Moderate use of soyfoods reduces blood cholesterol levels in women.

A number of studies have found that adding generous amounts of soy protein to people's diets leads to a reduction in blood cholesterol levels. Is it possible to see an effect with intakes of soy that are closer to what people typically eat? A study from the University of Oxford examined vegetarians, vegans, and non-vegetarians to address this question. More than 1,000 postmenopausal women, including 570 vegetarians and 102 vegans, were studied. Women were asked about their diets, and blood was collected. Women who had the highest intakes of soy protein (11 grams, the equivalent of 3 ounces of tofu and 1/3 cup soymilk) had the lowest total cholesterol and LDL-cholesterol (bad cholesterol) levels. Many of these women were either vegan or vegetarian. Women with a soy protein intake of six or more grams per day had a 12 percent lower LDL-cholesterol level than women who ate less than half a gram per day of soy protein. The authors of this study conclude, "moderate intakes of soy foods as part of a regular diet are associated with favorable blood cholesterol concentrations. This may be partly due to a biological effect of soy and partly due to the overall composition of diets with a high soy content."

Rosell MS, Appleby PN, Spencer EA, Key TJ. 2004. Soy intake and blood cholesterol concentrations: a cross-sectional study of 1033 pre- and postmenopausal women in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. Am J Clin Nutr 80:1391-6.