American men are 16 times more likely to die from prostate cancer than men from China. Scientists think soy consumption may reduce the risk of the disease because the food is so prevalent in the Chinese diet. Soy products are high in antioxidants called isoflavones that protect the cells from free radical damage and lower blood cholesterol.
The body produces highly reactive chemicals during metabolism called free radicals that can destroy genes, break down cell membranes and promote cardiovascular disease and cancer.
Antioxidants, such as isoflavones, bind with these chemicals and reduce their damage. Unfortunately, you may need 25 grams or more of soy products to get these effects. Isoflavones may reduce the risk of cardiovascular disease and cancer, but their safety is unknown. Soy contains estrogen-like compounds that can interfere with reproductive hormones in women and men. Soy-based foods are probably safe if eaten as part of a well-balanced diet.