Smarter Living: Family Health
Chemical Culprits: Bisphenol A
Bisphenol-A (BPA) is everywhere. Among other places, it is found in the lining of nearly every can in the grocery store. Nearly every person in America has some BPA in his or her body. And yet, this food-packaging chemical may cause problems in developing fetuses, infants and children by altering behavior and increasing the risk of prostate cancer, as a government report concluded nearly two years ago.
Since then, even more scientific studies have been published linking bisphenol-A to other developmental problems as well as a variety of adult health concerns, including erectile dysfunction, breast cancer, heart disease, and diabetes. BPA interferes with the female sex hormone, estrogen, and is suspected of interfering with other hormones, such as thyroid hormone, that direct many functions in the body. A study published in the journal PLOS ONE earlier this month found that Americans with higher levels of BPA in their urine in 2005-2006 were twice as likely to have suffered a heart attack or other symptoms of heart disease. While the study does not prove that BPA causes heart attacks, it does indicate that the health risk should be further explored. The researchers used data from a nationwide survey conducted by the Centers for Disease Control and Prevention (CDC) in 2003-2004 and 2005-2006.
The Food and Drug Administration (FDA), which only last year said the chemical was safe at low levels, now acknowledge that they share concern about exposures in developing children and provided information for consumers to reduce their exposure to the chemical. (See What You Can Do below). Yet the FDA stopped short of calling for a complete ban on the chemical, saying more study was needed.
Reducing exposure is hard to do, however. The main way that people are exposed is through eating and drinking contaminated food and beverages from containers containing BPA. The chemical is found in polycarbonate plastic (#7) bottles, as well as the epoxy resins lining the interiors of food and beverage cans and liquid infant formula. Some cardboard food boxes, water supply pipes, dental sealants and composite filling material may contain BPA.
Although the six major manufacturers of baby bottles have phased out the use of BPA, the chemical is still used in the linings of canned liquid baby formula, canned foods, sodas and juice. Infants are born with BPA that they absorbed from their mothers in the womb. Because infants and children consume more food and liquid on a per pound basis than adults, they are the segment of the population with the greatest exposure to BPA.
Fetuses, infants and children are also at the greatest risk because their brains and other organs are undergoing rapid development. They also have relatively immature systems for dealing with toxic chemicals. Current levels of bisphenol-A exposure have been demonstrated in animal studies to cause reproductive harm, alter development of the brain resulting in behavioral changes and increase the risk of breast and prostate cancer. There is also evidence that it may hasten puberty. Fruthermore, some scientific evidence suggests that estrogen-like chemicals such as BPA may contribute to obesity and insulin resistance (pre-diabetes) by by interfering with fat metabolism.
Studies conducted by the CDC have found over 90 percent of people tested have BPA residues in their urine. Since BPA does not stay in the body for long, the results suggest we are continually exposed to the chemical.
The most recent survey data, collected in 2005-2006, found that BPA levels in the American public had dropped by about 30 percent, compared to 2003-2004. It may be that manufacturers were already responding to consumer pressure to reformulate products.
A number of states have already enacted bans on BPA in children's drinking items. However, fetuses and breastfeeding infants are being exposed through their mothers' diets. Many public health and environmental groups, including NRDC, are calling for regulations that eliminate BPA from all food packaging.
What You Can Do
Replace any hard polycarbonate plastic baby bottles with BPA-free alternatives, such as glass or polypropylene. If possible, avoid using liquid infant formula in favor of breastfeeding or powdered dry formula. FDA has stated that powdered formula does not contain BPA. (BPA has been found in breastmilk. However, the health benefits of breastmilk outweigh the risk of toxicity.)
Discard toddler drinking cups made from polycarbonate plastic.
Eat fresh or frozen produce, choose processed foods in bpa-free packaging such as glass jars or cardboard packaging.
Look for plastics labeled BPA-free. Polycarbonate plastic can be recognized by the recycling triangle with the number "7" and letters "PC." Not all #7 plastics are contain BPA, since #7 is a catch-all category for many types of plastic. If in doubt, contact the manufacturer.
When purchasing water bottles, search for name brand BPA-free bottles made with Eco-Free coating (Sigg bottles) or Tritan (Nalgene products). A study in the July 8, 2011 Chemosphere found no BPA in water from these bottles after they had contained hot liquids. Avoid discount, off-brand, resin lined metal bottles, which can release relatively high levels of BPA.
When using plastics to store food, choose ones labeled #1, #2, or #5. Use glass containers when microwaving.
Ask your dentist if he or she uses BPA-free sealants and filling materials; don't allow them to be applied to your children's teeth or your own if pregnant. Shop around.
Reusable aluminum water bottles may contain BPA in the lining. Chose stainless steel bottles.
last revised 8/11/2011