No Cardiac Benefit for Omega-3 Fatty Acids

A systematic review and meta-analysis of 20 studies representing experience in 68,680 patients shows that use of omega-3 fatty acid supplementation does not improve cardiovascular risk factors. Published in The Journal of the American Medical Association, the report examined evidence from randomized clinical trials (RCTs) in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials from as early as 1989 through August 2012.

The RCTs included omega-3 administration and diet or placebo for primary or secondary cardiovascular disease (CVD). Studies with treatment duration less than 1 year were excluded to ensure sufficient time to prove efficacy of treatment in CVD prevention. The researchers also evaluated the methodological quality of the trials and assessed the risk of bias, using the Cochrane collaboration tool.

Most of the study participants were of European ancestry (15 studies; 49,314 participants) but the largest trial included 18,645 Japanese participants. In all but two trials, omega-3 supplements were used, at a mean dosage of 1.51 g/day; mean treatment duration was 2 years.

When all supplement studies were considered, no statistically significant association was observed for all-cause mortality (relative risk [RR], 0.96; 95% CI, 0.91 to 1.02; risk reduction [RD] -0.004, 95% CI, -0.01 0.02), cardiac death (RR, 0.91; 95% CI, 0.85 to 0.98; RD -0.01; 95% CI, -0.02 to 0.00), sudden death (RR, 0.87; 95% CI, 0.75 to 1.01; RD, -0.003, 95% CI, -0.012 to 0.006), myocardial infarction (RR, 0.89; 95% CI, 0.76 to 1.04; RD, -0.002; 95% CI, -0.007 to 0.002), or stroke (RR, 1.05; 95% CI, 0.93 to 1.18; RD, 0.001; 95% CI, -0.002 to 0.004). Neither study-specific nor population-specific characteristics were associated with the observed effect of omega-3.

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