The heart health benefits of omega-3 fatty acids are well-documented, being first reported in the early 1970s by Jorn Dyerberg and his co-workers in The Lancet and The American Journal of Clinical Nutrition. To date, the polyunsaturated fatty acids (PUFAs) have been linked to improvements in blood lipid levels, a reduced tendency of thrombosis, blood pressure and heart rate improvements, and improved vascular function.
The new study, published in the British Journal of Nutrition, reported that increased intakes of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) may reduce the risk of acute coronary syndrome (ACS), an umbrella term for a range of symptoms including unstable angina and chest pains.
The Danish Diet, Cancer and Health cohort study involved 57,053 men and women. During an average follow-up time of almost eight years, 1,150 people developed ACS. Men who consumed more than 0.39 grams of PUFAs per day had an associated risk of ACS 27 per cent lower than men who consumed less than 0.39 grams per day.
When the researchers looked at individual omega-3 fatty acids, they did note negative association for EPA, DPA and DHA, but these were considered “less consistent”.
No benefits were observed for women, noted the researchers.
“We found borderline significant negative associations between the intake of marine omega-3 PUFA and ACS among healthy men,” they concluded.
Half a gram needed for heart benefits?
Earlier this year, a ‘state-of-the-art’ review concluded that the science behind the cardiovascular health benefits of omega-3 fatty acids supports recommended daily levels of 500 mg.
“Compelling evidence” from studies involving almost 40,000 participants supports daily EPA plus DHA intakes of at least 500 mg per day for healthy individuals, while people with known heart disease or heart failure should aim for up to 1,000 mg daily, according to a review published in the Journal of the American College of Cardiology.
The recommendations for healthy people are double the recommended levels determined by the European Food Safety Authority’s (EFSA) Panel on Dietetic Products, Nutrition and Allergies (NDA).
EFSA determined in July that 250mg should be the labelling reference intake value for long-chain omega-3 fatty acids – most notably eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The European Commission backed the regulation last week that permits products to claim omega-3 content if they have significant proportions of dietary reference values (DRV) of 250mg of EPA (eicosapentaenoic acid) and/or DHA (docosahexaenoic acid) and 2g of ALA (alpha-linolenic acid).
The regulation was slammed by a group of 21 international leading omega-3 scientists who said the rule, which does not discriminate between plant and marine-sourced omega-3 sources for product labelling, was an “insult”.
Source: British Journal of Nutrition
Published online ahead of print, doi:10.1017/S0007114509992170
"Dietary intake of total marine n-3 polyunsaturated fatty acids, eicosapentaenoic acid, docosahexaenoic acid and docosapentaenoic acid and the risk of acute coronary syndrome - a cohort study"
Authors: A.M. Joensen, E.B. Schmidt, C. Dethlefsen, S.P. Johnsen, A. Tjonneland, L.H. Rasmussen, K. Overvad