May 22, 2024 – One of the most widely used dietary supplements may pose heart health risks to otherwise healthy people.
A large new study has linked fish oil supplements to getting heart problems like an irregular heartbeat or having a stroke.
For the study, published this week in BMJ Medicine, researchers analyzed in-patient hospital records and death data for 415,737 people ages 40 to 69 years old living in the United Kingdom. Nearly one-third of the people said they regularly took fish oil supplements, and those people were more likely to be women, older, and White.
Fish oil was linked to a 13% higher risk of having atrial fibrillation as a first-time heart problem, and also linked to a 5% higher risk of a stroke as a first-time heart problem. Atrial fibrillation is an irregular (and sometimes very rapid) heart rhythm that is linked to a higher risk of having stroke.
But there were groups of people in the study who took fish oil regularly who had a lower risk of heart problems. Those who had heart disease had a 15% reduced risk of progressing from atrial fibrillation to having a heart attack, and a 9% reduced risk of death after getting a blood-pumping condition known as heart failure.
The authors wrote that the data they used for the study, which came from the UK Biobank, a large database used for long-term research, didn’t include detailed information on specific types of fish oil supplements or dosage. Also, because most people in the study were White, the findings may not apply to people of other races or ethnicities, the authors cautioned.
Various risk levels were affected when researchers did a detailed analysis that looked at things like a person’s age, gender, smoking status, blood pressure, use of cholesterol drugs like statins, and how much fish they ate.
“Regular use of fish oil supplements might be a risk factor for atrial fibrillation and stroke among the general population but could be beneficial for progression of cardiovascular disease from atrial fibrillation to major adverse cardiovascular events, and from atrial fibrillation to death,” the authors said. “Further studies are needed to determine the precise mechanisms for the development and prognosis of cardiovascular disease events with regular use of fish oil supplements.”