Obesity, which affects one in six children and adolescents in the United States, is a growing public health concern especially among children living in poor areas. One study found children living in low-income neighborhoods had a 28 percent greater risk of becoming obese. New research published in the journal Environmental Health Perspectives found that in addition to socieoeconomic status, prenatal exposure to Bisphenol A (BPA), a common chemical used in plastic water bottles and canned food, can contribute to obesity.

The study, conducted by researchers from the Columbia Center for Children’s Environmental Health at the Mailman School of Public Health, is the first to show associations between prenatal exposure to BPA and body fat in school-aged children. Investigators analyzed urine samples and child body compositions from pregnancy through early childhood of 369 mother-child pairs who were participating in an ongoing urban birth cohort study in New York City. Researchers measured concentrations of total BPA and its metabolites in urine samples collected during the third trimester of the mother’s pregnancy and in children once they reached age 3 and age 5 to determine BPA exposure. Height and weight were measured for children at ages 5 and 7. Waist circumference and fat mass were also collected for children at age 7.

The data showed that prenatal exposure to BPA was positively associated with body mass index. In other words, the more BPA children were exposed to, the higher their body fat mass. Lead author Dr. Lori Hoepner told Medical Daily that the team saw a “linear association, meaning as exposure increases so does outcome.”

BPA is produced in large quantities and is one of the most widely used chemicals in the world. It can be found in products we use every day like plastic water bottles and metal food cans. There is concern that BPA may disrupt the body’s endocrine system, which impacts weight and obesity by regulating metabolism. What surprised researchers the most about their findings were how “clear” or consistent they are. “It is widely believed that obesity may simply be a result of an imbalance in calories in vs. calories out,” Hoepner said. “Our work suggests an alteration in that equation. This was exciting to us.”

The study suggests prenatal BPA exposure may be an underlying factor in the obesity epidemic, as it is believed that exposure to endocrine disrupting chemicals like BPA may alter the baby’s metabolism and how fat cells are stored early in life. BPA exposure has also been linked to other adverse health outcomes like asthma, ADHD, anxiety and depression.

More research is needed to address how BPA exposure may affect adolescents. For now, researchers suggest that pregnant women, or those planning to become pregnant should avoid plastic containers, shift from canned foods to fresh or frozen foods, and choose glass or stainless steel containers for hot food and liquids.

“Pregnant women, women planning pregnancy, and mothers should talk to their health care provider about strategies for healthy eating and lifestyle in order to reduce exposures to BPA,” Hoepner added.

Source: Hoepner L, Whyatt R, Widen E, et al. Bisphenol A and Adiposity in an Inner-City Birth Cohort.   Environmental Health Perspective s. 2016.