The Effects of Variations in the Fat and Carbohydrate Content of the Diet on the Levels of Magnesium and Cholesterol in the Serum of White Rats.

It has been well established that dietary constituents, such as saturated and unsaturated fats and magnesium, can influence serum cholesterol levels in man and various experimental animals : saturated fatty acids cause hypercholesterolaemia whereas polyunsaturated fatty acids give rise to hypocholesterolaemia (Groen, Tjong, Kamminga & Willebrand, 1952; Donath, Fischer, van der Meulen-van Eysbergen & de Wijn, 1953; Beveridge, Connell & Mayer, 1957). It has been shown that in population groups consuming a low-fat diet, in which the fat was predominantly of plant origin, the serum cholesterol level as well as the incidence of thrombosis and other circulatory disorders were comparatively very low (MCndez, Tejada & Flores, 1962). Further, it has become common therapeutic practice to replace all saturated fats by unsaturated fats in the diets of patients suffering from atherosclerotic heart disease (Beveridge et al. 1957 ; Beveridge, Connell, Mayer & Haust, 1958; Boyle, Nichaman & Moore, 1962; Beveridge & Connell, 1962). There appears to be an inverse relationship between the level of Mg and the level of cholesterol in the serum of man (Bersohn & Oelofse, 1957a). Dietary Mg has been shown to influence the deposition of fat in the arterial system in rats (Vitale, White, Nakamura, Hegsted, Zamcheck & Hellerstein, 1957). These authors found that circulatory disorders were commonly associated with low serum Mg levels. I t has further been shown that the abnormal lipoprotein pattern in coronary thrombosis patients, as well as their general clinical picture, are greatly improved by parenteral Mg sulphate therapy (Malkiel-Shapiro, Bersohn & Terner,