Conclusiveness of toxicity data and double standards

We would like to comment on your answers (Hayes, 2014a) concerning the retraction of our study (Seralini et al., 2012 and Hayes, 2014b) by Food and Chemical Toxicology (FCT). Our study investigated the long-term effects in rats of consumption of two Monsanto products, a genetically modified (GM) maize and its associated pesticide, Roundup, together and separately. The decision to retract the paper was reached a few months after the appointment of a former Monsanto employee as “editor for biotechnology”, a position created for him at FCT ( Robinson and Latham, 2013). In a recent editorial, Portier and colleagues express concern about the “dangerous erosion of the underpinnings of the peer-review process” in the case of our study ( Portier et al., 2014).

The criticisms from Monsanto and others focused on two aspects of our study: the relatively low number of rats used compared with the 50 per sex per group usual for carcinogenicity studies (OECD, 2009a) and the strain of rat used, the Sprague–Dawley. The critics alleged that the Sprague–Dawley rat was prone to tumours and that therefore the increased rate of tumorigenesis found in some of our treatment groups was purely random, even if this strain is commonly used in toxicology. Other answers to critics have been already published (Seralini et al., 2013).