Bisphenol A (BPA) is used in a variety of polycarbonate plastics and epoxy resins, and is used in food containers and other consumer products.
A study by North Carolina State University concludes that exposure to BPA in childhood causes significant gene changes in the brain and results in high levels of anxiety. Researchers also found that a soy-rich diet can reduce the effects.
Heather Patisaul, associate professor of biology at NC State and lead author of the recent study, says, “We knew that BPA could cause anxiety in a variety of species and wanted to begin to understand why and how that happens.”
To understand the why and how, Patisaul and her team exposed rats to low doses of the chemical during gestation, lactation and through puberty. One group of rats was fed only soy; one group was fed a soy-free diet; one group was fed only soy and was exposed to BPA, and the last group was fed no soy and was exposed to BPA.
Adolescent rats on the soy-free diet exhibited significantly higher levels of anxiety than did the animals that’d consumed soy. For the first time, researchers found gene expression changes in the amygdala, a brain region known to play a role in mediating responses to stress and fear among the on the soy-free diet.
Still, the investigators are cautious about a soy-rich diet. “Soy contains phytoestrogens that can also affect the endocrine system, which regulates hormones,” Patisaul says. “It is not clear whether these phytoestrogens are what mitigate the effect of BPA, or if it is something else entirely. That’s a question we’re hoping to address in future research.”
Source: ScienceDaily, September 7, 2012 Study published in PLoS ONE, September 5, 2012 and funded by the National Institute of Environmental Health Sciences