According to a new research study, fish oil supplements may pose a potential risk of developing heart conditions or strokes for individuals with no known cardiovascular disease. However, the study also revealed that these supplements could lower the risk of progression in patients already suffering from heart-related ailments.

Fish oil is well-known for its abundance of omega-3 fatty acids, which are believed to have various health benefits. The NHS advises consuming at least one portion of oily fish per week to reduce the risk of cardiovascular disease.

To determine the extent of protection afforded by fish oil supplementation, a team of researchers from China, the US, the UK, and Denmark conducted a study involving over 400,000 participants in the UK Biobank. The participants were monitored for an average of 12 years to assess the link between fish oil supplements and the occurrence of atrial fibrillation (irregular heartbeat), heart attacks, strokes, heart failure, and mortality in individuals with no pre-existing cardiovascular disease. The researchers also examined whether these supplements affected the progression of heart conditions.

The findings, published in the journal BMJ Medicine, revealed that regular use of fish oil supplements was associated with a 13% increased risk of developing atrial fibrillation and a 5% raised risk of experiencing a stroke in individuals without known cardiovascular disease. However, for patients already diagnosed with heart disease, fish oil supplementation was linked to a 15% lower risk of transitioning from atrial fibrillation to a heart attack and a 9% lower risk of progressing from heart failure to death.

Notably, the study highlighted that the risks and benefits of omega-3 supplementation were not consistent across all individuals. Specifically, healthy patients who were women or non-smokers had a 6% increased risk of developing heart attack, stroke, or heart failure. Conversely, older individuals and men with pre-existing heart conditions experienced a greater beneficial effect, with an 11% lower risk of transitioning from good health to death and a 7% lower risk, respectively.

The authors of the study caution that as an observational study, no definitive conclusions can be drawn regarding causal factors. Additionally, data regarding dosage and formulation of the fish oil supplements were not available. Furthermore, given that the majority of participants were of white ethnicity, the findings may not be universally applicable to individuals of other ethnic backgrounds.

Tracy Parker, a senior dietitian at the British Heart Foundation, commented on the research, advising that regular fish oil supplement users should not be overly concerned. However, she emphasized that this study should not be seen as a green light to start consuming these supplements for the prevention of heart and circulatory diseases. The Nice guidelines in the UK do not recommend fish oil supplements for preventing heart disease or subsequent heart attacks. Instead, Parker highlights the importance of adopting a holistic approach to diet, emphasizing the traditional Mediterranean diet, which has consistently shown to reduce the risk of heart attacks and strokes. This diet includes an increased intake of fish, both white and oily, while reducing red meat consumption and incorporating ample amounts of fruits, vegetables, legumes, nuts, seeds, and whole grains.

In conclusion, while fish oil supplements may increase the risk of heart disease and stroke in individuals without a history of cardiovascular disease, they could potentially benefit those already diagnosed with heart-related conditions. However, it is crucial to consider the limitations of observational studies, and individuals should consult healthcare professionals for personalized dietary advice to reduce their risk of heart and circulatory diseases.