BPA in Food Packaging Tied to Child Obesity: Study

The common chemical bisphenol A (BPA), found in the lining of many aluminum cans and a variety of food packaging, may be adding to the obesity epidemic among children and teens, according to a new study.

Recently, the U.S. Food and Drug Administration banned the use of BPA in baby bottles and sippy cups because of fears that it may cause developmental problems. BPA, however, remains in many products children and teens use daily, the study authors noted.

"BPA has been associated with adult obesity and heart disease," said lead researcher Dr. Leonardo Trasande, an associate professor of pediatrics at New York University. These new findings "raise further questions about the need to limit BPA exposure in children," he said. "This is the first study to find an association of an environmental chemical with childhood obesity in a nationally representative sample."

The study also suggests that diet and exercise are not the only factors involved in the obesity epidemic, he said.

Trasande speculated that because BPA can act like estrogen -- a female hormone -- it may have an effect on the body's hormones and fat cells, making them bigger.

Alternatives to BPA exist, he said. "This study raises the need to reconsider the decision not to ban BPA in aluminum cans and other food packaging," he said.

The report was published in the Sept. 19 issue of the Journal of the American Medical Association.

Trasande's team looked at urinary levels of BPA in almost 2,900 children and teens who took part in the 2003-2008 U.S. National Health and Nutrition Examination Surveys.

Comparing these urinary BPA levels with participants' weight, researchers found that about 10 percent of children with the lowest levels of BPA in their urine were obese, compared with more than 22 percent of those with the highest levels of BPA.

Additional analysis showed this connection was only significant for white children and teens. The findings were similar for boys and girls. The association was not connected to similar chemicals used in sunscreens, soaps and other products, the investigators found.

BPA is nearly everywhere, Trasande said. According to study background information, nearly 93 percent of Americans aged 6 and older have detectable BPA levels in their urine.

Another expert commented on the new findings, noting that they do not prove that the chemical causes obesity.

"Like all observational studies looking at associations, this one cannot prove cause and effect," said Dr. David Katz, director of the Yale University Prevention Research Center.

"It is possible that BPA is actually a cause of obesity. It could also just be a marker of, for instance, a diet made up of more processed foods that are the actual cause," he said.