Study Links Fish Oil to Increased Heart Risks

A significant British study, encompassing over 400,000 individuals aged 40-69, has raised concerns about the long-term cardiovascular effects of fish oil supplements. Published in BMJ Medicine, the research indicated that regular consumption of fish oil may be linked to a 13% increased risk of developing atrial fibrillation and a 5% increased risk of stroke in individuals without prior cardiovascular disease.

Conversely, for those already living with cardiovascular conditions, the findings suggest a potential benefit. Regular fish oil intake was associated with a 15% reduced risk of progression from atrial fibrillation to heart attack and a 9% reduced risk of mortality from heart failure.

The study, conducted between 2006 and 2010 using data from the UK Biobank, highlighted that while fish oil may pose risks for some, it could offer protective effects for others. Experts advise focusing on a balanced diet, including oily fish, for omega-3 intake rather than solely relying on supplements.

Further international research, such as the PISCES trial involving dialysis patients reported in March 2026, showed that a four-gram daily dose of fish oil significantly reduced life-threatening cardiovascular events by 43%. This trial, conducted across Australia and Canada, used supplements containing EPA and DHA.

Despite these varied findings, researchers acknowledge that observational studies cannot definitively establish causation. They emphasize the need for additional research to understand the precise mechanisms and dosages involved in fish oil's varied impact on cardiovascular health.