Effects of Saturated and Polyunsaturated Fatty Acids on Plasma Lipids, Platelets and the Vascular System

Abstract

The hypothesis that alterations in dietary fat intake may influence the development of atherosclerosis and thrombogenesis has been intensely studied for several decades (1). For example, in the early 1950’s, it was shown that the feeding of a diet high in saturated fat to humans would raise plasma cholesterol, whereas the substitution of polyunsaturated fatty acids into the diet would reduce the plasma cholesterol (2,3). Since atheromatous lipid deposits may occur in the arterial vasculature when plasma levels of cholesterol are high, a reduction in circulating cholesterol and low density lipoproteins may result in a reduced incidence of occlusive vascular disease in man (4). Diets rich in saturated fat may also predispose to vascular thrombosis as evidenced by a series of studies in animals and man which have been published in the last several decades (1). In one such study, the intravenous infusion of saturated fatty acids into animals led to thrombosis of the great vessels, whereas long-chain polyunsaturated fatty acids did not (5). Further, Renaud showed that animals fed butter or specific saturated fatty acids were more prone to venous thrombi after the infusion of endotoxin (6). Another animal model was developed by Hornstra, et al., who measured the number of hours required for the thrombotic occlusion of a polyethylene cannula inserted into the aorta of rats.