Results of a meta-analysis published Online First by Archives of Internal Medicine, indicate that there is not enough evidence that omega-3 fatty acid supplements have a secondary preventive effect against overall cardiovascular events among individuals who have a history of heart disease.
According to the researchers, results from some earlier trials indicate that omega-3 fatty acid supplements are effective in the secondary prevention of cardiovascular disease (CVD). However, the evidence remains inconclusive.
In order to analyze the link between the omega-3 supplements such as, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and the risk of developing heart disease among individuals with a history of CVD, Sang Mi Kwak, M.D., of the Center for Cancer Prevention and Detection, Republic of Korea, and colleagues, conducted a meta-analysis of 14 randomized, double-blind, placebo-controlled trials, conducted between June 1995 and November 2010.
In total, 20,485 individuals with a history of heart disease participated in the trials. 78.5% of the participants were men and the mean age of study participants was 63.4 years old. In addition, the daily dose of DHA or EPA ranged from 0.4 to 4.8 grams per day. Follow-up for participants ranged from 1 to 4.7 years.
The researchers said:
"Our meta-analysis showed insufficient evidence of a secondary preventive effect of omega-3 fatty acid supplements against overall cardiovascular events.
Likewise, we found no beneficial effect of omega-3 fatty acid supplements on other cardiovascular evens, such as sudden cardiac death, myocardial infarction (fatal or nonfatal heart attack), angina and unstable angina, congestive heart failure, and transient ischemic attack and stroke, or on all-cause mortality."