BPA, plastic news calls for further study
If plastiphobia is the psychological term for a fear of plastic, many people may have contracted the condition earlier this week. A controversial article in the Journal of the American Medical Association reported that adults with the greatest exposure to a chemical called bisphenol A or BPA were more than twice as likely to have cardiovascular disease, diabetes or evidence of liver damage. BPA is released in tiny amounts from certain types of hard plastic containers and the lining inside of most food cans.
Question: What did this study prove?
Answer: The study was not designed to prove anything. Rather, it raised some important questions. It is possible that other things associated with BPA exposure were the cause of the health problems they observed. But, the researchers stress that their study provides strong support for further research on BPA using study designs that can demonstrate cause-and-effect relationships.
Q: Has other research indicated problems from BPA?
A: Prior to this week's JAMA study, the major concern was for the potential effects of BPA on infants rather than adults. Animal studies indicate that BPA exposure early in life can affect nerve development and behavior.
Based on the BPA animal studies, Canada recently proposed the precautionary measure of banning polycarbonate baby bottles. When very hot or boiling liquids are put into these bottles, more BPA is released from the plastic. Cold or room temperature liquids cause very little release of BPA from the plastic.
Q: How does the body handle BPA?
A: BPA is rapidly detoxified by the liver and then filtered into the urine by the kidneys. That's the good news. It is not one of those things like lead or mercury that can build up in the body over time.
But while in the body, BPA functions somewhat like a very weak form of the hormone estrogen. Consequently, there is concern that long-term exposure to BPA may affect an infant's current health and possibly its health later in life.
Q: Should adults be concerned about BPA?
A: The Canadian experts think that adults do not need to be concerned about the "negligible" risk of BPA. Meanwhile, they are working with the food industry to reduce BPA levels in foods.
In the U.S., the National Toxicology Program recently reported conclusions similar to Canada's, expressing "some concern" about BPA effects on fetuses, infants and children, but negligible concern about adults. Adding to this week's BPA controversy, the U.S. Food and Drug Administration stated that current levels of exposure to BPA are safe. Stay tuned.
Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S. are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii-Manoa. Dr. Dobbs also works with University Health Services.