| Summary: | Several epidemiological studies have shown that a relationship exists between coronary heart disease (CIID) and dietary fat. These investigations demonstrated that the ingestion of dietary saturated fats is associated with a high CUD incidence and mortality, whereas dietary polyunsaturated fats appeared to reduce these. However, the studies of the Greenland Eskimos have clearly demonstrated that the use of the term polyunsaturated fat in community nutrition programmes should be qualified as to whether n-6 or n-3 polyunsaturated fatty acids are under discussion. Platelet aggregation is a central feature of atherosclerosis and thrombosis, the two main pathological events in CUD. Platelet aggregation induced by ADP, collagen, thrombin and arachidonic acid was measured in Wistar rats and New Zealand White rabbits fed on diets enriched with corn oil, linseed oil, fish oil and coconut oil, rich in C18:2, n-6, C18:3, n-3, C20:5, n-3 and medium-chain saturated fatty acids respectively. In general, the initial rate (VAmax) and maximum extent (Amax) of aggregation of platelets from Wistar rats fed corn oil enriched diets were higher than from those fed on diets supplemented with coconut oil. However, the Kaolin Cephalin clotting time of plasma from coconut oil-fed animals was significantly reduced. The inclusion in the diets of an antigenic soy protein did not appear to affect platelet aggregation. In studies with rabbits, fish oil-supplementation of diets resulted in an inhibition of platelet aggregation induced by ADP, collagen and thrombin, which was closely paralleled by changes in the fatty acid composition of platelet total lipids, particularly by increases in C20:9, n-3 and C22:6, n-3. Supplementing diets with linseed oil led to an inhibition of collagen- and thrombin induced aggregation only. No differences were observed when animals were fed corn oil- or coconut oil supplemented diets. Varying the ratio of n-3 to n-6 fatty acids resulted in increasing inhibition of aggregation with increasing amounts of dietary ...
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