The effect of camelina sativa oil and fish intakes on fatty acid compositions of blood lipid fractions.

BACKGROUND AND AIMS: Blood lipid fractions serve as objective biomarkers of dietary fat intake. It is unclear which fatty acid pool most accurately reflects the dietary intakes of different n-3 PUFAs. We aimed to investigate the effect of fish and camelina sativa oil (CSO) intakes on fatty acid composition of erythrocyte membranes (EM), plasma phospholipids (PL), cholesteryl esters (CE) and triglycerides (TG). We also aimed to identify the most appropriate blood lipid fraction for assessing n-3 PUFA intake. METHODS AND RESULTS: Altogether 79 volunteers with impaired glucose metabolism were randomly assigned either to CSO, fatty fish, lean fish or control groups for 12 weeks. Fatty acid compositions of lipid pools were measured by gas chromatography. The proportion of alpha-linolenic acid (ALA) increased in all lipid pools in the CSO group (false discovery rate (FDR) p < 0.001 for all). Similarly, the proportions of EPA and DHA increased in all lipid fractions in the fatty fish group (FDR p < 0.001 for EM, PL and CE; FDR p = 0.005 for TG; FDR p < 0.001 for EM, PL, CE; FDR p < 0.007 for TG, respectively). Changes in the dietary intakes of ALA, EPA and DHA correlated with the changes in their proportions in all lipid pools (r = 0.3-0.5, p < 0.05). CONCLUSION: There is no difference in the ability of blood lipid fractions in reflecting the dietary intake of different n-3 PUFAs over a time period of 12 weeks in subjects with high baseline omega-3 index. This trial was registered in Clinicaltrials.gov (NCT01768429).

Health economic consequences of reducing salt intake and replacing saturated fat with polyunsaturated fat in the adult Finnish population: estimates based on the FINRISK and FINDIET studies.

BACKGROUND/OBJECTIVES: To predict the health economic consequences of modest reductions in the daily intake of salt (-1.0 g per day) and replacement of saturated fat (SFA, -1.0 energy percent (E%)) with polyunsaturated fat (PUFA, +1.0 E%) in the Finnish population aged 30-74 years. SUBJECTS/METHODS: A Markov model with dynamic population structure was constructed to present the natural history of cardiovascular diseases (CVDs) based on the most current information about the age- and sex-specific cardiovascular risk factors, dietary habits and nutrient intake. To predict the undiscounted future health economic consequences of the reduction of dietary salt and SFA, the model results were extrapolated for the years 2010-2030 by replacing the baseline population in the year 2007 with the extrapolated populations from the official Finnish statistics. Finnish costs (€2009, societal perspective) and EQ-5D utilities were obtained from published references. RESULTS: During the next 20 years, a population-wide intervention directed at salt intake and dietary fat quality could potentially lead to 8000-13,000 prevented CVD cases among the Finnish adults compared the situation in year 2007. In addition, the reduced incidence of CVDs could gain 26,000-45,000 quality-adjusted life years and save €150-225 million over the same time period. CONCLUSION: A modest reduction of salt and replacement of SFA with PUFA in food products can significantly reduce the burden of CVD in the adult Finnish population. This impact may be even larger in the near future due to the ageing of Finnish population.

alpha-Lipoic acid supplementation enhances heat shock protein production and decreases post exercise lactic acid concentrations in exercised standardbred trotters.

Heat shock protein (HSP) expression is an adaptive mechanism against the disruption of cell homeostasis during exercise. Several antioxidant supplementation strategies have been used to enhance tissue protection. In this study, we examined the effects of a redox modulator, alpha-lipoic acid (LA) on HSP responses in six standardbred trotters following intense aerobic exercise. DL-LA supplementation (25 mg kg(-1) d(-1)) for five weeks increased the resting levels of HSP90 (1.02+/-0.155 in control and 1.26+/-0.090 after supplementation in arbitrary units) and the recovery levels of inducible HSP70 (0.89+/-0.056 in control and 1.05+/-0.089 after supplementation in arbitrary units) in skeletal muscle. Furthermore, LA increased skeletal muscle citrate synthase activity at rest and lowered the blood lactate concentration during exercise without any changes in the heart rate. LA had no effect on concentrations of HSP60, HSP25 or GRP75 in skeletal muscle. LA decreased the exercise-induced increases in plasma aspartate aminotransferase and creatine kinase concentrations during recovery. Our results suggest that LA supplementation may enhance tissue protection and increase oxidative capacity of the muscle in horse.

Serum fatty acid composition predicts development of impaired fasting glycaemia and diabetes in middle-aged men.

AIMS: Dietary fatty acid intake is reflected in serum fatty acid composition. Studies prospectively investigating serum fatty acids and development of impaired fasting glycaemia (IFG) or diabetes mellitus (DM) are largely lacking. We assessed the association of serum fatty acid composition with development of IFG or DM. METHODS: Middle-aged normoglycaemic men (n = 895) participating in a prospective cohort study were followed up after 4 years. RESULTS: At baseline proportions of serum esterified and non-esterified saturated fatty acids were increased and polyunsaturated fatty acids decreased in men who after 4 years had developed IFG (n = 56) or DM (n = 34). No differences in dietary fatty acid composition as recorded in 4-day dietary records were noted. In logistic regression analyses adjusting for age; obesity; and fasting lipid, glucose and insulin concentrations, men with proportions of non-esterified and esterified linoleate in the upper third had nearly half the risk for IFG or DM compared with the lower third. In covariate analyses, baseline non-esterified linoleate proportions were associated with changes in fasting insulin and glucose concentrations over the 4-year follow-up. Baseline esterified fatty acid composition was also associated with changes in insulin. CONCLUSIONS: High serum linoleate proportions decreased the risk of developing IFG or DM in middle-aged men over a 4-year follow-up, possibly mediated in part by insulin resistance. These findings support recommendations to substitute vegetable fat for animal and dairy fat in the prevention of disturbances of glucose and lipid metabolism.

Vitamin E regulates changes in tissue antioxidants induced by fish oil and acute exercise.

PURPOSE: Prooxidant effects of fish oil supplementation could unfavorably affect the cardiovascular benefits of fish oil. We tested the effects of 8 wk vitamin E cosupplementation with fish oil on antioxidant defenses at rest and in response to exhaustive exercise in rats. METHODS: Rats (N = 80) were divided into fish oil, fish oil and vitamin E (FOVE), soy oil, and soy oil and vitamin E (SOVE) supplemented groups. For the vitamin E supplemented rats, corresponding groups (FOVE-Ex and SOVE-Ex) performed an acute bout of exhaustive exercise after the supplementation period. RESULTS: Fish oil supplementation increased the activity of catalase, glutathione peroxidase, and glutathione-S-transferase in the liver and red gastrocnemius (RG) muscle. Fish oil decreased liver total glutathione (TGSH) levels. Vitamin E supplementation decreased antioxidant enzyme activities to levels at or near those in SOVE in a tissue specific pattern. Vitamin E increased TGSH in liver, heart, and RG. Regression analysis showed TGSH to be a negative determinant of protein oxidative damage as measured by protein carbonyl levels in both liver and RG. Catalase activity was associated with liver lipid peroxidation as measured by thiobarbituric acid-reacting substances. The exercise-induced decrease in hepatic TGSH tended to be less in FOVE versus SOVE. Exhaustive exercise also modulated tissue antioxidant enzymes. CONCLUSIONS: Vitamin E supplementation markedly decreased fish oil induced antioxidant enzyme activities in all tissues. Sparing of glutathione may be an important mechanism by which vitamin E decreased tissue protein oxidative damage.

Alpha-lipoic acid supplementation: tissue glutathione homeostasis at rest and after exercise.

Antioxidant nutrients have demonstrated potential in protecting against exercise-induced oxidative stress. alpha-Lipoic acid (LA) is a proglutathione dietary supplement that is known to strengthen the antioxidant network. We studied the effect of intragastric LA supplementation (150 mg/kg, 8 wk) on tissue LA levels, glutathione metabolism, and lipid peroxidation in rats at rest and after exhaustive treadmill exercise. LA supplementation increased the level of free LA in the red gastrocnemius muscle and increased total glutathione levels in the liver and blood. The exercise-induced decrease in heart glutathione S-transferase activity was prevented by LA supplementation. Exhaustive exercise significantly increased thiobarbituric acid-reactive substance levels in the liver and red gastrocnemius muscle. LA supplementation protected against oxidative lipid damage in the heart, liver, and red gastrocnemius muscle. This study reports that orally supplemented LA is able to favorably influence tissue antioxidant defenses and counteract lipid peroxidation at rest and in response to exercise.

Skeletal muscle and liver lipoyllysine content in response to exercise, training and dietary alpha-lipoic acid supplementation.

In human cells, alpha-lipoic acid (LA) is present in a bound lipoyllysine form in mitochondrial proteins that play a central role in oxidative metabolism. The possible effects of oral LA supplementation, a single bout of strenuous exercise and endurance exercise training on the lipoyllysine content in skeletal muscle and liver tissues of rat were examined. Incorporation of lipoyl moiety to tissue protein was not increased by enhanced abundance of LA in the diet. Endurance exercise training markedly increased lipoyllysine content in the liver at rest. A bout of exhaustive exercise also increased hepatic lipoyllysine content. A significant interaction of exhaustive exercise and training to increase tissue lipoyllysine content was evident. In vastus lateralis skeletal muscle, training did not influence tissue lipoyllysine content. A single bout of exhaustive exercise, however, clearly increased the level of lipoyllysine in the muscle. Comparison of tissue lipoyllysine data with that of free or loosely-bound LA results showed a clear lack of association between the two apparently related parameters. Tightly protein-bound lipoyllysine pool in tissues appeared to be independent of the loosely-bound or free LA status in the tissue.

Fish oil and vitamin E supplementation in oxidative stress at rest and after physical exercise.

Fish oil supplementation and physical exercise may induce oxidative stress. We tested the effects of 8 wk of alpha-tocopherol (vitamin E) and fish oil (FO) supplementation on resting and exercise-induced oxidative stress. Rats (n = 80) were divided into groups supplemented with FO, FO and vitamin E (FOVE), soy oil (SO), and SO and vitamin E (SOVE), and for FOVE and SOVE they were divided into corresponding exercise groups (FOVE-Ex and SOVE-Ex). Lipid peroxidation [thiobarbituric acid-reacting substances (TBARS)] was 33% higher in FO compared with SO in the liver, but oxidative protein damage (carbonyl levels) remained similar in both liver and red gastrocnemius muscle (RG). Vitamin E supplementation, compared with FO and SO, markedly decreased liver and RG TBARS, but liver TBARS remained 32% higher in FOVE vs. SOVE. Vitamin E also markedly decreased liver and RG protein carbonyl levels, although levels in FOVE and SOVE were similar. Exercise increased liver and RG TBARS and RG protein carbonyl levels markedly, with similar levels in FOVE-Ex and SOVE-Ex. FO increased lipid peroxidation but not protein oxidation in a tissue-specific manner. Vitamin E markedly decreased lipid peroxidation and protein oxidation in both FOVE and SOVE, although liver lipid peroxidation remained higher in FOVE. Despite higher levels of hepatic lipid peroxidation at rest in FOVE compared with SOVE, liver appeared to be relatively less susceptible to exercise-induced oxidative stress in FOVE.