Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize


I took the copy of “Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize” to bed with me last night for some late night reading. It got me so wound up that I almost got out of bed to write this. However, I pulled in the reins and waited until today. If you want to read it and I suggest you do, click here.

This is such great research for the following reasons:

  • It was undertaken by individuals without conflicts of interest.
  • It was long-term. This was a life-long rat feeding study. The study was over a two year period.  Much of the GE (GMO, genetically engineered) research has been criticized for being so short term that it misses any chronic health problems that would occur from ingesting GE food. This study gives us a good idea of what happens when human beings eat GE food long-term.
  • They used the actual formulation of Roundup that is used in agricultural use. Most research takes the active ingredient out and studies only the active ingredient called glyphosate. Glyphosate (active ingredient in Roundup is only able to penetrate target plant organisms with the help of adjuvants that are included in various formulations on the market. So these researchers used the actual Roundup formulation available on the market with adjuvants so it would mimic what people actually get in their food or what has been found in tap water.

The corn

The type of GE maize researched was MON-00603-6, also known as NK603. This is a Roundup-tolerant variety of corn owned by Monsanto. They compared it with a control group that was fed the nearest isogenic, non-transgenic corn. (So basically they compared Monsanto’s genetically engineered corn to a non-genetically altered corn that has similar DNA structure. (Remember,  Monsanto claims their corn is theoretically genetically identical to this isogenic corn and they claim they should not have to study long term effects of their GE corn for this reason.) Thank goodness, these researchers did not agree with Monsanto.

What specifically was studied — how did they grow the corn to be studied?

They studied both the NK603 grown in a field by itself with no Roundup applied as well as the NK603 which had Roundup applied to it. They were careful to grow the “Normal corn”, the NK603 and the NK603 with Roundup applied in similar fields and conditions. They also studied the effect of Roundup itself.

How it was done

There were 200 rats. 100 males and 100 females. Each were broken up in to ten different groups, each with ten rats.

The rats were fed balanced diets that had either 11%, 22% or 33% of GE maize, cultivated either with or without Roundup or 33% of the non-transgenic control line. They also gave three groups of rats the control diet (normal maize) with the addition of Roundup in their drinking water. One of the Roundup water groups had 1.1 x 10(-8%) an amount that is a level found regularly in some tap waters (according to them). The second Roundup water group had .09% which is half of the US MRL (maximum residue limit) of glyphosate in some GE feeds and .5% which is half of the minimal agricultural working dilution.

What body samples were examined

Blood samples looking at hormones, minerals, blood sugar, indicators of various organ diseases, and inflammatory conditions. They were very thorough.  The blood samples were taken often enough to get a good picture of the animals health over the two year period. They also took urine samples at various time. At the end of the rats lives they took weights and  samples of most of their organs.  It was very thorough!

Organ retrieval: The idea was to follow these rats throughout their entire life-span and examine their organs at the end of  two years. Some animals became so sick they had to sacrifice them during the research and examine them at that time. This was done according to ethical rules. At the end of the two year study, any animals who had not died due to the research induced pathologies or due to old age were sacrificed. They then collected most of their organs  for weight, tumors and microscopy examination.

Results & observations of researchers

Remember as you read this that this was a two year experiment and most lab rats live about two years. So this was an experiment following these animals through what a normal life-span would be for them.

They have a great summary table (Table 2) that you should take a look at. It gives you a quick comparison of the most frequent health effects caused by the GE corn and GE corn with Roundup and Roundup in water. The interesting thing that you notice right off is that indeed the GE corn and GE corn/Roundup and Roundup water groups always have more health problems than the controls.

The largest palpable growths were found to be non-regressive tumors. Tumors were found to increase in size and number over the course of the experiment. The tumors were usually 2-3 times more likely in the treated groups than controls. This was in both females and males.

In females the largest tumors were in total 5 times more frequent than in males after the 2 year period. 93% of them were mammary (breast) tumors. (Hmmm, anyone thinking about the increase of breast cancer in human females?) At the end of the two years 50-80% of the treated female animals had developed tumors while only 30% of the controls were affected. The Roundup treatment groups showed the greatest rates of tumor incidence with 80% of the animals affected. These mammary tumors are generally known to be mostly estrogen-dependent (Roundup has been shown to disrupt aromatase which synthesizes estrogens as well as interfere with estrogen and androgen receptors in cells).

The second most affected organ in the females was the pituitary gland. They were affected 2 times more than the controls for most treatments (The pituitary gland is very important as it regulates many hormonal systems of the body).

The big palpable tumors in the males (in their kidneys and skin mostly) were by the end of the two years on average seen twice as often as the controls.

The most affected organs in the male rats were the liver, digestive tract and kidneys. Liver congestion and both visible and microscopic areas of dead tissue were 2.5-5.5 times more frequent in all the treatment groups than the control groups.

In females the androgen/estrogen balance in serum was modified by the GM maize and Roundup treatments (again they have a great table you should view).

In the males at the highest Roundup treatment they had almost double the usual amount of estrogen. Any of you guys eating GE food that are using Cialis or some other erectile enhancer?

Does this finally make you think of throwing your GE food in the trash? (Now I am thinking about all the farmers reporting poor fertility in their animals eating GE food. Plus, have you noticed the huge increase in fertility clinics. Infertility in humans is skyrocketing.)

The interesting thing to note is that the groups with smaller amounts of GE corn, GE corn/Roundup and Roundup water  caused as much damage as the groups who consumed or drank larger amounts. When you see this table, you realize people who are ingesting as much as 11% of their diet as GE food could be causing themselves as much organ damage and growing as many tumors as those  eating 33% of their diet as GE food. How scarey is that? People who think it is okay to eat a little bit of GE food better rethink that idea.


They pointed out some things in their discussion that I thought were noteworthy.

  • As I just mentioned similar pathological effects were seen to happen from lowest to highest doses. This suggests some sort of threshold effect. More about this below.
  • The first large tumors in the rats occurred around 4-7 months in both males and females (This would relate to 13-22 years of age in a human eating GE food and Roundup sprayed food since birth. So far we have not gotten this far along in our human large scale experiment. Are you still a human rat or have you thrown out your GE food?) This proves that the standard 3 month studies are ridiculous as they won’t catch much.
  • Roundup all by itself is hazardous, even in the smallest doses they used. (Remember they said this dose is found in some tap water? Plus the larger dose  (their medium amount) that was given to the rats corresponds to the amount of Roundup that is acceptable levels of this pesticide as a residue on GE food.  Eeeek!!!
  • You might start thinking that Roundup itself is the problem and not the GE food. However, the groups fed the NK603 corn without Roundup application still had the enhanced tumor activity and increased mortality rates.
  • It is interesting to note that these researchers measured caffeic and ferulic acids in the GE diets. These  were significantly reduced. They hypothesized that this may lower the protective effects against carcinogenesis and mammalian tumors. Ferulic acid may also modulate estrogen receptors or the estrogenic pathway in the cells of mammals.  They thought this might explain why the effects of NK603 and Roundup are not additive and reach a threshold level. They think that both of them may cause hormonal disturbances in the same biochemical and physiological pathway. Another thing regarding caffeic and ferulic acid is they have been shown to promote detoxification of embryonic kidney cells after Roundup contamination in prior research by Ganier in 2011. The decreased amount of them in the GE diet could account partially or wholly for the kidney damage.
  • The disturbances found in the male’s livers were indicative of long term chronic intoxication. The researchers thought the females were less effected by the liver intoxication due to their being better adapted to estrogen metabolism. They also mention that liver enzymes have been demonstrated to be sex-specific in their expression patterns. Deeper analysis at an ultra-structural level did show defects in cell nuclear structure that were similar in both sexes.
  • They also point out that prior research had already shown glyphosate consumption in water above authorized limits can provoke liver and kidney failure. This study simply proves that lower levels of glyphosate (Roundup), below those set as safety limits can cause severe hormone-dependent breast, kidney and liver disturbances. In addition, GM NK603 maize can cause similar pathologies that may be linked to abnormal or unbalanced phenolic acids, metabolites, or related compounds. However, they do not exclude the possibility of other mutagenic or metabolic effects. (Okay, if you have not ran to your pantry and thrown out your GE food yet, what are you waiting for?)
  • This makes me really glad that I and my animals eat organic food. Hope any of you reading this who are currently eating conventional food, will go throw out all your products with corn, soy, cotton seed oil, and canola oil from your pantry immediately and consider eating only organic in the future.

I take my hat off to the researchers Gilles Eric Seralini, Emile Calir, Robin Mesnage, Steeve Gress, Nicolas Defarge, Manuela Malatesta, Didier Hnnequin, Joel Spiroux de Vendomois. The planet is indebted to you and those like you who are spending countless hours working for the better of planetary life. You and others like you are in my prayers. You are going to need all the support you can get as you just took on a monster. Let us all support you in any way we can.

Shortlink to this article: http://wp.me/p25sNy-a5


22 thoughts on “Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize

  1. I have some doubts, that Prof. Seralini (Criigen) is really independent. In the mentioned publication there is nothing said about conflicts of interests. Is that a proof? But who is funding research? Is the money really derived from independent state insitutions, or is it derived from groups fighting against gene technology?

  2. Thanks for an excellent summary of a landmark article! With regard to a previous comment, the authors specifically state at the end of their article that they have “No Conflicts of Interest.”

    • What’s your conflict of interest? I see your email address is @rbutr.com and your nickname is craigrbutr. Come on! The New Scientist article is clutching at straws. 1. Not enough controls… so if I had 20 controls and 20 test rats that would be OK, but if I have 20 control and 4 groups of 20 test rats that’s not OK? 2. Fungus may be skewing the data, highly unlikely, straws. 3. This strain of rat is prone to breast cancer… this is common practice in studies, like researchers studying obesity use rats prone to obesity. It’s the canary in the coal mine, researchers use test subjects that are sensitive to the conditions they’re looking for. 4. “Other long-term studies do not show this.” WHAT other studies, where are the citations? You can’t just say studies show, you have to CITE them!! There are no other 2 years studies.

      This research team is looking at genetic engineering yes that’s true, and it’s a good job SOMEBODY is. Biotech companies stop researchers having access to seeds for independent testing, NOW I smell a rat there alright.

      This so called rebut is just a bunch of extremely weak arguments put together to try to discredit this research which clearly shows a need for more science and a moratorium on GMOs in our food.

    • I agree with Lawrence Woodward who left this comment on the New Scientist…

      “This is a prejudicial article which lets down the New Scientist.

      Of course it is only one study must be kept in perspective but neither should it be dismissed out of hand, swept under the carpet or be the target of obfuscating comments designed to undermine it.

      The scientists quoted here seem to be have been dredged up as a job lot from the website of industry lobbyists, the Science Media Centre.

      The facts are; the research was published in a well regarded, peer reviewed journal that does not publish sub standard research, which is more than can be said for a lot of the reseach that informs the current GM regulatory process;the strain of rats is one commonly used in such studies;the numbers and group sizes are consistent with OECD guidelines and are in keeping with studies accepted by the European Food Standards Authority;the statistical methods are appropriate to such studies.

      Of course no piece of research or statistical method should be immune from justified criticism and this one is not perfect.But there is more than enough here for it to be taken seriously and followed up with some urgency.

      No tumours were present in the rats at 90 days, the time at which current regulatory assessments are allowed to stop; tumours began appearing in the treated groups at 120 days and at levels that demand further research; health problems associated with non glyphosate treated maize raise questions about the risk implications of the genetically engineered event itself; which is of such significance for our use of the technology that follow up work is essential.

      The findings about dose rate and effect may be unusual but the authors offer an explanation that the paper’s reviewers felt had at least some plausibility; certainly enough to merit more than the cavalier attention given here.

      This is an important piece of work and should be looked at and considered intelligently and not in the blinkered and biased way it has been treated in this article.”

  3. rbutr is a website for following interwebsite debates. One of our users added the new scientist link, and I found this page. We don’t have an agenda, our purpose is to show counter arguments to web pages, and I just thought this new scientist article was worth reading.

    I agree it’s good people are doing this research, and I hope it spurs some more research, but I agree with the NS article, there are plenty of problems with this study that make it’s claims pretty shaky.

    You claim that the NS article is “extremely weak arguments put together to try to discredit this research”, but it’s written by a well know science journalist with 146 articles for new scientist, and many more on other sites. I can’t see her agenda, but the way the french researchers went about getting the press out shows an agenda I think.


    It seems plenty of researchers are disputing this study, and more are upset about the way it was distributed to the media (under non-disclosure agreements).


    Anyhow, not trying to upset anyone, rbutr is just about trying to give balance.

    • The “User” who created the page, is also called Craig, that’s a coincidence. Also, that page is really unclear about what one is voting for by doing thumbs up or down. The evidence against GMOs doesn’t even rely on any one study. AND I’ll tell you, Monsanto’s influence reaches and corrupts every corner of the industry from politics to science. If you trust them, good luck to you and enjoy your GMO food (I assume you DO eat GMOs?).

      • In my opinion, the 2 year study simply verifies/helps explain the mass amounts of cancerous tumors and disease that we’re seeing here in the US. Lab testing is valuable and necessary in order to really see effects, but data charts from what’s going on in real life don’t lie…being healthy used to be the norm, whereas now, we’re having an explosion of cancer and other bad diseases, for what explainable reason? We are one of the sickest nations in the world.
        Honestly, anyone who’s paying attention, and with a little common sense can look at the picture, and figure all this out. You don’t have to be a rocket scientist – or a lab scientist for that matter. People have been lulled to sleep, have too much trust in the powers that be, not in their own instincts, and do not believe anymore that you are what you eat. If you eat/drink something over and over that is known to cause cancer, it’s by the power of your immune system that you don’t get seriously ill – and many people aren’t that lucky.
        Everyone being sick is the reason there are drug stores being built left and right – sometimes 2 on the same street corner. The pharmaceutical/chemical companies are ecstatic and very rich, thanks to everyone’s bad health. Why wouldn’t they want us to eat/drink their poison? Of course, they’re going to discredit any study that comes out with results that should scare the bejeebers out of everyone. Things come into really sharp, clear focus when you’ve sat with a loved one and watched the chemo IV drip into their veins, watched them get sick from the treatment, their hair fall out… knowing that it too, is a poison given to us by these same companies. Cancer is NOT supposed to be a common part of life, but here it is, and there is a reason for that.

        So, craigbutr…I’m saying all that to say, whether or not there is a conflict of interest for the data in this study, it does not change the facts, and right before our very eyes, in our very lives, is all the proof needed to verify the data. I agree with Mike, you go ahead and enjoy those GMO corn flakes tomorrow morning – and make sure to stay hydrated with your 8 glasses of (acceptable traces of roundup) water during the day, just like they told us to do, maybe you’ll be one of the lucky ones with a good immune system.

      • Hi Lori,

        Cancer rates have been steadily dropping for quite a long time.


        Anyhow guys, I’m not making any statements one way or the other about GMO’s, I’m just pointing out that this particular study, that is being repeated all over the internet currently is not a very high quality study, and it has some serious problems with it. I’ll bow out with that. You’ve got both sides, it’s up to you guys to decide.

        P.S. Mike, I wasn’t the first one to post the new scientist article to rbutr, but I was the person that linked it to this page. I found out about the NS article when another user linked another site posting this study to rbutr. You can dig into the rebuttals on rbutr and see what I mean if you are interested. I’m just interested in higher quality information for us all. Again, no offence intended, just adding opposing views, which I find helpful for understanding issues better.

    • Thanks Craig I get what you’re trying to do. With a complex subject like GMOs and $billions at stake, it’s easy to confuse and deflect by argument. I recommend people watch Genetic Roulette and get the big picture. I’ve been studying health and food for over 20 years and I am absolutely crystal clear that life and health depend on nature’s synergy. We move away from that at our peril.

      • I’m pretty open minded about the whole thing. I did google “Genetic Roulette review”, and this is the top review. It’s pretty damning..


        Hard for me (as a skeptic) to see a good reason to trust this book/video. I accept there might be some dodgy science funded by companies like monsanto, but it seems Jeffrey Smith has a very clear agenda and bias too. I don’t trust either of them..

        That said, I’m sure that at least some GMO’s are safe and fine, and I don’t think it’s very different to the selective breeding we’ve been doing for centuries. And I think you and I would at least agree we should be proceeding with caution and doing lots of independent safety testing.

      • I trust nature Craig. Humans have a long and glorious history of screwing things up. 100 years ago everything was organic, and you can stretch that back to beginning of life on Earth. I see no reason to put spider genes in goats, cow genes in pigs, human genes in cows and bacteria genes in corn. Why are we doing this? It’s about making money Craig, that is all it’s about.

      • Yeah, I wish much more GMO stuff was about improving health and nutrition, not just farming yields. There is one great GMO though, golden rice. Hopefully this will save lots of third world children (by making rice more nutritious). I wish there was more GMO’s that were about humanitarian goals like this, but this one is inspiring I think. A GMO very much NOT about the profit motive (it’s intended to be free).

        P.S. I don’t trust anything in particular, although the scientific method is pretty impressive. But I think we have great challenges to feed the world, and we couldn’t be doing it now if we were doing it completely naturally (whatever that means). We are a technology creating species, which I suppose is obvious as I spurt electrons across the world from my typing ;) I’m in Australia.

      • From http://www.goldenrice.org right at the top “The best way to avoid micronutrient deficiencies is by way of a varied diet, rich in vegetables, fruits and animal products.” Why not do it the best way? Why don’t we have a humanitarian effort to do that? Humans are always trying to sticky-plaster problems instead of getting to the roots.

        You exist because of nature Craig, and lucky for you, you can still call yourself a natural human being, and not some human-cow-spider freak hybrid. I believe in the integrity of nature and natural processes, natural evolution, boy meets girl, birds, bees etc. Just because science can produce inter-species hybrids, it doesn’t mean we should. Where is the ethical framework? There isn’t one. Biotechnology in the hands of companies like Monsanto is a frightening thought.

      • Hi Mike,

        “Why not do it the best way”. Well, poverty.. Golden rice isn’t for you and I, it’s for the worlds poor, many of whom live almost exclusively rice. Many go blind because it doesn’t have β-carotene in it. And many children die young because of this missing micro nutrient. It’s a gift to them to try to solve a serious health issue. And it’s hard to imagine a safer or more ethical GMO.

        By the way, virus’ and possibly bacteria have been hacking our DNA for millennia! Almost 50% of your DNA seems to come from non relative sources. So, you might not be a human-cow-spider freak, but we are all human-virus hybrid freaks ;)


        Anyhow, I share some of your concerns, but I respectfully disagree that GMO’s are inherently evil and inherently dangerous. I believe we should be making informed choices, and I’m all for GMO labelling (which we have in Australia).

      • Yes to labeling Craig, I’d be happy with that. I hear you about viruses, that’s a good point but still this is a way nature NATURALLY introduces mutations into the gene. That’s different to using a gene gun. Also the whole gene gun thing is old, there is better way to select for genes using marker technology.

    • It’s not terribly flawed Craig, that’s very naughty to include that as a secondary message. The arguments in NS are WEAK, very WEAK, and purely designed to confuse, divert and instill doubt. The one thing I DO seriously doubt is YOUR agenda. Put yourself in Monsanto’s position. What’s the best way to take the study down (what with prop 37 coming up). It’s to get all the scientist in your camp to get an article in the most respected magazine, journal, whatever. Then everyone else FOLLOWS like little lambs. Wake up man.

      • Mike, I don’t have an agenda here, except for better quality information for everyone.

        I understand science well enough to be able to understand the problems with this study. If you care about if I’m right or wrong about that, you’ll need to read a bit more to have an informed opinion I’m afraid. But if you just believe in conspiracy theories about it, there isn’t any point reading, your mind is already made up..

        It surprises me that anyone CAN’T see the flaws in this study when the control group only had 10 males and 10 females, and the rats were of a strain where about 85% of the males are expected to get tumors with a normal diet in 2 years (I assume you know that cancer is the norm with these rats).

        Me wake up? Hmm.. Anyhow, night night.

      • You’re very funny Craig because I’ve had my head into the GMO saga for years, and you think I need to read more. And yet because you “know a bit if science” you think you can critique the whole GMO issue? Puurlease. Watch “The World According to Monsanto” if you’re not prepared to see Genetic Roulette. It’s free to view and if you click the movies category on this site, you’ll see it. And… if it’s all a conspiracy theory, then 50 countries including the EU have been duped because they all have restrictions on bans on GMOs. Russia has just stopped an import of corn based on the findings of this study… poor Russians have fallen for the conspiracy theory too it seems. Sweet dreams.

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