Chemical structure of bisphenol A. Calvero / wikipedia.org 

ScienceDaily (Aug. 25, 2010) — An international group of researchers led by the Peninsula Medical School and the University of Exeter have for the first time identified changes in sex hormones associated with exposure to bisphenol A (BPA) in men, in a large population study. The study results are published in the latest issue of Environmental Health Perspectives. Researchers analysed data from the InCHIANTI study, an Italian population sample. The team measured the amount of BPA excreted per day in urine samples. 715 adults aged between 20 and 74 years were studied. The study aimed to measure the daily BPA loads excreted by adults, and to examine statistical associations between the amount of BPA exposure and serum estrogen and testosterone concentrations. The average BPA daily exposure level in this European study population (over 5 micrograms per day) was slightly higher than recent comparable estimates for the USA population. The study found that higher BPA exposure was statistically associated with endocrine changes in men, specifically small increases in levels of testosterone in the blood. BPA has a similar molecular structure to estrogen and does cause some disruption of sex hormone signalling in laboratory animals, but this is the first large human study to suggest that it may have similar effects in adults at ‘background’ exposure levels. Professor David Melzer, Professor of Epidemiology and Public Health at the Peninsula Medical School (Exeter, UK), commented: “This is the first big study of BPA from a European country and confirms that ‘routine’ exposures in the population are not negligible. It also shows that higher exposure to BPA is statistically associated with modest changes in levels of testosterone in men. This finding is consistent with the evidence from laboratory experiments. However, this is just the first step in proving that at ‘ordinary’ exposure levels, BPA might be active in the human body. This new evidence does justify proper human safety studies to clarify the effects of BPA in people.” …

BPA and testosterone levels: First evidence for small changes in men