Your child can develop a greater risk for asthma by eating from containers that have BPA, (the chemical bisphenol A) according to a new study from Columbia University's Mailman School of Public Health and the NIH/National Institute of Environmental Health Sciences, Environmental Protection Agency.
The results are published in the March 2013 issue of the Journal of Allergy & Clinical Immunology. To reduce exposure to BPA, the National Institute of Environmental Health Sciences (NIEHS) recommends avoiding plastic containers numbers 3 and 7, eating less canned food, and, when possible, choosing glass, porcelain, or stainless steel containers, especially for hot food and liquids.
You want to choose a water bottle brand that's free of the controversial carbonate plastic bisphenol-a (BPA), one of the most widely used synthetic chemicals in industry. National Institutes of Health's National Toxicology Program has concluded that the estrogen-like chemical in the plastic, which is also used in many baby products, beverage and food containers, and as linings in food cans, could be harmful to the development of children's brains and reproductive organs. Some makers of such bottles have recognized the concern, including Nalgene and CamelBak, have begun producing BPA-free alternative containers. (Photo by David McNew/Getty Images).
Children exposed to the plastics chemical bisphenol A had an elevated risk for asthma in new study
Watch those canned food linings and plastic bottles containing food and beverages children consume. It may be convenient to open up a can or use that bottle for water, but if the container has BPA, it poses a problem related to raising the risk for developing or worsening asthma in children, asthma that may not be outgrown. In July 2012, the Food and Drug Administration banned BPA in baby bottles and sippy cups. But what about the BPA in canned food? It's found in the linings of some cans. There also are water bottles where the plastic toxins seep out into the water with repeated use.
Researchers at the Columbia Center for Children's Environmental Health at the Mailman School of Public Health are the first to report an association between early childhood exposure to the chemical bisphenol A (BPA) and an elevated risk for asthma in young children. BPA is a component of some plastics and is found in food can liners and store receipts.
Association between early childhood exposure to BPA and elevated asthma risk
"Asthma prevalence has increased dramatically over the past 30 years, which suggests that some as-yet-undiscovered environmental exposures may be implicated. Our study indicates that one such exposure may be BPA," says lead author Kathleen Donohue, MD, an assistant professor of Medicine at Columbia University College of Physicians and Surgeons and an investigator at the Center for Children's Environmental Health, according to the March 1, 2013 news release, "BPA raises risk for childhood asthma."
Dr. Donohue and her co-investigators followed 568 women enrolled in the Mothers and Newborns study of environmental exposures. BPA exposure was determined by measuring levels of a BPA metabolite in urine samples taken during the third trimester of pregnancy and in the children at ages 3, 5, and 7. Physicians diagnosed asthma at ages 5 to 12 based on asthma symptoms, a pulmonary function test, and medical history. A validated questionnaire was used to evaluate wheeze.
Secondhand smoke also is a problem known to be linked to childhood asthma
After adjusting for secondhand smoke and other factors known to be associated with asthma, the researchers found that post-natal exposure to BPA was associated with increased risk of wheeze and asthma. BPA exposure during the third trimester of pregnancy was inversely associated with risk of wheeze at age 5. This unexpected finding is in contrast to the results of a previous study, which found that BPA exposure during the second trimester, a critical period for the development of airways and the immune system, was positively linked with risk for asthma.
Increased risk for wheeze and asthma was seen at "fairly routine, low doses of exposure to BPA," says Dr. Donohue in the press release. "Like most other scientists studying BPA, we do not see a straightforward linear dose-response relationship."
Most kids have detectable levels of BPA in their bodies
At all three time points, more than 90% of the children in the study had detectable levels of BPA metabolite in their bodies, a finding that is in line with previous research. This does not mean that they will all develop asthma, cautions Dr. Donohue in the news release. "Just as smoking increases the risk of lung cancer but not everyone who smokes gets lung cancer, not every child exposed to BPA will develop asthma."
The biological mechanism behind the BPA-asthma connection is unclear. The current study found no evidence that exposure to BPA increased the risk that the immune system would develop more antibodies to common airborne allergens. "Other possible pathways may include changes to the innate immune system, but this remains an open question," says Dr. Donohue.
The new study builds on existing evidence linking BPA exposure to respiratory symptoms, as well as to obesity, impaired glucose tolerance, and behavioral issues, among a range of health problems
"It is very important to have solid epidemiologic research like ours to give the regulators the best possible information on which to base their decisions about the safety of BPA," says senior author Robin Whyatt, DrPH, professor of Environmental Health Sciences and deputy director of the Columbia Center for Children's Environmental Health, according to the news release.
The study was supported by grants from the NIEHS (RC2ES018784, R01ES014393, P30ES009089, R01ES08977, and PO1ES09600), U.S. Environmental Protection Agency (R827027, RD832141, and RD834509), and private foundations. Additional authors include Rachel L. Miller, Matthew S. Perzanowski, Allan C. Just, Lori A. Hoepner, Srikesh Arunajadai, Stephen Canfield, David Resnick, Antonia M. Calafat, and Frederica P. Perera.
For pregnant moms: Loose joints score points?
On another note, a fascinating new study looks at why women's feet get larger after pregnancy, and the growth usually is permanent. Check out the article, "Pregnancy permanently changes foot size." A study from the University of Iowa, the NIH/National Institute on Aging, and the American Geriatrics Society of women's feet during and after pregnancy shows that arch height and arch rigidity decrease significantly from early pregnancy to five months after childbirth, causing corresponding increases in foot length that appear to be permanent.
Flat feet are a common problem for pregnant women. The arch of the foot flattens out, possibly due to the extra weight and increased looseness (laxity) of the joints associated with pregnancy. The new study, published in the March issue of the American Journal of Physical Medicine & Rehabilitation, suggests that this loss of arch height is permanent.
Women, and especially women who have had children, are disproportionately affected by musculoskeletal disorders. But do the foot changes that occur during pregnancy explain why, in comparison with men, women are at higher risk for pain or arthritis in their feet, knees, hips, and spines? If research turns out to show this, perhaps, women (who aren't pregnant) might explore the alternative choices in nutrition that help delay or prevent arthritis in the joints?