High concentrations of omega-3 fatty acids in the blood do not affect the risk of cardiovascular complications. The study authors, on the contrary, suggest treating this supplement with caution.
A secondary analysis of the large, double-blind, multicenter STRENGTH study examining the benefits of omega-3 fatty acids was presented at the 70th Annual Scientific Meeting of the American College of Cardiology (ACC). It was conducted at 675 sites in 22 countries between 2014 and 2017 and included 13,078 participants at high risk of major cardiovascular events. The results were published in JAMA.
Groups of participants received 4 g of omega-3 carboxylic acid (a combination of eicosapentaenoic acid and docosahexaenoic acid) or corn oil daily as a placebo. Preliminary analyzes showed no significant differences in the rates of cardiovascular mortality, myocardial infarction, stroke, or surgery.
Secondary analysis was also inconclusive. It covered 10,382 patients, of whom 5,175 received omega-3 carboxylic acid and 5,207 received corn oil. In both groups, the proportion of cardiovascular complications was 11%.
The average age of the participants was 62.5 years, a third of the patients had diabetes, and two thirds were men. Blood levels of omega-3 fatty acids were assessed at baseline and one year after randomization.
According to the researchers, if fatty acids had protective properties, then cardiovascular complications would be observed less frequently in groups with high concentrations of these acids in the blood. Conclusion: Fish oil is completely useless for cardiovascular health. On the contrary, the authors suggest using this supplement with caution.
The results of the STRENGTH study are completely contrary to the results of another large randomized clinical trial, REDUCE-IT, which found that consumption of omega-3 fatty acids reduced cardiovascular risk by 25%.