Does Fish Oil Supplement Increase Risk of Stroke and Atrial Fibrillation?

General information is that fish oil supplements are beneficial for cardiovascular health. Recommendation from UK National Institute for Health and Care Excellence is that people with or at high risk of cardiovascular disease consume at least one portion of oily fish a week. Still, a report published in BMJ Medicine paints a different picture. The authors reported that the regular use of fish oil supplements might be a risk factor for atrial fibrillation among general population. But a contradictory statment in their conclusion is that it could be beneficial for progression of cardiovascular disease from atrial fibrillation to major adverse cardiovascular event, and from atrial fibrillation to death [1]. They were using data from the UK Biobank participants dated 2006 to 2010 and follow UP till the end of March 2021.

In their study healthy stage was considered as primary stage, occurrence of atrial fibrillation as secondary stage, major adverse cardiovascular events tertiary stage and death as end stage. When used as primary prevention in healthy persons, fish oil supplements were associated with an increased risk of atrial fibrillation. There was also mild harmful effect on transition from healthy state to stroke. But potential beneficial association was noted between regular use of fish oil supplements and transitions from atrial fibrillation to myocardial infarction, atrial fibrillation to death and heart failure to death. There is a disparity between the effect on stroke and other major adverse cardiovascular events, in those with atrial fibrillation who took fish oil supplement as secondary prevention. In a database analysis like this, limitations exist regarding confounding factors.

Reference

1. Regular use of fish oil supplements and course of cardiovascular diseases: prospective cohort study. https://doi.org/10.1136/bmjmed-2022-000451