A protective effect of high intakes of omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) was also observed in women, but this was only a tendency, according to findings published today in the European Journal of Heart Failure.
Non-diabetic men, however, and the study population in general, did not receive any benefits from high intakes of the omega-3 fatty acids.
“This prospective population-based study in a general older Dutch population did not confirm the hypothesis of a protective effect of fish intake against heart failure,” wrote the researchers. “On the basis of our findings, however, we cannot exclude a protective effect of EPA plus DHA against heart failure in specific subgroups like diabetics.
“However, confirmation of these findings in other prospective cohort studies is warranted,” they added.
Omega-3 fatty acids, most notably DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), have been linked to a wide-range of health benefits, including reduced risk of cardiovascular disease (CVD) and certain cancers, good development of a baby during pregnancy, joint health, and improved behaviour and mood.
The results do go against a study published earlier this year in the European Heart Journal by researchers from Beth Israel Deaconess Medical Center (BIDMC) and the Karolinska Institute in Sweden. In this study the highest intake of marine omega-3 fatty acids linked to a reduction in the risk of heart failure of 33 per cent. However, larger intakes did not appear to offer any additional benefit.
"Scientists and health authorities are increasingly persuaded that the intake of fish - even in small amounts - will protect against the risk of fatal myocardial infarction," said study investigator Dr Marianne Geleinjse from Wageningen University.
"However, there is no strong evidence that eating fish will protect against heart failure. One study has suggested that this might be so, but we could not confirm it in our cohort study of older Dutch people," she added.
The Netherlands-based researchers recruited 5,299 men and women in 1990 with an average age of 67.5 who were free of heart failure. Over an average of 11.4 years of follow-up a total of 669 people developed heart failure.
Heart failure, which arises when the heart can no longer pump enough blood to meet the body’s needs, is the leading cause of hospitalisation among the over 65s, and is characterized by such symptoms as fatigue and weakness, difficulty walking, rapid or irregular heartbeat, and persistent cough or wheezing.
The highest average intake of EPA plus DHA (over 183 mg per day) was associated with an 11 per cent reduction in the risk of heart failure, compared to the lowest average intake (less than 34 mg per day), but this was not statistically significant.
In women, the highest intakes were associated with a 25 per cent risk reduction, and this was approaching significance, said the researchers.
The strongest effects were observed for diabetics, with the highest versus lowest intakes associated with a 42 per cent reduction in risk.
A study with older US adults, published in the Journal of the American College of Cardiology in 2005 (Vol. 45, pp. 2015-2021), reported risk reduction of about 20 per cent for one to two weekly servings of fish
“The mean intake of fish in our study was about 16 g, which roughly equals one serving of fish per week,” wrote the Dutch researchers. “It is possible that the type of fish consumed, or preparation methods, differs between Europe and the USA. Regrettably, our data did not allow examination of these different aspects of fish intake.”
Source: European Journal of Heart Failure
October 2009, Volume 11, Pages 922-928, doi:10.1093/eurjhf/hfp126
“Intake of very long chain n-3 fatty acids from fish and the incidence of heart failure: the Rotterdam Study”
Authors: C. Dijkstra, I.A. Brouwer, F.J.A. van Rooij, A. Hofman, J.C.M. Witteman, J.M. Geleijnse