Background: Previous findings concerning the serum levels of fish-derived (n-3) fatty acids and coronary heart disease are inconsistent. The purpose of this study was to investigate the association between the serum n-3 end-product fatty acids docosahexaenoic acid (DHA), docosapentaenoic acid (DPA), and eicosapentaenoic acid and the risk of acute coronary events in middle-aged men.
Methods and results: We studied this association in the Kuopio Ischaemic Heart Disease Risk Factor Study, a prospective population study in Eastern Finland. Subjects were randomly selected and included 1871 men aged 42 to 60 years who had no clinical coronary heart disease at baseline examination. A total of 194 men had a fatal or nonfatal acute coronary event during follow-up. In a Cox proportional hazards' model adjusting for other risk factors, men in the highest fifth of the proportion of serum DHA+DPA in all fatty acids had a 44% reduced risk (P=0.014) of acute coronary events compared with men in the lowest fifth. Men in the highest fifth of DHA+DPA who had a low hair content of mercury (</=2.0 microgram/g) had a 67% reduced risk (P=0.016) of acute coronary events compared with men in the lowest fifth who had a high hair content of mercury (>2.0 microgram/g). There was no association between proportion of eicosapentaenoic acid and the risk of acute coronary events.
Conclusions: Our data provide further confirmation for the concept that fish oil-derived fatty acids reduce the risk of acute coronary events. However, a high mercury content in fish could attenuate this protective effect.