Is there evidence supporting a link between autism and GMOs

| May 9, 2014 |
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The alleged link between autism and GMOs is heavily promoted by notorious alternative medicine and natural products advocate Dr. Joseph Mercola, as well as Jeffrey Smith, the controversial founder of the anti-GMO one-man Institute for Responsible Technology. Mercola even promotes a Smith video headlined: “Monsanto’s Roundup Herbicide May Be Most Important Factor in Development of Autism and Other Chronic Disease”. Is there any truth to their claim of a GMO-autism link?

The autism spectrum disorder (ASD) is characterized by “difficulties in social interaction, verbal and nonverbal communication and repetitive behaviors”. There is a broad range in the severity of these symptoms, which is why the term “spectrum” is used in the definition of the disorder. It is hypothesized that there are multiple causes for ASD, including genetic, epigenetic and environmental factors. The heritability of autism has been studied in twins and historical data suggest 80-90% values, while more recent data using different ascertainment criteria suggest roughly 50% heritability.

A study in 2011 found that the recurrence risk of autism is ~19% in infants if an older sibling is autistic, with a roughly three-fold increase in risk if the infant is male and a two-fold increase in risk if there is more than one older sibling with autism. A recent review highlighted that a genetic cause can be elucidated in 10-30% of cases of ASD depending on the technology used and cohort examined, and that exome and whole genome sequencing of ASD patients has led to the discovery that there are “hundreds of genes” involved in the disorder.

However, genetics does not account for all cases of autism and many studies have focused on identifying non-genetic causes of ASD. Environmental risk factors that have been associated with ASD include parental age, pre- and peri-natal complications (particularly respiratory distress), air pollution, maternal use of valproate and maternal exposure to pesticides, among others. It is this last factor that is being exploited by Mercola and Smith to fuel their campaign against genetically modified foods.

I do not use the word “exploit” lightly, but can find no better term. The link between autism and GMOs is most often restricted to the criticism of glyphosate-use. Glyphosate, which is the active ingredient in Monsanto’s Round-Up, is used on genetically modified crops that are made to resist this herbicide. However, whether you are searching for a link between autism and GMOs or autism and glyphosate, your findings can be summarized in one brief sentence: “there is no data that I could find”.

Throughout the course of doing research for this piece, I contacted several research scientists including my former lab, which is now one of Canada’s leading autism research laboratories and part of a project that is sequencing the genomes of ten thousand ASD patients (note that I am not an ASD research scientist). My request for an opinion on the topic was passed from one research scientist to the next and across the board, I got the same message: “there is no evidence-based data we are aware of”. That is not to say that a link does not exist or may not be identified in the future, but as I write this article, there is no credible research linking GMOs to autism.

However, the memes and websites preying on the fears of parents and the vulnerabilities of those with autistic children abound, which is why I consider this to be exploitation of the worst sort. Mercola’s website features a one hour interview with Dr. Stephanie Seneff, a computer scientist and electrical engineer who has written about autism and glyphosate. Dr Seneff, whose previous work include a thoroughly lambasted paper in a low tier journal providing a “link” between autism and vaccines, also wrote a paper in 2013 in a similar marginal journal outlining a hypothetical link between glyphosate and multiple disorders, including “gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’s disease.”

Unfortunately, the paper, which did not include any novel research was legitimized by Carey Gillam at Reuters, whose news story was headlined “Roundup linked to health dangers”. Multiple reviewers have since noted the incoherent nature of Seneff’s paper and the pay-for-play nature of the publishing journal. Seneff hypothesized that glyphosate causes nutritional deficiencies and systemic toxicity, primarily by impacting the bacteria in the gut, yet fails to provide any evidence supporting her hypothesis.

There have been very few studies that have specifically examined glyphosate and ASD. In 2007, one study examined maternal exposure to pesticides during gestation and ASD among children in the California Central Valley. The pesticides selected for analysis were based on the toxicological and physical properties of the compound, as well as substances that were of community concern. The final list of pesticides included in the analysis lists glyphosate, yet fails to find association between maternal exposure to the chemical and ASD.

Pesticide use is recorded in the United States and there are multiple databases that house this information, ranging from the amount of pesticide used to the exposure that handlers have experienced. As such, it stands to reason that if glyphosate were associated with autism, there would be more instances of ASD in regions of the US where glyphosate use is high. Geographic clusters of ASD cases do exist in the US (see here and here for example studies), but the analysis of these clusters has not identified glyphosate exposure as a possible cause, despite the availability of data.

The onus is on the researcher to disprove the null hypothesis, i.e. to prove that something exists or that there is a link. Until that point in time, there is no link. Seneff points to glyphosate as the cause of autism based on her observation that glyphosate use has increased while the rate of autism has increased in the same time period. Seneff states, “I’ve watched the rate of autism skyrocket in the last 5 years. It’s extremely scary. One in 150, one in 100, one in 88, and the most recent numbers from March 2013, one in 50… You do the math… 20 years from now every other boy in this country will be diagnosed on the autism spectrum.”

Yet the Center for Disease Control and Prevention has stated that “the recent prevalence increase [of ASD] is likely attributable to extrinsic factors such as improved awareness and recognition and changes in diagnostic practice or service availability”. This is supported by the fact that recent statistics have noted an increase in the incidence of autism in specific populations and racial backgrounds, suggesting increasing awareness in such groups. But for the sake of argument, let’s acknowledge that there has been an increase in the occurrence of autism. The link is a classic case of association with no causation.

There’s a plethora of items whose prevalence or use has increased during the past 20 years: the number of electronics we own, the number of pedicures women get, the amount of coffee we drink, etc, and each would make an equally convincing graph if their rate was compared to the incidence of ASD over time. This is not to say that glyphosate should not be studied; yet until a link is identified, its association with ASD is equivalent to that of eating organic food, whose salves have also risen in tandem with the increase in incidences of autism.

ScreenHunter_04 Jan. 07 23.11, an organization that promotes the labeling of GM ingredients, also has an article promoting the autism-GMO link on its site. The article shares anecdotal stories about the commonality of gastrointestinal symptoms between autistic patients and GMO-fed animals. Gastrointestinal symptoms in patients with ASD are well documented and recent funding grants will infuse hundreds of thousands of dollars to better understand this relationship. But as it stands today, “there is no data”.

I searched publication databases to find a scientific article providing evidence for gastrointestinal symptoms associated with GMOs and was unable to find even one. Additionally, glyphosate is not used exclusively on GMOs: it is used for a wide-range of different applications including “weed control in vineyards, olive groves, fruit orchards, grass pastures, forestry, parks, gardens and underwater usage in rivers and lakes”. In fact, it could not be avoided through a GMO labeling law or ban.

There are those who will read this article and will conclude that research has not been done examining the link between autism and GMOs because corporate interests have silenced researchers, that corporations paid off scientists or that universities threatened to cut off funding. However, I think that there are very few scientists who wouldn’t give their life savings and the naming rights for their first born for the opportunity to identify an environmental cause for autism. Monsanto, Dow Agro, and Syngenta combined aren’t big enough to silence that. The reason it hasn’t been examined is far simpler: there is no likely connection based on the known comparatively benign toxic profile of glyphosate and most researchers do not want to waste their time and effort and preciously limited support dollars on a project that would most likely find no association with ASD.

Although the world of science has tried to study the emotional toll that ASD takes on families, I think that there’s nothing that could fully describe the full range of emotions that parents experience when their child is diagnosed with ASD. I know I’m lucky to be the parent of a healthy and rambunctious toddler, and I feel arrogant even imagining myself in the shoes of families with ASD. But there is one thing that I know that I share with all parents: we are equally concerned about the health and well-being of our children.

I wrote this article more harshly than I generally would and condemned scientists for poor research more strongly than I generally would because they have made conclusions where none are to be made and would have us believe facts where none exist by exploiting the concern we have for our children. So rather than listening to the advice of Mercola, Seneff or Jeffery Smith, consult your pediatrician or GP and have them address any concerns that you may have about your family’s diet.

Layla Katiraee, contributor to the Genetic Literacy Project, holds a PhD in Molecular Genetics from the University of Toronto and is a Senior Scientist in Product Development at a biotech company in California. All opinions and views expressed are her own.

  • 2

    It is very easy to prove your point, if you are SO sure glyphosate is SO safe, Why dont you get expose to it and get pregnant? would you do it? surely not, you are murderers that is what you are

    • BioChicaGMO

      If you’re asking me to expose myself to the limits that are allowed in our food supply and get pregnant, I did and my family’s doing great. Thanks for asking. If you’re asking me to expose myself to limits beyond what is recommended, why would I do that? There’s a reason why there are recommended limits for glyphosate in our food supply and why there are strict guidelines for those who handle it. After all, it is an herbicide. But it’s all in the dose and there’s no evidence to suggest that we should be concerned with the amount of glyphosate currently in our food supply. If you know of a legitimate source that would suggest otherwise, please let me know. Please see this excellent graphic:

    • First Officer

      Is that the way your parents told you how people get pregnant?

  • Sarah []

    I’ve had two healthy pregnancies and two healthy babies and my husband works closely with glyphosate and sprayed right by our home in both pregnancies. With the logic you likely have, therefore we can assume glyphosate has no negative impacts on pregnancy. Throwing a “murderer” stone at someone for writing an article, “2”, really?

    • Flatulentia Buttox

      First class rebuttal of the Luddites!

      • Bill Carey

        Your “nom de plume” was aptly chosen. Or was it awarded?

    • jlfenton

      So called “organic foods” have been all that has been available since the begining of mankind. NOW we have GMs (for about 25 years) and the rise in Autism started, or what, 25 years ago..!

  • Eric Bjerregaard

    Mr. First Officer, Thanks for the chuckle. I enjoy it when you smart folks display a bit of smart aleck.

  • Alaric Quema

    I hate evil Monsanto, I prefer to eat organic food and I have an Autistic child. But it’s very suspicious that this anti-GMO activist has supposedly have found the cause of autism.

    > autism rates in other countries that doesn’t use roundup or glycophosphates are about the same as in the U.S.
    > this theory hasn’t been backed by any scientific study.
    > statistical correlations can be very tricky.

    I think it’s very arrogant and irresponsible to make this claim without scientific proof.

    It’s like that debunked vaccine-autism link all over again. People can get hurt by this false science.

    I hate these unvaccinated hippies. I hope a plague would wipe them out.

    • Alaric Quema

      I googled “evil companies”. Monsanto comes up #1 in every list. Ha ha! at least my sentiments were right.

      my list:
      3)Chase, Goldman Sachs and most big banks
      4)All health insurance companies

  • blue horse

    Wrong! Pesticide use is NOT recorded in many parts of the US as you stated. At current time, activists in Maryland are trying to get a law enacted to do just that, for agricultural pesticides. But still, no one is keeping track of the data of the astronomical amount of pesticides put on lawns. Birth defects in many areas are also not recorded. THERE IS A COMPLETE LACK OF DATA WHEN IT COMES TO PESTICIDE USE.

  • Flatulentia Buttox

    Even if a link were to be established between glyphosate and ASD, this would have no bearing on the safety of GMO’s. The only inference of any relevance to GMO science would be that there was no point in engineering glyphosate-resistant GMO’s. There would be no inference validating the hypothesis that glyphosate-resistant GMO’s – let alone GMO’s quite generally – were unsafe.

  • peter

    Senior Scientist in Product Development at a biotech company in California…enough said, why would anyone listen to you, this is your bread and butter of course your going to defend it…

    • BioChicaGMO

      Ummm… Take a second and look me up in Linkedin. Then come back and chat.

  • marie72

    It all has to to do with gut flora…

  • LaurentS

    Layla, I would take your article more seriously if you weren’t funded by Monsanto.

    • BioChicaGMO

      Hi Laurent,
      Do you have evidence for this allegation? If so, please share with all the readers here.

      • BioChicaGMO

        On second thought, I’m not sure if I should have asked you to do that… I had been pretty successful at setting up off-shore accounts for Monsanto to funnel money into without my husband or my employer’s knowledge. If you’ve managed to find my accounts in the Cayman Islands, let me know and I’ll give you a cut of my income rather than exposing me so openly!

        • Leah

          What does your comment mean? Are you exadurating since you just openly let everyone know something you supposedly want to keep hidden?

          • BioChicaGMO

            I was being sarcastic.

  • LG

    THIS IS BOGUS! I have an autistic son and I never ate organic. Organic eating has been around aince the beginning of time but autism didn’t start to rise til after the patten ended, as you know. FACTS ARE FACTS! YOU ARE GETTING PAID FROM SOMEWHERE OR YOU WOULDNT BE DEDICATING SO MUCH TIME TRYING TO PROVE MONSATO RIGHT! Aspartame eats holes in ur brain, NO MATTER HOW MANY RATS OR HOW LONG THE TESTING OCCURED (according to your other comments). Shame on you for ATTEMPTING to misinform the people around you!!!

    • BioChicaGMO

      I think that you didn’t read the article. I never said that organic food causes autism. I pointed out that just because two things are correlated, it doesn’t mean that one causes the other.

      • marie72

        The title of this article is confusing,It sounds like it’s saying organic food causes Autism and that makes no sense.

  • glamourschatz

    Laylaaaa… why don’t you take your fancy PhD and create a correlation chart that compares glyphosate to women who use nail polish and also drink coffee so you can keep this sham of an SEO propaganda site going. I’m sorry that there are not real opportunities for scientists like yourself and you get stuck keeping the bottom line of corporations like Monsanto looking good to Wall Street. Do we have to wait for the entire Gulf of Mexico to die from de-oxygenation and the collapse of insects that pollinate a large supply of our food? We need weeds, we need insects! We need ecosystems to thrive. We have to get our country out of this monoculture mess created by Agribusiness and get back to loving “weeds” in our backyards. I’m optimistic that in 100 years our non-autistic offspring will laugh at their grandparents “science” that believed there would be no repercussions for introducing “weed” killing genetic modification into our water and food supply. Just zoom out a bit and get away from your spreadsheets…

    • BioChicaGMO

      Well, aside from the claim that I work for Monsanto (which I don’t) or get paid for writing articles (which isn’t true), you raise valid concerns, such as monocultures, weeds, etc. But instead of attacking me, why don’t you offer your thoughts/concerns/suggestions on these issues. For example, given the fact that 96% of US farms are family owned (, how would you resolve these issues? Given the fact that most individuals in North America don’t live in a climate where they could have a year-round garden, how should they grow their own food? What about in urban areas?

  • jlfenton

    The dramatic rise in organic foods stems from the dramatic rise in GMOs. the correlation between GMOs and Autism is direct.

    • Genevieve Malouin Diraddo

      I agree 100%. I tell ya … in a few generations… all there will be left are the people who’s parents and grandparents ate organic because everyone else will be infertile. I think it’s Mother Earth’s way of purging herself of her human infestation.

  • bill

    It is my understanding Norway prohibits GMOs and the autism rate is 1 in 2000. USA rate is 1 in 68 and GMOs dominate our food supply.

    • hyperzombie

      So, denmark does not consume any GMOs and their cancer rate is the highest in the world.

  • JustTellingYouTheTruth

    How could you link ANYTHING to organic food?? That’s the dumbest title for an article I’ve seen in a while.. Organic food is food, without added chemicals, pesticides, fertilizers, and the countless other chemicals that are put in. So tell me again how organic food is causing problems? If this were the case, food would always have caused these problems.
    Do some more research on neurotoxins and their effect on a developing child’s brain.. blood brain barrier, etc.

    • BioChicaGMO

      Read the very first sentence.

    • cmac

      this is a demonstration of shooting blanks. Read the article before making an opinion, or you just look like an idiot.

  • Genevieve Malouin Diraddo

    Glyphosate (Round-Up) = Autism (amongst many other conditions)

    Dr. Thierry Vrain (Retired Genetic Engineer) showed your “Organic Food Sales” chart immediately after Stephanie Seneff’s chart, at the GE Foods & Human Health Speakers’ Tour.

    The correlation between Glyphosate and Autism is a fact and demands further investigation including Glyphosate testing upon request at all laboratories in Canada. It is too important to ignore or to call a coincidence.

    The correlation chart between Autism and Organic Sales is completely useless and used by Monsanto Supporters as a way of saying “nani nani poopoo” It’s just a pathetic little attempt to defend dangerous fat-cats playing Russian roulette with our food supply and frankly that chart is a joke. Everyone who sees that chart says “D’you think we’re idiots?”

  • Genevieve Malouin Diraddo

    Glyphosate (Round-Up) = Autism (amongst many other conditions)

    Dr. Thierry Vrain (Retired Genetic Engineer) showed your “Organic Food Sales” chart immediately after Stephanie Seneff’s chart, at the GE Foods & Human Health Speakers’ Tour.

    The correlation between Glyphosate and Autism is a fact and demands further investigation including Glyphosate testing upon request at all laboratories in Canada. It is too important to ignore or to call a coincidence.

    The correlation chart between Autism and Organic Sales is completely useless and used by Monsanto Supporters as a way of saying “nani nani poopoo” It’s just a pathetic little attempt to defend dangerous fat-cats playing Russian roulette with our food supply and frankly that chart is a joke. Everyone who sees that chart says “D’you think we’re idiots?”

    • BioChicaGMO

      Hi Genevieve,

      Sure, the number of individuals diagnosed with autism and the amount of glyphosate used may correlate. This paper draws graphs for 22 different disorders and how they correlate with glyphosate, very similar to the graph you’ve shared: As you can see from the link, GMO Inside has been promoting this paper. Somehow, 22 disorders with vastly different aetiologies are all caused by glyphosate!

      No, I don’t think you’re an idiot. I included the graph to highlight there’s the same amount of evidence for a link between glyphosate and autism as there is for a link between organic food and autism, i.e. no evidence whatsoever. But somehow you’re convinced that glyphosate causes autism. I’d like to know how you reached that conclusion.

      If you want someone to examine the autism/glyphosate correlation, you’ll have to convince a researcher that a compound that inhibits a biochemical pathway that does not exist in mammals has an impact on human development, and that the impact is specific to humans since it hasn’t been seen in animal feeding studies.

  • Eliza

    Did no one think that the rise in organic food and autism are linked because many parents who have children with autism switch to organic diets since research does show that these diets help? I find the article hard to believe. I have a child with HFA and my husband and I have just recently been looking at going all organic or possibly gluten free. Seems to me that this article is promoting an invalid correlation.

    • BioChicaGMO

      Hi Eliza,
      The whole point of the article is that correlation does not imply causation, and that there’s no evidence to suggest that glyphosate use or GMOs cause autism. The # of individuals diagnosed with ASD correlates both with the amount of glyphosate use correlate and organic food sales. There’s no evidence to suggest that either one of them cause autism.

  • cmac

    The comments below reming me of the quote of Daniel Patrick Moynihan: “everyone is entitled to his own opinion, but not his own facts”.

  • Rachel

    An article like this is a dis-service to both sides. It is written by a smart-ass, a clever smart-ass that will say anything to make a point. You CAN’T argue with somebody that thinks they know everything because they will do everything to make sure they WIN because their end game is more about winning than being right. The person writing this article is a tool that obviously lives in a test tube and doesn’t play well with others. Holds a PhD. Whoopie! Scientist in Product Development = Part of the problem. Biotech means “I think I’m better than God” and so that’s all I need to know about Layla Katiraee.

    • BioChicaGMO

      Hi Rachel,
      Could you explain why you think this article is a disservice to both sides? Is there anything in the article that is incorrect?
      Could you also explain why my job as a scientist in product development is part of the problem? For the past 7 years, I’ve been working on making assays and machines to better diagnose genetic disorders, and I currently work only on human DNA sequencing. So I’m not sure what problem you’re referring to or why you think I’m better than God?