I have a new rule for debating anti-GMO people:
If you favorably cite the 2012 Séralini rats fed on Roundup ready maize study, you just lost the argument.
If you cite this study as demonstrating any dangers in genetically modified food, you are either (a) so clueless as not to have spent 30 seconds checking to see if there are any reported problems in the study, or (b) so dishonest in citing a blatantly fraudulent study, that you are not worthy of any more serious consideration. You just lost the debate and you’re done. (Obviously you don’t lose the if you cite the study to demonstrate its flaws, only if you claim the study’s conclusions are valid.)
This is the study: Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize. Here is a summary of the main problems with the study:
- Unscientific study design. For example, only 20 control rats in a study with a total of 200 rats, and no blinding between control and experimental groups
- Large number of small sub-groups - 18 groups of 10 test subjects each making for a complicated experimental design virtually guaranteed to generate some positive results
- Cherry picking - ignoring negative results
- Poor choice of statistical analysis (a “fishing trip”)
- Poor choice in animal model - the rat type is prone to cancers with exactly the same incidence as that reported in the Séralini study whether fed GMO food or not
- No dose-response - a critical component of demonstrating a toxic effect (some rats fed higher doses did better than the others)
- Effects of feeding Roundup ready maize, and the effects of feeding Roundup (ie feeding rats the actual pesticide) were identical - a highly dubious result
- No idea of what the biological reason might be to give the claimed results
- Didn’t allow any outside comment on the paper before its publication and won’t release the data now and so the experiment can’t be replicated
Here are some links to independent scientists who explain the study’s flaws in much more detail:
- Academics Review: Scientists Smell A Rat In Fraudulent Study
- Declan Butler writing in Nature.com: Hyped GM maize study faces growing scrutiny
- Respectful Insolence: Bad science about GMOs: It reminds me of the antivaccine movement
- Steven Novella: The GM Corn Rat Study
- The European Food Safety Authority (EFSA): Séralini et al. study conclusions not supported by data, says EU risk assessment community
- Mark Hoofnagle of Denialism Blog: Anti-GMO study is appropriately dismissed as biased, poorly-performed
- Emily Sohn, a freelance journalist working for Discovery.com: GM Corn-Tumor Link Based on Poor Science
- Deborah Blum: A rancid, corrupt way to report about science
- Carl Zimmer: Journalists should not let themselves be played
- Debora MacKenzie writing in New Scientist: Study linking GM crops and cancer questioned
- John Entine of the Genetic Literacy Project: Scientists savage study purportedly showing health dangers of Monsanto’s GM corn and Does the Seralini Corn Study Fiasco Mark a Turning Point in the Debate Over GM Food?
- Dan Charles, NPR's food and agriculture correspondent: As Scientists Question New Rat Study, GMO Debate Rages On
- Kevin M. Folta: Rats, Tumors and Critical Assessment of Science
- Scicurious, a postdoc in biomedical research: Under Controlled: Why the New GMO Panic Is More Sensational Than Sense
Compare this fraudulent anti-GMO study with the 600 studies (and counting) in the GENERA database, that show the safety of GM foods. Or if you prefer, 126 with independent funding (although lack of independent funding doesn’t invalidate a study).
Ask yourself: if anti-GMO experimenters are so sure of their conclusion, why would they not design a study that was based on sound scientific practices? Why would they not, in a study with 200 rats, have 100 controls and 100 experiment rats: 100 just fed on GMO food and 100 fed on non-GMO? Why make it more complicated than it needs be and confuse the results? Why not use rats that were less prone to tumors to start with, rather than rats where 80% or so will always develop tumors no matter what? Why not just design a study that would clearly show if there was any difference when rats are fed with GMO maize? The obvious conclusion is that they knew there is really no difference between GMO and non-GMO feed and so they designed a study to obfuscate and confuse.
Why This Matters
Most of the people citing this study this would ridicule climate change deniers for citing a dubious climate study, but when any study suggests GMOs are doing some harm, no matter how dubious the study, they report it uncritically. For example, the “Yes on 37” campaign (to require labeling of genetically modified foods) immediately and un-skeptically cited this study on its website. Although they played it down a bit after the criticisms appeared, they still left the main claims on their website (still there now) and right before the election, secretly included the bogus claims in their phone bank scripts. What this shows is that such people aren’t interested in facts, but are only interested in pushing their anti-GMO conclusion that must be true no matter what the data shows. The scientific way is to follow the evidence, and change your views if the evidence contradicts what you previously thought. The anti-science way is to form your conclusion, and then twist the evidence to support your conclusion (by for example, designing a study like this one), and to ignore everything else. People who do this are not interested in science and there is no point in trying to engage them in any more debate.