February 19 2013
The chem-nannies have been very effective in scaring women (particularly moms) about BPA—a chemical used in a variety of everyday items from eyeglasses to plastic food containers to water bottles. Today, the chemical is banned in all baby bottles and other baby products (only because industry requested an across-the-board ban, not because BPA was found to be toxic) and attempts are being made nationwide to ban the chemical entirely.
Despite thousands of studies that confirm BPA’s safety, the chem-nannies continue to characterize BPA as a dangerous toxin that mimics estrogen in the human body which, they claim, can lead to sexual disorders, obesity, cancer, thyroid issues, and neurological disorders.
Yet, a new meta-analysis of 150 BPA exposure studies involving 30,000 individuals, including women and infants across 19 countries, shows that people's exposure to BPA may be many times too low for the chemical to effectively mimic estrogen in the human body.
The Wall Street Journal reports that Justin Teeguarden, a toxicologist at the federal Pacific Northwest National Laboratory, has re-examined 150 studies covering blood levels of BPA, in order to determine if BPA concentrations are sufficiently high to be a significant source of estrogen-like activity in the blood. The Lab’s own press release explains that exposure levels are generally much too low to affect the human body:
Researchers have long known that BPA can bind to the same proteins that estrogen does — called estrogen receptors — when estrogen is doing its job in the body. However, in most cases, BPA does so much more weakly than estrogen. To trigger biological effects through receptors, BPA concentrations have to be high enough in the blood to overcome that weakness.
The results showed that human blood levels of BPA are expected to be too far below levels required for significant binding to four of the five key estrogen receptors to cause biological effects.
Teeguarden's analysis also confirmed the findings of many academic and government scientists that biologically active BPA is at such low concentrations in the blood that it is beneath toxicologists' current ability to detect it, raising questions about the role of sample contamination in studies reporting high levels of BPA.
In science, consistency matters. In fact, it’s the only thing that really matters when deciding whether a product is toxic. So called “studies” claiming BPA is dangerous are sure to continue to emerge even in the face of this important new research. Yet, it’s important to understand that, as Teeguarden’s established, there’s a large and very consistent body of evidence that shows BPA is safe.