Genistein for Prostate Cancer |
Purpose:Genistein is an isoflavone or plant estrogen. There are two main types of plant estrogens: isoflavones and lignans. Isoflavones are like human estrogen in chemical shape and properties, but are much weaker than the human form. Soybeans are concentrated sources of isoflavones. What Has Been Proven?Studies in laboratories have shown that genistein has a strong inhibitory ability in a number of breast and prostate cancer cell lines. Genistein has been shown in laboratories to reduce the growth of cancer cells no matter if these were androgen-dependent or -independent cells. The exact system that genistein works by is not fully understood. There is the belief that genistein blocks a key cellular pathway in cancer cells. Much of the interest in soy stems from the fact that Asian men who have diets high in soy have a lower rate of death for prostate cancer than American men do. Asian men tend to have higher levels of phytoestrogens in their bodies. This may partially account for the large difference in mortality rates. There are limited human data available for evaluating the link between soy foods and prostate cancer. Studies in mice and rats fed high soy diets show good outcomes in retarding tumor growth. Finally, it is also thought that genistein intake reduces prostatitis-- inflammation of the prostate gland. What Does it Cost?Varies according to product. One quart of soy milk ranges in price from $1.70 to $2.50 at the local grocery store. How to Eat More Soy:There are many soy products available now: soy milk, soy nuts, tofu (soybean curd) and tempeh are the most common. Not all soy foods contain isoflavones. Soy foods that are made from soy protein concentrate may have little or no isoflavones. The current advice is to eat 30 to 50 mg of isoflavones each day to reduce risk of cancer. The following breakdown may help you plan the content of soy in your diet:
Soy milk . . . . 30 mg isoflavones in 8 ounces The table above is an estimate of the amounts of isoflavones in soy foods. It is important to read the label on a particular soy food product to obtain the correct amount of isoflavones. Possible Side Effects:None. Special Considerations/Contraindications:Remember that soy foods and isoflavone extracts (in the form of pills or tablets) are not equivalent. While there is little danger in eating an abundance or soy foods, taking isoflavone supplements has not been studied and may be dangerous. As with all complementary therapies, individuals considering a therapy should talk to their doctor to avoid harmful interactions with current medications and treatments. Written 3/00 |
