Fish oil supplements may be harmful to the heart. Know when to avoid them

Fish oil supplements could increase a person’s risk of developing heart disease or stroke, but could reduce the risk for those who already have cardiovascular disease. This is what researchers reveal in a recent study which goes against what we might think.

13% increased risk of developing atrial fibrillation

Researchers monitored the health of more than 400,000 participants (registered with the UK Biobank) for an average of 12 years and their fish oil intake. The goal: to establish whether there is a link between fish oil consumption and the occurrence of atrial fibrillation (irregular heartbeat), heart attacks, strokes and heart failure, or even death in people. without known cardiovascular disease.

The study revealed surprising data:

• In people without known cardiovascular disease at the start of the monitoring periodregular consumption 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 who started without heart problems were 6% more likely to have a heart attack, stroke or heart failure if they took fish oil supplements.

But a reduced risk in the event of existing heart disease

In contrast, for patients with heart disease early in the study period, fish oil supplements worked since they were associated with a 15% lower risk of progression from atrial fibrillation to heart attack, and a 9% lower risk of progression from heart failure to death.

“The benefits and risks of omega-3 supplementation have not been uniformly observed,” notes the study. This is an observational study, so no conclusions can be drawn about causal factors, the authors caution.

A question of dosage to study more closely

The risk noted in the current study may reflect the fact that some people were taking higher doses, since the researchers only asked people to report their supplement use and were unable to verify either their actual use or the doses they took. took nor the type of fish oil supplements consumed.

The reason for the risk could be related to the physiological effects of fish oil. When the dose is too high, more than 1g per day, the omega-3 fatty acids contained in fish oil can affect the electrical rhythms of the heart, particularly the beats of the upper or ear chambers. It is because of this risk that theAmerican Heart Association does not recommend fish oil supplements to prevent heart disease.

Prevention does not rely only on food supplements

Rather than relying all on this supplement, people wanting to protect themselves from heart problems should follow a healthy diet, which involves eating fish about once or twice a week, exercising regularly, minimizing stress and getting enough sleep. , according to the authors.

“But for people at higher risk of heart problems, the risk of atrial fibrillation is balanced by the potential anti-inflammatory, anticoagulant and triglyceride-lowering benefits of omega-3 fatty acids, which tend to protect the heart and reduce the risk of coronary events” concludes JoAnn Manson, head of the division of preventive medicine at Harvard Medical School in The Time.