Journal to Retract Seralini Rat Study

Last year French scientist Gilles-Eric Seralini made news when a paper by his team was published in Food and Chemical Toxicology.  Data concerning long-term feeding of genetically modified Monsanto corn and the herbicide glyphosate (Roundup) in the Seralini study suggested the rats being studied developed cancerous tumors.  Of course this news spread around the internet like wildfire among those who detest biotech crops.  Finally they had a really high profile study published proving their point.


Criticism of Seralini Study

The scientific community widely criticized the study’s statistical methods.  The number of rats used was questionable, and the data drawn from test and control groups seemed incomplete at best. Test groups of Harlan Sprague-Dawley rats used in the feeding study were given various amounts of NK603 corn over a two-year period.  Test subjects were also given varying amounts of glyphosate in drinking water.  Control rats received non-GM corn and regular drinking water.  Rats fed GMO corn and glyphosate developed tumors during their two-year life span, and pictures of tumor riddled rats plagued the internet.

Seralini Rats via

Seralini rats as described by scientist Kevin Folta. “Sometimes the way data are presented can expose the relative objectivity and hidden intent of a study. Left-rat that ate GMO corn. Center- rat eating GMO corn and roundup. Right- rat fed roundup. Their associated tumors shown on the right. Wait! What about the control rats, the ones that also got tumors? How convenient to leave them out!”


But what about the control rats?  They developed tumors as well.  Sprague-Dawley rats are known to develop tumors during their lifespan. In fact a majority of them are known to do so within two years.  Further analysis of Seralini’s data shows rats fed NK603 corn and Roundup-laced water sometimes had less incidence of tumors than the control group.  Shouldn’t that bit of information thrown up some red flags possibly before the study was originally published in Food and Chemical Toxicology?  Flags were thrown for and by many scientists, and now the tables are turning as the editor of the journal, A. Wallace Hayes, stated this week he would retract the paper from the journal if Seralini did not withdraw it himself.

When I first heard news of Seralini’s study in 2012 I was skeptical as you might imagine.  Livestock have been fed GM corn and soybeans for almost 20 years now.  If it was so awful as to cause all the ailments claimed by those who seem to pander to anti-GMO sentiment I think it stands to reason that farmers would have backed off the stuff long ago.  But that kind of logic doesn’t fit the narrative of GMO = Bad.  The Seralini paper was, and likely still is, validation for those who were predisposed to interpret it as definitive proof that biotechnology should be outlawed.

Seralini Going Forward

Although I am glad to see this fear mongering study being pulled from publication I’m afraid the damage has already been done.  And if you’re a GMO hater you can still easily feel like you’ve won.  I’ve already seen the internet gearing up to portray the retraction as a result of great pressure applied to the journal by Big Ag and the politicians supposedly paid off by industry money.  People who believe such narratives don’t have to change their minds when new information comes to light.  Even if the old information was questionable to begin.  All they need do is move the goal post.  Kevin Folta agrees “we’ll see the wagons circle” while suggesting steps for Seralini to take since he is standing behind his team’s research.

Science is a process, and I’m happy the process is working.





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  1. Thank you for the information. I was a skeptic of GMO products for quite some time and when the study with the rats was published it was like “see what the scientific evidence has shown?” But as often happens in studies there is something left out which causes cracks to appear. The type of rat used develops tumors in their lifespan was a fact not shared and the control rats were also left out. Very interesting and I appreciate the light of day you have provided.

  2. As you point out, the statistical analysis done in this study was questionable and it is unlikely that any valid conclusions can be drawn from it (except perhaps that ideology and science make poor bedfellows).

    However, another recent study titled “Glyphosate and AMPA inhibit cancer cell growth through inhibiting intracellular glycine synthesis” suggests that glyphosate may actually offer a new treatment for cancer. As poorly done as Séralini’s study was, it may offer a modicum of support for that hypothesis, given the reduced incidence of tumors in the male experimental rats vs. male controls that you mention.

    Healthy cells are powered by oxygen respiration that is performed by mitochondria. The mitochondria are also involved in signalling programmed cell death (apoptosis) which is how old and damaged cells are eliminated by the body. When cells become cancerous, it is often because their mitochondria have become so damaged or otherwise inactivated that they can no longer signal to the cell that it is time to die, so the cell replicates out of control. In order to do that, it still needs a source of energy (since oxygen respiration requires healthy mitochondria). So most cancer cells switch over to glycolysis as an alternative form of metabolism for obtaining energy. It seems there’s evidence that glyphosate interrupts glycolysis in cancer cells while not harming healthy cells that don’t need glycine.

    So again, while we can’t really draw any valid conclusions from the Séralini study, it will be profoundly ironic if the reduced number of tumors in the experimental groups is actually due to this effect!

  3. Isn’t it true that Seralini’s used the same protocol as the Monsanto study however tested more parameters more frequently. The rats were studied much longer, a full two year average life-time instead of just 90 days in the Monsanto study. The first tumors appeared at 4 to7 months into the study. The study was also done with the highest number of rats ever measured in a standard GMO diet study. They tested for the first time 3 doses (rather than two in the usual 90 day long protocols) of the GMO maize alone, the GMO maize treated with Roundup, and Roundup alone at very low environmentally relevant doses starting below the range of levels permitted by regulatory authorities in drinking water and in GM feed.”

    I also believe the study concluded, “In females, all treated groups died 2–3 times more than controls, and more rapidly. This difference was visible in 3 male groups fed GMOs…Females developed large mammary tumors almost always more often than and before controls; the pituitary was the second most disabled organ; the sex hormonal balance was modified by GMO and Roundup treatments. In treated males, liver congestions and necrosis were 2.5–5.5 times higher. This pathology was confirmed by optic and transmission electron microscopy. Marked and severe kidney nephropathies were also generally 1.3–2.3 greater. Males presented 4 times more large palpable tumors than controls…””

    Based on these findings, the only responsible next step should be an independent (non industry) study to be requested by the FDA.

    It appears three month rat studies just aren’t adequate to insure GMO safety.

    1. You are right McNamara about the inadequacy of 90 day trials and the need for further studies as Seralini recommended in his conclusions. As a result of the work Seralini and others have done, the European Food Safety Authority this year published new protocols for 2 year studies that should replace the 90 day standard. See: Longer studies and more rigorous regulatory assessment should definitely be required.

  4. The study is perfectly valid. The tumor incidence was 2.1 to 3.3x higher than in the control rats. This article is a false flag proclaiming the study to be invalid. The only reason the study was retracted was because the journal in question hired a Monsanto employee to be one of their primary editors. Politics of gmo as usual, corruption posing as “scientific rigor”

    1. So you think eating nonGMO corn can cause cancer too, but just at half the cancer rate as GMO corn? Is that your claim? You need to think about the math you just wrote.

      If nonGMO corn caused cancer I would think we would have heard about it about hundreds of years ago.

    2. The study wasn’t even remotely valid. The statistical analysis was simply terrible. If one tests hundreds of times without adjusting for the fact that one tests hundreds of timesone is bound to find *something*. Trouble is, one is bound to find false positives.

      As a serious scientist, Seralini should have learned that long time ago. Either, he is a very inapt scientist who doesn’t even know the basics or he is a very corrupt scientist who was willing to throw his principles for increased publicity overboard.

  5. Yes Adam. The editors of Food and Chemical Toxicology were foolish to give as the grounds for retraction that: “the results presented (while not incorrect) are inconclusive.” All results in all scientific papers are inconclusive, as they must be provisional and open to refutation by the finding of further research. Findings that are not open to such challenge are not scientific. Seralini’s findings stand, despite Elsevier’s retraction under pressure. They passed the hurdle of peer-review and have not been refuted despite the storm of self-interested criticism, including online petitions that include many unqualified signatories.

  6. It would seem, it’s always possible to blame something on somebody that once worked for Monsanto. Regardless what you think of this study or any other study ( and you could read studies on GMO for weeks on end) this is the most studied food ever! Do your own research. If you do not want to consume any GMO, that is your right in this country. You do not need any new labeling to do so. Find a organic market, and get to know who raises your food. But…….for the hungry person trying to feed her family, high priced food is not an option. It’s not an option for me. I will feed my family what tastes best, with the best nutrition, and best price period. Not one study I have read makes me shy away from any food with GMO in it!!

  7. The Seralini study should never have been published in the first place. There were grammar and spelling mistakes which makes me question the quality of peer review in this case. Not to mention the low number of rats used and lack of controls. These are huge red flags. There are (well articulated) OECD guidelines about numbers of rats required / to be used in studies of this nature. And to draw such broad sweeping conclusions based on a shoddy study is inappropriate. And we can’t forget that Seralini also violated science based rules regarding the ethical treatment of rats in studies like this. Those rats suffered needlessly.

    Seralini spent in excess of 3 M Euros on this study. An enormous amount of money. And he made such FUNDAMENTAL mistakes in developing and executing the methodology. If I were funding this study, I’d be less that satisfied with how things were managed. Unless, of course, I was just interested in the PR and political shenanigans that came with it. Then the outcomes are exactly what I would have wanted. Which means that I may have had another agenda when I funded this study…and not really interested in having the subject matter objectively investigated.

    We can’t hold progressive and innovative science to such low standards as was demonstrated by the Seralini study. Society deserves better than that.

  8. Back in college, my roommates girlfriend had a leftover plate of pot brownies in the kitchen. While in class, her Lab ate them, and died later that night. Clearly, that is concrete proof that marijuana and brownies must be toxic to humans, after all, the dog was dead in hours.

  9. Real scientists WELCOME review and criticism of their work. The body of anti-GMO research, if it were legit, would be HELPED by retractions such as this. If the study was genuine, just crowd fund and repeat the results, that simple. The fact that there is now a conspiracy theory (pressure from big ag, riiiight) is evidence that Seralini and his crew of activists are worthless to the world of rational evidence-based thinking. Activist pseudoscience is poison.

  10. Brian, Though I disagree with most of your story, and do my best to fight GMO’s in food. I do respect what you have written. I am looking forward to reading more of your blog. I an very interested in how you use your UAV’s on your farmland.
    Minnesota Gardens

  11. Hi Brian ! I know you because I am an administrator of the Facebook french page VIP Very Important Paysans. But today, I talk as the human being I am.
    That is not because Seralini is french that I defend his work. His work is bad on a scientific point of view. But you know, the TEAM had to hide the Work. Why ? Maybe because people tried to stop them. This is my demand to Monsanto, Syngenta, BASF, Dow and others : test your GMOs as long as herbicides/pesticides are tested before approval. SHARE every line of the patents. DON’T pay people to do the testing, use FREE-Minded scientists.
    As you maybe know transgene on canola jumped to NON-GMO canola. Why ?
    Of course RoundUp alone is not so harmful, BUT the combination of toxical products are though. Example : We know why to many bees (your n°1 ally in crop raising) die. The larvae are weakened by the chemistry cocktails created by all the products used on fields. This weakness allows a virus to destroy them easily now.
    To my mind, the day when GMOs will not be a way to make profit for the industry, then I will believe they are good for the whole Mankind.
    Believe it or not : The earth is able to feed 11 billion people right now. When we consider that more or less 80% of farmers are organic producers on this planet, I’m sorry but I can’t trust GMOs suppliers more than 30 secs. I can’t bear their false humble speeches. In 2006, I was harvesting in Northern Saskatchewan, I saw what round-up tolerant crops can bring to farmers. It’s kind of easier to manage weeds, combines were incredibly faster picking-up the swaths. But the Bertha ArmyWorm came to life one day, nobody forecasted this and I’m pretty sure that there will never be a GMO to fight this canola-eater coming back every 17 years…
    The Nature brought us a mind but we use it to fight against her and to overpass the laws. This instead of using all of her gifts. Genetics won’t save us. She will decide when to destroy us and these sad days come in 1 million years, maybe the Earth will think : ” Well, 4 million years of life for this bullshitting Human species, thats 1% of time in my Life. That’s all they disserved”

    Yours 😉

    1. I’ve gotten to know quite a few scientists working in biotech through social media and they are very serious about their work, and take great offense at the thought the source of their paycheck would guide their results. A good place to start is Kevin Folta’s Illumination blog. He doesn’t pull any punches with this stuff. Folta offered to sequence Don Huber’s mystery organism and was turned down. Take a few minutes to search out Biofortified and Applied Mythology. Those are two of my favorite science sites.

      I could see canola pollinating canola although I don’t know much about the crop. Are you referring to the Schmeiser case in Canada?

      I’m not so sure we do know why the bees die. I think the earth is more than capable of feeding the estimated 9 billion by 2050. We waste a lot of food in developed countries because we don’t worry about where our next meal is coming from. I don’t buy all the hype about needing GMO to feed the world. There’s lots of push in the US to reach a goal of 300 bushel corn crops as a normal thing. That’s fine to push the envelope, but if I nearly double the amount of corn I grow on the same acres that doesn’t really build roads and end dictatorships in third world countries. Those people will still suffer.

      I kind of agree with you nature. It may not consciously take us all out, but it definitely could happen!

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