Increased fish intake may lower risk of heart attack

The risk of myocardial infarction may be reduced by the consumption of fish high in essential fatty acids and low in mercury, suggests a new Swedish study.

To investigate how exposure to both marine omega-3 fatty acids and mercury relates to myocardial infarc-tion (MI) risk, blood concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the amount of mercury in hair and cases of MI were analyzed in 572 men (1). The results showed that higher mercury concentrations were associated with an increased risk of heart attack while higher EPA and DHA concentrations decreased the risk. The increased risk from mercury was noticeable only when the environ-mental pollutant was present in high concentrations in the body and if the level of the protective omega-3 fatty acids was concomitantly low.

The researchers concluded that it is important to keep a balance between healthy (omega-3 fatty acids) and hazardous environmental substances (mercury, PCB and dioxin) in fish. They recommended eating fish 2–3 times a week but avoiding fish with the highest concentration of pollutants (e.g. pike, perch, pike-perch). According to a recent study from the National Food Agency, 7 out of 10 Swedes eat too little fish. Several studies have shown that people who eat fish have a lower risk of cardiovascular disease than those who eat very little or no fish.

1. Wennberg, M. et al. Myocardial infarction in relation to mercury and fatty acids from fish: a risk-benefit analysis based on pooled Finnish and Swedish data in men. Am J Clin Nutr. 2012; 96(4):706–713.