A Randomized Trial Comparing the Effect of Casein With That of Soy Protein Containing Varying Amounts of Isoflavones on Plasma Concentrations of Lipids and Lipoproteins

Abstract
CARDIOVASCULAR morbidity and mortality rates are lower in inhabitants of the Pacific Rim than in Western countries,1-3 and some of the reduced risk is likely attributable to differences in diet. One of the more dramatic dietary differences is the high consumption of soybean products in the Pacific Rim compared with Western countries, which has been postulated to decrease risk of coronary heart disease.4-6 There is good rationale for this: soy is not only an excellent source of protein,7 but also contains high concentrations of isoflavones8,9 (micronutrient substances shown in nonhuman primates to have many of the properties of mammalian estrogen, including the lowering of cholesterol levels10), reducing the risk of atherosclerosis,11 and improving vascular function.12