Image courtesy of Rodale

You would never give your child a birth control pill. But the food industry is feeding children something almost as damaging every time it packages food in a can. Bisphenol A, a chemical that was initially developed as a drug to aid in healthy pregnancy, is commonly used in the epoxy linings of canned goods and some plastics, and it's being linked to a growing number of health problems, from heart disease to metabolic disorders in adults.

Few researchers have looked at the chemical's effect in children, though, and a new study published in the Journal of the American Medical Association suggests that it could be contributing to America's childhood obesity epidemic.

The study authors analyzed data from the National Health and Nutrition Examination Survey (NHANES), an ongoing study conducted by the Centers for Disease Control and Prevention, which recruits a random sampling of Americans to donate blood and urine samples and fill out health survey data every two years. For this study, the authors looked at a random sampling of 2,800 children, ages 6 to 19, from three different NHANES surveys, and compared their body mass index (BMI) with levels of BPA detected in their urine.

The Long Lasting Effects of Canned Foods

While nearly all the children had detectable levels of BPA in their urine, kids with the highest levels of BPA in their systems were more likely to be obese or overweight, with higher BMIs, than kids with the lowest levels, even after the researchers factored in caloric intake, physical activity levels, and other genetic factors that can influence obesity risk. In fact, they divided the children into quarters based on who had the lowest levels of BPA and who had the highest. Just 10.3 percent of children in the lowest quarter were obese or overweight, compared to 22.3 percent of children in the highest quarter.

Oddly, however, the effect was seen only in white children. The BPA-obesity association wasn't significant in black or Hispanic children.

The authors were quick to point out that the association they found doesn't necessarily mean that BPA causes obesity. For instance, it could be that overweight children eat more canned food or drink more canned beverages; although the authors controlled for caloric intake when calculating their results, they didn't know where those calories came from. Also, growing evidence suggests that BPA is stored in body fat, and if that's the case, it would stand to reason that obese children would have more BPA in their bodies than children with less body fat.

Still, the results suggest that exposing children to constant low levels of a chemical known to interfere with hormonal development may not be the best antidote to an obesity epidemic, yet the Food and Drug Administration (FDA) has decided not to formally ban the chemical, which is used in canned foods and other food packaging (such as the linings of glass-jar lids), but instead encourage food companies to seek safer alternatives.

Past studies suggest that 99 percent of the BPA in children's bodies comes from their diet. The nonprofit Breast Cancer Fund has tested canned foods marketed to children and found that all of them contained the harmful chemical. In addition to obesity, the chemical has been associated with aggressive behavior and other behavioral problems in children.

Bpa and Aggressive Behavior In Children

Though it's impossible to protect your children from all the BPA in the food system, here are the three simplest steps you can take.

Avoid cans. They're lined with an epoxy resin that contains BPA. Many companies are switching over to "BPA-free" cans, but they aren't disclosing the replacement chemicals they are using. According to the canned-food industry, the most popular replacement is vinyl, another chemical that contains hormone-disrupting chemicals and is considered a carcinogen by the Environmental Protection Agency.

Never microwave plastic. Even "microwave-safe" containers can leach chemicals such as BPA that can interfere with a child's hormones.

Opt for stainless steel sippy cups. Even though the FDA has banned BPA from baby bottles and sippy cups, the replacement plastics could be just as damaging, according to a 2011 study published in the journal Environmental Health Perspectives. Stainless steel is a safer alternative.

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