Fish oil supplementation produces small, yet clinically significant, cardioprotective effects, including reduced risk of MI and death from coronary heart disease, a major meta-analysis shows.

The findings show a clear dose–response relationship between marine omega-3 supplementation and key cardiovascular outcomes, the US researchers say.

In their updated meta-analysis of 13 randomised controlled trials, researchers from Harvard University and the Brigham and Women’s Hospital in Boston analysed data from more than 127,000 participants (mean age 64) who were given either fish oil supplements between 370mg/d and 4000mg/d or placebo.

The study, which represents the most up-to-date evidence on the topic, incorporates data from three recent trials: the large-scale ASCEND (A Study of Cardiovascular Events in Diabetes), VITAL (Vitamin D and Omega-3 Trial) and REDUCE-IT (Reduction of Cardiovascular Events with Icosapent Ethyl–Intervention Trial).