Long-chain n-3 fatty acids and cardiovascular disease: further evidence and insights

The traditional Inuit diet was rich in long-chain n-3 polyunsaturated fatty acids (PUFAs), and this is believed to account for the low incidence of cardiovascular disease in Inuit populations. Epidemiological studies in Europe and North America demonstrate inverse relationships between consumption or status of long-chain n-3 PUFAs and cardiovascular morbidity and mortality. Long-chain n-3 PUFAs might act through modification of recognized risk factors such as hypertriacylglycerolemia and hypertension. Secondary prevention studies in post-myocardial infarction patients demonstrate that long-chain n-3 PUFAs, provided in the form of fish oil, reduce cardiovascular events and mortality, with an especially potent effect on sudden death. The anti-thrombotic and antiarrhythmic actions of long-chain n-3 PUFAs may explain these effects. In addition, long-chain n-3 PUFAs are anti-inflammatory and so may act to increase atherosclerotic plaque stability. This may explain the observed reduction in cardiovascular events and mortality. A recent study has investigated this possibility. Patients awaiting carotid endarterectomy consumed control, sunflower oil, or fish oil capsules until surgery, when the atherosclerotic plaque was removed. The proportions of long-chain n-3 PUFAs were higher in carotid plaque lipids in patients receiving fish oil. Plaques from patients in the fish oil group were more likely to have thick fibrous caps and fewer signs of inflammation and to contain fewer macrophages. This may be indicative of increased plaque stability. (C) 2004 Elsevier Inc. All rights reserved.