Response by Delaney et al. on the contamination of their control diets

Wednesday 17 September 2014

In July 2014, the team of Prof. Séralini published an article 1 in the scientific journal Food and Chemical Toxicology (FCT) in which they challenged the conclusions of researchers from DuPont 2, following the publication of their toxicity study on a GMO. The counter-expertise report produced by Professor Séralini and his team highlighted the presence of residues of Roundup and GMOs in the pellets used to feed the rats.


Conducted in accredited laboratories, analysis revealed that the food given to control rats contains 33% of genetically modified maize (18% of NK603 Roundup tolerant corn and 15% corn insecticide MON810) and 310 ppb (parts per billion or micrograms / kg) of glyphosate and AMPA, its degradation product.


This contamination, contrary to the claim of Delaney et al., disallows any conclusion that the GMO is safe to eat. This overlooked contamination in the control diets, which may be common to similar studies by industry, may be sufficient to justify the retraction of this study, according to the French research team.

The results of this analysis were sent to the DuPont researchers. In return, they have not provided any analytical results to demonstrate the validity of their study, as befits a dispassionate academic debate. Instead they sent a letter without scientific arguments 3, in which they accuse Professor Séralini’s team of failing to understand their protocol. Despite the short experimental duration and the evidence of a serious experimental error, this study remains in publication and could be used in the future to justify the placing on the market of new GMOs from DuPont.

In keeping this study in publication, once again the journal Food and Chemical Toxicology  demonstrates that it applies double standards in favouring studies claiming the safety of GMOs. We recall that in 2013, the editor of the same journal withdrew the toxicity study on NK603 GMO maize and Roundup published by Professor Séralini (the study was republished in Environmental Sciences Europe in June 2014), while admitting that there was no fraud or deliberate error.

These double standards are not surprising when we discover the presence in the FCT editorial office of one of the authors of the DuPont study, Bryan Delaney, as well as that of Richard E. Goodman, a former Monsanto researcher. This partial publication is therefore just another clear demonstration of the consequences of conflicts of interest to the independence and quality of scientific publishing.

1 Mesnage R, Defarge N, Spiroux de Vendômois J, Séralini GE. Letter to the Editor regarding "Delaney et al., 2014": Uncontrolled GMOs and their associated pesticides make the conclusions unreliable. Food Chem Toxicol. 2014. doi: 10.1016/j.fct.2014.07.003.

2 Delaney B, Appenzeller LM, Roper JM, Mukerji P, Hoban D, Sykes GP.Thirteen week rodent feeding study with processed fractions from herbicide tolerant (DP-Ø73496-4) canola. Food Chem Toxicol. 2014. 66:173-84.

3 Delaney B. Response to "Letter to the Editor regarding '': Uncontrolled GMOs and their associated pesticides make the conclusions unreliable" Food Chem Toxicol. 2014. doi: 10.1016/j.fct.2014.07.004.