Bisphenol A (BPA) is a controversial compound found in plastics, canned foods and receipts that may disrupt our hormone-regulating endocrine system. It’s been linked to early puberty in girls and erectile dysfunction and demasculation in men, and with every passing day researchers discover not only another way BPA harms us, but another way we’re unknowingly binging on the stuff.
Say what? We just replaced all the plastic in our house with fragile (but healthy!) glass containers!
The headline was spurred by a recent study study by endocrinologist Justin Teeguarden of Pacific Northwest National Laboratory, measuring the blood and urine levels of BPA in 20 volunteers after they ate a meal containing high levels of BPA from canned foods. Teeguarden and team found that, despite ingesting high levels, blood concentrations of BPA were below our body’s abilty to detect them.Can we now lick cash register receipts with reckless abandon?
Nope. Many more studies say BPA does matter to health. But what this means is that reciepts are the real problem, and the BPA from canned foods may not be as worrisome as we thought. To help digest this news, I caught up with Gary Ginsberg, Ph.D., public health toxicologist and author of “What’s Toxic, What’s Not.” Here’s our discussion (P.S. I’m YDM, short for Young Dr. Mike, my favorite nickname.)
YDM: In the study, BPA appeared to be excreted so quickly that it didn’t stick around in the body long enough to show up in blood and urine tests. This flies in the face of past studies on larger samples (300 women were tested in Korea), which detected high BPA levels in blood serum. Is this right, Gary?
GG: Yep. The confusion may lie in the fact that different BPA sources may linger in the body longer than others, and may be absorbed in different ways. Teeguarden and team looked only at people eating canned foods. Oral exposure from canned food is cleared relatively quickly.
YDM: Yes, other studies take into account absorbing the chemical from the skin (like your hand) that you touch to your mouth, from sources like cash register receipts. In fact most moms collected their receipt and then touched their kid’s or their own food without washing their hands first (we filmed fast food restaurants for the “Dr. Oz Show“). Their hands transferred 1,000 times as much BPA on their fast food, as they would have taken in during a day of eating food from old soup cans, correct?
GG: Yes. And this study also ignores recent BPA research. Even after BPA leaves your system, a version of it called BPA-conjugate can be reactivated in your tissues by enzymes called glucuronidases. This then makes any BPA-conjugate in blood a potential source of endocrine disruption in the key hormone responsive tissues.
YDM: We know the feminizing effect of BPA on male toads. In addition, high levels seem to make the sperm of male sperm donors dorky (a real medical term, I know), and deficient in number. Bottom line? I don’t see this changing the landscape much, except maybe to point to dermal exposure (cash register receipts) as the more important BPA exposure source.What does this mean for you? You touch your face 50 times an hour (kids do it 100 times an hour) even when not applying makeup. The most important thing you can do to avoid BPA exposure is to wash your hands immediately after touching a fast food or gas station receipt.