What is Coeliac Disease? 
Your Questions Answered...
or read: What is Dermatitis Herpetiformis?

Frequently asked questions about Coeliac Disease
by: Dr Nick Kennedy
Department of Clinical Medicine, Trinity College Dublin.

1. What is coeliac disease?
2. What is gluten?
3. What can I eat?
4. How do people get coeliac disease?
5. How common is coeliac disease?
6. How would I know if I had coeliac disease?
7. How is coeliac disease diagnosed?
8. Can coeliac disease be cured?
9. How is coeliac disease treated?
10. Now that my biopsy is back to normal, can I relax my gluten-free diet?
11. How much gluten can I eat without harm?
12. Why avoid gluten if I have no symptoms when I eat it?
13. What are the health implications of coeliac disease?
14. Can coeliac disease be prevented?
15. I have been told that I am allergic to wheat. Does that mean I have coeliac disease?
16. Where can I get practical advice and help?

1. What is coeliac disease?
Coeliac Disease is a condition in which there is a persistently abnormal immunological reaction to dietary gluten, giving rise to tissue damage in the presence of gluten In order to follow a strict gluten free diet, a Coeliac must not eat foods that contain any form of gluten, which is found in WHEAT, BARLEY, RYE and OATS. Eating gluten causes the lining of the small intestine to become damaged thus reducing the coeliacs ability to absorb certain foods. The only treatment generally required is adhering to a strict gluten-free diet for life after a positive diagnosis has been made. Medicine or drugs are not required. The extent of the reaction to gluten and the degree of resultant damage is variable between and within individuals.

2. What is gluten?
"Gluten" is a general term used for a particular type of protein (proline-rich protein, or prolamin) found in wheat. This protein gives dough made from wheat flour it's elasticity and plasticity, which gives it good baking properties. The various strains of wheat have varying gluten content, so different flours may have more or less gluten depending on which type of wheat they are derived from. For example, "strong" flour (used for bread) has a higher gluten content than "soft" flour (used for cakes). In the context of coeliac disease, the term "gluten" is also loosely used to include similar proteins in rye, barley and oats. The prolamins in wheat (i.e. gliadin), rye (i.e. secalin), barley (i.e. hordein) and oats (i.e. avenin) are not identical, although they are closely related in structure.

3. What can I eat
Many foods are naturally gluten-free such as unprocessed fruit, vegetables, milk, eggs, rice, fish and meat. The main foods to be avoided include breads, biscuits, cakes, pastries, pizzas, pasta, sausage meats, spaghetti, certain soups, certain sauces, certain gravies and certain breakfast cereals. It is also important when cooking that care is taken not to use breadcrumbs, or to dust meat, fish or poultry with flour before cooking. Sauces and gravies that are thickened with flour or starch containing gluten should be avoided. Wheat products such as wheat flour, wheat bran, noodles, spaghetti, macaroni, ravioli should be avoided. Coeliacs should carefully study the listed ingredients on food packet labels, keeping a constant lookout for terms such as cereal binder, noodles, starch, starch, filler etc. Coeliacs should also be aware that even 'safe' products might be changed by processing, cooking methods, embellishments and additives.

However the following are gluten free and could be used as a substitute; Ground rice, rice flour, cornflour, maize flour, potato flour, soya flour, arrowroot, rice, sago, tapioca, sweetcorn, maize, buckwheat, millet, commercial gluten free flours and breads which comply with the International Standard for gluten-free food (Codex Alimentarius)

4. How do people get coeliac disease?
There is clear evidence of a genetic predisposition to developing this condition, although the onset of the abnormal reaction to gluten is triggered in susceptible people by an environmental event. When this reaction is initiated, there is a permanent intolerance to gluten (although the vigour of the reaction to gluten may fluctuate with time).

A genetic predisposition to coeliac disease is clear from a familial tendency, and a clear link exists between coeliac disease and certain tissue types (e.g. HLA DQ2 among others). HLA markers are found on white blood cells and are similar, in a way, to other markers found on red blood cells, which are used to distinguish between blood groups (e.g. A, B, O). To date, genetic research has failed to identify a specific gene that confers coeliac disease susceptibility.

Several types of event have been proposed to trigger the abnormal immune reactivity to gluten in coeliac disease, but the process is not yet understood. It seems that the introduction of gluten to the diet during weaning (too much or too early) may have an influence, and a variety of viral infections have also been implicated.

5. How common is coeliac disease?
Coeliac disease is more common than most people realise. Estimates of prevalence have been made by screening various population groups with blood tests for specific antibodies that appear in active coeliac disease. In some studies, screening results have been confirmed by taking biopsies of the small intestinal lining to look for damage typical of coeliac disease.

Several such screening studies suggest that between 1 in 200 and 1 in 300 people of northern European extraction have coeliac disease. It has been believed for a long time that Irish people have a higher than average risk of coeliac disease. Research in Northern Ireland (reported in 1998) suggests that as many as 1 in 122 individuals there have coeliac disease. Earlier data from Galway (Gumaa et al, 1997) suggest that the incidence of coeliac disease in children is declining (perhaps due to changes in weaning practices with time?), but that the incidence in adults is increasing (perhaps to greater awareness and increasing rate of diagnosis?). Nationwide figures are not available.


Gumaa, S. N., McNicholl, B., Egan Mitchell, B., Connolly, K. & Loftus, B. G. (1997). Coeliac disease in Galway, Ireland 1971-1990. Ir Med J, 90(2), 60-1.

Johnston, S. D., Watson, R. G., McMillan, S. A., Sloan, J. & Love, A. H. (1998). Coeliac disease detected by screening is not silent--simply unrecognized. QJM, 91(12), 853-60.

6. How would I know if I had coeliac disease?
Coeliac disease is under-diagnosed because it is often not obvious. There may be a tendency to recurrent tiredness and anaemia, to vague recurrent gastrointestinal complaints or to recurrent bouts of diarrhoea. The "classical" case has diarrhoea, weight loss, anaemia, recurrent mouth ulcers, etc. If there is a family history of coeliac disease (or any other auto-immune disease), then investigation of recurrent anaemia or recurrent gastro-intestinal complaints should include tests to look for coeliac disease. Anyone with dermatitis herpetiformis should be tested for coeliac disease.

7. How is coeliac disease diagnosed?
Blood tests for antibodies against alpha-gliadin (AGA), endomysial antibody (EmA) or tissue transglutaminase (tTG) are helpful in screening for coeliac disease, but are insufficient to make a definite diagnosis. The only way to diagnose coeliac disease properly is by taking a sample (biopsy) of tissue from the lining of the small intestine (usually the duodenum, sometimes the jejunum) for examination under the microscope. The standard way to take the biopsy is through a gastroscope. The procedure of upper gastro-intestinal endoscopy (or oesophagogastroduodenoscopy, OGD) is usually carried out as an outpatient. An OGD and biopsy takes about 10-15 minutes (excluding waiting times!). To confirm the diagnosis correctly, a biopsy is taken when on a normal (gluten-containing) diet and may be repeated after a period of gluten exclusion to make sure that the initial abnormalities are responding to treatment. It may take over a year for the gut lining to recover completely on a gluten-free diet.

8. Can coeliac disease be cured?
There is no cure for coeliac disease, but it can be effectively controlled by dietary means alone.

9. How is coeliac disease treated?
The mainstay of treatment for coeliac disease is to avoid eating gluten-containing foods. Dietary supplements may be recommended, particularly when the disease is not fully controlled or if nutritional deficiences are found. However, when the condition is under control with adequate exclusion of dietary gluten there should be no need for dietary supplements if a well-balanced and nourishing diet is taken. Rarely, the extent of intestinal inflammation caused by the immune reaction to gluten may require treatment with corticosteroids temporarily. Other conditions co-existing with coeliac disease may require additional treatment.

10. Now that my biopsy is back to normal, can I relax my gluten-free diet?
No! If you start taking dietary gluten again, it is a matter of time before your abnormal response to gluten reactivates and starts causing damage again.

11. How much gluten can I eat without harm?
There is no clear answer to this question. Some coeliacs are more sensitive to gluten than others. Immune reactivity to gluten varies with time also, and may be altered by hormonal state (e.g. in pregnancy) or by coincident stresses on the immune system (e.g. infection, allergic reactions, cancer, certain medications). The best approach is to eliminate as much gluten as possible from the diet at all times and not to take any chances. Mistakes are bound to happen occasionally, but deliberate ingestion of gluten is reckless. Remember that any gluten present in the diet is more likely to get into the system if the gut is inflamed and the lining is "leaky". This situation occurs during an episode of gastroenteritis, for instance.

12. Why avoid gluten if I have no symptoms when I eat it?
People vary in how symptomatic they are even when they have they same level of damage to their intestinal lining. Some feel fine when their duodenal lining is flat (with severe damage to the villi), others feel sick when the changes in their gut lining are minimal. The health risks of coeliac disease are more closely related to the extent of immune reactivity and tissue damage than they are to the extent of symptoms. In coeliac disease, intermittent or recurrent low-level exposure to dietary gluten can perpetuate the immune reactivity and tissue damage. The best outcome of treatment is expected when this process is minimised.

13. What are the health implications of coeliac disease?
Active coeliac disease impairs absorption of nutrients in the upper small intestine (especially iron, folate and calcium). When absorption is markedly affected, diarrhoea and weight loss can occur. In children, growth retardation can result. Deficiency of iron or folates may lead to anaemia. Calcium deficiency can retard bone development in children (with retardation or loss of axial growth) or accelerate bone loss in adults (leading to premature osteoporosis). Fat-soluble vitamin deficiencies may be present in those with longstanding diarrhoea. These can lead to reduction in night vision, osteomalacia or bruising tendencies

Ongoing inflammation and damage in the intestinal lining, due to the presence of gluten, also increases the need for continuing tissue repair. This, in turn, substantially increases the risk of several cancers of the intestine. The presence of gluten in the bloodstream increases the likelihood of gluten sensitivity being manifested in organs other than the gut, such as the skin (e.g. dermatitis herpetiformis) or, rarely, the nervous system (e.g. gluten ataxia).

14. Can coeliac disease be prevented?
At present, we cannot predict which genetically susceptible individuals will develop coeliac disease in time. Until the triggering event(s) are understood, it is hard to see how the onset of coeliac disease can be prevented. The only rational precaution at present is to avoid weaning infants with a family history of coeliac disease onto gluten too early. The current guideline is that gluten should not be introduced before six months of age. There is a wide selection of gluten-free weaning foods available.

15. I have been told that I am allergic to wheat. Does that mean I have coeliac disease?
Not necessarily. It is possible to have adverse immune reactions to wheat without having coeliac disease. In this case, the harmful reaction may not be directed at gluten, but at other components of the wheat grain, and may be IgE-mediated (like hayfever, or allergic asthma, but unlike coeliac disease). The small intestinal lining would not be harmed in the same way (if at all). It may not be necessary to avoid all gluten-containing cereals. If coeliac disease is suspected, it must be diagnosed correctly with a biopsy before a life-long gluten-free diet is imposed.

16. Where can I get practical advice and help?
The Coeliac Society of Ireland is a good source of information for Irish coeliacs. They circulate a newsletter, publish a list of gluten-free foods and hold regular meetings around the country to provide people with updates on gluten-free products, opportunities to get local information about suppliers, and a chance to meet others with the same condition. Click here to find out how to join.