BALTIMORE (Johns Hopkins) - Too much of the hormone estrogen in the body can raise the risk for breast cancer in women. Do outside sources, so-called environmental estrogens, have the same effect?
The truth is, no one can answer that for sure. There are chemical compounds found in pesticides and certain kinds of plastic that seem to mimic the effects of estrogen. At least they do in some animal models. Some researchers think that in humans these compounds may stimulate the growth of breast cancer cells or somehow modify the effects of naturally occurring estrogen. But it's a difficult theory to prove, in part because there's no consensus on even what constitutes an environmental estrogen.
"The evidence as far as I can gather from the literature that I read that this is a problem with humans is not definitive at all. That doesn't mean we shouldn't be concerned about it," says Dr. Yager of the Johns Hopkins School of Public Health.
There are no reliable tests yet for determining whether any substance suspected of being an environmental estrogen really does have a harmful effect upon the body.
Source: Johns Hopkins University