Soy and cholesterol reduction: clinical experience

A role of vegetable proteins in reducing coronary artery disease risk was postulated as long ago as 1909 in Russia by Ignatowski. The protein hypothesis of atherosclerosis was pursued by many investigators, who studied the possible role of animal vs. vegetable protein in modifying concentrations of plasma lipids and thus cardiovascular disease risk. Over the past 20 y, our research group has examined the potential of a diet based on vegetable protein (in most cases, textured vegetable protein, or TVP) to modify plasma lipid concentrations. Textured products allow administration of a large percentage of protein (up to 50-60% in the product) and are available in a variety of food items. We studied > 1000 patients. An extensive review of the literature indicates that similar findings have been reported by others when administering TVP or TVP-like items to subjects with well-characterized hypercholesterolemia (Fredrickson type II). Data are less consistent for treatment of patients with marginal hypercholesterolemia or hypercholesterolemia already corrected by a standard diet before administration of soy products. The TVP diet, is, however, effective when normolipidemic individuals are made hypercholesterolemic by dietary cholesterol administration. These and other findings suggest that, in man, similar to experimental animals, soy protein may in some way up-regulate LDL receptors depressed by hypercholesterolemia or by dietary cholesterol administration.