Does BPA Cause Early Puberty?
The FDA has just rejected a call to ban BPA, a chemical found in some plastic bottles and canned food liners. But some people say it causes early puberty in girls, and a host of other bad things. Who's right?
The Natural Resources Defense Council, an environmental group, had petitioned the FDA to ban the chemical, which is found in some plastic bottles and canned food liners, arguing that it causes "reproductive harm, cancer, and abnormal brain development." And in a "New York Times Magazine" story this weekend, Elizabeth Weil listed it as one possible cause of increasingly early puberty in girls.
Today, the FDA rejected that petition, saying, "While evidence from some studies have raised questions as to whether BPA may be associated with a variety of health effects, there remain serious questions about these studies, particularly as they relate to humans."
Some researchers Shift spoke to were disappointed with the FDA's decision. Patricia Hunt, a biologist at Washington State University, said the news had been a hot topic among her colleagues — and that "the weight of evidence is just overwhelmingly strong" that BPA is dangerous. As to whether BPA could cause early puberty, she said it was possible, since the chemical has been linked to certain markers of early sexual maturity in mice. She also pointed to a study showing that prenatal BPA exposure can affect children's behavior — girls whose mothers had high levels during pregnancy were more likely to be hyperactive, anxious, or depressed at age 3.
Irva Hertz-Picciotto, chief of environmental and occupational health at the University of California, Davis and chair of an Institute of Medicine panel that studied environmental contributors to breast cancer, said that animal studies on BPA clearly showed it interacted with endocrine systems and "to say that it has no impact on humans would be a difficult stance to take." She added, "I don't know that we have a lot of super-conclusive data on the health effects, but there is circumstantial evidence, there is correlational data, and to the extent that there are alternatives, they should be pursued."
When it comes to hard evidence for the BPA-early puberty link, though, there doesn't seem to be any. Mary Wolff, professor of preventive medicine and oncological sciences at Mount Sinai School of Medicine, has conducted several studies on BPA and found no connection to early puberty (by contrast, she found in another study that exposure to the chemicals phenols, phthalates, and phytoestrogens were associated with early breast development). She told me that "at present there is no evidence to support the idea" that BPA causes early puberty, and noted that by and large, Americans' exposure to BPA is extremely low.
While Wolff wouldn't comment directly on the FDA decision, she said she did favor reduction of humans' exposure to BPA. And Hertz-Picciotto pointed out that girls' development isn't the only thing BPA could affect — she notes preliminary studies showing a correlation between BPA exposure and diabetes diagnoses. This data suggests, she says, that beyond sexual development, "there could be other systems that are affected."
So while no one can say for sure that BPA is safe (including the FDA), nobody can pin early puberty on it yet. It does seem, however, that it's probably best avoided.