For years, many scientists have thought of BPA, also called bisphenol A, as a potent hormone disruptor that acts like fake estrogen in the body. But mounting studies show that it's so much more, too. "It binds to many receptors in the cell, so it might mimic other hormones and alter other cellular pathways," explains BPA expert Laura Vandenerg, PhD, assistant professor of environmental health sciences at University of Massachusetts–Amherst. (She was not involved with the latest study.)
This latest study, published in Environmental Health Perspectives,found mice exposed to BPA through their mothers during pregnancy and nursing were more likely to develop liver tumors. It's a big deal, too: This University of Michigan study is the first statistically significant finding of tumors in any organ in wake of BPA exposure. "We found that 27 percent of the mice exposed to one of three different doses of BPA through their mother's diet developed liver tumors and some precancerous lesions. The higher the dosage, the more likely they were to present with tumors," says Caren Weinhouse, University of Michigan doctoral student in the School of Public Health's department of environmental health sciences and lead author of the paper.
The study authors said mice whose mothers received the highest dosage were seven times more likely to have tumors than those whose mothers were not exposed to BPA, citing the need for more research to see if this finding translates to human health.
"This study raises the bar," says Vandenberg. "We aren't just concerned about BPA because it is an estrogen mimic. Now we should be concerned because it could be a frank carcinogen—a chemical that can cause cancers to grow all by itself."
Last year, another study found BPA could induce mammary cancers, too, while a study earlier this year linked BPA to prostate cancer. The latest studies suggest we need to rethink BPA safety again.
Interestingly, it seems to take a long time between exposure to BPA and disease, meaning exposure in the womb might not show up as a health problem for months, years, or decades down the line. So far, the chemical's also been implicated in behavioral problems in children, certain cancers, obesity, infertility, and a host of other ills.
It's a burden we all share, too; BPA has been detected in the bodies of more than 90 percent of Americans.
The Food and Drug Administration restricted the use of BPA to keep it out of baby bottles, but the truth is, it's not clear how tightly that move's been enforced. Beyond that, Vandenberg says this and previous studies show that one of the majorly problematic exposure points is before the baby is born—the exposure it's receiving in the womb from the mother.
To fix the BPA problem, we likely need broad legislation keeping it out of everyday products. So make sure your elected officials know this is important to you! In the meantime:
•Avoid eating and drinking out of plastic containers.
•Don't heat food in plastic containers in the oven or the microwave—this accelerates leaching.
•Say no to frivolous cash-register receipts, and immediately store any you need to save. •Leaving them in the bottom of your purse could lead to more exposure.
•Eat fresh or frozen food as much as possible to avoid BPA in canned foods. (Eden Foods is one company that offers a vegetable-based BPA replacement.)
•Be wary of other BPA-free canned foods and products. Replacements include vinyl and BPS, another hormone disruptor, which are often just as dangerous.
Need more inspiration to kick your BPA habit? Check out 5 Weird Things BPA's doing to your body.