I've been working on my forthcoming book. Right now, I'm in the midst of updating the portion of the book on Bisphenol A (BPA). BPA is a key monomer of polycarbonate plastic, but BPA leaches out from the plastic under certain conditions. Since polycarbonate plastic is used for, among other things, plastic baby bottles, there has been significant concern about the potential health effects from babies drinking formula or breast milk from polycarbonate plastic baby bottles.
But what is even more frightening is the health effects associated with in utero exposure to bisphenol A. It seems that BPA exposure during pregnant, especially certain critical times, can affect the way genes are expressed. I've had a series of email communications with Randy L. Jirtle, PhD, Director of the Jirtle Laboratory at Duke University. His research team published study that showed pregnant Agouti mice fed BPA had offspring that were, instead of lean and brown-haired as they normally would have been, obese and blond haired.
BPA passes across the placenta. And fetuses (and newborns) do not metabolize BPA quickly, unlike adults. Fetuses and newborns lack or express at low levels the liver enzyme needed to deactivate BPA. The necessary liver enzyme is not expressed until after birth, with the full complement at 3 months, but at about 25% of the adult level. Thus, fetal and infant exposure at critical development stages may cause significant health effects, as Dr. Jirtle's research indicates. Other scientists have similarly found low level exposures in utero in animal studies to cause significant ill effects.
What scared me those most is that according to Dr. Jirtle, “[t]he time between fertilization and blastocyst implantation is really the most sensitive period for deregulating the epigenome by environmental factors.” It was at this time of early development that his study determined that exposure to BPA would change the coat color of Agouti mice. Dr. Jirtle states that “if I was a woman who was pregnant – or thinking about becoming pregnant – I would try hard to avoid exposure to BPA.”
If you are trying to get pregnant, then you might want to work to eliminate BPA exposure.
So what can you do? If you are trying to get pregnant, eliminate exposures to BPA. It is important to eliminate exposures when you are trying because the window Dr. Jirtle identified is usually before we even know we are pregnant. Do not use polycarbonate plastic. Choose glass, stainless steel, polyethylene plastic, and ceramic over polycarbonate plastic. Polycarbonate plastic is identified by the "7" (although this actually means "other plastic" so not all "7" plastic is polycarbonate plastic). If you are using polycarbonate plastic, don't heat it! Heat increases leaching significant. Since BPA is also present in epoxy linings of metal cans, choose glass containers for "canned" goods instead. And, Dr. Jirtle's research shows that folate shields fetuses against BPA, so make sure you are taking a supplement – just don't over do it!