The list of adverse health effects from BPA exposure continues to grow.
Bisphenol A, or BPA, is commonly used to line food and beverage cans, and helps to keep plastics flexible, but studies suggest the compound can leach into the foods we eat. High levels of BPA in the urine have been tied to behavior problems, obesity, hormone abnormalities and even kidney and heart problems. Now, new research from scientists at the Columbia Center of Children’s Environmental Health is linking the compound to an increased risk for asthma.
“Asthma prevalence has increased dramatically over the past 30 years, which suggests that some as-yet-undiscovered environmental exposures may be implicated. Our study indicates that one such exposure may be BPA,” lead author Dr. Kathleen Donohue, an assistant professor of Medicine at Columbia University College of Physicians and Surgeons and an investigator at the Center for Children’s Environmental Health said in a statement.
Donohue and her colleagues followed 568 women participating in the Mothers & Newborns study on environmental exposures. They measured the BPA levels in the women’s urine during their third trimester of pregnancy, and also tested their kids’ urine for BPA when they were aged 3, 5 and 7. At ages five and 12, based on their symptoms, tests and medical history, their physicians diagnosed the children who met the criteria for asthma with the respiratory disorder.
Each time the children were evaluated, more than 90% of the kids had detectable levels of BPA. The higher their BPA levels, the more wheezing and asthma the researchers found. But higher levels of BPA in pregnant moms during the third trimester of pregnancy were associated with lower rates of wheezing in children at age 5. That confirms previous work that showed that the timing of exposure to the chemical may be important when it comes to asthma risk. In that study, expectant moms with higher BPA levels early on in pregnancy were more likely to have children who developed asthma.
The current study, however, raises concerns about how much BPA infants are exposed to after birth, possibly from plastic bottles and sippy cups, and the role this exposure may have in raising their risk of asthma. “We found that post-natal BPA exposure is associated with increased odds of wheeze and asthma in young children. Specifically, that BPA exposure measured at child ages three, five and seven years was associated with increased odds of wheeze at ages five, six and seven years, and increased odds of asthma between ages five and twelve years,” says Donohue in an email response to questions about the findings. “At a population level, our study suggests that BPA may be an important and understudied environmental risk factor for child asthma.” In July 2012, the Food and Drug Administration (FDA) banned BPA use in baby bottles and sippy cups, but this study was conducted prior to the change.
How BPA might affect respiratory development and raise the risk of asthma isn’t clear. “We did see evidence that exposure to higher levels of BPA was associated with higher levels of exhaled nitric oxide, a biomarker of airway inflammation,” says Donohue. “The current study found no evidence that exposure to BPA increased the risk that the immune system would develop more antibodies to common airborne allergens. Other possible pathways may include changes to the innate immune system, but this remains an open question.”
While the FDA deemed BPA unsafe in baby bottles, it says the evidence doesn’t support a wider ban on its use in food packaging. The National Institute of Environmental Health Sciences (NIEHS), however, advises avoiding plastic containers marked with recycle codes 3 and 7, which are more likely to contain BPA. Avoiding canned food and choosing glass, porcelain or stainless steal containers for hot foods and liquids can also reduce your risk of exposure to the chemical.