The role of essential fatty acids in the control of coronary heart disease.
Evidence from various research paradigms supports the cardiovascular benefits of a high intake of n-3 polyunsaturated fatty acids (PUFAs), especially the long-chain, marine-derived n-3 PUFA, eicosapentaenoic acids and docosahexaenoic acids. The effect of the plant-derived alpha-linolenic acid (ALA) is, however, not clear. Concerns about a high n-6 PUFA intake has been raised, because n-6 PUFA may weaken the effects of n-3 PUFA. Most previous observational studies on the intake of PUFA and the risk of coronary heart disease (CHD) did not specify the replacement nutrient. A recent meta-analysis of cohort studies suggested that replacing saturated fatty acids with PUFA may lower the risk of CHD. On the other hand, recently published studies do not suggest that higher linoleic acid intake is associated to a lower risk of CHD or to give support for a negative association between ALA and CHD. Furthermore, recent studies do not suggest that the association between ALA and CHD is modified by linoleic acid. Recent meta-analyses of cohort studies have reported a lower risk of CHD when PUFA replaces SFA in the diet. However, recent studies do not suggest that a higher linoleic acid intake is related to a lower risk of CHD. The effect of ALA on the risk of CHD is not clear.