While this study didn't look specifically at BPA health effects, it did focus on better understanding how our bodies metabolize the hormone-mimicking chemical once it's present. This breakdown process helps remove BPA from our bodies.
The new animal study, published in the journal Environmental Health Perspectives, found BPA is readily absorbed through the tiny blood vessels under the tongue, meaning the BPA in canned food and drinks, and stray BPA on our fingers from handling thermal cash-register receipts, could be readily absorbed into the bloodstream, bypassing the gut where it's more quickly broken down into a less dangerous form.
"It stays in free form longer—it stays estrogenic longer," explains Laura Vandenberg, PhD, postdoctoral fellow of regenerative and developmental biology at Tufts University.
BPA has and has been linked to all types of health problems, including breast cancer, obesity, poor dental health, and behavioral problems in children, among other ills. The results of this research, Vandenberg says, also raise concerns about BPA-containing dental sealants, which could be leaching directly into the bloodstream.
This study is different from others because it more closely mimics real-life exposure. Usually in lab studies investigating potentially toxic chemicals, scientists use a tube to deliver the chemical directly into a lab animal's stomach. Researchers know that when BPA is sent directly to the gut and broken down, it takes about a full day to get rid of it. It's unclear how long it remains in the body when it's absorbed directly into the bloodstream via the mouth.
"The problem is we're continuously exposed," Vandenberg explains. "Also, the problem with how we study metabolism in animals is that we look at single doses of chemicals and see how long long it takes to leave the body. But you and I are getting constant doses. It will probably have peaks but never go away in body."
In fact, we don't know all of the sources of BPA yet. "This chemical has been incorporated into so many consumer products, and when that happens, companies don't put a sign on it that says, 'Now with more BPA,'" Vandenberg says.
Companies generally aren't very direct when it comes to identifying BPA in packaging or other products. In fact, scientists were the ones to ID BPA in things like thermal reciept paper, cigarette butts, and even in some personal care products.
How to reduce your exposure to BPA:
• Keep receipts out of your mouth and wash your hands after handling them. The European Food Safety Authority recently said at least 15 percent of BPA exposure could be coming from things other than canned foods, including thermal paper.
• Opt for fresh or frozen foods instead of canned food.
• Don't trust BPA-free labels. A recent study found the most common BPA replacement, BPS, disrupts hormones, too.
• Avoid plastic food and drink packaging. Some #7 plastics contain BPA. Never heat food in plastic in the microwave or dishwasher—it can accelerate leaching.
For more reasons to get BPA out of your life, read 5 Weird Things BPA Is Doing to Your Body.