London, July 19 : Taking omega 3 through food or supplements is likely to have little or no effect on our risk of experiencing heart diseases, stroke or death, a new study challenging previously held theories says.
Increased consumption of omega 3 -- a type of fat normally found in plant foods like walnuts, rapeseed as well as in fatty fish such as salmon and cod liver oil -- has been widely promoted because of a common belief that it will protect against heart diseases.
However, the findings, published in the Cochrane Library, showed that the risk of death from any cause was 8.8 per cent in people who had increased their intake of omega 3 fats, compared with 9 per cent in people who did not.
Intake of omega 3 fats (including EPA and DHA), primarily through supplements, probably makes little or no difference to risk of cardiovascular events, coronary heart deaths, coronary heart disease events, stroke or heart irregularities.
"We can be confident in the findings of this review which go against the popular belief that long-chain omega 3 supplements protect the heart..we don't see protective effects," said lead author Lee Hooper from the University of East Anglia, UK.
"The review provides good evidence that taking long-chain omega 3 (fish oil, EPA or DHA) supplements does not benefit heart health or reduce our risk of stroke or death from any cause.
"On the other hand, while oily fish is a healthy food, it is unclear from the small number of trials whether eating more oily fish is protective of our hearts," Hooper said.
Eating more ALA -- an essential fatty acid and important part of a balanced diet -- through food or supplements probably decreases the risk of heart irregularities from 3.3 to 2.6 per cent.
However, the reductions are very small -- 143 people would need to increase their ALA intake to prevent one person developing arrhythmia and 1,000 people to prevent one person dying of coronary heart disease or experiencing a cardiovascular event, Hooper said.
The study combines the results of seventy-nine randomized trials involving 1,12,059 people from North America, Europe, Australia and Asia.