A number of studies have been conducted to date on the effects of BPA, particularly as it affects hormones and the reproductive system. But a new study emerged today that for the first time looks at how BPA might be affecting gender behavior patterns that also affect reproduction.

The study, conducted at the University of Missouri, found that BPA causes male deer mice to become demasculinized and behave more like females in their spatial navigational abilities, leading scientists to conclude that exposure to BPA during human development could be damaging to behavioral and cognitive traits that are unique to each sex and important in reproduction.

In the study, female deer mice were fed BPA-supplemented diets two weeks prior to breeding and throughout lactation. At weaning (25 days of age), the deer mice offspring were placed on a non-supplemented BPA diet and their behavior tested when they matured into adults.

The male deer mice that were exposed to BPA showed poor spatial navigational skills — skills that male deer mice need to find females in the wild — in comparison to their peers. The mice couldn't navigate mazes very well, nor could they remember they way out once they discovered it. When they did meet up with females, the BPA-enhanced mice were also less desirable to female deer mice by a ratio of two-to-one. 

“The BPA-exposed deer mice in our study look normal; there is nothing obviously wrong with them. Yet, they are clearly different,” said Cheryl Rosenfeld, associate professor in biomedical sciences in the College of Veterinary Medicine and investigator in the Bond Life Sciences Center. “Females do not want to mate with BPA-exposed male deer mice, and BPA-exposed males perform worse on spatial navigation tasks that assess their ability to find female partners in the wild." 

BPA emasculates male mice
New study finds that BPA might make males less desirable to females.