What is Coeliac disease?
Coeliac disease is a life-long inflammatory condition of the gastrointestinal tract. This is caused by sensitivity to gluten, a protein in wheat, and in some individuals, similar proteins in rye, barley and oats. When eaten, gluten causes changes in the lining of the upper part of the intestine that impairs its ability to absorb nutrients from food.
How does it develop?
Since Coeliac disease runs in families, it seems that some people have a genetic predisposition to this condition. The result is that sub-sections of the proteins (peptides) found in wheat, in gluten and gliadin, become toxic to the lining of the gut.
What are the symptoms?
In childhood, the condition most often apparent between 9 months and 3 years of age after the introduction of solid foods to the diet. The child starts to lose or fails to gain weight, loses appetite, and the stools become softer, paler, larger and more frequent than usual. The stomach may appear swollen and the muscles weak and floppy. Vomiting, diarrhoea or constipation may also occur. In childhood or adolescence there may be stunting of growth.
As gluten damages the lining of the small intestine, the ability of the gut to absorb nutrients from food is greatly reduced. Wasting can occur, leading to severe illness resembling malnutrition. Tiredness and irritability are common. The skin and tongue may appear pale due to lack of iron in blood (anaemia). Problems with bones may occur, such as deformity, pain or liability to fracture. Since nutrients are incompletely absorbed, increased bowel frequency with the passage of bulky pale stools may occur and there may be associated abdominal pain and/or distension. However, many sufferers experience no bowel disturbance, and they can be constipated.
Women with untreated gluten sensitivity can experience infertility that is restored by withdrawal of gluten from the diet. Before and during pregnancy, women with gluten sensitivity should be particularly careful to take a supplement of folic acid, as advised for all women.
A few people with the condition do not show the usual rapid response to exclusion of gluten and special advice may be needed. More severe damage than usual, including narrowing of the intestine, and even the development of a form of cancer can rarely occur, but these complications are very uncommon, especially if the condition is well treated.
A skin condition with a red blistery rash, known as Dermatitis Herpetiformis, is associated with gluten sensitivity. Adopting a Gluten-Free Diet also treats this, although medication is also sometimes used in its treatment.
Who is at risk?
In Britain, the condition affects approximately one in a thousand people but it is more frequent in parts of Ireland. Its frequency is increased among family members of a person affected. The condition also occurs among other ethnic races, especially from northern India. The frequency of gluten sensitivity is greater than expected among people with some other disorders, particularly those with insulin-dependant diabetes.
Coeliac disease used to be thought of as a childhood condition but now it is recognised that many more adults than children are diagnosed. Coeliac symptoms can manifest themselves at any age and, according to Coeliac Society statistics, most Coeliacs are diagnosed when aged between 30 and 45 years. Recent figures even show more over-60s than under-16s being diagnosed in a year.
How is it diagnosed?
The doctor is likely to arrange a blood test to check for anaemia and also a special blood test (anti-gliadin antibodies and/or endomysial antibodies). A stool sample will also be tested to exclude infection.
If the blood test is abnormal, your doctor will arrange for you to see a specialist, who is likely to look inside the stomach and duodenum using an endoscope, taking specimens (biopsies) from the lining of the duodenum. This may show a worn-down sort of appearance typical of coeliac disease, which returns to normal if a further biopsy is taken after a period of excluding all foods from the diet that contain gluten.
How is it treated?
The only treatment necessary to return the intestine to normal is a strict gluten-free diet. Sometimes vitamin or mineral supplements may be required to start with to restore a healthy nutrition status. Supplements should NOT be taken without medical supervision.
The potentially harmful effect of gluten on the intestine is life-long and the diet should therefore be followed as a permanent change in lifestyle.
What is gluten?
Gluten is the protein found in wheat. Similar proteins which are toxic to coeliacs are present in rye, barley and oats. Therefore, wheat, rye, barley and oats are all usually excluded in a Gluten Free Diet. The sensitivity to oats varies between individuals however and some coeliacs can tolerate up to 50 grams of oats per day (an average serving).
What is naturally gluten-free?
Many foods are naturally gluten-free as they do not contain any wheat, rye, barley and oats. For example, all fresh meat, fish, cheese, eggs, milk, fruit and vegetables are gluten-free.
Obvious sources of gluten in the diet.
Wheat is usually made into flour and any food such as ordinary bread, breakfast cereals, biscuits, cakes, pastries, puddings and pies made from flour will contain gluten.
Hidden sources of gluten.
Gluten is contained in manufactured and processed foods where wheat flour is commonly used as a processing aid, a binder, a filler or as a carrier for flavourings and spices. Contamination with wheat or wheat flour can also occur during cereal production, storage, processing or manufacture.
Specially-manufactured gluten-free foods
There are a variety of specially-manufactured branded gluten-free and wheat-free products now produced in the UK. For people medically diagnosed as having Coeliac disease or dermatitis herpetiformis, basic foods such as breads, flours, mixes, biscuits, crackers and pasta are available on a doctor's prescription. A complete up-to-date list of items available on prescription can be obtained from the Coeliac Society. Some of these foods may also be available in supermarkets and health foods stores.
Other gluten-free luxury items such as cakes, chocolate and fancy biscuits, and seasonal foods like mince pies, can be bought over the counter at pharmacies and some health food stores although they may have to be specially ordered and can be expensive.
Unfortunately, food labels do not always tell consumers everything. Labelling will indicate the obvious presence of wheat or wheat flour. However, where gluten-containing flour is used as a processing aid or as a small percentage of a compound ingredient, it does not have to be declared on a label. Labelling regulations are getting stricter, but at the present time coeliacs are advised to use the Coeliac Society's Food List rather than rely on information given on a label. If a product is not in the Society's Food List then it should be avoided.
These days, many restaurants can help if you tell them the problem, however, the patient or the parents have to become expert in what they can or cannot take.
Gluten sensitivity is curable by avoiding gluten in all food. The results of this treatment are excellent but it can be inconvenient. A temporary or occasional lapse in the diet is unlikely to do harm but everyone with this condition should be advised to exclude gluten from their diet for the rest of their life. If they do, they should have no further trouble but they will need help and encouragement to persevere with this alteration to their lifestyle.