Fish oil supplements linked to lower risk of heart disease, early death: Study

Regular use of fish oil supplements may be associated with a lower risk of premature death and cardiovascular disease (CVD) events, such as heart attack and stroke, a study unveiled on Thursday claims.

Further studies should explore what dose is needed to achieve a clinically meaningful effect, noted the researchers, including those from Brown University in the US.

Some evidence suggests that omega-3 fatty acids in fish oil may help prevent cardiovascular disease and reduce mortality, but conclusive evidence is still lacking, they said.

To explore these potential associations further, a team of researchers based in China and the US drew on data from the UK Biobank -- a large population based study of more than half a million British men and women.

The analysis, published in The BMJ, included 427,678 men and women aged between 40 and 69 years, without CVD or cancer.

They were enrolled in the study from 2006 to 2010 and completed a questionnaire on supplement use, including fish oil.

Death certificates and hospital records were used to monitor deaths from any cause ("all-cause mortality"), CVD deaths, and CVD events, such as heart attack and stroke, through to 2018.

Almost a third (31 per cent) of participants reported taking regular fish oil supplements at the start of the study.

The research found that fish oil supplements were associated with a 13 per cent lower risk of all-cause mortality, a 16 per cent lower risk of CVD mortality, and a 7 per cent lower risk of CVD events.

The association between fish oil use and CVD events appeared to be stronger among those with high blood pressure.

These favourable associations remained after taking account of traditional risk factors, such as age, sex, lifestyle habits, diet, medication and other supplement use.

Results were also unchanged after further analyses, suggesting that the findings withstand scrutiny. Several mechanisms could explain these results, the researchers said.

For example, omega-3 fatty acid supplements have shown beneficial effects on blood pressure, cholesterol levels, and heart rate, all of which would exert a protective effect against the development of CVD events.

Despite the large sample size, this is an observational study, so can't establish cause, and the researchers point to some limitations, such as lack of information on dose, duration, and side effects of fish oil use.

However, they conclude that habitual fish oil use "is associated with a lower risk of all-cause and CVD mortality and a marginal benefit against CVD events among the general population".