When we think of the drivers behind America’s obesity epidemic, sugar-laden beverages, such as soda and sports drinks, and too little exercise might come to mind. Efforts like First Lady Michelle Obama’s “Let’s Move” campaign are being implemented nationwide to help rein in the childhood obesity rate, which has tripled over the past three decades.
But parents beware – a recent study in the Journal of the American Medical Association adds another potential offender to the list: the chemical Bisphenol A, or BPA, commonly found in canned food, bottled liquids, and other consumer products. Researchers found that children and teens with higher concentrations of BPA in their body were more likely to be obese.
We asked Dr. Emily Barrett, a scientist (and parent!) who studies the influence of various chemicals on development, to shed some light on BPA and what the findings mean for moms and dads trying to raise healthy kids.
Scripts: Studies show that most of kids’ exposure to BPA is through food. Are we exposed mainly through canned goods and other packaged foods? What about fresh fruits and vegetables?
Barrett: Food does appear to be a main source of exposure to BPA, and several studies have now shown that BPA levels drop when individuals avoid processed foods. Many studies suggest that cans are a major source; the linings are often made with an epoxy resin containing BPA.
But BPA is probably lurking in a lot of other foods as well, since the food can be exposed to the chemical during processing. And unfortunately, environmental chemicals like BPA might even be found in foods that we typically think of as unprocessed, like fresh meats and dairy. That said, fresh fruits and vegetables are unlikely to be a major source of BPA and remain a smart choice.
Scripts: Why might higher levels of BPA be tied to obesity in kids and teens? And why was a link only found among whites – not blacks or Hispanics?
Barrett: At this point, we don’t understand much about the mechanisms by which current BPA levels might be connected with obesity, as most of the research so far has focused on prenatal exposures. One possibility, though, is that kids who are obese eat greater quantities of foods that are high in BPA, such as fast food, than slimmer kids.
Another possibility is that higher consumption of BPA might actually change metabolism in some way that promotes obesity.
Still, another possibility is that BPA is stored in and released from fat tissue, and since obese kids have more fat, the levels they excrete will be higher. Further study is needed to better understand these possibilities.
As far as racial differences in the relationship, it may simply be due to different eating patterns and behaviors across cultures. It could also be due to genetic or metabolic differences, but again, more research is needed.
Scripts: What is your advice for parents raising kids and teens? Should they work hard to avoid foods containing BPA? Or should they focus more on common sense recommendations, like eating more fruits and vegetables and getting more exercise?
Barrett: The good news is that by following already tried-and-true recommendations, you’ll likely avoid foods that contain high levels of BPA. We know that highly processed foods tend to be bad for you nutritionally, and those foods are also more likely to have high levels of BPA. So, if you’re encouraging your kids to eat fresh, minimally processed foods, you’re already doing the right thing.
Parents who want to go a step further may think about reducing their use of canned goods – fresh and frozen alternatives are likely to be better for you, plus they taste better, too. They may also want to check their food packaging, plastic food storage containers, and water bottles; those marked with 1, 2, 4, 5, and 6 recycling codes are unlikely to contain BPA. Those marked with 3 and 7 might. One final tip: Avoid putting plastics in the microwave, as they might release toxins under high heat.
Up to 80 percent of children who are obese remain overweight as adults, according to the National Institutes of Health (NIH). Learn more about child obesity in URMC’s health encyclopedia, linked here.
Emily Barrett, Ph.D., is an assistant professor in the Department of Obstetrics and Gynecology at URMC.