Celiac disease is a chronic disease of the intestine triggered by the consumption of gluten, a mixture of proteins contained in certain cereals (wheat, barley, rye, etc.). The disease manifests itself mainly by digestive symptoms (diarrhea, pain, bloating, etc.).

In people with celiac disease, ingestion of gluten causes a abnormal immune reaction in the small intestine, which creates inflammation and damages the intestinal wall. More precisely, it is the intestinal villi that are destroyed. These are small, wave-shaped structures that make up the “folds” of the intestine and allow the absorption of most of the nutrients, vitamins and minerals (see diagram above).

If the inflammation persists, theintestine damaged becomes unable to absorb certain nutrients, vitamins and minerals. It may follow a malnutrition despite a normal diet.

Other symptoms of varying intensity may occur, such as fatigue, depression and joint pain. Over time, more serious health problems can develop.

However, sufferers can regain their health by removing gluten from their food.

Differences with gluten sensitivity

The term “gluten intolerance” is often used for celiac disease which is an immune reaction involved.

The abnormal reaction of the immune system also turns against the body by attacking the lining of the small intestine. Celiac disease is therefore a autoimmune disease induced by the ingestion of gluten.

In recent years, sensitivity to non-celiac gluten (NCGS) has appeared in scientific studies. It is manifested by symptoms similar to those of celiac disease and irritable bowel syndrome when eating foods containing gluten. A prevalence of 3 to 6% of the population is estimated but it is poorly defined due to the frequency of self-diagnosis without medical advice.

Celiac disease, an inherited disease 

Celiac disease has a component héréditaire. When a close family member is affected, the likelihood of being affected is around 20%¹². Researchers now know the main genes involved, called HLA genes of the DQ2 and DQ8 type. It is known that 95% of patients express the HLA DQ2 genotype, and almost all the others DQ8. But DQ2 is found in 30 to 40% of the general population. It therefore appears that genetic predisposition is a necessary condition but not sufficient to trigger the disease. As in many other cases, genetic predisposition must combine with different factors to trigger the disease.¹³.

These other elements that come into play have not yet been identified with precision. It seems that environmental factors (intestinal infections, trauma, stress caused by an operation or pregnancy …) can sometimes be responsible for triggering the disease.

There would be a greater intestinal permeability in people predisposed to this disease. This would allow part of the gluten to penetrate the wall of the small intestine, triggering an immune response.

Possible complications

If the gluten free diet is not adopted, celiac disease, in its most severe forms, can have several health consequences. The most common complications are related to the poor absorption of nutrients in the intestine:

• Malnutrition, due to the malabsorption of nutrients in the intestine. Malnutrition leads to fatigue, weight loss, muscle weakness and many deficiencies.
• Lactose intolerance. Due to damage to the intestinal wall, lactose intolerance can occur. Usually, it goes away sometime after adopting a gluten-free diet.
• Anemia. Due to the poor absorption of iron, the body’s iron stores are depleted, causing anemia.
• osteoporosis. Poor absorption of calcium and vitamin D leads to loss of bone density which can lead to osteoporosis.
• Kidney stones. There is a relatively low risk of kidney stones which is caused by abnormal absorption of oxalates¹⁴.

Other complications, which are not related to the intestinal involvement, can occur in case of gluten sensitivity, but the link is not always well understood:

• neuropathy (damage to the nerves). Gluten sensitivity is sometimes associated with damage to the nerves, most often causing numbness in the limbs or even pain. Migraines, seizures or other neurological disorders are sometimes observed.
• Infertility. Infertility is more common among people with gluten sensitivity. The risk would be increased by about 12%. The miscarriages are also more common.
• Arthritis. Inflammation of the joints, responsible for pain, occurs in some affected people.
• Herpetiform dermatitis. It is a skin condition that is associated with gluten sensitivity in 15% to 25% of cases¹¹. It is characterized by itching, a burning sensation and the appearance of red blisters, especially on the elbows, knees and buttocks.
• Certain types of cancer. The disease is associated with an increased risk of intestinal lymphoma, bowel cancer and other types of cancer, in the long term.

How many people are affected by celiac disease?

The prevalence data fluctuate widely, as the diagnosis of the sensibility gluten is not easy. Experts and patient associations believe that many people have it without knowing it, and that the disease is more common than people think.¹.

The frequency of the disease depends on the regions of the world and the ethnicity. The Caucasian populations (Europe, Whites in North America, Australia) are the most affected, the prevalence varying between 1 in 100 and 1 in 300 people.^1,11. The disease appears to be rarer in people of Asian or African descent. The presence is 1% in France.

A long and difficult diagnosis

The diagnosis is often difficult and long to establish (12 years on average in Canada¹⁰), due to the wide variety of symptoms and the fact that they are not specific to this disease at all. The doctor should first rule out the possibility that it is a more common digestive problem (for example, irritable bowel syndrome, food intolerance, or inflammatory bowel disease).

The more specific diagnosis is generally made in 3 stages.

• The first is a blood test which makes it possible to detect the level of certain antibodies (anti-endomysium or anti-tissue transglutaminase). Their presence in high amounts indicates that the body is reacting abnormally to gluten. This test helps to know the people most likely to have the disease, especially in families at risk.
• We then proceed to one tissue removal (biopsy) in the small intestine. A thin flexible tube (an endoscope) is inserted through the mouth to the small intestine. In the event of intolerance (celiac disease), the villi of the intestine are no longer visible, since they have been totally or partially destroyed by the immune system.
• The effect of gluten free diet confirms or denies the diagnosis.