Celiac (or Coeliac) disease (also known as: Celiac Sprue; Non-tropical Sprue; Endemic Sprue, Gluten or Gluten-sensitive Enteropathy and Gluten Intolerance) is a digestive disorder that affects the small intestine. The condition is characterized by sensitivity to gluten, a protein present inside the seeds of certain grass-related grains. Intake of gluten-rich foods, such as barley, rye and wheat initiates an immune (allergic) response in the small intestine that irritates and damages the intestinal surface, leading to destruction of the anatomical structures responsible for absorption of nutrients (the villi). This causes a reduction in the amount of nutrients that people can withdraw from ingested food, including proteins, carbohydrates, fats, vitamins, calcium, and other essential nutrients. Deprivation of nutrients can lead to other illnesses and impaired growth in children.
Cealic disease is quite common, affecting about 1 in 250 to 1 in 150 individuals. In certain populations, the prevalence can be higher than 1%. However, people of African, Chinese and Japanese descent have a much lower probability of displaying gluten sensitivity.
Currently, there are no treatments to cure celiac disease, but the condition can be effectively managed through changes one's diet.
The exact disease mechanism is not well understood, but is recognized that many factors, both environmental and genetic, contribute to the manifestation of the condition. The principal cause of celiac disease is an immunological response to gluten. This is not a common Immunoglobulin E (IgE) type reaction (typical in other food allergies), but a cell mediated reaction.
The genetic component seems to be considerable since predisposition to gluten sensitivity often appears to be inherited along the blood-line. There is also evidence indicating the involvement of certain genes in the pathological mechanism of the condition.
Environmental factors such as bacteria, virus, severe stress and surgery that cause changes in the small intestine may eventually contribute to gluten sensitivity and lead to celiac disease. The disease is more frequently diagnosed in individuals who have autoimmune thyroid disease, type 1 diabetes, and Down syndrome.
Celiac disease causes the destruction of the intestinal wall structures important for absorption of nutrients (the villi). For this reason, the disease frequently leads to nutritional deficits. Of all major classes of nutrients, fats are the most frequently affected, leading to characteristic symptoms of fat malbasorption, such as diarrhea, fatty stools (steatorrhea), flatulence and abdominal bloating (see "Symptoms").
The symptoms of celiac disease are quite broad and variable. Few, if any, can be considered specific symptoms of the disease. The range and severity of the symptoms depend on the extent of the intestinal damage and the time length during which malabsorption occurred. The symptoms can be grouped in: physical and psychological.
- Abdominal pain and/or cramping
- Diarrhea (recurrent or chronic) or constipation
- Pale, foul-smelling, or oily stool (steatorrhea)
- Mouth sores or cracks in the corners of the mouth
- Bone or joint pain
- Muscle weakness
- Infertility (in women)
- Numbness and/or pain in extremities (hands or feet) – peripheral neuropathy
- Bone loss or osteoporosis
- Skin rash or itchy skin rash (dermatitis herpetiformis)
- Missed menstrual periods (amenorrhea)
- Anemia (Iron-deficiency anemia)
- Weight loss
- Bruising easily
- Mood changes
- Unable to concentrate
Symptoms related to growth and development are observed in children:
- Low weight and short height (failure to thrive)
- Delayed puberty
- Dental enamel defects of the permanent teeth
- Poor memory
People with celiac disease may not display any symptoms, but can still develop complications of the disease in the long-term.
Celiac disease is sometimes under-diagnosed or misdiagnosed because the disorder mimics several other conditions that can cause malabsorption. This is one of the reasons why recognizing celiac disease can be challenging. Lately, doctors are more aware of this disorder and there are increasingly specific blood tests available to determine whether an individual has celiac disease or not. Conclusive and accurate diagnosis is very important in order to choose adequate therapeutic strategies, and because treatment of celiac disease involves life-long changes in diet and lifestyle.
Immunological Blood Test (initial detection)
Patients with celiac disease have higher levels of certain antibodies (anti-gliadin, anti-endomysium and anti-tissue transglutaminase). In celiac disease, the immune system recognizes gluten as a foreign substance and produces high levels of antibodies to eliminate it. The immunological blood tests available are able to detect the presence of these antibodies with high sensitivity.
Prior to the blood test, the patient should not stop eating gluten-rich food, because halting the intake of gluten may lead to a negative result even if the disease is present.
If the blood test results suggest celiac disease, the doctor may need to perform a biopsy of the small intestine to confirm diagnosis and evaluate the extent of any intestinal damage. The biopsy is performed by inserting an endoscope through your mouth, passing through the esophagus and stomach into the small intestine, to then take a small sample of tissue. A small portion of the intestinal tissue is examined to check for damaged villi.
Some patients develop dermatitis herpetiformis, a very itchy, burning rash that occurs in about 10% of people with celiac disease. The rash typically appears on elbows, knees and buttocks. Dermatitis herpetiformis arises in response to ingestion of food rich in gluten. In these cases, a blood test and skin biopsy (rather than intestinal biopsy) are performed. If the antibody test is conclusive and the skin biopsy confirms celiac disease, patients no longer need to undergo an intestinal biopsy.
Celiac disease can result in deficiency of vitamins and minerals - notably, iron and calcium. For this reason, diagnostic tests should also include a survey of the patient's nutritional status. The following diagnostic tests may be performed:
- Complete blood analysis – to look for common nutritional deficits associated with celiac disease, in iron, calcium, folic acid and vitamin B12.
- Bone density exams – to check for osteoporosis.
- Thyroid function exams – to look for potential hypothyroidism.
Celiac disease has no cure. However, the disorder can be kept under control with a gluten-free diet. A person diagnosed with celiac disease should avoid gluten for the rest of his/her life.
Ingredients to avoid include:
- Wheat and its derivatives - including einkorn, emmer, spelt, kamut, wheat starch, wheat bran, wheat germ, cracked wheat, hydrolyzed wheat protein.
- Oats – some people with celiac disease my tolerate oats on the short term, however, long term safety has not been established conclusively.
Celiac disease patients may eat gluten-free food, including:
- Fresh meats, fish and poultry (without gluten-rich additives)
- Most dairy products
- Gluten-free flours (rice, soy, corn, potato)
Usually, a physician recommends seeking guidance from a dietitian before starting a gluten-free diet. Dietitians can help you in food choices, reading and understanding labels and additional strategies to manage the disease.
Particular attention should be taken relative to processed foods. Although the main ingredient might seem safe (gluten-free), other ingredients may contain gluten. Read carefully the labels of any processed food, such as: canned soups and meats, dressings and sauces, pastas, ice creams, and yogurts. Be also aware of supplements and preparations that might contain gluten.
When celiac disease is not under control, ingestion of lactose-containing foods should be avoided since many patients develop lactose intolerance due to malabsorption of this sugar.
In rare occasions, people with severely damaged small intestines don't improve on a gluten-free diet. Patients who become non-responsive or refractory to diet changes are normally indicated for immunosuppressive therapy, including corticosteroids (prednisone), to ease the inflammation and reduce damage to the small intestine.
For patients with dermatitis herpetiformis, dapsone is usually given to ease the condition.
Individuals with nutritional deficiencies should be given mineral and vitamin supplements in order to regain nutritional balance.
The celiac patient needs a diet that is not only gluten-free, but that also supplements the body with essential minerals and vitamins to compensate for the impaired absorption of nutrients. Multivitamin and multi-mineral supplements are, therefore, recommended for people suffering from celiac disease. Herbs such as echinacea and goldenseal work as boosters of the immune system and may help to accelerate the healing process. Ginger and other natural anti-inflammatory agents may help in reducing the inflammation responsible for injury to the small intestine wall.
Physical exercise is recommended to reduce stress levels and to help with regulation of intestinal function.
A person with celiac disease should follow a gluten-free diet to prevent additional damage to the small intestine and to permit recovery of the intestinal tissue. The improvements might be noticed within the following days, but full recovery is only expected within several months to years. In adults, the healing process may take 2 to 3 years, while in children, recovery is much faster and occurs within 3 to 6 months.
There are some consequences of celiac disease that might not be reversible. This happens particularly with developmental problems, such as shorter-than-expected height and damage to definitive teeth.
Celiac disease is associated with a higher risk of other conditions. These include: small intestine ulcers, cancers, and collagenous celiac disease. These are rare, but serious complications. In particular, the less known collagenous celiac disease is characterized by resistance to a gluten-free diet and the build-up of scar tissue (collagen) in the intestine. This condition has no treatment and is associated with a poor prognosis.
Celiac disease can be effectively prevented by avoiding ingestion of gluten. Although the intrinsic cause (gluten-sensitivity) is not removed or altered, the absence of the disease trigger (gluten) is normally sufficient to avoid the development of celiac disease.
People that have a family history of celiac disease or that, for other reasons, suspect that they are sensitive to gluten, might want to discuss these concerns with their physician.
Living with celiac disease is challenging due to the wide availability and frequent presence of gluten-containing foods and their derivatives in our dietary choices. It can be difficult to strictly follow a gluten-free diet, and can be problematic to find appropriate menus. Dietitians can be very helpful because they have a deep understanding of the dietary aspects of food composition, processing and preparation. Cookbooks specific for a gluten-free diet are also very useful and are now widely available. People living with celiac disease and looking for a pleasant dinning-out experience should search for restaurants that present gluten-free dishes.
It is important to read food labels before you buy any product. There are several foods that may seem acceptable, but contain gluten. Fortunately, strict gluten-free diets are becoming easier to follow as an increase in gluten-free products are being properly labeled and developed. On the other hand, celiac disease awareness is increasing as well as public and private support for this condition.
There is now a large amount of information about celiac disease. You may ask guidance from your doctor and search for information in books, brochures and on the internet. Sharing the experience with other people suffering from celiac disease can be reassuring, comforting and helpful. There are now support groups specific to people with this condition.
Investigators are developing strategies that will enable patients with celiac disease to eat foods that are otherwise not recommended. In one experimental approach, a mixture of enzymes that are able to breakdown gluten and neutralize its allergenic potential is being developed. On the other hand, wheat species that do not carry allergenic components are being genetically engineered.
The National Institute of Diabetes and Digestive and Kidney Diseases is conducting research on celiac disease. Part of their research is aimed to develop a capsule-size camera, that once swallowed, will capture images of the gastrointestinal tract, including the small intestine. This probe will be able survey areas that normally cannot be assessed by a traditional endoscopic exam.
Research is also aimed at better defining and understanding the disease. In particular, specific markers of celiac disease are being identified that will enable a more clear discrimination between sensitivity to gluten and other similar conditions, such as irritable bowel syndrome.