Soy provides many valuable components, including protein, isoflavones, saponins, and phytosterols. The isoflavones in soy (primarily genistein and daidzein) have been well-researched for their antioxidant and estrogenic properties. More recent research has focused on the role of soy in supporting healthy bone structure, cardiovascular health, and menopausal support.
The isoflavones genistein and daidzein are protective phytoestrogens. Soy protein with intact genistein and daidzein has been shown to significantly decrease LDL cholesterol 30-40% and significantly increase HDL cholesterol to LDL cholesterol ratios by up to 15%. Possible mechanisms for soy’s cholesterol-lowering effect include an increase in bile acid excretion, a preferable ratio of the amino acids arginine and lysine, and changes in the liver’s metabolism of cholesterol.