WASHINGTON – The first U.S. study of the effect on people of exposure to a hormone-disrupting chemical widely used in food packaging showed that levels the Food and Drug Administration deems “safe” can alter insulin response, a key marker for diabetes.

The groundbreaking study, published in the Journal of the Endocrine Society, administered low doses of bisphenol A, or BPA, to 16 people, then tested their insulin production in response to glucose, commonly called blood sugar. When insulin and blood glucose levels were compared to the same measurements taken without exposure to BPA, researchers found that BPA significantly changed how glucose affected insulin levels. Similar insulin and glucose tests are used by doctors for diagnosing diabetes.

"We're living in an age where type 2 diabetes is rampant. Here is a signal of a new path to explore for what is causing it," Pete Myers, a co-author of the study, told Environmental Health News.

Myers is founder, CEO and chief scientist of Environmental Health Sciences. Other researchers for the study were from the University of Missouri at Columbia, Carnegie Mellon and the University of Elche in Spain.

“These troubling findings should raise alarms at the Food and Drug Administration and ignite renewed efforts to drastically reduce all Americans’ exposure to BPA,” said Alexis Temkin, Ph.D., an EWG toxicologist. “It’s appalling that the FDA and other federal agencies continue to say current exposure levels to BPA are safe, and refuse to ban BPA from food and food packaging.”

The study also adds to the body of literature suggesting that insulin response could be a key link between BPA exposure and obesity. In recent years, studies from researchers at the University of California at Berkeley, Columbia University and the University of Michigan reported that children exposed to BPA had increased amounts of body fat.

In the new study, people who were less effective at controlling blood sugar levels seemed more sensitive to BPA's effects. In addition to diabetes and obesity, has been linked to ADHD in children and breast cancer in laboratory animals.

It leaches from can linings into foods, beverages and even infant formula, and ends up in the bodies of more than 9 in 10 of Americans. Another main route of exposure to BPA comes from handling store receipts. In 2010, EWG found BPA in 40 percent of receipts sampled from major U.S. businesses and services, including outlets of McDonald's, CVS, KFC, Whole Foods, Walmart, Safeway and the U.S. Postal Service.

Independent research consistently documents serious health problems associated with low-dose exposure to BPA, yet the FDA continues to insist that the chemical is “safe at the current levels occurring in foods.”

This week, independent scientists who have studied BPA held a webinar discussing results of a joint FDA and academic study that found statistically significant adverse health effects associated with low level exposure to BPA. The webinar presenters stated the FDA’s reference dose for BPA would need to be cut by 20,000 times in order to protect public health.