Posted: Sep 18, 2012 2:01 PM
Sept. 18, 2012 -- Add the risk of childhood obesity to the list of health ills that may be linked to the controversial chemical bisphenol A (BPA), a new study shows.
BPA is used to manufacture many metal food and beverage cans. It may act as an endocrine disruptor in the body, meaning that it can affect hormone activity.
The FDA has banned BPA in baby bottles and sippy cups, but it stopped short of a full ban, stating there is no evidence that very low levels of human exposure to BPA through the diet are unsafe (although they continue to study the issue).
In the new study, children with the highest levels of BPA in their urine were more than twice as likely to be obese as children who had the lowest levels.
As critics are quick to point out, the study can't say that BPA causes obesity. It simply shows a link. More studies are needed to clarify the relationship.
The findings appear in the Sept. 19, 2012, issue of the Journal of the American Medical Association.
"It demonstrates the need for a broader paradigm in the way we think about childhood obesity," says researcher Leonardo Trasande, MD, an associate professor of pediatrics and environmental medicine at the New York University School of Medicine. "We often think of it as a byproduct of an unhealthy diet and lack of physical activity, but environmental exposures including chemicals may play a role, too."
Trasande and his colleagues studied BPA levels in the urine of almost 3,000 children and teens ages 6 through 19.
Slightly more than 10% of kids with the lowest levels of BPA were obese, compared with 22.3% of kids with the highest levels of BPA, the study shows.
So what can concerned parents do?
"We know that 99% of our exposure to BPA is from food, and cans are currently the major source," Trasande says. Choosing fresh fruits and vegetables can limit BPA exposure. "The power of the purse or wallet can't be underestimated. Families have a lot of latitude to choose a healthier lifestyle."
William Muinos, MD, is the co-director of the gastroenterology department at Miami Children's Hospital. He reviewed the new study for WebMD. "BPA may play a role in childhood obesity," he says.
The middle man may be all those cans of sugary soda that children and teens like to guzzle. In addition to the empty calories in these beverages, they are also in BPA-laced cans.
"Try to avoid any aluminum cans or plastic containers," he says.
Muinos recommends non-processed foods, but notes that canned vegetables are less expensive than fresh veggies. "It is better to have vegetables in a can than Doritos," he says.
Frozen vegetables may also be a healthier alternative than canned, he says.
"This study only shows an association, it doesn't tell us that BPA causes obesity," says Goutham Rao, MD, a pediatrician at the University of Chicago Pritzker School of Medicine. But "it would be prudent advice to avoid BPA where you can."
"People who are struggling with their weight should avoid sugary sodas and other high-calorie canned beverages," he says. "If you are not concerned about the caloric content, this study provides another reason to cut back on soda."
As for canning the cans, not so fast, says Steven G. Hentges, PhD. He is a spokesman for the American Chemistry Council in Washington, D.C.
"Attempts to link our national obesity problem to minute exposures to chemicals found in common, everyday products are a distraction from the real efforts underway to address this important national health issue," he says. What's more, he says, "the study measures BPA exposure only after obesity has developed, which provides no information on what caused obesity to develop."