A study, published in the journal Endocrinology, has found that the chemical bisphenol A (BPA) can disrupt important effects of estrogen in the developing brain. Lead researcher Dr. Scott Belcher, from the University of Cincinnati (UC), said the negative effects in brain tissue occurred "at surprisingly low doses." The study is worrying because so many common household items use BPA. "BPA molecules are linked into polymers used to create plastics and epoxy resins that are widely used," said Dr. Belcher. "While plastics are typically thought of as being stable, scientists have known for many years that the chemical linkage between BPA molecules was unstable, and that BPA leaches into food or beverages in contact with the plastics."
BPA is known to act as an artificial estrogen; a hormone involved in female sexual development, and has previously been shown to increase breast cancer and prostate cancer cell growth. As well as its function as a female sex hormone, Dr. Belcher explained, estrogen also has very important roles in the developing brain of both males and females. But BPA can mimic the actions of estrogen in developing neurons, and very low doses of BPA completely inhibited the activity of estrogen. Because estrogen normally increases the growth and regulates viability of developing neurons, it's likely that BPA may harm developing brain cells.
"We have now shown that environmental estrogens like BPA appear to alter, in a very complicated fashion, the normal way estrogen communicates with immature nerve cells," Dr. Belcher explained. "The developmental effects that we studied are known to be important for brain development and also for normal function of the adult brain."
The effects of BPA on rat brain neurons not only occurred "at surprisingly low" doses, they also happened in a matter of minutes. "From other studies it's clear that these low concentrations are in line with human fetal exposures, and at levels one might even see in the water supply," said Dr. Belcher. "These are important considerations in view of the widespread presence of low concentrations of BPA in the environment."
BPA has previously been implicated in disease or developmental problems. But despite more than 100 studies showing the detrimental effects of BPA, the chemical industry and federal regulatory agencies have resisted banning BPA from plastics used as food and beverage containers, despite the fact that plastics free of BPA and other toxic chemicals are available.
Source: University of Cincinnati
