A study on this dietary supplement suggests that it increases the risk of stroke in people without cardiovascular problems.
Dietary supplements are intended to provide additional nutrients. However, some may also have harmful effects on health. This is what a study published in BMJ Medicinewhich used a UK Biobank database of 415,737 people aged 40 to 69 who were interviewed between 2006 and 2010 and followed up until 2021.
The researchers were particularly interested in their consumption of fish oil as a dietary supplement. More than a third of those surveyed took it regularly. This product is often sold in capsules or tablets, but also exists in liquid form. Fish oil is often seen as an ally for cardiovascular health thanks to its richness in omega 3. The researchers then looked at cases of atrial fibrillation, heart attacks and strokes among the participants.
Among those taking fish oil, over a 12-year period, 18,367 participants developed atrial fibrillation and 22,636 had a heart attack, stroke or developed heart failure. Additionally, 3,085 of them went from being healthy to having heart failure, 1,180 who had no problems had a stroke and the same for 1,415 healthy people who suffered a heart attack.
The researchers concluded that “for people with no known cardiovascular disease at the start of the monitoring period, 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.” Women and non-smokers would be particularly concerned.
Conversely, in participants who already had health problems, fish oil would have shown its beneficial effect by reducing the risk of worsening atrial fibrillation towards a heart attack by 15% and by 9% the risk of going from heart failure to death. Men and the elderly would be those who benefit the most from this protective effect.
The experts were keen to point out, however, that this was an observational study and that although “regular use of fish oil supplements could play different roles in the progression of cardiovascular disease, further studies are needed to determine the precise mechanisms of the development and prognosis of cardiovascular disease in the case of regular consumption of fish oil supplements.”