October 7, 2012 - According to a new study at the University of California, Berkley and published in the journal 'Environmental Health Perspectives', Bisphenol A (BPA), a synthetic chemical, has been linked to changes in thyroid hormone levels in pregnant women and newborn boys. Normal thyroid function is essential for healthy growth and cognitive development of fetuses and children.
Study shows significance of BPA in Boys - Not Girls
Researchers analyzed BPA levels in urine samples of 335 women during the second trimester of pregnancy, and thyroid hormone levels in blood samples from mothers during pregnancy and from newborns within a few days of birth. Where BPA levels were doubled, there was an associated decrease of 0.13 micrograms per decilitre of total thyroxine (T4) in mothers during pregnancy suggesting a hypothyroid (underactive) effect. As well, newborn boys each with doubled BPA levels were linked to a 9.9% decrease in thyroid stimulating hormone (TSH) suggesting a hypothyroid effect. Several studies in recent years linked lower thyroid hormone levels to delays in cognitive and motor development in young children.
Jonathan Chevrier, Study lead author and Research Epidemiologist at UC Berkeley's Center for Environmental Research and Children's Health (CERCH) stated, "…studies suggest that small changes in thyroid level, even if they're within normal limits, may still have a cognitive effect."
It was not clear why the same results were not found among newborn girls other than to revert to a study on female rats, which had higher levels of an enzyme integral in metabolizing BPA.
Study shows BPA in Caucasians but not African American or Hispanic People
According to a new study in the American Journal of Medical Association, exposure to BPA 'may' increase the risk of obesity and coronary artery disease in children and adolescents. The study included 2,838 participants aged 6 to 19 who were randomly selected of which 1,047 participants or 34.1% were overweight and 590 or 17.8% were obese. The association between urinary BPA concentrations and obesity risk was significant among Caucasians, but not African American or Hispanic children. The researchers could not explain their findings.
Our bodies excrete the BPA chemical in a matter of hours so it is possible that the study simply indicates that children may have recently consumed food or a beverage from a BPA container. At this point, it is impossible to state conclusively that BPA causes childhood obesity.
The National Institute of Environmental Health Sciences stated that, "Attempts to link our national obesity problem to minute exposures to chemicals found in common, everyday products are a distraction from the real efforts underway to address this important national health issue."
While the U.S. government health officials have deemed low levels of BPA to be safe they have not come to any conclusion as to what level of BPA would become a health concern.
This study recommends that if you want to reduce your exposure to BPA, then you must reduce using processed food and beverages packaged in cans, plastic bottles, and containers.
Health Canada says BPA is Safe
Health Canada's Updated Assessment of Bisphenol A (BPA) Exposure from Food Sources found that BPA is safe for use in food-contact materials and the American Chemistry Council issued the following statement on September 28, 2012.
"Health Canada's announcement today once again confirms that BPA is safe for use in food-contact materials, said Steven G. Hentges, Ph.D. of ACC's Polycarbonate/BPA Global Group, and he added, "…this new assessment further indicates that consumers don't need to be concerned with the minute exposures to BPA from food contact and should be confident in its safe use in everyday consumer products."
Based on the overall evidence experts concluded that current dietary exposure to BPA through food packaging use is not expected to pose a health risk to the general population, including newborns and young children.
BPA is in the lining of tin cans, coffee cup lids, pre-packaged salad containers, polycarbonate-bottled food and beverages, store receipts made of thermal paper, hard plastics, and dental sealant. On July 2012, the U.S. Food and Drug Administration officially banned BPA in the manufacture of baby bottles and cups because environmental groups and parents voiced their profound concerns that BPA was interfering with children's development.
BPA has been associated with a rather large range of heath conditions and diseases including obesity, neurological disorders, disruption of the dopaminergic system, leukemia, testicular interstitial cell tumours in male rats, breast cancer, neuroblastoma, prostate cancer, impaired reproductive system, sexual dysfunction, and brain tumours – but with no conclusive evidence.
Health Canada states in their report, "BPA is one of the most thoroughly tested chemicals in the market used today and has a safety track record for the past 50 years. The consensus of government agencies across the world is that BPA is safe for use in food-contact materials. Not only has the U.S. Food and Drug Administration recently confirmed that it is very unlikely that BPA could cause human health effects but the European Food Safety Authority and a World Health Organization panel have also supported the continued use of BPA in products that come in contact with food."