Thanks to modern medicine, we have an amazingly precise picture of what's inside our bodies--and one of those things is the chemical bisphenol-A (BPA). How common is BPA? A survey by federal scientists found that 93% of Americans have at least trace amounts of it in their bodies. That makes sense. BPA is virtually everywhere, especially in many plastics and in liners for nearly all food and beverage cans.
A new study in the Journal of the American Medical Association (JAMA) underscores just how easy it is to raise your BPA levels without even knowing it. Researchers had subjects eat either soup made from fresh vegetables or canned vegetable soup each day for five days. After a two-day pause, the researchers had the groups switch roles. After eating fresh soup for five days, the subjects had BPA levels that were about normal, but after they ate canned soup, their BPA levels increased by more than 1,200%. Those results represent some of the highest BPA levels recorded outside factories where the chemical is used. "We were surprised," says Jenny Carwile, lead author of the study and a Harvard University epidemiologist. "This is really big."
Results like these are worrying to many researchers because BPA--an endocrine-disrupting compound that can interfere with hormones--has been linked to heart disease, diabetes and obesity, as well as potential problems in fetal development and in young children. Such studies have prompted Canada and Europe to ban BPA from baby bottles, a step many manufacturers of children's products have taken independently in the U.S. The Food and Drug Administration last year expressed "some concern" about the potential effects of BPA--midlevel on its scale of alarm.
The FDA's cautious position is not entirely unwarranted, since the science on BPA is still far from clear. Industry groups like the American Chemistry Council point to hundreds of studies that show BPA has no ill effects, and a panel of experts from the World Health Organization agreed last year that it was premature to take steps to ban the chemical. What's more, BPA doesn't stay in the body very long, leaving via urine in a matter of hours. Stop exposing yourself to the chemical, and you should become BPA-free.
Of course, as the JAMA study shows, that's easier said than done. The challenge for scientists is to get a better fix on how dangerous BPA is; for consumers, it's to find out which products contain the stuff--and to demand that information from manufacturers--so they can avoid it if they choose.