A new study published today in the Journal of the American Medical Association shows that children and adolescents who had higher concentrations of bisphenol A (BPA) in their urine also had significantly increased odds of being obese. The study looked at a nationally representative sample of around 3,000 children and adolescents of ages 6 to 19.
BPA is a manufactured chemical found in consumer products. The study's authors stated that, to their knowledge, this is the first report, in a nationally representative sample, of an association of childhood obesity with an environmental chemical exposure.
“In the U.S. population, exposure [to BPA] is nearly ubiquitous, with 92.6 percent of persons 6 years or older identified in the 2003-2004 National Health and Nutrition Examination Survey (NHANES) as having detectable BPA levels in their urine," said Dr. Leonardo Trasande, associate professor at New York University School of Medecine. "A comprehensive, cross-sectional study of dust, indoor and outdoor air, and solid and liquid food in preschool-aged children suggested that dietary sources constitute 99 percent of BPA exposure. In experimental studies, BPA exposure has been shown to disrupt multiple metabolic mechanisms, suggesting that it may increase body mass in environmentally relevant doses and therefore contribute to obesity in humans.”
The researchers stopped short of saying BPA causes obesity in children, saying only that a link is plausible. When the children in the study were separated into quartiles based on their urinary BPA levels, 10.3% of the children in the quartile with the lowest concentrations of BPA were obese, compared to 22.3% in the highest quartile. Oddly, further analysis showed that the results were only statistically significant for white children and white adolescents.
“We note the recent FDA ban of BPA in baby bottles and sippy cups, yet our findings raise questions about exposure to BPA in consumer products used by older children," said researchers. "Last year, the FDA declined to ban BPA in aluminum cans and other food packaging, announcing ‘reasonable steps to reduce human exposure to BPA in the human food supply’ and noting that it will continue to consider evidence on the safety of the chemical. Carefully conducted longitudinal studies that assess the associations identified here will yield evidence many years in the future.”