Thank you for your quesstion and for requesting I post in the answer box.
As stated in clarification:
AVOID CAFFEINE, ESTROGEN, PHYTOESTROGEN, & XENOESTROGEN
(quite a long article)
Scroll midway down the page to:
"Soy Foods - the effects of soy phytoestrogens on cancer are still
being investigated and controversial. The National Cancer Institute is
promoting soy?s role in protecting against breast and prostate cancer
(JAMA, Vol 275, 1996). There are some conflicting results and can be
explained by the fact that isoflavones are selective as to where in
the body they are a ?pro-estrogen? and where they act as an
?anti-estrogen.? They may also be pro or anti estrogen depending on
the dose-At low doses isoflavones have an estrogen-like stimulating
effect, while at higher doses it appears to have anti estrogen
effects. In the absence of any estrogens, genistein in low doses has a
weak pro estrogen effect on breast cancer cells in a test tube (Hsieh,
Cancer Res, 1998).
However, in that same test tube, when adding higher doses of
genistein, it inhibits the growth of breast cancer cells (Zava, Nutr
Cancer, 1997 and Peterson, Cell Growth Diff, 1996). That being said,
in over 150 test tube studies, genistein has been found to inhibit the
growth of cancer cells (Messina, Adjuvant Nutrition in Cancer
Treatment Symposium, 1995 and Fotsis, Baillieres Clin Endocrinol
Metab, 1998). Soy phytoestrogens inhibit the proliferative effect of
both estrogens and xenoestrogens (chemicals that act like estrogens in
the promotion of breast cancer) (Herman, J Nutr, 1995 and Verma, Nutr
Cancer, 1998). An Italian test tube study found that the combination
of genistein and the chemo drug Adriamycin showed an increased,
synergistic effectiveness in halting human breast cancer cell growth
(Monti, E, Anticancer Res, 1994)."
"Of late, there has been some discussion about soybeans in any form
causing the human body to produce natural estrogen. Menopausal women
are being bombarded with numerous supplements. In some physique
culture circles, men are being told to avoid soy products at all costs
or they will lose their virility. Tell that to the Samurai!
The ingestion of soy alone is not the problem because all males need a
certain amount of estrogen. However, when soy products are eaten along
with all the xenoestrogens found in many foods and containers, this
may not be such a far-fetched idea."
various combinations of the following keywords used for search:
xenoestrogens soy meal fed to poultry breast cancer body absorb