Phytosterols may exert a beneficial effect in preventing colon cancer by protecting the colonic mucosa against bile acids and their metabolic products. Flavonoids , in general, have many diverse nutritional and biological effects. These enzymes play a role in the pathogenesis of diseases such as cancer, arthritis, heart disease and inflammatory diseases. In reality, isoflavones act as antiestrogens by binding to estrogen receptors and making the receptors unavailable to the more potent natural estrogen. This is important since many cancers contain estrogen receptors.
Soy foods are one of the few natural sources of isoflavones in human diets.
The most notable studies have shown the association of a decreased breast cancer risk and isoflavone dietary intake. There are numerous studies that show that the replacement of animal protein with vegetable protein lowers the risk of coronary heart disease. Isoflavones may lose their magic when extracted from soy proteins. The cause of osteoporosis remains unknown. The frequency of hip fractures in countries that consume high levels of calcium is incongruous with the importance of calcium in the prevention of osteoporosis.