Results were also estimated according to the weight of fish consumed; but even for a high daily fish consumption of more than 20 grams a day there appeared no added protection against heart failure. Incidence rates were the same in those who consumed no fish (incidence rate of 11 per 1000), moderate fish (median 9g per day, 12.3 per 1000) or high fish (9.9 per 1000). The relative risk of heart failure in the high intake groups was 0.96 (0.78?”‚?.18) when compared with no intake.

Variations in risk were seen in various sub-groups according to age, sex and body mass index (BMI), but once again the differences were not statistically significant. In diabetic subjects, however, an inverse association of EPA plus DHA intake with heart failure was observed (RR 0.58 (0.32?”‚?.06) for top vs. bottom quartile), which was just of borderline statistical significance. Similarly, a high EPA plus DHA intake tended to be protective (but not statistically significant) in women (RR 0.75, 0.54?”‚?.04), although not in men.

Commenting on the public health implications of the study Dr Geleijnse said: "Many health authorities recommend two weekly servings of fish - particularly fatty fish like salmon, mackerel and herring - for the prevention of cardiovascular disease. Based on our data we would not change this advice, even though fish intake was not associated with the development of heart failure in our cohort. Fish intake in the Netherlands is extremely low - on average less than one portion per week - so maybe higher intakes are needed for any protection against heart failure.

"Apart from n-3 fatty acids, fish also contains other healthy components such as vitamin D and selenium. Fish is a good source of protein and is more healthy than, for example, red meat."

According to the authors this is only the second ever study to examine the relationship between PUFAs and the risk of heart failure; the other, over 12 years of follow-up among older adults, did find that consumption of tuna or other broiled or baked fish (but not fried fish) was associated with a lower incidence of heart failure.

Source: European Society of Cardiology