Individuals given omega-3 fish oil supplements in randomized clinical trials had a lower risk of heart attacks and other cardiovascular disease (CVD) than those given placebo, according to a new meta-analysis from the Harvard TH Chan School of Public Health Women’s hospital.
The researchers found an association between daily omega-3 fatty acid supplementation and a reduced risk of most CVD outcomes, including heart attack, death from coronary artery disease, and death from CVD, but saw no benefit for stroke. Additionally, higher doses of omega-3 fish oil supplements seemed to offer even greater risk reduction.
The study was published online today in the Journal of the American Heart Association.
“This meta-analysis provides the very latest information on the effects of omega-3 supplementation on the risk of multiple CVD outcomes. We found significant protective effects of daily omega-3 fatty acid supplementation against most CVD outcome risks, and the associations appeared to be dose-response, ”said first author Yang Hu, a postdoctoral fellow in the Department of Nutrition Harvard Chan School.
While observational studies have shown an association between fish consumption and a lower risk of heart disease, the results of randomized controlled trials have been inconsistent. Two reviews published last year found no clear evidence of benefit.
In this new analysis, the researchers performed an updated meta-analysis that included three recently completed large-scale studies that increased the sample size by 64 percent. The total population analyzed by Hu and colleagues comprised more than 120,000 adults in 13 randomized studies worldwide. The analysis included the VITAL study, the largest randomized study to date on omega-3 fatty acids.
The results showed that people who took omega-3 fish oil supplements daily, compared to those who took a placebo, reduced their risk for most CVD outcomes other than stroke, including an 8 percent reduced risk of heart attack and death coronary artery disease (CHD). ). The link was particularly evident with higher doses of omega-3 fish oil supplementation. This result could suggest that marine omega-3 fatty acid supplementation above the 840 mg / day used in most randomized clinical trials may lower the risk of CVD more significantly. Given that millions of people worldwide suffer from these cardiovascular diseases each year, the researchers say even small reductions in risk can result in hundreds of thousands of heart attacks and avoided cardiovascular deaths.
“Although public health recommendations should focus on increased fish consumption, an overall heart-healthy diet, physical activity and other healthy lifestyles, this study suggests that omega-3 supplementation may play a role in eligible patients,” said Senior Author JoAnn Manson, director of the Preventive Medicine Department at Brigham and Women’s Hospital and Professor in the Epidemiology Department at Harvard Chan School. Manson is also the director of the large-scale VITAL study.
Other authors from Harvard Chan School were Frank Hu.
VITAL was supported by grants U01 CA138962 and R01 CA138962 from the National Institutes of Health. Pharmavite LLC from Northridge, California, (vitamin D) and Pronova BioPharma from Norway and BASF (Omacor fish oil) donated the study active ingredients and matching placebos.