|Facts About Soy and Cancer
The Japanese, who have low rates of breast and prostate cancer, consume daily 20-80 mg of genistein, a phytochemical almost entirely derived from soybeans. But in the United States, the daily dietary intake of genistein is only 1 to 5 mg.
When Japanese women move to the United States and consume the standard American diet, their risk of breast cancer increases dramatically. Previously, doctors thought that this was because of the high fat content of the western diet, but new studies fail to show a significant link between dietary fat and breast cancer risk. Many researchers now think that the increase in breast cancer results from a diet that is deficient in soy.
The following forms of cancer have been shown to respond favorably to soy adjuvant therapy: prostate cancer, leukemia, glioblastoma multiforme, and bladder cancer. Genistein and other soy components provide anticancer protection by the following mechanisms:
- Blocking the cell mutating actions of pesticides, herbicides, fungicides and other pollutants by preventing their binding to estrogen-testosterone cell receptor sites in the breast and prostate.
- Inhibition of the activity of tyrosine kinase, an enzyme required for most tumor cell proliferation
- Inhibition of new blood vessel growth required to feed tumors
- Inhibition of cancer cell protein synthesis
- Induction of cancer cells to differentiate into normal cells
According to published studies, the daily intake of sufficient soy isoflavones may also alleviate post-menopausal symptoms, stimulate bone formation, inhibit LDL cholesterol levels, reduce total and LDL cholesterol levels, inhibit the development or progression of atherosclerosis, prevent gallstones, reduce the risk of cancer at multiple sites, and protect kidney function.
CAUTION: Soy extracts have become very popular in the last few years as an adjuvant (assisting) cancer therapy. Treating cancer, however, is not simple and some cancer patients are less likely to benefit from soy, while others should not use it at all. Those considering soy extract supplementation should remember that while it does have documented anticancer benefits that may work synergistically with other conventional and alternative cancer therapies, soy in not a cancer cure.
Excerpt from Soy in The Directory of Life Extension Supplements, 2000, pg 200.