Associations of Omega-3 fatty acid supplement use with cardiovascular disease risks

Meta-analysis of 10 trials shows that there is no significant association with reductions in fatal or nonfatal coronary heart disease

Supplementation with omega-3 fatty acids for a mean of 4.4 years had no significant association with reductions in fatal or nonfatal coronary heart disease or any major vascular events, finds a meta-analysis of 10 trials involving 77 917 participants. 

The results provide no support for current recommendations to use omega-3 fatty acid supplements for the prevention of fatal coronary heart disease, researchers explain. 

Observational studies in Western and Asian populations have reported that regular consumption of fish once or twice a week is associated with lower risks of death from coronary heart disease (CHD). Current guidelines advocate the use of marine-derived omega-3 fatty acids supplements for the prevention of coronary heart disease and major vascular events in people with prior coronary heart disease, but large trials of omega-3 fatty acids have produced conflicting results.

A total of 77 917 participants were involved, and trials ranged in size from 563 to 18 645 participants. Of the 10 trials, 8 had a double-blind design and used a placebo control, and 2 trials had an open-label design. The risk of bias of the included trials was low, with exception of the 2 trials that did not use a placebo-treated control group. 

Combinations of polyunsaturated fatty acid ethyl esters of EPA and DHA were used in all but 1 trial, which tested daily dose of 1800 mg EPA alone. The daily doses of EPA varied from 226 to 1800 mg/day, and DHA varied from 0 to 1700 mg/day. The mean duration of treatment in individual trials varied from 1.0 year to 6.2 years (weighted mean, 4.4 years).

The results of the study were reported in JAMA Cardiology.