Researchers from Harvard T.H. Chan School of Public Health and Brigham and Women's Hospital carried out a new updated analysis, published in the Journal of the American Heart Association, that included three recently completed large-scale trials, which increased the sample size by 64%.
The total population analysed included nearly 130,000 adults in 13 randomised trials worldwide including the VITAL trial, the largest randomised trial of omega-3s to date.
Results showed people who took daily omega-3 fish oil supplements, compared with those who took a placebo, lowered their risk for most CVD outcomes except stroke, including an 8% reduced risk for heart attack and coronary heart disease (CHD) death.
The association was particularly evident at higher doses of omega-3 fish oil supplementation. This finding may suggest that marine omega-3 supplementation dosage above the 840 mg/day used in most randomised clinical trials may provide greater reductions in CVD risk.
First author Yang Hu, a postdoctoral fellow in the Department of Nutrition at Harvard Chan School, said: "This meta-analysis provides the most up-to-date evidence regarding the effects of omega-3 supplementation on risk of multiple CVD outcomes. We found significant protective effects of daily omega-3 supplementation against most CVD outcome risks and the associations appeared to be in a dose-response manner."
While observational studies have shown an association between fish consumption and lower heart disease risk, results from randomised controlled trials (RCTs) have been inconsistent.
The researches not that, given that several million people experience these CVD events worldwide each year, even small reductions in risk can translate into hundreds of thousands of heart attacks and CVD deaths avoided.
Senior author JoAnn Manson, chief of the Division of Preventive Medicine at Brigham and Women's Hospital, professor in the Department of Epidemiology at Harvard Chan School and director of the large-scale VITAL trial of omega-3s, adds: "Although public health recommendations should focus on increasing fish consumption, having an overall heart-healthy diet, being physically active, and having other healthy lifestyle practices, this study suggests that omega-3 supplementation may have a role in appropriate patients,"
Source: Journal of the American Heart Association (2019).
Authors: Hu. Y., Hu. F.B, and Manson. J.E.
"Marine Omega‐3 Supplementation and Cardiovascular Disease: An Updated Meta‐Analysis of 13 Randomized Controlled Trials Involving 127 477 Participants"