Our updated review Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease has hit the headlines and has reached a very large audience as it challenges the widespread belief that omega 3 supplements reduce the risk of heart disease.
Omega-3 fatty acids are widely thought to be essential for good cardiovascular health and are naturally found in fatty acids from oily fish [long-chain omega-3 (LCn3), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)], as well as from plants [alpha-linolenic acid (ALA)]. These fatty acids have been widely promoted globally, and even though increasing their intake (food or supplements) is recommended in guidelines, recent trials have not confirmed their benefit.
This new review update, assessing effects of long-chain omega-3 fats separately from effects of alpha-linolenic acid, includes 79 RCTs and data from 112,059 participants with at least one year of follow-up. Atrial fibrillation and cardiovascular mortality are outcomes which have now been included.
Results of this review fail to confirm most of the beneficial effects of Omega-3 fatty acids: moderate and high-quality evidence suggests that increasing EPA and DHA has little or no effect on mortality or cardiovascular health (evidence mainly from supplement trials). Interestingly, low-quality evidence suggests that, in spite of some uncertainty, ALA may slightly reduce CVD event risk, CHD mortality and arrhythmia.
Expert scientists have commented via the Science Media Centre on this review.