Fish Oil Is Associated with Increased Risk for Atrial Fibrillation

Fish oil (marine omega-3 fatty acid) supplements are sometimes recommended for prevention of cardiovascular events, but whether they, as a class, provide cardiovascular benefit remains controversial. In addition, a signal of concern has arisen that atrial fibrillation (AF) risk may be increased with their use.

To investigate the risk for AF in this setting, researchers conducted a meta-analysis of data from more than 81,000 participants of seven RCTs examining the effect of fish oil on cardiovascular outcomes. Nearly three fourths of participants were enrolled in trials testing doses of ≤1 g/day and the remainder were in trials testing doses >1 g/day. Participants' mean age was 65 years, and 40% were women.

During a median follow-up of 5 year…