Packaging chemical robs men of sex appeal

Now, a new study by the University of Missouri in the US has found that male mice who were exposed to bisphenol A as babies became demasculanised and “behaved more like females”, the Daily Mail reported.

Lead author Prof Cheryl Rosenfeld said the chemical had suppressed the early production of testosterone, which the females could sense.

“The BPA-exposed deer mice in our study look normal; there is nothing obviously wrong with them. Yet, they are clearly different. Females don’t 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,” she said.

Implications

The research could have implications on how BPA affects human development and behaviour, say the scientists.

“These findings presumably have broad implications to other species, including humans, where there are also innate differences between males and females in cognitive and behavioural patterns.

In fact, in the study, female deer mice were fed BPA-supplemented diets two weeks prior to breeding and throughout lactation. The mothers were given a dose equivalent to what the US Food and Drug Administration considers a non- toxic dose and safe for mothers to ingest.

At weaning the deer mice offspring were placed on a non-supplemented BPA diet and their behaviour tested when they matured into adults. Male deer mice exposed to BPA were less desirable to female deer mice, who literally turned their noses up at them. This meant the females did not consider them genetically suitable mates.