A review of 25 trials that evaluated the risk of CHD related to the body’s omega-3 levels showed that there was an inverse relationship with major cardiovascular (CV) events and tissue levels of EPA and even more so, with DHA. [1] There have been three large randomized trials documenting omeg-3 polyunsaturated fatty acids (PUFA) in both primary and secondary prevention of CHD. In the Diet and Reinfarction Trial (DART),[2] men with recent MI (myocardial infarction) showed that omega-3 PUFA either in dietary oily fish or fish oil capsules, but far more in the fish oil capsules, reduced 20 year all-cause mortality by 29% and mostly all due to reduction in CHD mortality. The Gruppo Italiano per lo Studio della Sopravvivenza nell’ Infarto Miocardico (GISSI) [3] randomized 11,323 post MI patients with 1 capsules of 850 mg EPA/DHA in a 1.2:1 ratio versus customary care. After one year, patients taking the fish oil had a 21% reduction in total mortality and a 30% reduction in CV mortality. In addition, there was a highly significant 45% reduction in sudden cardiac death (SCD) after only 4 months.
The JELIS (Japan EPA Lipid Intervention Study) trial [4] included a total of 18,645 subjects (men 
aged 40-75 and postmenopausal women aged > 75 and a mean age of 61 years and 31% men). Those with a serum total cholesterol level of > 250 mg/dL were eligible. About 36% were hypertensive, 15% had diabetes and 20% had coronary artery disease. Subjects were randomized to pravastatin 10mg/day or simvastatin 5mg/day or the same statin doses with 1,800 mg/day of EPA. After 5 years, those in the EPA group had a 19% reduction in major cardiac events.
These three trials indicated that omega-3 PUFAs lowered the risk of CV disease in both primary and secondary prevention. While not all studies have shown favorable results, the numbers of patients treated, the doses used, and the results of the DART, GISSI and JELIS study are strong motivations to increase dietary fish intake and especially fish oil supplementation. In order to test and remove heavy metals, pesticides, other environmental contaminants and microbes, look for products that can produce independent third part testing for each lot of supplements.
Recommended doses for primary and secondary prevention:
1,000 mg/day of combined EPA/DHA
References:
[1] Harris W, Poston W, Hadock C. Tissue n-3 and n-6 fatty acids and risk for coronary heart disease events. Atherosclerosis 2007;193:1-10.
[2] Burr M, Fehily A, Gilbert J, et al. Effects of changes in fat, fish, and fibre intakes on death and myocardial reinfarction: Diet and Reinfarction Trial (DART). Lancet 1989;2:757-761.
[3] Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI. Lancet 2001; 357;642 and Lancet 2007;369:106 and Lancet 1999;354;447-455.
[4] Yokoyama M, Origasa H, Matsuzaki M, et al. Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis. Lancet 2007;369:1090-1098.
