Furthermore, researchers have shown that merely substituting soy milk for cow's milk can reduce cholesterol levels. Isoflavones Soybeans also contain isoflavones, which play a crucial role in soy's disease-fighting properties. Isoflavones also protect against heart disease by helping to relax the artery walls, which promotes flexibility, thereby ameliorating the harmful effects of cholesterol buildup, says Dr. Messina. A diet high in soluble fiber reduces the risk of heart disease, although the effects are more modest than the effects of soy protein alone. Furthermore, genistein inhibits angiogenesis, the growth of blood vessels needed for tumors to enlarge.
Researchers dispute the role of genistein in preventing and treating specific types of cancer.
According to Dr. Mark Messina, the studies conducted on the relationship between soyfoods consumption and prostate cancer have yielded encouraging results. Unfortunately, Dr. Messina reports that the relationship between soyfoods consumption and breast cancer has become less clear as the research has progressed. This had been a promising avenue of research, because of the low rates of breast cancer in Asian countries, where individuals consume a lot of soyfoods. In addition to genistein, protease inhibitors may contribute to the cancer-fighting properties of soyfoods. Unfortunately, protease inhibitors also interfere with the digestion of dietary protein.