Popular supplement may increase risk of heart disease and stroke, new research suggests

A recent study from the UK has raised concerns that fish oil supplements, traditionally seen as beneficial for health, may actually increase the risk of heart problems. Fish oil is rich in Omega 3 fatty acids and is commonly thought to support brain function, heart health, and gut wellness.

Yet, the long-term study suggests that regular intake of fish oil supplements could raise the likelihood of developing heart disease or having a stroke. On the other hand, for individuals already suffering from cardiovascular conditions, taking fish oil regularly may slow down the progression of these diseases.

"Regular use of fish oil supplements might be a risk factor for atrial fibrillation and stroke among the general population," the study's authors stated in their report, which was released in BMJ Medicine last Tuesday. The research involved 415,737 participants, including 55% women, aged between 40-69 years, drawn from the UK Biobanka comprehensive database containing detailed information on the diets, lifestyles, and health statuses of thousands of UK residents.

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These participants were surveyed from 2006 to 2010, with the study collecting basic demographic data, including typical dietary habits concerning the consumption of oily and non-oily fish and fish oil supplements, according to the Mirror US. The study aimed to assess how these supplements might influence the progression of risks from healthy cardiac conditions to atrial fibrillation, leading to severe cardiovascular events such as heart attacks and death.

Participants were split into groups and their health was tracked until March 2021 or until they passed away, using data from medical records. Almost a third (130,365; 31.5%) of the participants reported regular use of fish oil supplements, reports Wales Online.

This group had higher proportions of older white individuals and women.

The researchers noted that the group consuming more oily fish and alcohol also had fewer current smokers and residents in deprived areas. The results suggested that regular use of fish oil supplements played varying roles in cardiovascular health, disease progression and death.

For those with no known cardiovascular disease at the start of the monitoring period, regular use of fish oil supplements was associated with a 13% heightened risk of developing atrial fibrillation and a 5% heightened risk of having a stroke, according to a press release by the research team.

However, among those who had cardiovascular disease at the start of the monitoring period, regular use of fish oil supplements was associated with a 15% lower risk of progressing from atrial fibrillation to a heart attack and a 9% lower risk of progressing from heart failure to death. Digging deeper into the analysis, it was unveiled that various factors such as age, sex, smoking habits, intake of non-oily fish, high blood pressure, and the use of statins and blood pressure-lowering medicines heighten the risk for heart diseases, alongside the consumption of fish oil.

A recent observational study has connected consistent consumption of fish oil supplements to a 6% increased risk of severe cardiovascular incidents in women and non-smokers. However, men taking the same supplement saw their death rates drop by 7%.

The researchers have stipulated that due to the nature of their study, a definitive cause and effect cannot be established. Additionally, they emphasised the lack of information regarding the dosage or type of supplements ingested by the participants.

Nevertheless, keeping these limitations in mind, the researchers stated: "Regular use of fish oil supplements might have different roles in the progression of cardiovascular disease. 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."