One study in the journal Environmental Health Perspectives found that plastic products advertised as BPA - free still leached chemicals
with estrogenic activity — and some of these chemicals were even more potent than BPA.
BPA is a chemical
with estrogenic activity (EA), meaning it mimics the estrogen hormone.
Chemicals
with estrogenic activity «have been reported to have potential adverse health effects in mammals, including humans, especially in fetal and infant states,» says Dr. George Bittner, a professor of neurobiology at the University of Texas at Austin who has served on many National Institutes of Health panels.
Not exact matches
made
with medical and food grade silicone and nylon, free of BPA, BPS, latex, phthalates, lead and all known EA (
Estrogenic Activity) agents.
All eight chemicals demonstrated varying
estrogenic and / or anti-androgenic properties,
with some showing high or little to no
activity, the investigators reported.
Alfalfa also has components that promote
estrogenic activity in women whose own sex hormone production has declined; thus, it is thought to have helped many women
with the discomforts of menopause and pre-menstrual syndrome.
2 - OH E1, a Phase I metabolite of estrone, has weak
estrogenic activity and is associated
with protection against prostate cancer.
A scientific research study on eight healthy male volunteers showed that subjects supplementing
with 10 mg of boron significantly increased free (active) testosterone levels and decreased
estrogenic activity as measured by a significant decrease in estradiol after only seven days.
In the research on BPA - free plastics led by Bittner, he asserts that plastics can be made
with existing inexpensive materials that don't have
estrogenic activity.
Edit 2017: Recently, after learning about new research and working
with even more women, I'm finding that plant - based phytoestrogens may promote ER beta
activity, which can lower
estrogenic potency in the body as a whole, thereby decreasing the risk for certain cancers (this is not true of synthetic estrogen, like that in hormonal birth control or estrogen replacement therapy).
While this type of
estrogenic activity has been associated
with certain reproductive cancers, intervening
with a therapeutically prescribed dosage of milk thistle extract metabolizes excessive amounts, filtering potentially cancer - causing hormonal «residue» from the body.
«Clear evidence of adverse effects of genistein in studies
with gestational, lactational and post-weaning treatment,» and that «Daidzein has
estrogenic activity of its own.»