Weed Killer Roundup and Celiac and Gluten Sensitivity

No research suggesting a causal link to glyphosate

Could exposure to glyphosate, the active ingredient in the weed killer Roundup, cause celiac disease or non-celiac gluten sensitivity? Two scientists argue in a research review that glyphosate could be to blame, but it's not clear they've proven their case.

The researchers, consultant Anthony Samsel and Massachusetts Institute of Technology senior research scientist Stephanie Seneff, theorize in the journal Interdisciplinary Toxicology that "glyphosate [Roundup] ... is the most important causal factor in this epidemic."

However, their research hasn't been backed up by others in the field. While it's not clear what, exactly, is causing spikes in the diagnosis of celiac disease and non-celiac gluten sensitivity, possible reasons for the increases include better awareness and detection of the conditions, increases in the gluten content of wheat, and increases in the amount of wheat consumed in many people's daily diet.

wheat harvest
Andy Sacks / Getty Images

The Purpose of Roundup and How It Is Used

Roundup (glyphosate) is produced by Monsanto Company and is used extensively in farming. So-called "Roundup-ready crops," which are crops designed to withstand the application of glyphosate so that the chemical can be used to kill off weeds in fields where the crops are grown, include corn, soybeans, canola, cotton, sugar beets, and alfalfa.

Contrary to popular belief, there's no "Roundup-ready" version of genetically modified wheat on the market right now. However, it is a common practice among farmers to spray their wheat crops with glyphosate immediately prior to harvest—doing so actually kills the plant, which speeds the required drying of the grain.

This is called "desiccation." This practice makes it easier for farmers to time when they harvest their wheat crops and allows for more uniform drying. Samsel and Seneff noted that the incidence of celiac disease and gluten sensitivity has risen dramatically worldwide, but especially in North America and Europe, and they blame the weed-killer glyphosate for this increase.

They write: "Fish exposed to glyphosate develop digestive problems that are reminiscent of celiac disease. Celiac disease is associated with imbalances in gut bacteria that can be fully explained by the known effects of glyphosate on gut bacteria."

According to the authors, the characteristics of celiac disease indicate impairment of particular enzymes the body uses to process vitamin D (frequently low in people with celiac disease) and also to produce the digestive juices needed to digest food properly. Glyphosate is known to inhibit those enzymes, they write.

In addition, the authors note, "celiac disease patients have an increased risk to non-Hodgkin's lymphoma, which has also been implicated in glyphosate exposure. Reproductive issues associated with celiac disease, such as infertility, miscarriages, and birth defects, can also be explained by glyphosate."

Roundup and Celiac or Gluten Sensitivity

There's no question that glyphosate use is growing rapidly. Monsanto Company markets it in conjunction with genetically modified "Roundup-ready" seeds designed to resist glyphosate's effects. Farmers plant the genetically modified seeds and then use the glyphosate to kill weeds in the fields, knowing that the crops themselves will not be affected by the otherwise lethal herbicide.

It's true that dousing everything we grow and then eat in massive doses of chemicals (including glyphosate) may have some as-yet-undiscovered health effects. However, the World Health Organization downplayed any cancer risks when it issued a report in 2016 stating that glyphosate is "unlikely to pose a carcinogenic risk to humans from exposure through the diet."

No researchers have performed a study looking at whether glyphosate might cause celiac disease or non-celiac gluten sensitivity. Samsel and Seneff's paper did not involve any laboratory research; instead, it's hypothetical.

A Word From Verywell

Despite the anecdotal evidence and reasoning laid out in Samsel and Senoff's paper, there's still no direct causal link between glyphosate and celiac disease or non-celiac gluten sensitivity.

The case they make is circumstantial, based on the reasoning that "if A causes B and B causes C, then A causes C." In this case, there are far too many other potential variables involved in the reasoning to hold up.

It is possible that overuse of pesticides and herbicides—including glyphosate—could be contributing to our epidemic of celiac disease and non-celiac gluten sensitivity. But researchers haven't shown that any link, let alone a causal link, exists.

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Samsel A, Seneff S. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdiscip Toxicol. 2013;6(4):159-84. doi: 10.2478/intox-2013-0026

  2. Caio G, Volta U, Sapone A, et al. Celiac disease: a comprehensive current review. BMC Med. 2019;17(1):142. doi: 10.1186/s12916-019-1380-z

  3. Vainio H. Public health and evidence-informed policy-making: The case of a commonly used herbicide. Scand J Work Environ Health. 2020;46(1):105-109. doi: 10.5271/sjweh.3851

  4. United States Department of Agriculture, Economic Research Service. ERS Charts of Note: Fertilizers & Pesticides.

  5. World Health Organization. Joint FAO/WHO Meeting on Pesticide Residues.

Additional Reading

By Jane Anderson
Jane Anderson is a medical journalist and an expert in celiac disease, gluten sensitivity, and the gluten-free diet.