Just about everyone living in an industrialized country has some exposure to bisphenol A or BPA -- the industrial chemical that can be found in food and beverage cans, water bottles and even thermally-printed receipts -- but new research suggests pregnant moms might want to pay particular attention to how much exposure they're getting.
The authors of the new study, published in the journal Pediatrics, found BPA exposure during gestation may negatively impact the behavior of girls at age 3.
Relying on urine samples from nearly 250 moms and children near Cincinnati, Ohio, researchers found that BPA exposure during pregnancy was linked with anxious, depressive and hyperactive behaviors in girls in age 3. The higher the BPA urine levels, the more pronounced the effects.
Notably, boys did not seem to be particularly affected by gestational exposure, nor did the researchers find any significant link between BPA exposure during early childhood and behavioral issues in toddlers of either sex.
"It’s still early to say what this means overall for a public health message, because it’s only one study and it clearly needs to be validated and replicated,” said lead author Joe Braun, Ph.D., a research fellow in environmental health at the Harvard School of Public Health, acknowledging that there is still much debate over the toxicity of low-level BPA exposure.
"However, it suggests that regulatory efforts aimed at reducing childhood exposure to BPA may not be effective enough," he continued.
The authors are not yet sure precisely what mechanisms are behind the possible link, but Braun theorized that BPA, which is thought to be an endocrine-disrupting compound, may work almost as a sex steroid when present in the female brain during gestation, somehow "masculanizing" it.
Laura Vandenberg, a postdoctoral fellow at Tufts University who studies BPA, said that while the new research is preliminary, it does join several animal studies that have shown exposure to low doses of BPA both during gestation and lactation alters behavior.
"Brain development is largely happening in utero, so those aspects of the brain that control behavior may be more sensitive during gestation," she said, offering an explanation for why researchers did not see a tie between early childhood BPA exposure and behavioral issues.
Vandenberg was critical of what she called a "lazy attempt" to regulate exposure by simply removing BPA from some products, like baby bottles, and not those that may impact women during pregnancy, like canned food and thermally-printed receipts.
For its part, the American Chemistry Council issued a statement on the new study saying it has shortcomings in design and that the conclusions are of "unknown relevance" to public health.
The Food and Drug Administration has said that low-levels of exposure to BPA are safe. However, recent studies suggesting it may be harmful to the brain, behavior and prostate glands in fetuses, babies and young children have prompted it to further investigate what it calls "key questions" and "uncertainties" about the chemical's risks.
In the meantime, Braun said that pregnant women who are concerned about their exposure should try and limit their consumption of canned and packaged food, if possible, but should also balance that with the need for good nutrition. If canned vegetables are an important source of nutrients for you, he said, you shouldn't go out and swap them for, say, hamburgers because you are concerned about BPA.
Joy Hatch, who co-writes the blog Greenbabyguide, seconded that need for balance. When she recently posted a pumpkin bar recipe with a photo of organic, canned pumpkin, a reader immediately wrote in about the dangers of BPA and suggested she cook it herself.
"Honestly, I have to admit that I don't really have time to roast a whole pumpkin every time, so I think it's important to strike a balance," she said. "Neurosis and anxiety about BPA aren't healthy, but ignorance isn't either. Awareness is the middle ground that is most helpful for new parents."