The Gut Puzzle: Is It Gluten or Glyphosate to Blame for Your Tummy Troubles?

Intolerance to gluten, and the incidence of autoimmune disorder coeliac disease are on the rise. It’s hard to miss the growth of ‘gluten free’ endorsements on food packaging, and the wide selection of gluten free products available to us. Meanwhile, in the media and in the health space we are hearing more about glyphosate; a broad-spectrum agricultural herbicide and its implications in the cause of various cases of cancer.  

Here, we will address the possibility that glyphosate may also contribute to, or even explain many of the symptoms of coeliac disease.

What do we currently know about Coeliac Disease?

On average, coeliac disease affects 1% of people globally. In Australia, it is estimated that 1 in 70 people have coeliac disease, and that 80% of these cases have not yet been diagnosed [1]. In the U.S. there has been a 4 times increase in prevalence over the last 50 years [3]. Improvements in testing accuracy have certainly led to more diagnoses; however, there has also been a true rise in incidence [1, 3, 6]. The possible reasons behind the growth in coeliac disease is a much-studied area in the scientific community at present.

Individuals with coeliac disease experience an immune response to gluten; a protein found in some grains like wheat, barley and rye. When ingested, gluten can trigger a range of mild to severe symptoms including gastrointestinal irregularities and pain, nausea, fatigue, anaemia, micronutrient deficiencies, weight changes, mouth ulcers, irritability, skin irregularities such as rashes and bruising. A strict gluten-free diet typically alleviates symptoms [1, 3, 6].

Nutrient deficiencies are associated with coeliac disease due to inflammation of the upper small intestine; causing the microvilli lining the intestine to flatten and absorb nutrients with less efficiency [6].

Other associated conditions include an increased risk of non-Hodgkin’s lymphoma, impaired reproductive health, and birth defects in children of coeliac mothers [6].

There are evident genetic links in coeliac disease, with almost all patients having variants the HLA-DQA1 and HLA-DQB1 genes [1, 3]. It is thought that in addition to the presence of the genetic variation and gluten consumption, the microbiome and environmental factors are also important in the development of the condition [3].

Glyphosate and Coeliac Disease

In a 2013 study, researchers Samsel and Seneff proposed that many key clinical symptoms and associated disorders of coeliac disease could be explained by long-term exposure to glyphosate rather than the ingestion of gluten. Glyphosate is a popular agricultural herbicide and the active ingredient in Monsanto's product Roundup, which was acquired by Bayer in 2018. [5, 6].

The authors state that the in the U.S., where increases in coeliac disease are particularly high, glyphosate is the most popular herbicide and has been so since 2001. Furthermore, the U.S. represents one quarter of the total herbicide usage globally. They also state that glyphosate is the most popular herbicide worldwide, and became so due to its low-cost and ill perceived lack of toxicity [6].   

Their theory is that the effects of glyphosate contribute to the expression of coeliac disease through a variety of mechanisms including:

• Cytochrome P450 enzyme inhibition

• Chelation of transition metals, selenium and sulphur

• Disrupted amino acid synthesis

• Altering gut microbiome balance

[6]

So, how worried should we be about glyphosate?

Glyphosate herbicide exposure at an occupational level has been found to be associated with both non-Hodgkin’s lymphoma and birth defects. Occupational exposure, however, does not reflect typical dietary levels of exposure as concentrations used in the agricultural industry are far greater. The prevalence of gastrointestinal disorders such as coeliac disease has increased in line with the high consumption of processed foods, animal-based protein, and excessive sugars and fats that feature heavily in typical Western diets. That’s not to say, however, that exposure to toxic chemicals such as glyphosate does not play a part in altering our gut microbiome. At this stage, more research is needed to further explore this theory [5].

Source: Walsh, Hill & Ross (2023). https://doi.org/10.1080/19490976.2023.2263935

It is important to be wary here… Evidence exists for and against the safety and use of glyphosate herbicides in the agricultural industry. Companies that commercialise glyphosate herbicides look to profit from scientific and public approval, while other parties such as some non-Government health organisations and environmental agencies report that the chemical has toxic effects at even below the regulatory levels. The research conducted by Samsel and Seneff has also been challenged in subsequent articles, one reason being that the connections between glyphosate and coeliac disease were based on animal studies and cannot be applied to humans. Authors of a 2017 review of glyphosate toxicity believe that the conclusions drawn by Samsel and Seneff in regards to glyphosate and coeliac and other chronic diseases are not supported by current scientific evidence and deem their reasoning inappropriate [5].

One thing we can be certain of is that we will continue to see glyphosate in the media. Despite assurances from Monsanto of Roundup, and therefore glyphosates safety, U.S. courts have recently begun hosting a string of lawsuits against the agri-chemical giant. As of October 2019, there were over 42,000 plaintiffs seeking compensation over links to various cancers [4].

Update: As of September 2024, Monsanto has settled nearly 100,000 lawsuits related to Roundup, amounting to approximately $11 billion in payouts. Bayer have accomplished this by negotiating block settlements with lawyers representing major plaintiffs and by reaching agreements before trial. While these settlements cover nearly two-thirds of all Roundup claims, it is estimated that around 54,000 active lawsuits are still ongoing [7].

Glyphosate in the Australian diet

Glyphosate-based herbicides are currently used in Australian agriculture to control weeds. The Australian Pesticide and Veterinary Medicine Authority (APVMA) regulates the use of glyphosate and in collaboration with Food Standards Australia New Zealand (FSANZ), sets limits to how much chemical residue is acceptable in our food. It begs the question though... Can a safe level of a toxin truly be determined? Isn't this somewhat paradoxical?

The Australian Total Diet Study conducted in 2019 found that glyphosate was present at only low levels in the food supply, and that 77% of food products tested were free of glyphosate. Based on these results FSANZ state that glyphosate does not pose a health risk to the Australian population [2]. 

At this stage, exercising caution is sensible and as always, we should continue to do our own research. To avoid exposure to glyphosate you can include more organic food products in your diet, which are free from chemical herbicides and pesticides.

Note: In 2023 the Australian government referred the APVMA to an independent review for serious misconduct and systemic issues relating to conduct and governance

Originally published: 2020.

Words by Iydi Willis (RPHNutr) for Well College Global.

Well College Global are Australia's top provider of credible, evidence based health and coaching courses with pathways to nutrition degrees.

References

1. COELIAC AUSTRALIA. 2019. Coeliac Disease [Online]. Available: https://www.coeliac.org.au/coeliac-disease/ [Accessed 23 October 2019].

2. FOOD STANDARDS AUSTRALIA NEW ZEALAND. 2019. Glyphosate [Online]. Available: http://www.foodstandards.gov.au/consumer/chemicals/Pages/Glyphosate.aspx [Accessed 23 October 2019].

3. LEBWOHL, B., SANDERS, D. S. & GREEN, P. H. R. 2018. Coeliac disease. The Lancet, 391, 70-81.

4. LOH, T. & FEELEY, J. 2019. Bayer’s Roundup Headache Grows as Plaintiffs Pile Into Court. Bloomberg, 29 October 2019.

5. MESNAGE, R. & ANTONIOU, M. N. 2017. Facts and Fallacies in the Debate on Glyphosate Toxicity. Frontiers in public health, 5, 316-316.

6. SAMSEL, A. & SENEFF, S. 2013. Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance. Interdisciplinary toxicology, 6, 159-184.

7. MILLER, RV. 2024. Monsanto Roundup Lawsuit Update [Online[. Available: https://www.lawsuit-information-center.com/roundup-lawsuit.html. [Accessed 12 October 2024].