Gluten – what is it? Who should avoid it? - Blog

As early as the 1940s, a Dutch paediatrician described an improvement in the health of children with coeliac disease following the elimination of wheat from their diet. His observations contributed to the subsequent discovery of a link between gluten consumption and the symptoms of the disease. Today, gluten is one of the best-understood components of cereals. Although for most people it is a normal part of their daily diet, in certain medical conditions it is necessary to restrict or completely eliminate it.

gluten

What is gluten and in which products is it found?
Who should avoid gluten for health reasons?
Is a gluten-free diet beneficial for people without gluten intolerance?
FAQ – Frequently Asked Questions

What is gluten and in which products is it found?

Gluten is a collective term for storage proteins found in certain cereals, primarily wheat, rye and barley. In wheat, its main components are gliadins and glutenins, whilst rye contains secalins and barley contains hordeins. These proteins differ in structure but share similarities that are significant for people with coeliac disease. Gluten is not a separate food additive, although it can also be extracted from flour and used as a processing aid.

Its main sources are wheat and rye bread, pasta, semolina, couscous, bulgur and baked goods made from traditional flours. Gluten is also found in spelt and durum wheat, which, despite their different names, are cereals containing these proteins. Ingredients derived from gluten-containing cereals are also used in the production of sauces, breaded meat products, confectionery, spice mixes and certain ready-made products. Barley malt may also be a source of gluten. Its presence cannot therefore be assessed solely on the basis of the product’s appearance or type.

Estimated gluten content in 100 g of selected cereal products

Product	Gluten (g/100 g)
Wheat bread	5-8 g
Wheat flour	7-11 g
Dried wheat pasta	8-12 g

Who should avoid gluten for health reasons?

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The most important indication for a strict gluten-free diet is coeliac disease, a chronic autoimmune condition that develops in genetically predisposed individuals. Consumption of gluten leads to an abnormal immune response and damage to the lining of the small intestine. A characteristic consequence is the atrophy of the intestinal villi, which can impair the absorption of nutrients.

Symptoms of coeliac disease include, amongst others, chronic diarrhoea, bloating, abdominal pain, weight loss and anaemia resulting from iron deficiency. However, the condition may present without any obvious gastrointestinal symptoms. One of its manifestations is herpetiform dermatitis, known as Duhring’s disease, in which a gluten-free diet is also essential.

A separate condition is wheat allergy, in which the reaction may be triggered by various proteins in the grain, not just gluten. Symptoms may include urticaria, pruritus, gastrointestinal symptoms and, in severe cases, anaphylaxis. The mainstay of treatment is to avoid the allergen identified during diagnosis; however, a wheat allergy does not always require the exclusion of all gluten-containing cereals.

Non-coeliac gluten or wheat sensitivity is also recognised. A diagnosis is considered after ruling out coeliac disease and wheat allergy, and assessing the relationship between diet and symptoms. There is no single laboratory test to confirm this sensitivity. Before starting a gluten-free diet, a diagnosis of coeliac disease must be carried out, as excluding this protein too early may result in false-negative results.

Is a gluten-free diet beneficial for people without gluten intolerance?

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In people without a diagnosed gluten-related condition, eliminating gluten is not considered an essential part of a healthy diet. No convincing benefits have been demonstrated from the exclusion of gluten alone in terms of weight loss, improved metabolism or general health. Any change in well-being following a switch to a gluten-free diet may also result from simultaneous changes to other components of the diet.

Eliminating traditional cereal products without adequately replacing them with other sources of nutrients may reduce the intake of dietary fibre, folate and certain minerals. Some commercially available gluten-free products also contain less protein and fibre than their traditional counterparts.

"Gluten in itself is not harmful to most people. The problem arises primarily in patients with coeliac disease, a wheat allergy or certain forms of food hypersensitivity. Therefore, before excluding gluten from the diet, it is worth determining whether it is actually responsible for the symptoms. Unnecessary elimination may not only hinder diagnosis but also limit the variety of your daily diet." Anna Zięba – Dietitian

FAQ – Frequently Asked Questions

What is gluten and where is it found?

Gluten is a collective term for proteins found in wheat, rye and barley. It is found, amongst other things, in traditional bread, pasta, semolina, couscous, bulgur and many baked goods. It may also be an ingredient in some sauces and ready-made food products.

Is gluten harmful to health?

For most people, gluten is a normal part of the diet and there is no need to avoid it. However, it can cause health problems in people with coeliac disease, a wheat allergy or non-coeliac gluten or wheat sensitivity.

What are the symptoms of gluten intolerance?

The symptoms depend on the type of condition. Coeliac disease can cause abdominal pain, bloating, diarrhoea, anaemia and chronic fatigue. However, similar symptoms can have many other causes, so they do not in themselves confirm a problem with gluten.

How can I find out if I have a gluten intolerance?

Diagnosis depends on the suspected condition. If coeliac disease is suspected, the doctor will usually order tests for IgA-class antibodies against tissue transglutaminase and an assessment of total IgA. In certain situations, further tests are required. It is important not to cut out gluten before diagnosis without consulting a doctor.

Is it possible to have coeliac disease without realising it?

Yes. Coeliac disease does not always cause the characteristic intestinal symptoms. In some people, anaemia, fatigue or other non-intestinal symptoms predominate, and sometimes the condition progresses without any obvious symptoms.

Does gluten cause bloating and abdominal pain?

For some people, foods containing gluten may be associated with such symptoms, but gluten itself is not always to blame. Research suggests that in some people reporting gluten sensitivity, the symptoms may be linked to fructans – fermentable carbohydrates found in wheat, amongst other foods.

Is a gluten-free diet healthier than a normal diet?

There is no convincing evidence that simply eliminating gluten improves the health of people who have no medical reason to avoid it. The value of a diet is determined primarily by its overall composition, variety and adequate supply of nutrients.

Does cutting out gluten help you lose weight?

Simply eliminating gluten is not a proven method of weight loss. Any changes observed after switching to a gluten-free diet may result from a simultaneous change in the quantity and type of food consumed, rather than from the removal of gluten.

Do oats contain gluten?

Pure oats contain avenins, which are proteins different from the typical gluten proteins found in wheat, rye and barley. The problem may be contamination of oats with these cereals during cultivation or production. Therefore, people with coeliac disease should choose appropriately labelled gluten-free oats and discuss their tolerance with a doctor or dietitian.

Is spelt gluten-free?

No. Spelt is a variety of wheat and contains gluten. It is therefore not suitable for people with coeliac disease, even though it is sometimes presented as an alternative to ordinary wheat.

Do rice, potatoes and buckwheat contain gluten?

Rice, potatoes and buckwheat are naturally gluten-free. They can form part of a person with coeliac disease’s diet, but in the case of processed products, it is important to check the ingredients and the risk of gluten contamination.

Do you have to avoid gluten for life?

In the case of coeliac disease, it is essential to strictly adhere to a gluten-free diet for life. With a wheat allergy, the rules for elimination depend on the diagnosis and course of the condition, whilst in non-coeliac gluten sensitivity, the approach is tailored to the individual. Not every reaction to wheat products necessitates the permanent elimination of all sources of gluten.

Sources:

Jansson-Knodell, C. L., & Rubio-Tapia, A. (2024). Gluten-related Disorders From Bench to Bedside. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association, 22(4), 693–704.e1. https://doi.org/10.1016/j.cgh.2023.09.042
Skodje, G. I., Sarna, V. K., Minelle, I. H., Rolfsen, K. L., Muir, J. G., Gibson, P. R., Veierød, M. B., Henriksen, C., & Lundin, K. E. A. (2018). Fructan, Rather Than Gluten, Induces Symptoms in Patients With Self-Reported Non-Celiac Gluten Sensitivity. Gastroenterology, 154(3), 529–539.e2. https://doi.org/10.1053/j.gastro.2017.10.040
Mármol-Soler, C., Matias, S., Miranda, J., Larretxi, I., Fernández-Gil, M. D. P., Bustamante, M. Á., Churruca, I., Martínez, O., & Simón, E. (2022). Gluten-Free Products: Do We Need to Update Our Knowledge?. Foods (Basel, Switzerland), 11(23), 3839. https://doi.org/10.3390/foods11233839