The most important safety risk of fish oil from the latest meta-analysis?

Type of funding sources: Foundation. Main funding source(s): This project was supported by the National Natural Science Foundation of China (No. 81670325 and No. 81370325).

Fish oil supplements are popular worldwide, and many people believe that fish oil supplements are beneficial to their health. However, there is still controversy about whether Omega-3 fatty acids can reduce the cardiovascular risk of users. In recent years, the publication of several large randomized controlled trials has pointed out the direction for us to use fish oil supplements.

We conducted a meta-analysis of recently released large randomized controlled trials to evaluate the clinical value of fish oil supplements.

Five latest large randomized controlled trials on Omega-3 fatty acids were included, including the ASCEND study, VITAL study, REDUCE-IT study, STRENGTH study and OMEMI Study. We analyzed the effects of fish oil supplements on the incidence of major cardiovascular events, myocardial infarction, stroke, atrial fibrillation, death from cardiovascular cause and death from all-cause.

Fish oil supplements can significantly reduce the risk of myocardial infarction in users (RR 0.85, 95%CI 0.72- 0.99; P = 0.04), however, significantly increase the risk of atrial fibrillation (RR 1.32 95%CI 1.11-1.58; P=0.002). The use of fish oil supplements had no effect on the incidence of major cardiovascular events (RR 0.93, 95%CI 0.84-1.04; p=0.23) and stroke (RR 0.99, 95%CI 0.84-1.17; P = 0.93). Similarly, there was no effect on death from cardiovascular cause (RR 0.91, 95%CI 0.79-1.05; P = 0.20) and death from all-cause (RR 0.99, 95%CI 0.92-1.07; P = 0.79).

The results of this meta-analysis showed that fish oil supplements can reduce the incidence of myocardial infarction, but significantly increase the risk of atrial fibrillation. We should reconsider the role of fish oil supplements in preventing cardiovascular disease. We also need some large randomized controlled trials to verify the risk of atrial fibrillation caused by the use of fish oil supplements.