Pregnant women who are exposed to bisphenol A, a chemical commonly used to make plastic, may be more likely to develop type 2 diabetes later on, a study published today in the journal Endocrinology suggests.

More than 96 percent of Americans have bisphenol A, or BPA, in their bodies, according to the Centers for Disease Control and Prevention.

Whether exposure to BPA poses any concrete risk to our health is the subject of much debate. BPA mimics the natural function of the hormone estrogen, and concern has focused on exposure during pregnancy and shortly after birth. In 2012, the Food and Drug Administration banned BPA in plastic baby bottles and children’s drinking cups.

Find Out: Can BPA Tank Your Baby’s IQ? »

Many studies have explored the effects of a mother’s exposure to BPA from drinking and eating out of BPA-lined bottles and cans on a developing fetus. The research published today focuses instead on BPA’s effects on the mother herself.


Researchers exposed pregnant mice to enough BPA to simulate levels found in human blood tests. More than six months after they gave birth, the mice showed altered insulin sensitivity and a loss of beta cells in the pancreas that produce insulin. The mice exposed to BPA also had slightly higher body weights than those that were not.

Both insulin resistance and excess weight are risk factors for type 2 diabetes. Rates of type 2 diabetes and obesity have increased dramatically in the United States in the past 30 years.

Related News: Doctors Are Finally Doing Something to Treat Obesity »

During a normal pregnancy, mothers develop some insulin resistance and hyperinsulinemia, an excess of insulin in the blood, related to high estrogen levels.

The researchers hypothesize that exposure to BPA, which acts like estrogen, pushes this natural phenomenon into high gear in the pregnant mice, exhausting their beta cells.

“We speculate that treatment with BPA during pregnancy may result in the overworking of pancreatic beta cells,” the researchers concluded.

A separate European analysis found that BPA had a 20 to 70 percent probability of having caused childhood obesity in more than 42,000 European kids, costing the healthcare system about $1.7 billion during their lifetimes.