According to a review published in Cochrane Database of Systematic Reviews, researchers reviewed 79 studies that compared consumption of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and alpha-linolenic acid (ALA) with cardiovascular health. Long-chain fatty acids from fish oil supplements did not protect against all-cause mortality and did not reduce the risk for cardiovascular events.
Results showed increased consumption of ALAs from plant-foods provided a protective effect against coronary heart disease, arrhythmia, and other cardiovascular events. The authors note that previous recommendations for fish oil supplementation derived from biased research.
Abdelhamid AS, Brown TJ, Brainard JS, et al. Omega 3 fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database Syst Rev. Published online July 18, 2018.