Soya protein and athersclerosis

Abstract

Cholesterol‐free, semipurified diets produce hypercholesterolemia and atherosclerosis in rabbits when casein is used as dietary protein, but not when the casein is replaced by soya protein. In general, animal proteins produce higher levels of plasma cholesterol in rabbits than plant proteins. At least part of this difference appears to be related to differences in the amino acid composition of the proteins. Rabbits fed soya protein had a faster turnover of plasma cholesterol, absorbed cholesterol from the intestine less readily, and excreted more fecal neutral sterols and bile acids than rabbits fed casein. Differences in composition and turnover of plasma lipoproteins were also observed. Some, but not all, studies on humans with either normal or elevated levels of plasma cholesterol have shown that these levels can be lowered by replacing animal protein in the diet by soya protein. Epidemiological data have also provided evidence of an association between coronary heart disease and amount of animal protein in the diet. Relatively small changes in the diet can substantially decrease the ratio of animal to plant protein, and this may offer a means of lowering serum cholesterol levels and decreasing the high incidence of coronary heart disease in industrialized countries. The use of soya protein for this purpose minimizes the risk of essential amino acid deficiency, because its amino acid composition tends to complement that of cereal proteins, which are the major source of plant protein in most human diets.

The Effect of Individual Amino Acids on ApoB100 and Lp(a) Secretion by HepG2 Cells

“…Although Kritchevsky (65) suggested that the lysine/arginine ratio was important, experimental studies by others failed to show a correlation (66). Lysine and branched chain amino acids (leucine, isoleucine, and valine) were associated with hypercholesterolemia and hypertriglyceridemia (38,67,68) in humans and rats.…”

Water-Soluble Viscous Substance of Jew's Mellow Leaves Lowers Serum and Liver Cholesterol Concentrations and Increases Fecal Steroid Excretion in Rats Fed a High Cholesterol Diet.

“…JML powder contains protein, lipid and chlorophyll in addition to DF. Then, involvement of these components should not be disregarded in studying the effective component for suppressing the serum TC elevation as vegetable protein such as soybeans (12)(13)(14)(15) and chlorophyll (its derivatives) (16) are known to be effective for decreasing serum TC. However, despite a high protein content in the residue after extraction with water, a cholesterol-lowering effect was not seen.…”

Heart Disease, Diabetes, Gut Immune Suppression and Epidemiology Studies

“…However, there is a large body of literature on casein consumption and heart disease in animals [11][12][13]. Casein has been recorded as causing heart disease, or hypercholesterolaemia, in rabbits [14][15][16][17][18][19][20], rats, pigs [21] and monkeys [22,23].…”