Fish oil may increase the risk of stroke and heart disease such as atrial fibrillation, a new study shows.
The study, published Tuesday in the BMJ Medicine magazine, followed more than 400,000 people in the UK aged 40 to 69 for 12 years. These people regularly used fish oil supplements.
Fish oil supplements are a source of omega-3 fatty acids and are well known to help with cardiovascular disease.
The study found that fish oil supplements may increase risks for someone who does not already have heart disease, but for those who already have cardiovascular problems, the supplement may reduce risks.
The study found that regular use of fish oil supplements was associated with a 13 percent increased risk of developing atrial fibrillation and a 5 percent increased risk of stroke if the person had no known heart disease.
In patients with known heart disease, fish oil supplements were associated with a 15 percent lower risk of atrial fibrillation.
The authors noted that further research is needed to determine the development and prognosis of cardiovascular disease and how it interacts with fish oil supplements because the benefits and risks were not uniformly observed over the course of the study.
