Coeliac Disease and Diet: A Guide to Gluten-Free Living

About one per cent of people in Europe have coeliac disease, many of them without knowing it. Women are affected about twice as often as men, and the autoimmune disease can begin at any age. To this day, the only effective treatment is a lifelong, strictly gluten-free diet. This guide helps you get started and summarises the new approaches research has to offer in 2026.

Diagnosis first, then the diet

A common mistake: the diet is changed before the condition has been investigated. Antibodies and mucosa then return to normal, and the diagnosis can no longer be made reliably. According to the German S2k guideline, the antibody against tissue transglutaminase (tTG-IgA) is first measured in the blood together with total IgA while gluten is still being eaten. In adults, the diagnosis is usually confirmed by a tissue sample from the duodenum. In children with very high antibody levels, biopsy can be dispensed with under certain conditions. You can read more about causes, symptoms and diagnosis in our article Coeliac disease – an autoimmune disease.

Why even traces can do harm

In coeliac disease, the immune system reacts to certain components of gluten (gliadins). The enzyme tissue transglutaminase modifies these proteins in such a way that they trigger an immune response in people with the genetic markers HLA-DQ2 or HLA-DQ8. The result is inflammation in which the small intestinal villi flatten and nutrients are absorbed less well. Studies show that even regular amounts in the range of a few dozen milligrams of gluten per day can trigger mucosal changes in sensitive people. One slice of wheat bread contains several grams of gluten.

What is allowed and what is not?

The most important rule for everyday life is: always read the list of ingredients. Gluten-containing cereals are among the 14 major allergens that must be highlighted in the list of ingredients in the EU.

Naturally gluten-free	Rice, wild rice, maize, millet, buckwheat, amaranth, quinoa, teff; potatoes, pulses, chestnuts, nuts and seeds, and flours and starches made from them (e.g. potato, maize, rice and tapioca starch)
Contains gluten – avoid	Wheat (including spelt, green spelt, einkorn, emmer, kamut), rye, barley, triticale and flours made from them, semolina, pearl barley, couscous, bulgur, breadcrumbs, baked goods, pasta, beer, malt beer, malt coffee
Oats – only special ones	Ordinary oats are usually contaminated with wheat. Oats explicitly labelled gluten-free are tolerated by most of those affected, but should only be introduced after consultation and preferably after the mucosa has healed.
Caution, often hidden	Ready-made sauces, seasoning mixes, stock cubes, soy sauce, fruit yoghurt, sweets, ice cream, chips, crisps, sausage products, ready meals, breaded products – and medicines (check the excipients, ask at the pharmacy)

Unprocessed foods are naturally gluten-free: fruit, vegetables, salad, potatoes, pulses, meat, fish, eggs, milk and natural dairy products, oils, butter, nuts, pure spices, sugar, honey as well as coffee, tea, juices, wine and sparkling wine.

Reading labels correctly

• “Gluten-free”: under EU law (Implementing Regulation (EU) No 828/2014), no more than 20 mg of gluten per kilogram of food. This value is considered safe for people with coeliac disease.
• “Very low gluten”: no more than 100 mg per kilogram – only suitable to a limited extent for people with coeliac disease.
• Crossed grain symbol: a protected licence symbol, awarded in Germany by the German Coeliac Society (DZG). Products bearing this symbol are checked regularly.
• “May contain traces of gluten”: a voluntary note on possible contamination during manufacture. Those affected should avoid such products. Conversely, the absence of the note does not guarantee that a product is gluten-free.

Avoiding nutrient gaps

At diagnosis, deficiencies are often already present because the damaged mucosa absorbs nutrients less well. Deficits of iron, folic acid, vitamin B12, vitamin D and calcium are typical. They should be checked at diagnosis and during follow-up and specifically corrected. In the long term, attention should be paid to an adequate intake of dietary fibre, as many gluten-free substitute products consist of refined starches. Good sources are pulses, vegetables, fruit, nuts, seeds, buckwheat, millet, quinoa and gluten-free brown rice. Because of the increased risk of osteoporosis, bone density is also often measured in adults.

Gluten-free convenience products: practical, but not automatically healthy

Gluten-free bread, pasta, cakes or pizza are available in supermarkets, chemists, health food shops and online. To make them light and moist, they often contain more fat, sugar and starch and less fibre than gluten-containing versions. Anyone who wants to maintain their weight should take this into account. Specialist products are also considerably more expensive. Baking yourself and cooking fresh takes more time, but is cheaper and allows a higher proportion of wholegrain and fibre. Gluten-free flours and starches, rice noodles or gluten-free soy sauce are also available in Asian supermarkets.

Tips for the kitchen and everyday life

• Avoid contamination: your own toaster, your own baking trays and sieves, separate butter and spreads, sealable storage containers. Clean work surfaces thoroughly, especially after handling flour (flour dust spreads widely).
• Baking without gluten: gluten-free doughs are runnier and need binding agents such as psyllium husks, locust bean gum or xanthan, often also more liquid and eggs. A bowl of water in the oven prevents drying out.
• Stocks: bread and baked goods freeze well. Home-baked goods are often moist and go mouldy more quickly.
• Restaurants: since December 2014, catering businesses have been required to provide information on allergens. Nevertheless, explicitly mention coeliac disease and ask about separate preparation, for example regarding frying fat or pasta water.
• Travel: translation cards for restaurants and a list of suitable products in the destination country make holidays easier.
• Counselling: qualified nutritional counselling after diagnosis is highly recommended. Health insurers often contribute to the costs if it is recommended by a doctor.
• Exchange: the German Coeliac Society (DZG), the Austrian Coeliac Society (Österreichische Arbeitsgemeinschaft Zöliakie) and the IG Zöliakie of German-speaking Switzerland offer information, product lists, apps and local groups.

Coeliac disease in children and the introduction of gluten

For a long time it was debated whether a particular timing of gluten introduction in infancy or breastfeeding could protect against coeliac disease. Large studies have not confirmed this. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) recommends introducing gluten between the completed fourth and twelfth months of life and not giving large amounts in the first weeks. Breastfeeding is valuable for many other reasons, but does not prevent coeliac disease. Children with coeliac disease can develop normally if they follow the diet consistently.

Consequences of untreated coeliac disease

If coeliac disease is not recognised or the diet is not followed, the following may result:

• deficiency of iron, folic acid, vitamin B12, vitamin D, vitamin K and calcium, anaemia,
• in children, growth and developmental disorders,
• osteoporosis, tooth enamel defects, raised liver values,
• menstrual disorders, reduced fertility, and in pregnancy an increased risk of premature birth and low birth weight,
• an increased risk of certain lymphomas of the small intestine. With a consistent diet, this risk falls significantly.

Research: what is new in treatment?

There is no approved medicine as yet. However, several approaches are being tested in clinical trials – usually with the aim of supplementing the diet and protecting against accidental gluten intake, not replacing it.

• Transglutaminase 2 inhibitors (ZED1227/TAK-227): the active substance developed in Germany by Zedira and Dr. Falk Pharma blocks the enzyme that makes gluten “visible” to the immune system. In a phase 2 trial (published in 2021 in the New England Journal of Medicine), it protected the small intestinal mucosa of patients who ate 3 g of gluten daily from damage. A follow-up analysis in Nature Immunology (2024) showed that the gluten-induced inflammatory signals in the mucosa largely normalised. Since 2022, the company Takeda has been involved in further development. Further trials, including in people whose symptoms persist despite the diet, have begun.
• Enzymes that break down gluten in the stomach (glutenases): these are intended to render accidentally ingested gluten harmless. Results so far have been mixed.
• Tolerance therapies: approaches intended to accustom the immune system specifically to gluten, for example using nanoparticles, are being tested in early trials.
• Other approaches: blocking inflammatory messengers such as interleukin-15 and agents intended to strengthen the intestinal barrier. Development of the active substance larazotide was discontinued in 2022 after an interim analysis of the phase 3 trial.

It is likely to be years before one of these agents is approved. A gluten-free diet remains the basis of treatment.

Frequently asked questions

Is gluten intolerance the same as coeliac disease?

No. In addition to coeliac disease, there is wheat allergy and non-coeliac gluten/wheat sensitivity. The treatment and the necessary strictness of the diet differ. This is why a medical assessment is important.

May I make an occasional exception?

No. Even without noticeable symptoms, gluten can damage the mucosa and have long-term consequences.

How quickly will I feel better on the diet?

Many symptoms improve within a few weeks. In adults, the mucosa often needs months to years to heal completely. If symptoms persist despite the diet, hidden sources of gluten and other causes should be looked for.

Note: This article is for general information and does not replace medical advice or nutritional counselling. First version: December 2018, last revised and updated by the editorial team: October 2026.

Sources

• DGVS u. a.: S2k-Leitlinie Zöliakie, AWMF-Register 021-021 (2022)
• Durchführungsverordnung (EU) Nr. 828/2014 über Angaben zur Abwesenheit oder zum reduzierten Vorhandensein von Gluten
• Schuppan D et al.: A Randomized Trial of a Transglutaminase 2 Inhibitor for Celiac Disease. New England Journal of Medicine 2021
• Deutsche Gesellschaft für Immunologie: Neue Erkenntnisse für die Behandlung der Zöliakie (Nature Immunology, 2024)
• Takeda, Zedira, Dr. Falk Pharma: Collaboration and licensing agreement (2022)
• Szajewska H et al.: Gluten Introduction and the Risk of Coeliac Disease: A Position Paper by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition. Journal of Pediatric Gastroenterology and Nutrition 2016
• Deutsche Zöliakie Gesellschaft e. V.