Cholesterol, High Cholesterol

A double-blind randomized parallel trial of 156 healthy men and women with LDL cholesterol levels between 3.62 mmol/L (140 mg/dL) and 5.17 mmol/L (200 mg/dL) were studied to identify the the link between isoflavones isolated together with soy protein or soy protein itself and cholesterol. Participants were randomly assigned to one of 5 daily diets: 25 g of casein [for isoflavone-free comparison] or 25 g of isolated soy protein containing 3, 27, 37, or 62 mg of isoflavones. Crouse et al found significant decreases, compared with casein, in LDL cholesterol after the consumption of isolated soy protein containing 62 mg isoflavones (4% vs 6%, respectively) but not after the consumption of that containing 37, 27, or 3 mg isoflavones. These results support the conclusion that isolated soy protein containing isoflavones lowers cholesterol. Isolated soy protein containing isoflavones were also found to not have a harmful affect on plasma concentrations of triglycerides or HDL, cholesterol. (36)