[quote]Kuz wrote:
Huh. What is it about processed materials that is believed to contribute to gyno? Some kind of exogenous estrogen?[/quote]
Bisphenol A, a component of plastics, has been shown to increase the release of prolactin levels, acting like a weak estrogen in rats. I am not aware of studies proving the same occurs in humans but there is much speculation.
[quote]Endocrine researchers at the University of Cincinnati Medical School and Indiana University School of Medicine discovered that bisphenol A can bind to the estrogen receptor in the pituitary and stimulate the release of prolactin in laboratory rats. The pituitary, located at the base of the brain, is the master endocrine gland which controls many important functions such as growth, metabolism and reproduction. In humans, prolactin is normally involved in the production of milk in nursing mothers. When prolactin is produced in excess amounts, however, it can cause infertility in women and impotence in men.
Like naturally occurring estrogen, bisphenol A increased the release of the hormone prolactin from pituitary cell cultures. Under these conditions, bisphenol A was found to be much weaker than estrogen, and approximately 1,000-5,000 more was needed to produce the same effect as estrogen. When given to live rats, however, approximately 100 times more of the component of plastic was needed to raise the blood levels of prolactin.
“Our objective was to examine the effects of bisphenol A on the reproductive system and explore its mechanism of action,” said Nira Ben-Jonathan, PhD, who led the investigative team. “We suspect that in the living animal, bisphenol A may be metabolized in such a manner as to increase its potency.” She added, “Because the workings of the endocrine system are very complex, and still not fully understood, it is critical that additional research continues in this area.”
“These are intriguing results, but we cannot jump to conclusions,” said Society President P. Michael Conn, PhD. “While these results are significant in a laboratory setting, until further work is done, it is premature to draw any conclusion about potential effects of bisphenol A on humans.”
“The study does illustrate, however, the importance of endocrine research,” said Dr. Conn. “It is critical that potential effects of so-called ?endocrine disruptors? be studied by endocrinologists, the experts in the human endocrine system.”
An editorial accompanying the study, also published in the May issue of Endocrinology, calls for a reasoned discussion of the study.
“The public health question raised by all of these studies is: are the amounts of ingested bisphenol A from all sources substantial enough to cause significant estrogenic effects in the population? It is difficult to answer this question because there are no data available yet on the estrogenic potency of bisphenol A via the oral route,” writes the editorial author, David Feldman, MD, of Stanford University.
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I will see if I can find more info but this was posted back in '97 in a newspaper article.
Some other web sites you may find interesting:
http://www.sierraclub.org/sierra/199909/estrogen.asp
http://www.westonaprice.org/women/natural_protection.html