Jun 08 2018

Séralini Fails Replication

Gilles-Éric Séralini is a French researcher who came to fame from publishing a study in 2012 claiming that herbicide-tolerant GMO corn, with or without combination with glyphosate herbicide, increased tumor risk in rats. He used this study to call into question the safety of GMOs generally, and to call for long term feeding studies. His results were embraced by the anti-GMO crowd, and to this day are cited as evidence GMOs are not safe.

One small problem, however, is that Séralini’s study was terrible. It immediately came under intense criticism. Specifically, the study had small sample size, and used a strain of rats known to have a high background rate of tumors. The data, therefore, was full of noise and was essentially uninterpretable. This is probably the reason for the lack of statistical analysis – because there were no significant findings. For these reasons in 2013 the study was retracted. In 2014 the paper was republished in a new open-access journal,  Environmental Sciences Europe, without additional peer-review.

It is pretty clear that Séralini is anti-GMO, and this likely biased his research. But regardless, the study methodology is terrible and the results worthless. But it did serve its (what I believe to be its true) purpose – to stoke fears about GMOs and to provide published “scientific” evidence to support the claims of anti-GMO activists.

This creates a problem similar to the “fake news” issue – in this case, you generate terrible scientific results and put them up against more rigorous scientific studies, and it becomes a false-equivalency of dueling scientific narratives. If your only goal is to create doubt and fear, this strategy works really well. If your goal is to use scientific evidence to form reliable conclusions and base policy on those conclusions, then terrible studies like Séralini’s just muddy the waters.

There is a path out of the swamp, however, and it is to follow the usual process of science. When different groups interpret existing evidence differently, they can resolve their differences by doing replications and consensus studies. So you repeat the studies, but fix all the problems that any “stakeholders” (as they are called) have with the previous research, and do it all in a transparent way where everyone gets to weigh in on the study design and execution. Everything is done in the open, everyone is happy, and you just let the chips fall where they may.

This is a great strategy, because you get people to agree to a study design before the results are known. Some diehards will still disavow the results if they don’t go their way, but they tend to be marginalized as obviously biased.

As you may have guessed by now, I am discussing all this because this is exactly what was done. There have now been three replications of Séralini’s original study – and all of them show no toxicity from GMO corn or glyphosate.

As Alliance for Science reports:

“The G-TwYST (GM Plant Two Year Safety Testing) data from 90-day and long-term rodent feeding studies did not identify potential risks as well, and therefore support the results from the initial analyses,” according to the study’s conclusions and recommendation’s document, which was presented at an April 29, 2018 conference in Bratislava, Slovaki.

“It was concluded that there were no adverse effects related to the administration of the GM maize NK603 cultivated with or without Roundup,” the report stated.

The research included a combined chronic toxicity and carcinogenicity study, and “no toxicologically relevant effects related to the GM maize NK603 or the GM maize NK603 treated with Roundup were observed,” the report stated.

The second was the GRACE study. They report:

In this study, which was published recently in Archives of Toxicology, scientists conducted a 90-day feeding trial on rats. The animals were given two different varieties of MON810 GM maize. The control groups were given the non-GM parent variety or one of four conventional maize varieties as part of their diet. The results showed that the two GM maize varieties tested did not trigger any negative effects in the trial animals.

The third was the GMO90+ study. This was a 180 day feeding trial, and included Bt corn as well, and also found no adverse health effects associated with consuming GM corn in rats.

Three transparent and more rigorous studies all showing no negative effects of rodents consuming GMO corn. That is the problem with spurious findings from poor-quality studies – they tend not to replicate. They don’t replicate because the results were never real.

Séralini’s findings were always an outlier. In 2016, for example, the National Academies of Sciences, Engineering, and Medicine released their report of hundreds of studies, and after listening to public testimony from all sides, and concluded that they, “found no substantiated evidence that foods from GE crops were less safe than foods from non-GE crops.”

There have been over 2000 studies, carried out in many different countries by many different research teams, and reviewed by many different scientific organizations, with a clear consensus that there is no evidence that existing GMOs pose any health risk. With all of this evidence, there are a few outliers, one of which being Séralini’s research. Now his findings have been directly refuted.

I hope this matters to the general public, but of course it won’t have an affect on those with a dedicated anti-GMO ideology. People seem to have no problem cherry picking a few outlier studies that agree with their position, and dismissing hundreds or thousands of studies that disagree with them.



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