Celiac Disease

What is it?

Celiac disease is considered a disease of the digestive system as well as an autoimmune disease. It causes damage to the small intestine, which interferes with the absorption of nutrients from food and triggers an abnormal immune response to foods containing gluten. The disease affects people worldwide, including more than 2 million people in the United States.

Gluten, which is a protein found in wheat, rye, and barely, may also be present in products such as medicines, vitamins, lip balms, and many processed foods. Because people who have celiac disease cannot tolerate gluten, it’s very important that they learn to carefully read labels and identify foods that may contain gluten.

How does a person with celiac disease react to eating gluten?
Gluten triggers an abnormal immune, or autoimmune, response among people with celiac disease. This abnormal activity involves the villi, which are small, fingerlike protrusions that line the small intestine. The villi are supposed to allow nutrients from food to be absorbed into the bloodstream, but in celiac disease, the immune system destroys or damages the villi when gluten is ingested. As a result, it’s impossible for a person with celiac disease who eats gluten-containing foods to be properly nourished, as the digestive system cannot absorb nutrients in food.

What are the symptoms?
Celiac disease runs in families, so those with a genetic risk should be particularly aware of its symptoms. But because the disease may be diagnosed late in life or misdiagnosed, not having an immediate relative who’s been diagnosed doesn’t mean that you’re not at risk—celiac disease may run in your family but may not have been detected yet. Anyone who experiences the following symptoms should consult their healthcare provider about celiac disease.

Symptoms of celiac disease in adults:

  • Fatigue
  • Bone or joint pain
  • Iron-deficiency anemia with no known cause
  • Arthritis
  • Bone loss or osteoporosis
  • Depression or anxiety
  • Tingling numbness in hands and feet
  • Seizures
  • Missed menstrual periods
  • Infertility or recurrent miscarriage
  • Itchy skin rash

As you can tell from the list above, the symptoms of celiac disease of varied, as is the age when symptoms appear. The reason for this is not fully understood but may be related to factors including the length of time a person was breastfed, the age at which a person began eating foods containing gluten, the amount of gluten-containing foods consumed, and age at diagnosis (though some people have celiac disease long before it’s diagnosed).

It’s also true that not everyone with celiac disease will develop symptoms. Even without symptoms, however, the disease can still cause serious health complications related to malnutrition. Anyone who has a close family member with celiac disease should consider screening (see more about screening in “How is it diagnosed?”).

Celiac disease also affects children, though symptoms tend to be different from those of adults—namely, children are more likely than adults to have digestive symptoms. Celiac disease is a particular concern among children because they need to properly absorb nutrients from food to ensure healthy growth and development. Children may experience the following symptoms:

  • Abdominal bloating and pain
  • Chronic diarrhea
  • Vomiting
  • Constipation
  • Pale, foul-smelling, or fatty stool
  • Weight loss

How is it diagnosed?
Celiac disease can be difficult to diagnose because its symptoms may be confused with other diseases, such as irritable bowel syndrome, chronic fatigue syndrome, and inflammatory bowel disease. Fortunately, however, effective screening tests are increasingly available and doctors are becoming more familiar with symptoms. Here, some of the screening tests currently being used are described.

Blood Tests
Because celiac disease involves an autoimmune response, people with the disease have a higher blood level of proteins that react against the body’s own cells or tissues when they eat gluten. Called autoantibodies, these proteins can be measured with a blood test. Because autoantibody levels will be raised by eating gluten, it’s important to continue to eat gluten before the test. Otherwise, test results may not indicate celiac disease even if it is present.

Intestinal Biopsy
When a blood test indicates celiac disease, the next step is to confirm the diagnosis with an intestinal biopsy. This involves the removal of tiny tissue samples from the small intestine, which the doctor inspects for damage to the villi. An intestinal biopsy is performed using an endoscope, a tube passed through the mouth and stomach and into the small intestine.

Dermatitis Herpetiformis
Dermatitis herpetiformis (DH) is the “itchy skin rash” listed under symptoms of celiac disease. DH is an intensely itchy irritation that can also cause blisters and usually occurs on the elbows, knees, and buttocks. It affects 15 to 25 percent of people with celiac disease; these people may have no digestive symptoms.

To diagnose DH, a doctor will use a blood test and a skin biopsy. Because celiac with DH is both an intestinal disease and a skin disease, it’s treated with two approaches: 1) a gluten-free diet to manage intestinal symptoms and 2) antibiotics to treat the skin disease (skin symptoms will also improve with a gluten-free diet).

Screening
To screen for celiac disease, a doctor will test for the same blood proteins discussed above—autoantibodies—in patients who don’t have symptoms. Who should be screened? People with family members with celiac disease may want to best tested, as it is hereditary and 4 to 12 percent of the relatives of someone with celiac disease will also have it.

How is it treated?
There’s only one way to treat celiac disease, and that’s with a gluten-free diet. Most people with celiac disease will begin to experience improvement of symptoms within days of eliminating gluten from their diet, but healing of the small intestine can continue for years in adults and up to six months in children. Once healed, the small intestine can absorb nutrients from food into the bloodstream; as a result, many health problems associated with celiac disease can be resolved.

To ensure improvement, it’s important that the diet is strictly gluten-free. Even small amounts of gluten, like those used in processed foods as preservatives and stabilizers or foods produced in factories that also manufacture wheat, can interfere with healing.

To make sure that the extended healing process is successful and to stay healthy, people with celiac disease need to avoid gluten for the rest of their lives. Some patients work with a dietician to learn more about eating gluten-free, including learning to read labels to recognize hidden sources of gluten. Find more information about a gluten-free diet below in “A Gluten-free Diet.”

Although a gluten-free diet successfully treats most people with celiac disease, some people do not improve with dietary changes. These cases are known as refractory celiac disease. People with this condition may receive nutrients intravenously (though a vein) because their intestines cannot absorb enough nutrients. Drugs to treat refractory celiac disease are currently being evaluated.

A Gluten-free Diet
The foundation of a gluten-free diet is to not eat foods that contain wheat, rye, and barley. Foods that contain wheat, rye, and barley—in other words, gluten—include many grains, standard pastas, cereals, and many processed foods. Some grains, however, don’t contain gluten (quinoa, for example); a dietician can help you select gluten-free grains.

Although the transition to a gluten-free diet may sound dramatic, you can still enjoy a well-balanced and satisfying diet. A dietician can help you find nutritious and delicious gluten-free options. For example, instead of wheat flour, you can substitute flour made with potatoes, rice, amaranth, quinoa, buckwheat, or beans. Increasingly more gluten-free products including breads and pasta are available; find them at health-food stores and in many supermarkets.

As well, whole foods like meats, fish, fruits, and vegetables that aren’t prepared with gluten-containing products can be enjoyed on a gluten-free diet. Again, a dietician can help you find ways to prepare these foods that don’t use gluten.

In addition to assistance from a dietician and your healthcare team, you may find that reaching out to support communities for people with celiac disease (in-person and online) will help with your transition to a gluten-free life. Such groups can provide encouragement, understanding, and offer tips like recipes and how to navigate restaurant menus to make sure your selections are gluten-free.

Examples of gluten-free foods (Make sure that these foods do not come from a factory that manufactures wheat, rye, or barley.)

  • Wild rice
  • Seeds
  • Corn
  • Rice
  • Nuts
  • Buckwheat
  • Legumes
  • Potatoes

Examples of gluten-containing foods to avoid

  • WheatThis includes all varieties of wheat (such as einkorn, emmer, spelt and kamut), wheat starch, wheat bran, wheat germ, cracked wheat, and hydrolyzed wheat protein. Also, all flours that contain wheat must be avoided, meaning that plain flour, white flour, bromated flour, enriched flour, phosphated flour, self-rising flour, durum flour, farina, semolina, and graham flour are all off limits.
  • Barley (used as a whole grain or processed, such as in barley flour or flakes, and used in beer)
  • Rye (eaten whole or used in flour, rye bread, rye whisky, and some vodkas)
  • Cross-bred grain varieties, such as triticale (a cross between wheat and rye).

Examples of processed foods that may contain gluten (Read labels carefully!)

  • Soy sauce
  • Soups
  • Bouillon cubes
  • Candy
  • Brown rice syrup
  • Potato chips and all chips
  • Processed meats (hot dogs, salami, sausage, cold cuts)
  • Beer
  • Certain distilled beverages, or spirits

Resources

American Celiac Disease Alliance

American Dietetic Association

Celiac Disease Foundation

SOURCES

Celiac Disease. National Digestive Diseases Information Clearinghouse Web site (a service of the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health). http://digestive.niddk.nih.gov/ddiseases/pubs/celiac/index.htm. Accessed May, 2010.
The American Dietetic Association. www.eatright.org. Accessed May, 2010.

CONDITIONS OF THE GI TRACT