American Heart Association Supports EPA/DHA Supplementation for Heart Disease and Heart Failure
Siscovick, D. S. et al. (on behalf of the American Heart Association Nutrition Committee), Circulation, in press, 2017
In 2002, the American Heart Association (AHA) published a scientific statement (Circulation, 106: 2747-2757 (2002)) with the recommendation that patients with documented coronary heart disease (CHD) consume close to 1 gram (1000 mgs) per day of polyunsaturated fatty acids (PUFA) as EPA plus DHA from oily fish or via supplementation as an option in consultation with a physician. The present 2017 update has reviewed large randomized clinical trials (RCTs) of such omega-3 fatty acid supplementation in relation to major clinical cardiovascular disease (CVD) outcomes. The advisory has now provided recommendations for both clinicians and patients.
Conclusions: ‘Taken together, the cumulative findings from RCTs suggest that the omega-3 PUFA supplements may reduce CHD death, possibly through a reduction in ischemia-induced SCD (sudden cardiac death), among patients with prior CHD…’. ‘…the majority of co-authors concluded that treatment with omega-3 PUFA supplements is reasonable for the secondary prevention of CHD death…’. ‘Although based on a single, large RCT, treatment with omega-3 PUFA supplements is reasonable among patients with heart failure with reduced ejection fraction’.
Regarding the aforementioned likely benefit of omega-3 PUFA therapy offered in CHD mortality (presumably via reducing SCD), the report based on a meta-analysis of 20 studies calculated the expected reduction in CHD death and SCD to be in the order of 10 % overall. Furthermore, they note that even such a modest benefit justifies the use of a relatively safe therapy such as omega-3 PUFA. In this regard, it is noted that the daily supplemental dose of omega-3 PUFA (EPA/DHA) in the RCTs as reviewed ranged from 0.5 gm (500 mgs) to 1.8 gm (1800 mgs). The trial on the secondary prevention of outcomes in patients with heart failure as referred to in this report employed a daily dose of supplemental EPA/DHA amounting to 0.84 gm (840 mgs) and a reduction in total mortality of 9 %.
Dr. Holub's Comments:
It is noted that the daily doses of supplemental EPA/DHA (omega-3 PUFA) as used in the studies (RCTs) as reviewed by the AHA committee are not total EPA/DHA intakes. Total intakes will of course be higher to varying degrees due to the presence of EPA/DHA from dietary sources (fish/seafood and foods enriched with EPA/DHA). Such ‘background’ intakes from dietary sources were not scientifically quantified in almost all studies. These would be expected to range from approx. 100-150 mgs EPA/DHA daily (eg., in North American trials) to much higher intakes (averaging approx. 500 mgs/day) in Japanese-based trials. There are extensive ongoing clinical trials which will be employing considerably higher dosages of omega-3 PUFA than has typically been used in the past. The REDUCE-IT trial is designed to determine if 4 gm (4000 mgs) daily of EPA will reduce ischemic cardiac events in patients at increased CVD risk who are already being treated with statins (for blood cholesterol-lowering). The EVAPORATE trial will employ statin-treated patients with elevated blood triglyceride levels (200-400 mgs/100ml) to determine if 4 gm (4000 mgs) daily of EPA can retard the progression atherosclerotic plaque. Typical EPA intakes in North Americans (not taking omega-3 supplements) via dietary sources are very low - ranging from 25-50 mgs/person/day.