Celiac disease is digestive disorder in which people experience an immune response to eating gluten. A gluten-free diet is necessary for managing symptoms and preventing damage to the small intestine.
Celiac Disease Overview
Celiac disease is an immune disorder in which people cannot tolerate eating gluten because it damages the inner lining of their small intestine and prevents it from absorbing nutrients. (The small intestine is the tube-shaped organ between the stomach and large intestine.) Gluten is a protein found in wheat, rye, and barley. Occasionally, it is found in products such as vitamin and nutrient supplements, lip balms, and certain medications. People who must avoid all gluten should read all food and nutrition labels carefully.
An estimated 1 in 141 people in the U.S. have celiac disease, although the disease often goes undiagnosed. Celiac disease is most common in Caucasians.
The immune system is the body's natural defense system and normally protects the body from infection. However, when a person has celiac disease, gluten causes the immune system to react in a way that can cause intestinal inflammation, including irritation or swelling. When people with celiac disease eat foods or use products containing gluten, their immune system responds by damaging or destroying the tissue that lines the small intestine. This lining normally absorbs nutrients from food and passes the nutrients through the walls of the small intestine and into the bloodstream. Without this absorption, people can become malnourished, no matter how much food they eat. The intestinal damage can cause weight loss, bloating and sometimes diarrhea. Eventually, your brain, nervous system, bones, liver and other organs can be deprived of vital nourishment.
Celiac disease affects each person differently. Symptoms may occur in the digestive system, or in other parts of the body. One person might have diarrhea and abdominal pain, while another person may be irritable or depressed. Irritability is one of the most common symptoms in children. Some people have no symptoms. In children, malabsorption can affect growth and development. The intestinal irritation can cause stomach pain, especially after eating.
Celiac disease is genetic. Blood tests can help your doctor diagnose the disease. Your doctor may also need to examine a small piece of tissue from your small intestine. The only treatment is eating a gluten-free diet.
Celiac Disease Symptoms
The signs and symptoms of celiac disease vary greatly among people with the disease.
The classic signs of celiac disease are diarrhea and weight loss, but most people with celiac disease experience few or no digestive signs or symptoms. Only about one-third of people diagnosed with celiac disease experience diarrhea and about half have weight loss. Approximately 20% of people with celiac disease have constipation and 10% are obese.
As many as 75% of children with celiac disease are overweight or obese. Digestive signs and symptoms are experienced by 20 to 30% of children with the condition and may include:
- abdominal bloating
- chronic diarrhea
- pale, foul-smelling, or fatty stool
- stomach pain
Being unable to absorb nutrients during the years when nutrition is critical to a child's normal growth and development can lead to other health problems, such as:
- failure to thrive in infants
- slowed growth and short stature
- weight loss
- irritability or change in mood
- delayed puberty
- dental enamel defects of permanent teeth
Adults are less likely to have digestive signs and symptoms and may instead have one or more of the following:
- bone or joint pain
- canker sores inside the mouth
- depression or anxiety
- dermatitis herpetiformis, an itchy, blistering skin rash
- fatigue, or feeling tired
- infertility or recurrent miscarriage
- missed menstrual periods
- tingling numbness in the hands and feet
- weak and brittle bones, or osteoporosis
Intestinal inflammation can cause other symptoms, such as
- feeling tired for long periods of time
- abdominal pain and bloating
- blockages in the intestine
Celiac disease can produce an autoimmune reaction, or a self-directed immune reaction, in which a person's immune system attacks healthy cells in the body. This reaction can spread outside of the gastrointestinal tract to affect other areas of the body, including the:
- nervous system
Celiac Disease Causes
Researchers do not know the exact cause of celiac disease. Celiac disease sometimes runs in families. Approximately half of people who have celiac disease also have a family member who also has the disease.
In celiac disease, certain gene variants and other factors, such as a person's exposure to things in his or her environment, can lead to celiac disease. For most people, eating something with gluten is harmless. For others, an exposure to gluten can cause, or trigger, celiac disease to become active. Sometimes surgery, pregnancy, childbirth, a viral infection, or severe emotional stress can also trigger celiac disease symptoms.
Cceliac disease tends to be more common in people who have autoimmune diseases, including:
- type 1 diabetes
- autoimmune thyroid disease
- autoimmune liver disease
- rheumatoid arthritis
- Addison's disease, a condition in which the immune system damages the glands that produce critical hormones
- Sjögren's syndrome, a condition in which the immune system destroys the glands that produce tears and saliva
- Down syndrome or Turner syndrome
- Microscopic colitis (lymphocytic or collagenous colitis)
Celiac Disease Diagnosis
A health care provider diagnoses celiac disease with:
- a medical and family history
- a physical exam
- blood tests
- an intestinal biopsy
- a skin biopsy
In some cases, a health care provider will order genetic blood tests to confirm or rule out a diagnosis of celiac disease. Most people with celiac disease have gene pairs that contain certain gene variants. However, these variants are also common in people without celiac disease, so their presence alone cannot diagnose celiac disease.
Living With Celiac Disease
If you have been diagnosed with celiac disease, avoid all foods that contain gluten. Ask your doctor for a referral to a dietitian, who can help you plan a healthy gluten-free diet.
Avoid food and drinks containing:
- Graham flour
- Spelt (a form of wheat)
Packaged foods should be avoided unless they're labeled as gluten-free or have no gluten-containing ingredients. In addition to cereals, pastas and baked goods — such as breads, cakes, pies and cookies — other packaged foods that may contain gluten include:
- Imitation meats or seafood
- Processed luncheon meats
- Salad dressings and sauces, including soy sauce
- Self-basting poultry
Certain grains, such as oats, can be contaminated with wheat during growing and processing. It is not clear whether oats are harmful for most people with celiac disease, but doctors generally recommend avoiding oats unless they are specifically labeled gluten-free. Occasionally, even pure oats can be a problem for people with celiac disease.
Many basic foods are allowed in a gluten-free diet, including:
- Fresh meats, fish and poultry that are not breaded, batter-coated or marinated
- Most dairy products
- Wine and distilled liquors, ciders and spirits
- Grains and starches allowed in a gluten-free diet include:
- Gluten-free flours (rice, soy, corn, potato, bean)
- Pure corn tortillas
Fortunately, an increasing number of gluten-free products are commercially available. There are also gluten-free substitutes for many gluten-containing foods.
If your nutritional deficiencies are severe, your doctor or dietitian may recommend taking vitamin and mineral supplements. You may need to supplement your levels of:
- Vitamin B-12
- Vitamin D
- Vitamin K
Celiac Disease Treatments
Most people with celiac disease have a significant improvement in symptoms when they follow a gluten-free diet. Health care providers typically refer people to a dietitian who specializes in treating people with the disease. The dietitian will teach you how to avoid gluten while following a healthy and nutritious diet. The dietitian will give the person instructions for how to:
- read food and product labels and identify ingredients that contain gluten
- make healthy choices about the types of foods to eat
- design everyday meal plans
For most people, following a gluten-free diet will stop symptoms, heal existing intestinal damage, and prevent further damage. Symptoms may improve within days to weeks of starting the diet. The small intestine usually heals in 3 to 6 months in children. Complete healing can take several years in adults. Once the intestine heals, the lining of the small intestine will absorb nutrients from food into the bloodstream normally.