Why is Gluten Bad? | The Ins and Outs | Sensitivity Check
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Seemingly overnight, gluten went from being an unknown component in bread, pasta, and other wheat-based products to a major cause for concern. Suddenly, supermarket shelves and restaurant menus were filled with gluten-free options, while health bloggers and nutritionists warned of the long-term dangers of gluten.

Indeed, according to a 2020 review, the incidence of coeliac disease (an autoimmune disease triggered by gluten) has increased an average of 7.5% per year for several decades. Correspondingly, a sizeable proportion of Western populations are now choosing gluten-free lifestyles, including one-third of Americans and 15% of Brits.

It raises the question, why is gluten bad for you?

What is Gluten?

Gluten is a protein found primarily in wheat, barley, and rye, making it a common component in foods such as bread, pasta, and cereal. It gives dough its elasticity, helping it rise and maintain its shape, and often gives the final product a chewy texture.

Gluten is safe for most people; however, for those with conditions like coeliac disease, wheat allergy, or non-celiac gluten sensitivity, it can cause adverse reactions. These reactions range from mild digestive discomfort to severe allergic responses.

Gluten-free diets exclude foods containing these grains, using substitutes like rice, corn, or gluten-free oats instead.

Conditions Involving Gluten

Several conditions attribute their underlying cause to gluten. While some of the conditions are little more than a nuisance, others are highly severe and can lead to long-term complications.

Here’s a quick overview of conditions that involve sensitivity or reactions to gluten:

  1. Coeliac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine, interfering with nutrient absorption.
  2. Non-Coeliac Gluten Sensitivity (NCGS): Causes symptoms similar to celiac disease, including gastrointestinal complaints, fatigue, and joint pain, but without the intestinal damage associated with celiac disease.
  3. Wheat Allergy: An allergic reaction to proteins found in wheat, including but not limited to gluten. Symptoms can range from mild (rashes, hives) to severe (anaphylaxis).
  4. Dermatitis Herpetiformis: An itchy, blistering skin disease that stems from gluten ingestion and is linked to coeliac disease.
  5. Gluten Ataxia: An autoimmune disorder affecting certain nerve tissues and causing problems with muscle control and voluntary muscle movement, which is triggered by gluten consumption.

Why is Gluten Bad For You?

The most common theory behind rising gluten sensitivity and coeliac disease is inflammation. The proteins in gluten – gliadin and glutenin – are part of the prolamin superfamily of proteins. According to the theory, in some individuals, exposure to these proteins triggers an inflammatory response.

So, why are some people affected and not others?

The answer lies in people’s underlying genetics. Individuals that carry the HLA-DQA1 and HLA-DQB1 genes have a greater risk of developing coeliac disease. These genes are part of a genetic family known as the human leukocyte antigen (HLA).

Leukocyte is just another term for white blood cells, and these genes help regulate the immune system’s foreign invader detection system. The genetic variants are susceptible to wrongly flagging gluten as an invader, leading to a severe inflammatory response.

Why Have Gluten Sensitivity Rates Been Rising?

Why Have Gluten Sensitivity Rates Been RisingSo far, so good – genes are responsible for increasing the risk of gluten-related conditions in some individuals. However, that still doesn’t explain why coeliac disease incidence has risen. Nor does it explain the cause of non-coeliac gluten sensitivity.

Several theories exist for the increase in gluten sensitivity. They range from modified cereal grains to FODMAPs, excessive antibiotic usage, and even pesticides. Let’s go through each one:

Cereal Grains

First, changing cereal grains. An extensive study of sixty German winter wheat cultivars from over a century observed a slight decrease in protein and gliadin contents. However, there was no change in gluten contents to support an increased immunostimulatory effect. So, we can strike it from our list of culprits.


Next, we have fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, or FODMAPS. Present in gluten-containing grains – mainly as fructans – they’re a popular candidate for NCGS. However, although fructan intolerance may be involved in non-coeliac gluten sensitivity, they do not explain extra-digestive symptoms nor the spike in coeliac disease. A 2019 review concluded that they may cause IBS-like symptoms but not immune activation.


Antibiotics, meanwhile, have a better evidence base. Several studies have found infections or antibiotic use in early life increases the odds of developing coeliac disease. However, their usage does not match the recent spikes in incidence nor explain the predominance of the condition in Western nations.


Glyphosate is a widely used herbicide found in products like Roundup. It is employed to eliminate annual broadleaf weeds and grasses that interfere with crops. With its low toxicity in mammals, glyphosate saw a surge in use in the Western world, particularly after 2000.

A landmark 2013 analysis raised concerns about glyphosate’s safety, suggesting it might contribute to conditions like celiac disease through several mechanisms:

  1. It could inhibit cytochrome P450 enzymes vital for detoxifying environmental toxins.
  2. It might lead to deficiencies in essential amino acids and minerals.
  3. It could disrupt the gut microbiome.

The third option aligns with observations in livestock exposed to glyphosate, showing increased intestinal inflammation and an imbalance in critical gut bacteria.

However, further studies are necessary, as some research disputes glyphosate’s impact on enzyme inhibition and nutrient deficiencies, though the potential for altering the gut microbiome remains less contested.

Get Tested for a Gluten Sensitivity

Gluten sensitivity presents with bloating, stomach pain, diarrhoea, constipation, and much more. If you suspect you may be affected, you should get tested.

The Individual Ultimate Test analyses a hair sample for 975 possible sensitivities, including gluten. After sending off your hair sample, you’ll receive the results within 7 business days, alongside a complete report detailing our findings.

Buy the Individual Ultimate Test today and find out if gluten is bad for you.

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This article was written by Joseph, our Health and Science Copywriter and Qualified Doctor

You can read more about them on their page.