Scientists weigh in on republication of flawed Seralini et al report

Following yesterday’s republication of Seralini’s retracted report, the London-based Science Media Centre, which assists reporters when major science news breaks, gathered expert views from renowned scientists’ take on this new development. As expected, the scientists maintained  that the study is at best a product of pseudoscience and therefore should not be relied upon for any decision making on safety of the maize variety or any other GM product in the market as happened before in countries like Kenya and Russia. It will be remembered that when the study first came out all major world academies of sciences and food safety authorities dismissed the report as unreliable heresy. It should not be lost on observers that the Séralini-led European Network of Scientists for Social and Environmental Responsibility (ENSSER), whose deputy chairman is co-author of the French study and whose membership is a ‘Who’s Who’ of anti-biotechnology scientists. Below are scientists withering critiques of the report and the overriding conclusion then as now is that the study not only swept aside all known benchmarks of scientific good practice but also ignored the minimal standards of scientific and ethical conduct.

David Spiegelhalter, Winton professor of the public understanding of risk at the University of Cambridge:

The article still does not appear to have had proper statistical refereeing, and the methods and reporting are obscure. The claimed effects show no dose-response, and so the conclusions rest entirely on a comparison with ten control rats of each sex. This is inadequate. The study needs replicating by a truly independent laboratory using appropriate sample sizes. I agree with the authors that this whole area would benefit from greater transparency of data and improved experimental and statistical methods.

Marcel Kuntz, biologist, director of research at Centre National de la Recherche Scientifique (CNRS, France) and professor at University of Grenoble-Alpes:

The authors reach essentially the same conclusions that were already refuted and they don’t take into account the fundamental criticisms addressed to them. Looking specifically at the tumors: The breed of rats used is subject to spontaneous tumor development. To identify a statistically reliable increase in tumors in a group of rats requires a large number of individuals. This re-publication is still deficient on this point.

These tumors were the most spectacular element of the media operation conducted by the authors. It should be noted that they showed photographs of three rats: a rat that used the GMO NK603, another that drank Roundup and a third absorbed both. Unlike the most basic scientific approach, no control rats (which didn’t eat GMO or drink herbicide) were shown. These control rats are still not shown in the re-publication.

Bruce Chassy, professor emeritus of food safety and nutritional sciences from the Department of Food Science and Nutrition at the University of Illinois, Urbana-Champaign:

The original Séralini paper was rejected for many reasons (including) the unethical use of animals in experiments which the Committee on Publication Ethics states is a reason for retraction. Séralini now states that the research was not a cancer study. If that is true, then there was no reason not to euthanize animals when tumors were first detectable. There was nothing to gain or learn. This is unethical treatment of animals.


Ian Musgrave
, senior lecturer in the Faculty of Medicine, School of Medicine Sciences, within the Discipline of Pharmacology at the University of Adelaide:

The major flaws in this study still remain.

1)      The wrong controls were used – there should have been a non-GMO control for each level of GMO corn (i.e. there should have been an 11 per cent control for the 11 per cent GMO corn, a 22 per cent control for the 22 per cent GMO corn and 33 per cent standard corn for the 33 per cent GMO corn. As energy content, carbohydrate load and other components of the corn may affect tumour formation, this is a fundamental flaw which invalidates any conclusions.

2)      There is no dose response. For a substance to be an attributable cause of cancer, being exposed to more of the substance should result in more cases of cancer this just does not happen in this study.

3)      Furthermore, there is no consistent response to any of the measured outcomes that would even hint at a real adverse effect. The GMO corn had no effect on the number of tumours – Roundup even decreased the number of tumours in male rats, as did the combination of roundup and GMO corn in male rats (there was no consistent effect in female rats). High levels of GMO corn and high levels of roundup both reduced spontaneous mortality and pushed back the onset of death in male rats.

This shows that all we are seeing in these results is due to random variation in a poorly controlled experiment. It does not show that GMO corn, or roundup, even at concentrations that no human would ever be exposed to through diet, have no effect on cancer or mortality.

Thomas Lumley, professor from the Department of Statistics, University of Auckland:

I do not think the republication of the Séralini paper and the responses to critics answer any of the statistical concerns I had with the original paper. The main point of the response over sample size is to argue that some standard toxicological studies also use small sample sizes, which may be true but would not be relevant. Although I do not find it convincing, I am pleased that the study is being republished. While I think it would have been reasonable to reject the paper initially, I was uncomfortable with a retraction that was not based on any new information or any accusation of wrongdoing, and said so at the time. Since the responses to critics claim that much of the opposition is a smear campaign by people funded by Monsanto and the GM crop industry, I think it is appropriate to point out that I have never received funding from Monsanto or any company involved in GM crop technology.

More critical reactions at: http://www.geneticliteracyproject.org/2014/06/24/scientists-react-to-republished-seralini-maize-rat-study/

The GMOSeralini site issued its defense of the new paper, quoting two well known anti-GMO scientists:

Dr Michael Antoniou, a molecular geneticist based in London, commented, “Few studies would survive such intensive scrutiny by fellow scientists. The republication of the study after three expert reviews is a testament to its rigour, as well as to the integrity of the researchers. “If anyone still doubts the quality of this study, they should simply read the republished paper. The science speaks for itself. If even then they refuse to accept the results, they should launch their own research study on these two toxic products that have now been in the human food and animal feed chain for many years.”

Dr Jack A Heinemann, Professor of Molecular Biology and Genetics, University of Canterbury New Zealand called the republication “an important demonstration of the resilience of the scientific community”. Dr Heinemann continued, “The first publication of these results revealed some of the viciousness that can be unleashed on researchers presenting uncomfortable findings. I applaud Environmental Sciences Europe for submitting the work to yet another round of rigorous blind peer review and then bravely standing by the process and the recommendations of its reviewers, especially after witnessing the events surrounding the first publication.

“This study has arguably prevailed through the most comprehensive and independent review process to which any scientific study on GMOs has ever been subjected. The work provides important new knowledge that must be taken into account by the community that evaluates and reports upon the risks of genetically modified organisms, indeed upon all sources of pesticide in our food and feed chains. In time these findings must be verified by repetition or challenged by superior experimentation. In my view, nothing constructive for risk assessment or promotion of GM biotechnology has been achieved by attempting to expunge these data from the public record.”

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One Response to Scientists weigh in on republication of flawed Seralini et al report

  1. Lets all use facts and focus on development to attain food security key to humanity.

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