Omega-3 fatty acids and cardiovascular risk.

Background: Omega-3 polyunsaturated fatty acids (PUFA's) have an FDA indication for triglyceride lowering in patients with hypertriglyceridemia. Some European agencies have also approved omega-3 fatty acids for cardiovascular risk modification. Several major societies in the US also recommend their use following myocardial infarction.

Objective: The purpose of this review was to assimilate available evidence from randomized controlled trials into one systematic review to determine the association between omega-3 fatty acids and cardiovascular outcomes.

Design: Systematic review of randomized, controlled trials with meta-analysis

Methods: PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials (up to August 2012) were searched using a predefined algorithm. All randomized trials evaluating omega-3 polyunsaturated fatty acid supplementation in adults were considered. Trials selected were all randomized, controlled against another diet or placebo, and implemented in primary or secondary cardiovascular disease (CVD) prevention settings. Trials with duration less than 1 year were excluded. Outcomes eligible for review included all-cause mortality, cardiac death, sudden death, MI, and all types of stroke. Fatty acids could be given through diet or through supplements. Additionally, references listed in reviews were screened. Two investigators independently extracted data. Another investigator resolved discrepancies.

Results: After retrieving 3,625 citations, 20 studies involving 68,680 participants were included. Two trials used dietary counseling to provide omega-3 fatty acids. The rest used supplements. In the 2 trials using dietary fatty acids, all-cause mortality and cardiac death were assessed and showed associations in opposite directions; therefore, with these discrepancies, quantitative synthesis of these trials was not performed.