April 24, 2017

expert reaction to bisphenol-A and autoimmunity in mice

Publishing in Proceedings of the National Academy of Sciences (PNAS) scientists investigate whether gestational exposure to BPA increases susceptibility of adult male mice to experimental autoimmune encephalomyelitis (EAE).

Prof. Richard Sharpe, Group Leader, MRC Centre for Reproductive Health, University of Edinburgh, said:

“Based on the exposures used for these mice studies, there would be no comparable autoimmune health risk to humans, as the lowest BPA dose used (1mg/kg/day per pregnant mouse) translates to a human equivalent dose of 81micrograms/kg/day, using established mouse-human conversion criteria (Reagan-Shaw 2008). Human BPA exposure across Europe (and in the US) is in the range of 20–40 nanograms/kg/day (Covaci 2015), which means that the highest (adult) human daily exposure to BPA is at least 2000 times lower than the lowest dose used in the mouse studies.”

Prof. Warren Foster, Professor of Obstetrics & Gynaecology, School of Biomedical Engineering, McMaster University, said:

“In this study BPA (1-3 mg/Kg body weight/day) was administered to female mice throughout gestation by oral gavage. The United States Center for Disease Control and Prevention estimates that typical human daily intake of bisphenol A is approximately 50 ng/kg body weight/day. Therefore, the mice in this study received a dose of BPA that was conservatively 60,000 times greater than the human exposure. Even if the faster metabolic rate of mice is factored into the comparison, the dose of BPA used is still very high relative to human exposure. Consequently, the results of the current study are at best phenomenology and of little if any relevance to human health.

* ‘Gestational bisphenol-A exposure lowers the threshold for autoimmunity in a model of multiple sclerosis’ by Rogers et al. will be published in Proceedings of the National Academy of Sciences (PNAS) on Monday 24^th April.

All our previous output on this subject can be seen at this weblink:  http://www.sciencemediacentre.org/?s=bisphenol&cat

Declared interests

Prof. Sharpe: “No conflicts to declare”

Prof. Foster: “I was not involved in this study and do not currently work with Bisphenol A. I am not employed by any chemical company and do not have any competing interests. I am not involved in any voluntary positions, policy groups or regulatory bodies involved with BPA. I have no financial interests or any conflicts of interest.”