. Among the 3504 participants, 304 participants self-reported CVD history. The highest quintile of elaidic acid intake was associated with a 233% higher CVD risk (p = .010). Adjusted for age, gender and race, palmitelaidic acid was associated with a decreased CVD risk, but the effect size was diminished in a subsequent analysis model. For stroke risk, we failed to identify any associations. In addition to elaidic acid, the health effect of palmitelaidic acid should be paid more attention in the future studies.

Topics: Adult; Aged; Aged, 80 and over; Body Mass Index; Cardiovascular Diseases; Cross-Sectional Studies; Diet; Fatty Acids, Monounsaturated; Female; Humans; Isomerism; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acid; Oleic Acids; Risk Factors; Self Report; Trans Fatty Acids; United States; Young Adult

A diet high in trans-fatty acids (TFA) induces insulin resistance in rodent models and primates. However, previous epidemiological studies on the association between TFAs, based primarily on self-reported intake from the diet, and diabetes in humans have yielded conflicting results. Herein we examined the associations of objectively measured plasma TFA concentrations with diabetes in a large population-based study among US adults.. We included 3801 participants aged ≥20 years from the National Health and Nutrition Examination Survey 1999-2000 and 2009-10. Four major TFAs, namely palmitelaidic acid (C16:1 n-7t), elaidic acid (C18:1 n-9t), vaccenic acid (C18:1 n-7t), and linolelaidic acid (C18:2 n-6t, 9t), were measured in fasting plasma using gas chromatography-mass spectrometry. Diabetes was defined by self-reported physician diagnosis, plasma fasting glucose ≥126 mg/dL, or HbA1c ≥6.5%.. After adjustment for other major risk factors, the odds ratios (95% confidence intervals) of diabetes comparing the highest with lowest quintile of plasma TFAs was 2.19 (1.27-3.79) for total TFAs (P. In a nationally representative population, plasma TFAs, in particular elaidic acid, were positively associated with diabetes and biomarkers of glucose metabolism.

Topics: Adult; Blood Glucose; Diabetes Mellitus; Fasting; Fatty Acids, Monounsaturated; Female; Humans; Insulin; Insulin Resistance; Linoleic Acid; Male; Middle Aged; Nutrition Surveys; Oleic Acid; Oleic Acids; Risk Factors; Trans Fatty Acids; United States

In humans, antidiabetics thiazolidinediones (TZDs) upregulate stearoyl-CoA desaturase 1 (SCD1) gene in adipose tissue and increase plasma levels of SCD1 product palmitoleate, known to enhance muscle insulin sensitivity. Involvement of other tissues in the beneficial effects of TZDs on plasma lipid profile is unclear. In our previous study in mice, in which lipogenesis was suppressed by corn oil-based high-fat (cHF) diet, TZD rosiglitazone induced hepatic Scd1 expression, while liver triacylglycerol content increased, VLDL-triacylglycerol production decreased and plasma lipid profile and whole-body glycemic control improved. Aim of this study was to characterise contribution of liver to changes of plasma lipid profile in response to a 8-week-treatment by rosiglitazone in the cHF diet-fed mice. Rosiglitazone (10 mg/kg diet) upregulated expression of Scd1 in various tissues, with a stronger effect in liver as compared with adipose tissue or skeletal muscle. Rosiglitazone increased content of monounsaturated fatty acids in liver, adipose tissue and plasma, with palmitoleate being the most up-regulated fatty acid. In the liver, enhancement of SCD1 activity and specific enrichment of cholesteryl esters and phosphatidyl cholines with palmitoleate and vaccenate was found, while strong correlations between changes of various liver lipid fractions and total plasma lipids were observed (r=0.74-0.88). Insulin-stimulated glycogen synthesis was increased by rosiglitazone, with a stronger effect in muscle than in liver.. changes in plasma lipid profile favouring monounsaturated fatty acids, mainly palmitoleate, due to the upregulation of Scd1 and enhancement of SCD1 activity in the liver, could be involved in the insulin-sensitizing effects of TZDs.

Topics: Adipose Tissue, White; Animals; Corn Oil; Dietary Fats; Fatty Acids; Fatty Acids, Monounsaturated; Glucose Clamp Technique; Glycogen; Hypoglycemic Agents; Insulin Resistance; Lipids; Liver; Mice; Muscle, Skeletal; Oleic Acids; Organ Specificity; Random Allocation; Rosiglitazone; Stearoyl-CoA Desaturase; Thiazolidinediones; Up-Regulation