Research shows that fish oil supplements can INCREASE the risk of heart disease and stroke when taken by healthy adults

It has been credited with everything from relieving joint pain to good heart and brain health.

Fish oil is a rich source of omega-3 fatty acids and is often recommended as a dietary preventative to prevent the development of cardiovascular disease.

But new research suggests that taking the popular supplement could actually increase the risk of heart disease and stroke in healthy adults, while reducing the risk in people with a history of disease.

The study, which involved more than 415,000 Britons, looked at the associations between fish oil supplements and new cases of atrial fibrillation, heart attacks, strokes and heart failure leading to death.

They assessed the potential of these supplements on the risk of transitioning from good heart health to the secondary stage of atrial fibrillation, the third stage of major cardiovascular events such as heart attack and death.

Nearly a third – 130,365 – of participants, aged 40 to 69, said they regularly used fish oil supplements, including large numbers of older white people and women.

The popular supplements may actually increase the risk of heart disease and stroke in healthy adults

Alcohol intake and the ratio of oily to non-oily fish eaten were also higher, while the numbers of current smokers and people living in deprived areas were lower.

During a follow-up 12 years later, 18,367 people had developed the abnormal heart rhythm (atrial fibrillation), 22,636 had had a heart attack, stroke or heart failure and 22,140 had died.

Of those who developed heart failure, 2,436 died, in addition to 2,088 who suffered a stroke, and 2,098 after a heart attack, according to findings published in BMJ Medicine.

Regular use of fish oil supplements played several roles in cardiovascular health, disease progression and death, the findings showed.

Those who used them regularly without signs of illness had a 13 percent higher risk of developing atrial fibrillation and a five percent higher risk of stroke.

But among those who had cardiovascular disease to begin with, regular use of fish oil supplements reduced the risk of progressing from atrial fibrillation to heart attack by 15 percent and from heart failure to death by 9 percent.

The risk of transitioning from good health to heart attack, stroke or heart failure was six percent higher in women. It was also six percent higher among non-smokers among fish oil users.

Meanwhile, the protective effect of these supplements on the transition from good health to death was greater in men (7 percent lower risk) and older participants (11 percent lower risk).

Led by Sun Yat-Sen University, China, researchers admit there are limitations to the study, including that the dosage and formulation of fish oil was not recorded, which experts say could be key to the results.

Nevertheless, they conclude: ‘Regular use of fish oil supplements could play several roles in the progression of cardiovascular disease.

‘Further research is needed to determine the precise mechanisms for the development and prognosis of cardiovascular disease with regular use of fish oil supplements.’

It’s not the first study to draw such conclusions in a 2018 Cochrane review of research that compared 79 studies and found it made “little or no difference to the risk of cardiovascular events, coronary heart deaths, coronary heart disease, stroke or heart irregularities’.