Fish Oil for Healthy Aging: Potential Application to Master Athletes

Master athletes perform high volumes of exercise training yet display lower levels of physical functioning and exercise performance when compared with younger athletes. Several reports in the clinical literature show that long chain n-3 polyunsaturated fatty acid (LC n-3 PUFA) ingestion promotes skeletal muscle anabolism and strength in untrained older persons. There is also evidence that LC n-3 PUFA ingestion improves indices of muscle recovery following damaging exercise in younger persons. These findings suggest that LC n-3 PUFA intake could have an ergogenic effect in master athletes. However, the beneficial effect of LC n-3 PUFA intake on skeletal muscle in response to exercise training in both older and younger persons is inconsistent and, in some cases, generated from low-quality studies or those with a high risk of bias. Other factors such as the choice of placebo and health status of participants also confound interpretation of existing reports. As such, when considered on balance, the available evidence does not indicate that ingestion of LC n-3 PUFAs above current population recommendations (250–500 mg/day; 2 portions of oily fish per week) enhances exercise performance or recovery from exercise training in master athletes. Further work is now needed related to how the dose, duration, and co-ingestion of LC n-3 PUFAs with other nutrients such as amino acids impact the adaptive response to exercise training. This work should also consider how LC n-3 PUFA supplementation may differentially alter the lipid profile of cellular membranes of key regulatory sites such as the sarcolemma, mitochondria, and sarcoplasmic reticulum.

Fish oil supplements, oxidative status, and compliance behaviour: Regulatory challenges and opportunities

BACKGROUND

Fish oil supplements that are rich in omega-3 long-chain polyunsaturated fatty acids (n-3 PUFAs). PUFAs are among the most widely-used dietary supplements globally, and millions of people consume them regularly. There have always been public concerns that these products should be guaranteed to be safe and of good quality, especially as these types of fish oil supplements are extremely susceptible to oxidative degradation.

OBJECTIVES

The aim of the current study is to investigate and examine the oxidation status of dietary supplements containing fish oils and to identify important factors related to the oxidation status of such supplements available in the United Arab Emirates (UAE).

METHODS

A total of 44 fish oil supplements were analysed in this study. For each product, the oxidative parameters peroxide value (PV), anisidine value (AV), and total oxidation (TOTOX) were calculated, and comparisons were made with the guidelines supplied by the Global Organization for EPA and DHA Omega-3s (GOED). Median values for each of the above oxidative parameters were tested using the Kruskal-Wallis and Mann-Whitney U tests. P values < 0.05 were chosen as the statistically significant boundary.

RESULTS

The estimate for the average PV value was 6.4 with a 95% confidence interval (CI) [4.2-8.7] compared to the maximum allowable limit of 5 meq/kg. The estimate for the average P-AV was 11 with a 95% CI [7.8-14.2] compared to the maximum allowable limit of 20. The estimate for the average TOTOX value was 23.8 meq/kg with a 95% CI [17.4-30.3] compared to the maximum allowable limit of 26 according to the GOED standards.

CONCLUSION

This research shows that most, although not all, of the fish oil supplements tested are compliant with the GOED oxidative quality standards. Nevertheless, it is clear that there should be a high level of inspection and control regarding authenticity, purity, quality, and safety in the processes of production and supply of dietary supplements containing fish oils.

Omega-3 Fatty Acids for the Management of Hypertriglyceridemia: A Science Advisory From the American Heart Association

Hypertriglyceridemia (triglycerides 200-499 mg/dL) is relatively common in the United States, whereas more severe triglyceride elevations (very high triglycerides, ≥500 mg/dL) are far less frequently observed. Both are becoming increasingly prevalent in the United States and elsewhere, likely driven in large part by growing rates of obesity and diabetes mellitus. In a 2002 American Heart Association scientific statement, the omega-3 fatty acids (n-3 FAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were recommended (at a dose of 2-4 g/d) for reducing triglycerides in patients with elevated triglycerides. Since 2002, prescription agents containing EPA+DHA or EPA alone have been approved by the US Food and Drug Administration for treating very high triglycerides; these agents are also widely used for hypertriglyceridemia. The purpose of this advisory is to summarize the lipid and lipoprotein effects resulting from pharmacological doses of n-3 FAs (>3 g/d total EPA+DHA) on the basis of new scientific data and availability of n-3 FA agents. In treatment of very high triglycerides with 4 g/d, EPA+DHA agents reduce triglycerides by ≥30% with concurrent increases in low-density lipoprotein cholesterol, whereas EPA-only did not raise low-density lipoprotein cholesterol in very high triglycerides. When used to treat hypertriglyceridemia, n-3 FAs with EPA+DHA or with EPA-only appear roughly comparable for triglyceride lowering and do not increase low-density lipoprotein cholesterol when used as monotherapy or in combination with a statin. In the largest trials of 4 g/d prescription n-3 FA, non-high-density lipoprotein cholesterol and apolipoprotein B were modestly decreased, indicating reductions in total atherogenic lipoproteins. The use of n-3 FA (4 g/d) for improving atherosclerotic cardiovascular disease risk in patients with hypertriglyceridemia is supported by a 25% reduction in major adverse cardiovascular events in REDUCE-IT (Reduction of Cardiovascular Events With EPA Intervention Trial), a randomized placebo-controlled trial of EPA-only in high-risk patients treated with a statin. The results of a trial of 4 g/d prescription EPA+DHA in hypertriglyceridemia are anticipated in 2020. We conclude that prescription n-3 FAs (EPA+DHA or EPA-only) at a dose of 4 g/d (>3 g/d total EPA+DHA) are an effective and safe option for reducing triglycerides as monotherapy or as an adjunct to other lipid-lowering agents.

Omega-3 Long-Chain Polyunsaturated Fatty Acid Content and Oxidation State of Fish Oil Supplements in New Zealand

Forty-seven fish oil products available on the New Zealand market were analyzed for eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, as well as for oxidative status in a collaborative effort by several analytical laboratories. Of the tested products, 72%, 86% and 77% complied with voluntary industry-set maximum limits on Peroxide Value (PV), para-Anisidine Value (p-AV), and TOTOX, respectively. 91% of the products complied with EPA/DHA content claims. All fish oils complied with a p-AV limit of 30, 98% with a PV limit of 10 meq O2/kg, and 96% with a calculated TOTOX value of 50, which are less stringent limits used by the European and British Pharmacopeia and the Australian authorities. The results are in stark contrast to the very low percentage of fish oil products reported to be in compliance with primary oxidation limits and EPA/DHA content by a recently published assessment of fish oil supplements in New Zealand. Possible reasons for this discrepancy are evaluated and discussed.

Improving lipids with prescription icosapent ethyl after previous use of fish oil dietary supplements

Managing dyslipidemia can be challenging in patients with statin intolerance. We describe the lipid effects of icosapent ethyl 4 g/day (high-purity prescription omega-3 eicosapentaenoic acid) in two coronary artery disease patients with statin intolerance who were self-treating with fish oil dietary supplements. After initiating icosapent ethyl, improvements were noted in the first and second patients, respectively, in total cholesterol (-12%; -21%), LDL cholesterol (-3%; -24%), triglycerides (-34%; -16%), non-HDL cholesterol (-12%; -22%), the omega-3 index (+42%; +8%) and eicosapentaenoic acid levels (+275%; +138%). Icosapent ethyl was well tolerated with no adverse events reported. These cases demonstrated favorable lipid effects with prescription icosapent ethyl treatment that may help optimize the care of high-risk coronary artery disease patients with statin intolerance.

Marine omega-3 highly unsaturated fatty acids: From mechanisms to clinical implications in heart failure and arrhythmias

Therapeutic implications of marine omega-3 highly unsaturated fatty acids (HUFA) in cardiovascular disease are still discussed controversially. Several clinical trials report divergent findings and thus leave ambiguity on the meaning of oral omega-3 therapy. Potential prognostic indications of HUFA treatment have been predominantly studied in coronary artery disease, sudden cardiac death, ventricular arrhythmias, atrial fibrillation and heart failure of various origin. It is suspected that increased ventricular wall stress is crucially involved in the prognosis of heart failure. Increased wall stress and an unfavorable myocardial remodeling is associated with an increased risk of arrhythmias by stretch-activated membrane ion channels. Integration of HUFA into the microenvironment of cardiomyocyte ion channels lead to allosteric changes and increase the electrical stability. Increased ventricular wall stress appears to be involved in the local myocardial as well as in the hepatic fatty acid metabolism, i.e. a cardio-hepatic syndrome. Influences of an altered endogenous HUFA metabolism and an inverse shift of the fatty acid profile was underrated in the past. A better understanding of these interacting endogenous mechanisms appears to be required for interpreting the findings of recent experimental and clinical studies. The present article critically reviews major studies on basic pathophysiological mechanisms and treatment effects in clinical trials.

Mechanisms increasing n-3 highly unsaturated fatty acids in the heart

Due to ambiguous findings on cardiovascular benefits of systemic omega-3 fatty acid therapy, endogenous mechanisms contributing to local organ-specific concentrations of highly unsaturated fatty acids (HUFA) were examined. Using gas chromatography, 43 fatty acids were analyzed in atrial and ventricular myocardium and in pericardial fluid of male Wistar rats. To examine the endogenous fatty acid metabolism, precursors were administered into the pericardial sac. Pro- and anti-inflammatory actions were induced by talc or fenofibrate, respectively. Physical exercise and a sedentary obese state were used for increased beta-oxidation. DHA (22:6n-3) was increased in ventricular when compared with atrial myocardium (9.0 ± 2.1% vs. 4.7 ± 1.0%, p < 0.001). Intrapericardial EPA (20:5n-3) application lead to an increase of the succeeding tetracosapentaenoic acid (24:5n-3) in atrial myocardium, which is a key precursor of DHA. In contrast, proinflammatory stimulation of the n-6 HUFA pathway did not influence the n-3 metabolism. Exercise- and obesity-induced increased beta-oxidation, the finalizing step of DHA synthesis, was associated with increased ventricular DHA concentrations (6.7 ± 1.0% vs. 8.4 ± 1.2%, p < 0.01). It is concluded that the endogenous metabolism contributes markedly to myocardial HUFA concentrations. The findings are supposed to influence the efficacy of oral HUFA treatment and provide a rationale for divergent findings of previous trials on omega-3 therapy.