Researchers at Yale School of Medicine have reportedly claimed in a new study that exposure to the food packaging chemical bisphenol A (BPA) during pregnancy can cause permanent abnormalities in the uterus of offspring, including altering their DNA. Jason G. Bromer, et al, “Bisphenol-A exposure in utero leads to epigenetic alterations in the developmental programming of uterine estrogen response,” Journal of the Federation of American Societies for Experimental Biology (March 2010).

According to a March 8, 2010, Yale University press release, the study is the first to show that BPA exposure permanently affects sensitivity to estrogen. Using two groups of mice, one exposed to BPA as a fetus during pregnancy and another exposed to a placebo, researchers examined gene expression and the amount of DNA modification in the uterus. Results showed that the mice exposed to BPA as a fetus had an exaggerated response to estrogens as adults, long after the exposure to BPA, and that the genes were permanently programmed to respond excessively to estrogen.

“What our mothers were exposed to in pregnancy may influence the rest of our lives,” said lead researcher Hugh Taylor. “We need to better identify the effect of environmental contaminants on not just crude measures such as birth defects, but also their effect in causing more subtle developmental errors.”

In another recent BPA study, Swiss researchers examined exposure pathways for nine different consumer groups and reportedly found that infants up to 6 months old were the most exposed. Natalie von Goetz, et al., “Bisphenol A: How the Most Relevant Exposure Sources Contribute to Total Consumer Exposure,” Risk Analysis: An International Journal, (January 29, 2010). Although the levels were “far below” safety limits set by European regulating authorities, they were of “the same order of magnitude as recently reported concentrations that caused low-dose health effects in rodents,” according to the study.

The researchers found exposure to BPA decreased as people got older and called for more study into exposure through food packaging. “Our results suggest that the most important pathways for infants and children are the use of polycarbonate (PC) baby bottles and for adults and teenagers the consumption of canned food,” the authors wrote.