Of the above bioactive constituents, isoflavones and protease inhibitors have been studied most thoroughly for their
anti-cancer ef ects. Soy isoflavones may reduce risk of breast, prostate and other hormone-dependent cancers.
The low breast cancer mortality rates in Asian countries and the putative anti-estrogen ef ects of isoflavones
support this contention. Strong evidence for the prevention of prostate cancer may explain, in part, the 80 percent
lower incidence of prostate cancer in Asia compared to Canada, the United States and other western countries,
that do not include Soy as a common dietary staple.
Soy and Soy isoflavones have been shown to decrease reproductive organ cancers in animal-based studies.
Human research also suggests a protective role of Soy against cancer, however, the data is currently insuf icient to
make formalized recommendations.
There are literally hundreds of in vitro studies showing that genistein (a predominant Soy isoflavone) inhibits the
growth of a wide range of both hormone-dependent and hormone-independent cancer cells, including breast,
prostate, colon and skin cells.
In vitro, genistein also inhibits the metastasic activity of both breast and prostate cancer cells independent of the
ef ects on cell growth.
Genistein is known to inhibit several enzymes involved in signal transduction, including tyrosine protein kinase,
MAP kinase, rhibosomal S6 kinase, and DNA topoisomerase I . Genistein also increases the concentration of
transforming growth factor B (TGF-B). Together these biological mechanisms account for the ability of genistein to
arrest cancer cell growth.
These findings may have important implications, as the breast cancer rate in Japan is only about one-quarter of
that of the United States. Similar data exists for prostate and colon cancer incidence.
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Meschino Health Comprehensive Guide to Accessory Nutrients and Essential Oils
Accessory Nutrients and Essential Oils
In vitro, genistein inhibits the growth of both androgen-dependent and androgen-independent prostate cancer cells.
Genistein has also been shown to inhibit the 5-alpha reductase enzyme that is strongly linked to prostate
enlargement (benign prostatic hyperplasia) and prostate cancer metastasis. The 5-alpha reductase enzyme
converts testosterone to dihydrotestosterone (DHT). DHT build up encourages more rapid prostate cell
proliferation leading to prostate enlargement and fuels the proliferation and spread of existing prostate cancer.
Increased Soy intake in men under clinical trial conditions demonstrates a reduction in DHT metabolites in the
blood, indicating that Soy consumption reduces DHT production in men.
Soy isoflavones concentrate in prostate fluid and increased isoflavone intake has been linked to significant
apoptosis (programmed cell death) of prostate cancer cells (adenocarcinoma) in a patient taking 160 mg of
isoflavone content per day, one week before prostate surgery.1
Genistein also inhibits angiogenesis, the growth of new blood vessels that contribute to the spread of cancer.5