bisphenol A and testicular cancerBisphenol A, a chemical used in the production of plastics, has been on the hot seat for more than a year. The chemical has been banned in Europe as of January 2011. France is following suit with a plan in place to ban Bisphenol A in the food market by July 2015. The chemical has been shown to cause harmful effects on the reproductive systems of animals thought to extend to the human population. Experimental data showing harmful side effects in humans remains minimal.

Researchers Rene Habert and colleagues shed light on the possible harmful effects of the chemical, including reduced testosterone production and a possible role in the rise of testicular cancer rate in recent years.

Using a novel approach developed by Habert, testicular tissue was kept alive in Petri dishes. Bisphenol A was added to some of the testicular tissue samples. Researchers noted a reduction in testosterone production with just 2 mcg of bisphenol A. Two mcg is equivalent to the amount of bisphenol A measured in blood samples from the general population.

In utero, testosterone plays an important part in gender development. Testosterone production in the testicles of the fetus sparks male development while a lack of testosterone leads to the development of a female fetus. Researchers believe reduced testosterone levels may play a role in the development of defects associated with congenital masculinization.

Exposure to bisphenol A during pregnancy may also increase the risk of testicular cancer, according to Habert, “it is also possible that bisphenol A contributes to a reduction in the production of sperm and the increase in the incidence of testicular cancer in adults that have been observed in recent decades.”

While researchers generally use mice in laboratory settings and propose a connection between animal results and possible human results, Habert believes this may underplay the danger of bisphenol A. “We have observed that the human species is far more sensitive to bisphenol A than the rat and the mouse. These results should encourage greater caution in regulatory toxicology in the extrapolation of data obtained on animals to define tolerable exposure thresholds in human health.”

Source: Thierry N’Tumba-Byn, Delphine Moison, Marlène Lacroix, Charlotte Lecureuil, Laëtitia Lesage, Sophie M. Prud’homme, Stéphanie Pozzi-Gaudin, René Frydman, Alexandra Benachi, Gabriel Livera, Virginie Rouiller-Fabre, René Habert. Differential Effects of Bisphenol A and Diethylstilbestrol on Human, Rat and Mouse Fetal Leydig Cell Function. PLoS ONE, 2012; 7 (12): e51579 DOI: 10.1371/journal.pone.0051579