Genetic: Celiac Disease
Genetic: Celiac Disease
Celiac disease is a digestive disorder that runs in families and interferes with the digestion and absorption of the nutrients in foods. It is triggered by an immune reaction to gluten, a protein found in wheat, barley, rye, and triticale (a grain that is a cross between wheat and rye).
When a person with celiac disease eats foods containing gluten, the tissues that line the walls of the intestine become inflamed because of an immune reaction. The tissues gradually lose their villi, which are small finger-shaped projections that increase the surface area and hence the absorptive capacity of the intestinal wall. Over time the patient may develop some symptoms in the digestive tract, some symptoms elsewhere in the body, or have no symptoms at all until the body's failure to absorb nutrients from the food leads to such conditions as anemia, osteoporosis, or malnutrition.
Although the classic symptoms of celiac disease are failure to thrive in children and diarrhea in adults, so many patients have atypical
symptoms or none at all that the disease is easily missed during medical checkups.
Celiac disease runs in families. A person with a first-degree relative (parent, child, or sibling) who has the disease has a 10 percent chance of developing it themselves. Researchers also think that celiac disease is more common than was once thought. In some parts of Europe, particularly Ireland and Italy, celiac disease affects between one in 250 and one in 300 people. In the United States, as many as one in 133 people, or 2 million in the general population, may have celiac disease.
Celiac disease is thought to be more common in persons of European descent than in Africans or Asians; however, some researchers think that the disease is more widespread in Asia, Africa, and South America than was previously thought.
Celiac disease is most likely to be diagnosed in infants between eight and twelve months of age and in adults between twenty and forty. It appears to be slightly more common in women than in men.
People with Down syndrome or type 1 diabetes are also at increased risk of developing celiac disease.
The basic cause of celiac disease is inflammation of the tissues lining the small intestine due to an immune reaction to gluten. The villi in the lining of the small intestine gradually flatten out and disappear, leading to an intestinal surface that is not able to absorb enough nutrients from food to foster growth (in children) or prevent weight loss and other complications in adults. It is not known exactly what triggers the onset of celiac disease; it can occur at any age. In adults, celiac disease often appears after a trauma of some kind, such as infection, physical injury, the stress of pregnancy, or surgery.
Some adults have symptoms in the digestive tract with celiac disease that are often mistaken for symptoms of irritable bowel syndrome:
- Diarrhea, often with watery or frothy stools that have a very foul odor and are usually light tan or gray in color
- Large amounts of intestinal gas
- Weight loss
- Fatigue and muscle weakness related to poor absorption of nutrients
- Abdominal cramps
Some symptoms may appear in other parts of the body:
- Loss of bone strength
- Seizures or tingling numbness in the legs from nerve damage
- In women, missed menstrual periods, difficulty getting pregnant, or repeated miscarriages
- Pale sores inside the mouth
- Tooth discoloration or loss of tooth enamel
- An itchy skin rash known as dermatitis herpetiformis
- Bone or joint pain
Researchers still do not fully understand why the symptoms of celiac disease vary so much from one individual to the next. Some think that the range and the severity of the symptoms are influenced by how long the person was breast-fed, how old they were when foods containing gluten were first added to their diet, and the amount of gluten-containing foods that they presently eat.
The Gluten-Free Diet (source: American Dietetic Association)
People with celiac disease can eat as much plain (without gravy) meat, fish, rice, fruits, and vegetables as they like because these foods do not contain gluten.
Starchy foods that are allowed: Amaranth, arrowroot, buckwheat, corn, flax, Indian rice grass, nuts, potatoes, quinoa, rice, seeds, soy, tapioca, and wild rice.
Grains to avoid: Wheat (including wheat starch, wheat bran, wheat germ, cracked wheat, and hydrolyzed wheat protein, which are often found in processed foods); barley; rye; and triticale, a grain that is a cross between wheat and rye.
Processed foods that may contain wheat, barley, or rye: bouillon cubes, potato chips, candy, cold cuts, hot dogs, Communion wafers, French fries, matzo, rice mixes, sauces, self-basting turkeys, soups, soy sauce, and vegetables packaged in sauces. Fortunately, most of these foods can be obtained in gluten-free forms from various manufacturers.
People with celiac disease are at risk for complications if the disease is not identified and treated:
- Malnutrition leading to stunted growth in children and osteoporosis in adults
- Lactose intolerance
- Kidney stones
- Certain types of cancer, particularly lymphoma and intestinal cancer
- An underfunctioning spleen that can be linked to certain serious infections
- Miscarriage of a pregnancy or birth defects in the baby
It is not unusual for people to suffer from celiac disease for as long as ten years before they are diagnosed. One reason for the delay is that some of the symptoms of celiac disease can be easily confused with the symptoms of other digestive disorders, including Crohn disease and irritable bowel syndrome. Another reason for delayed diagnosis is that many doctors are not knowledgeable about the disease and may not suspect it when a patient comes to them for a checkup. Still another reason is that there are not many laboratories with the special equipment needed to test for celiac disease.
There are several laboratory tests available to diagnose celiac disease. One is a blood test to detect certain autoantibodies in the patient's blood. Autoantibodies are proteins that the body forms in reaction against its own tissues. A more definitive diagnostic test involves taking a small piece of tissue from the lining of the patient's small intestine to check for damage to the villi.
It is important for a person scheduled for these diagnostic tests to keep eating foods containing gluten up to the time they take the tests. If the patient stops eating foods with gluten, the test results may be misleading, indicating that the person does not have celiac disease when in fact they do.
There is no cure for celiac disease. It is managed by keeping one's diet completely free of gluten and products containing gluten. Unlike lactose intolerance, in which patients can often have small amounts of milk or other dairy products without harm, celiac disease is a condition in which the ingestion of even small amounts of gluten can damage the intestines. A few patients with celiac disease know when they have accidentally eaten foods containing a small amount of gluten because they develop a skin rash.
A patient diagnosed with celiac disease should meet with a dietitian, who is a health care professional with special training in nutrition and in
planning specialized diets. The dietitian can help the patient plan meals that include favorite “safe” foods, teach the patient how to read labels on foods, and give advice about eating in restaurants and other situations where gluten-free food may not be readily available. Newly diagnosed people and their families may find support groups for celiac disease to be helpful as they learn to adjust to a new way of life that requires constant attention to food.
Patients with celiac disease who are careful to avoid gluten have an excellent prognosis. Healing of the intestine begins within days of excluding gluten from the diet. It takes about three to six months for the intestines to heal in children and younger adults and two years for older adults. A few people, however, have what is called unresponsive celiac disease, which means that their intestines do not heal despite a strictly gluten-free diet. People with this condition may need to be evaluated for complications of the disease, treated with steroid medications, and fed intravenously. Unfortunately, this small group of patients has a poor prognosis.
There is no known way to prevent celiac disease because the factors that trigger the appearance of the disease are not yet understood.
WORDS TO KNOW
Amaranth: An herb that produces seeds used as grain in India, Nepal, Mexico, and parts of South America.
Autoantibody: An antibody formed in reaction against the tissues of the individual producing it.
Gluten: A protein found in certain grains, particularly wheat, barley, and rye.
Quinoa: A plant grown in Peru and Bolivia for its edible seeds. It is high in protein and easy to digest.
Triticale: A grain that is a cross between wheat and rye, first grown in Scotland and Sweden in the nineteenth century.
Villi (singular, villus): Small finger-like projections along the walls of the small intestine that increase the surface area of the intestinal wall.
It is likely that improved diagnostic techniques and greater awareness of celiac disease will lead to a wider variety of gluten-free foods for those
who must avoid gluten. At least two dozen cookbooks and other guides to gluten-free nutrition have been published in the United States just since 2002. Perhaps a cure for the disease lies ahead as well.
SEE ALSO Crohn disease; Irritable bowel syndrome; Lactose intolerance; Lymphoma; Osteoporosis
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