Mayo Clinic Proceedings Review on Omega-3 for Cardioprotection
Lee JH et al. Mayo Clin Proc. 83:324-332, (2008)
Mid-America Heart Institute and the University of Missouri-Kansas City.
In the present review, the authors outline results from the three large controlled trials on 32,000 participants overall who were randomized to received either placebo (control) supplementation or supplements providing DHA+EPA. These trials showed overall reductions in cardiovascular events of 19-45 % which the current authors considered to be the most compelling evidence for the cardiovascular benefit provided by omega-3 fatty acids. The intakes from supplementation in the DART trial (in post-myocardial infarction patients) and the GISSI Prevenzione study (post-myocardial infarction patients also) range from 850-900 mg of DHA/EPA combined per day. In the more recent JELLIS trial, patients with hypercholesterolemia on statin therapy were randomly assigned to a placebo or an EPA concentrate at the level of 1800 mg/day. In contrast to the two aforementioned trials, the JELLIS trial was conducted on Japanese subjects who would be expected to have a much higher intake in their basal diet of DHA/EPA than those in the DART and GISSI studies. Thus, the total intake of EPA/DHA in the JELLIS trial would be approximately 2800 mg/day (approximately 900 mg/day in the basal Japanese diet + 1800 mg of EPA/day via supplementation). The authors recommend that patients should consume DHA+EPA and that the target DHA/EPA (combined) consumption levels should be approximately 1 gm/day for those with known coronary heart disease and at least 500 mg/day for those who are without disease. In addition, the authors indicate that two meals of oily fish per week could provide 400-500 mg/day of DHA/EPA and that supplementation with DHA/EPA up to 3-4 gm/day can provide marked triglyceride lowering ranging from 20-50% depending upon the background triglyceride levels and other parameters associated with the patients being so treated. Finally, the authors conclude that combination therapy with omega-3 fatty acids in addition to statin therapy is a safe and effective way to improve lipid levels and cardiovascular prognosis beyond the benefits obtained by statin therapy alone. In the future, blood measures for DHA/EPA could be used to identify patients with sub-optimal levels of circulating omega-3 fatty acids as a guide to individualized therapeutic recommendations.
Dr. Holub's Comments:
This newly-released review article provides an up to date summary of current knowledge on omega-3 fatty acids as DHA/EPA from fish and/or supplementation on cardioprotection- both preventive and for the management of patients with coronary heart disease who may or may not be on statin therapy. It is noteworthy that fatty fish intakes of 5-7 times per week can be expected to produce a daily intake of DHA/EPA (combined) of approximately 700-1000 mg/day on average. For blood triglyceride-lowering with targets of 25-40% reductions (within a 2-4 week period), supplementation will almost always be required to attain these much higher daily intakes. Pharmaconutrition and nutraceutical therapeutics including omega-3 therapeutics for clinical care by the practitioner, in particular when higher dosages of DHA/EPA are employed will require an awareness of potential contraindications for side effects in a very small number of patients (including those on various blood thinners having coagulation times monitored, other conditions which may be relevant).