by Fish oil supplements, rich in omega-3 fatty acids, have long been touted as a preventive measure against cardiovascular disease. However, a large-scale study published in BMJ Medicine challenges this notion, suggesting that regular use of these supplements might increase the risk of first-time heart disease and stroke among those in good cardiovascular health.
The researchers aimed to clarify the relationship between fish oil supplements and the risk of developing atrial fibrillation, heart attack, stroke, heart failure, and death in individuals with no known cardiovascular disease. They analyzed data from 415,737 participants in the UK Biobank study, who reported their usual intake of fish oil supplements, oily and non-oily fish, and other lifestyle factors.
During an average follow-up of 12 years, 18,367 participants developed atrial fibrillation, 22,636 had a heart attack or stroke, and 22,140 died. Among those who progressed from good cardiovascular health, regular use of fish oil supplements was associated with a 13% increased risk of developing atrial fibrillation and a 5% increased risk of having a stroke.
However, the story was different for those who already had cardiovascular disease at the start of the study. Regular use of fish oil supplements was linked to a 15% lower risk of progressing from atrial fibrillation to a heart attack and a 9% lower risk of progressing from heart failure to death.
The researchers also found that age, sex, smoking, non-oily fish consumption, high blood pressure, and use of statins and blood pressure-lowering drugs influenced the relationship between fish oil supplements and cardiovascular health.
Despite these findings, the researchers emphasize that this observational study cannot establish causality. They also acknowledge the lack of information on the dose and formulation of the fish oil supplements and the limited applicability to individuals of other ethnicities.
The researchers call for further studies to investigate the precise mechanisms behind the development and prognosis of cardiovascular disease events with regular use of fish oil supplements. In the meantime, individuals should consult their healthcare providers for personalized advice on fish oil supplementation and cardiovascular health.
