Does Glyphosate Contribute to Autism?

By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.

Of all developmental disabilities, autism is the fastest-growing. Between 2002–2010, its prevalence rose by 6–15% every year. In 2000, 1 in 150 children was diagnosed. In 2010, that number jumped to 1 in 68.1

Even more concerning, some prominent autism researchers predict that half of all kids will have autism by 2025.2

It’s possible that this increase could be attributed to widespread recognition of this disorder, as well as more thorough and accurate diagnoses. But I believe there are other factors involved in this dramatic rise…

Causes of Autism

Turns out there’s a good deal of research on the potential causes of autism. Scientists still don’t have all the answers, the most likely causes are:

  • More than 100 different genes may be involved in the development of autism. For some, autism may be the result of genetic disorders like Fragile X or Rett syndromes. For others, genetic mutations are the culprit. Genes may also be involved in problems with brain development, how brain cells communicate, severity of the disorder and symptoms, and more.3
  • Environmental factors. There’s also evidence that viral infections during pregnancy, certain medications and vaccines, and exposure to air and environmental pollutants all play a role in autism—especially when genetic predisposition is also present.4 There are many toxins of concern, but the one I want to focus on here is glyphosate.

Roundup for Breakfast?

The Far-Reaching Dangers of Glyphosate

Glyphosate is a powerful herbicide (weed killer). It was developed in the 1950s but really took off in the mid 1970s when the company Monsanto patented this chemical under the trade name Roundup. Monsanto’s patent expired in 2000, which means today there are hundreds of glyphosate-based herbicides on the market.

There are many problems with glyphosate—for the environment, animals, and humans.

You see, this compound is a “non-selective herbicide,” which means it can hurt or kill any plant it touches, even plants you want to protect from weeds. When you spray it, the aerosol droplets can travel in the air to surrounding plants unintentionally. And even if you spray it carefully, a certain amount of it seeps into the soil, disrupting not only vegetation but waterways.

Research has also found glyphosate harms animals such as monarch butterflies and honeybees, and even humans.5

A 2019 review looked at data from several studies on glyphosate’s carcinogenic effects. The review discovered that farmers exposed to the highest amounts of glyphosate had a 41% greater risk of Non-Hodgkin lymphoma.6-7

And it’s not just cancer. Glyphosate has been linked to:

  • Endocrine disorders and infertility
  • Liver disease
  • Disruption of the delicate microbiome
  • Celiac disease
  • Conditions related to neurotoxicity…including autism8-9

How Autism?

The connection between glyphosate and autism is an interesting one. Earlier I mentioned how both environmental factors and genetics can increase autism susceptibility. And they both come into play here.

Neurotransmitter dysfunction is commonly seen in people with autism. Very simply put, neurotransmitters are the molecules that carry messages between nerve cells. Research has found that children with autism tend to have high amounts of the neurotransmitter dopamine. The higher the dopamine level, the greater the severity of symptoms.10

Dopamine is sometimes called the “happy hormone” because it elicits feelings of pleasure and well-being. But having too much dopamine can cause aggressive behavior and poor impulse control—which are characteristics often seen in kids with more severe autism.

What causes dopamine levels to spike so high in the first place? Research points to elevated levels of a substance called HPHPA, which is a metabolite of a pathogenic strain of bacteria called Clostridia. (A metabolite is an end product of metabolism.) HPHPA interferes with the conversion of dopamine, which keeps dopamine levels abnormally high.

According to author and researcher William Shaw, PhD, “This connection between Clostridia and elevated dopamine is so prevalent in autism that elevation of Clostridia species is almost surely the major cause of severely abnormal behavior in autism.”11

The reason these kids have such high levels of Clostridia in the first place? Glyphosate.

Unfortunately, glyphosate is not easily washed off of plants before you eat them. So, the compound can easily get into your system, where it immediately destroys beneficial gut bacteria. At the same time, pathogenic forms (like Clostridia)—which happen to be resistant to the effects of glyphosate—thrive and multiply.

Glyphosate is also known to bind manganese and magnesium—minerals important in normal neuronal function.12

The problem isn’t isolated to kids. Babies in utero are also at risk! A May 2020 study found that pregnant women who were exposed to high levels of glyphosate had babies that displayed autism-like behaviors. The researchers also found abnormal composition of gut bacteria in the babies’ fecal samples.9

Another study found that pregnant women who lived near farms where pesticides are sprayed are more than 60% more likely to have children with autism.13

7 Reasons to Eat Organic

How to Protect Yourself and Your Kids

It goes without saying that one of the best ways to protect yourself and your kids from a potential autism diagnosis is to avoid glyphosate at all costs.

Easier said than done, considering it’s pretty much everywhere.

But there are things you can do to limit your exposure.

  • All children, and expectant/breastfeeding mothers, should eat only organic food. This is a no brainer. It’s not foolproof, as pesticides can still be found in some organic produce. But organic will always be far safer and healthier than conventional produce.

If you’re just starting out on an organic diet, good news: One study showed that going mainly organic for just one week can reduce pesticide exposure by 90%! Another study found that autistic children who followed an organic diet for six weeks had a 94% reduction in urinary glyphosate.14-15

This is, by far, the simplest step you can take to protect yourself and your family. If you can’t afford to go 100% organic, refer to the Environmental Working Group’s Dirty Dozen list, which highlights the 12 most heavily contaminated fruits and vegetables that should be purchased organically whenever possible. On the other hand, their Clean Fifteen spotlights the produce that doesn’t retain as much pesticide residue and is therefore less risky to buy non-organic for budgetary reasons.

  • Avoid all GMO (genetically modified organism) crops, which were developed to be resistant to glyphosate. These plants are usually sprayed heavily with the compound because they don’t die. The worst offenders are corn and soy. These grains and their byproducts are used in countless foods, including oils, margarine, baked goods, cereals, sodas, and other processed foods. If you aren’t buying USDA-certified organic foods (which are always non-GMO), look for “Non-GMO” labels on packaged foods.
  • Take protective supplements, including probiotics, manganese, magnesium, and glutathione—your body’s most important antioxidant and detoxifier. (While usually safe for kids, discuss these supplements with your child’s doctors before giving to him/her.)
  • Don’t use glyphosate-containing products, like Roundup, around your home. If your neighbors use it, stay indoors so you don’t inhale it. Unfortunately, it can take a couple days to fully dissipate, so do your best to not hang out too long around that area.
  • Eat more (organic) sulfur-rich foods. Glyphosate exposure depletes the body of sulfur, which impairs the body’s ability to detox naturally. Good examples of sulfur-rich foods include eggs, onions, garlic, broccoli, and other cruciferous veggies (organic, of course!).

Autism is, without a doubt, a scary and frustrating condition. As we continue to learn more about causes and prevention, I encourage you to make important changes to protect yourself and your family. Avoiding glyphosate is an excellent start.


  1. Autism Society. Facts and Statistics. Updated August 26, 2015.
  2. Alliance for Natural Health. Half of All Children Will Be Autistic by 2025, Warns Senior Research Scientist at MIT. 2022 Apr 11.
  3. National Institutes of Health. What Causes Autism? Updated January 31, 2017.
  4. Ratajczak HV. Theoretical aspects of autism: causes–a review. J Immunotoxicol. 2011 Jan-Mar;8(1):68-79. doi: 10.3109/1547691X.2010.545086. PMID: 21299355.
  5. Motta E, et al. Glyphosate perturbs the gut microbiota of honey bees. 2018 Sep 24;115(41):10305–10.
  6. Zhang L, et al. Exposure to glyphosate-based herbicides and risk for non-Hodgkin lymphoma: A meta-analysis and supporting evidence. Mutat Res Rev Mutat Res. 2019 Jul–Sep;781:186–206.
  7. Gillam C. Glyphosate fact sheet: Cancer and Other Health Concerns. 2021 Sep 27.
  8. Richardson JR, Fitsanakis V, Westerink RHS, Kanthasamy AG. Neurotoxicity of pesticidesActa Neuropathol. 2019;138(3):343-362. doi:10.1007/s00401-019-02033-9
  9. Pu Y, et al. Maternal glyphosate exposure causes autism-like behaviors in offspring through increased expression of soluble epoxide hydrolase. Proc Natl Acad Sci USA. 2020 May 26;117(21):11753–9.
  10. Samsel A and Seneff S. Glyphosate, pathways to modern diseases III: Manganese, neurological diseases, and associated pathologies. Surg Neurol Int. 2015;6:45.
  11. Shaw W. Is the Weed Killer Glyphosate Harming Your Health? Autism Parenting Magazine. 2021 Aug 5.
  12. Beecham J and Seneff S. The possible link between autism and glyphosate acting as glycine mimetic—a review of evidence from the literature and analysis. J Mol Genet Med. 2015 Oct;9:4.
  13. Autism-Pesticide Link Found in Calif. Study. 2014 Jun 23.
  14. RMIT University. Going Organic for One Week Cuts Pesticide Exposure Study. 2014 Apr 29.
  15. Shaw W. Elevated Urinary Glyphosate and Clostridia Metabolites With Altered Dopamine Metabolism in Triplets With Autistic Spectrum Disorder or Suspected Seizure Disorder: A Case Study. Integr Med (Encinitas).2017 Feb;16(1): 50–7.

© Stephen Sinatra, MD. All rights reserved.

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