28 November 2012

Fallout from “GM food causes cancers in rats” paper

Remember a few months back that there was a paper claiming genetically modified food caused cancers in rats?

A whole bunch of letters to the editors, and a response from the authors, are available as pre-prints in Food and Chemical Toxicology.

Criticisms (mostly)


(We feel) compelled to point out weaknesses in the paper by Séralini et al. (2012), the number and importance of which make the study reported very difficult to interpret scientifically.


(R)eporting and analysis of the study as presented in Food and Chemical Toxicology are inadequate and that this contribution is of insufficient scientific quality to be relevant in the safety assessment process

Wagner and colleagues:

(T)his study does not provide sound evidence to support its claims. Indeed, the flaws in the study are so obvious that the paper should never have passed review

de Souza and Oda:

This paper has some relevant flaws from the experimental design, through the statistical analysis and the way the data is presented. In addition, it lacks of some crucial information for the proper understanding and full assessment of the work.


I am writing to ask that the paper by Séralini et al. be retracted(.)


I was much involved with the problems that followed a similar failure of scrutiny of a paper about the MMR vaccine. This led to real injury to many and emphasized that careful consideration of the validity of results that appear to be outliers, is vital.

Le Tien & Le Huy

(P)resented here below are the three points that may constitute a sufficient ground to request an editorial retraction of the paper.


Analysis of the data suggests that no statistically significant findings of GMM toxicity were presented in the first place.

Grunewald and Bury:

Because of these fundamental flaws, the conclusions of Séralini et al. are not substantiated in any way.


I think that the readers of this important journal should have these answers from the authors to better understand and evaluate the results obtained in this work.

Hammond et al.:

(T)he study cannot be used to support any conclusions regarding the safety of NK603 glyphosate tolerant maize and Roundup® herbicide.


(O)ne can see that no value reaches the threshold of 7.815 needed for declaring the differences among treatments statistically significant at the 5% level.

Trewavas (With shout-out to science blogger Emily Willingham and her re-plot of the data):

(T)his paper and this journal have dealt the value of evidence-based knowledge a serious blow and it can only be rectified if the paper is withdrawn by the authors with an apology for misleading the public and the scientific community alike


The problems lie at several levels and bring into serious question the quality and standard of the editorial processes in your journal.

Heinemann, noteworthy for its positive tone:

(I)t is my view that the recent study is a valuable contribution to the scientific literature, debate and process of evaluating technologies


Since I last wrote to you, the scope and seriousness of the international scientific criticisms of the Séralini (2012) paper appearing in your journal has made me realise that my comments about the paper do not adequately describe the serious failures that have occurred in the peer review process at FCT.


The widely publicised Séralini paper does not survive such scrutiny.

Editor’s response

Wallace Hayes

Peer review does not end with publication. In the event that an accepted manuscript is questioned by the scientific community on the basis that the authors acted unethically, plagiarized, or where there are queries relating to the data or interpretation of the data, the editors will contact the authors to investigate unethical/fraudulent/plagiarized works or the journal editor will invite or accept letters to the editors.

Authors response

Séralini and colleagues

This may explain why 75% of our first criticisms within a week, among publishing authors, come from plant biologists, some developing patents on GMOs, and from Monsanto Company owning these products. ...

We encourage others to replicate such chronic experiment, with more statistical power. Now, the burden of proof has to be obtained experimentally by studies independent from industry. This was recommended by regulatory agencies that have assessed our work in France, even if it their objective is more to regulate products than to review research. GM NK603 and R cannot be regarded as safe as long as their safety is not proven by further investigations.

Related posts

What did you think those film crews were doing in the lab?
Why not retract the rat cancer / GM corn paper?

No comments: