When pregnant women eat foods that are stored in cans or packing containing BPA, their unborn child's exposure to the chemical could lead to behavioral problems by age 3.
Scientists tested 244 pregnant women and their 3-year-old children for BPA exposure. They found when the mothers' BPA levels were high, the children were more likely to show signs of hyperactivity, anxiety and depression. The study, published in the journal Pediatrics on Monday, found these behavior problems in girls - not in boys.
Researchers cannot explain why, but they have seen similar results in other studies. "Our study is consistent with some of the animal studies that say that BPA impacts brain development in monkeys and rodents," explains study author Joe Braun with the Department of Environmental Health at Harvard School of Public Health in Boston.
Bisphenol A or BPA is an industrial chemical used to make hard plastic bottles and re-usable cups. It's also used in the lining of canned foods and beverages including some types of liquid baby formula. BPA also known to be an endocrine disrupter, which means it interferes with how hormones - chemical signals - work in the body. When these signals are blocked or changed, organs may not develop normally.
Braun can't say why boys aren't affected the same way girls are. But he speculates that when expectant mothers ingest BPA, the fetus absorbs the chemical and it may lead to more testosterone in girls, affecting how their organs develop in utero, which might explain why some girls develop behavioral problems.
Experts from the American Academy of Pediatrics support the research findings and praise the design of the study. "It adds to the growing body of literature that BPA is harmful and it adds weight to the extensive calls for regulating BPA," explains Dr. Jerome Paulson, chair of the AAP's Council on Environmental Health.
The American Chemistry Council, which represents plastics manufacturers, tells CNN it strongly supports research that leads to better scientific understanding of chemicals. But in a statement, the council adds that "the study released in Pediatrics has significant shortcomings in study design and the conclusions are of unknown relevance to public health. The researchers themselves acknowledge that it had statistical deficiencies, including its small sample size and the potential for the results being due to chance alone."
In 2008, the Food and Drug Administration reviewed available research and concluded that food items containing BPA were safe. In 2010, the FDA changed that assessment somewhat, saying that the "FDA shares the perspective of the National Toxicology Program that recent studies provide reason for some concern about the potential effects of BPA on the brain, behavior, and prostate gland of fetuses, infants and children."
Large scale studies are now under way to look into the effects of low-dose BPA to give us more definitive answers.
The U.S. Department of Health and Human Services and other experts have several suggestions for limiting BPA exposure including:
- Avoid using plastic containers with recycle codes 3 and 7 because the may be made with BPA.
- Reduce your consumption of canned foods; choose fresh or frozen fruits and vegetables instead.
- Use glass containers to heat foods in the microwave, instead of polycarbonate plastic food containers because high temperatures may break down the chemical and increase the chances of BPA entering your food.
Paulson suggests, parents with concerns about BPA check out the website for thePediatric Environmental Health Specialty Units, a network of research facilities (mostly based at universities), which can provide advice on environmentally related health effects in children.
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