Coeliac Disease
Coeliac disease is a chronic condition where the body’s immune system reacts to gluten, a protein found in wheat, barley, and rye, damaging the small intestine and preventing proper nutrient absorption. While there is no cure, the condition can be successfully managed through a lifelong gluten-free diet.
Celiac disease, Celiac sprue, Nontropical sprue, Gluten-sensitive enteropathy
- Small intestine
- Digestive system
Table of contents
- What is Coeliac Disease?
- What Causes Coeliac Disease?
- Signs and Symptoms
- Possible Complications
- Who Is More Likely to Develop Coeliac Disease?
- How Is Coeliac Disease Diagnosed?
- Treatment and Management
- Living with Coeliac Disease
What is Coeliac Disease?
Coeliac disease is a chronic autoimmune condition that affects the digestive system, particularly the small intestine. An autoimmune condition is when your body’s own defense system mistakenly attacks healthy tissues instead of protecting them. In coeliac disease, this happens when you eat gluten, a protein found naturally in certain grains[1][2].
Gluten is present in wheat, barley, and rye. These grains are common ingredients in many everyday foods such as bread, pasta, cookies, cakes, and beer. When someone with coeliac disease eats gluten, their immune system responds abnormally, attacking the gluten protein. This reaction causes inflammation and damages the lining of the small intestine[2][4].
The small intestine is lined with tiny, finger-like projections called villi. These villi are responsible for breaking down and absorbing nutrients from food. When coeliac disease damages the villi, a condition called villous atrophy occurs. This inflammation seriously reduces the surface area available for absorbing nutrients and minerals, which can lead to malnutrition and various health problems[15][2].
Coeliac disease affects at least 1 in every 100 people in the United Kingdom, and approximately 2 million people in the United States. However, experts believe these numbers may be underestimated because many cases go undiagnosed, especially milder forms that might be mistaken for other digestive conditions[5][3].
What Causes Coeliac Disease?
Coeliac disease is caused by a combination of genetic and environmental factors. The disease can only occur in people who have certain genes. Almost everyone with coeliac disease has one of two specific gene changes called HLA-DQ2 or HLA-DQ8. These genetic changes are inherited from biological parents. However, not everyone who has these genes develops coeliac disease[4][13].
The exact reason why some people with these genes develop coeliac disease while others do not is not entirely clear. Researchers believe that other factors play a role in triggering the disease. Some experts suggest that the balance of microorganisms living in the gut might be involved. Others believe that a major physical event, such as a serious illness or surgery, might trigger the condition later in life[4][5].
It is important to understand that coeliac disease is different from gluten sensitivity or wheat intolerance. While gluten sensitivity can cause similar symptoms like abdominal pain and tiredness, it does not damage the small intestine like coeliac disease does. Coeliac disease is also different from a wheat allergy, which can cause symptoms like itchy eyes or breathing difficulties but does not cause long-term intestinal damage[3][6].
Signs and Symptoms
The symptoms of coeliac disease can vary greatly from person to person. Some people experience severe symptoms, while others have only mild symptoms or none at all. Symptoms can appear at any age, though healthcare providers most often see it develop during two distinct age periods: early childhood, between 8 and 12 months old when children begin eating solid foods containing gluten, and in mid-life, between the ages of 40 and 60[4][13].
Digestive symptoms are more common in children than in adults. These may include[2][6]:
- Diarrhea, which may smell particularly unpleasant
- Stomach aches and abdominal pain
- Bloating and feeling of fullness
- Gas and flatulence
- Nausea and vomiting
- Constipation
More than half of adults with coeliac disease experience symptoms that are not related to the digestive system. These can include[2][6]:
- Tiredness and fatigue as a result of not getting enough nutrients from food
- Unintentional weight loss in adults, or failure to gain enough weight in children
- Iron-deficiency anemia, causing paleness, extreme tiredness, and cold hands
- Bone or joint pain
- Problems getting pregnant or infertility
- Abnormal or missed menstrual periods
- Irritability or depression
- Dental enamel defects
- Delayed puberty or growth faltering in children
Around 15% of people with coeliac disease develop a specific skin condition called dermatitis herpetiformis. This is an itchy rash that looks like clusters of bumps or blisters. It typically affects the elbows, knees, buttocks, and scalp[4][6].
Possible Complications
If coeliac disease is left untreated or if gluten continues to be consumed, serious complications can develop over time. These complications occur because the damaged small intestine cannot properly absorb essential nutrients, leading to various deficiencies[4][5].
Potential long-term complications include[5][6]:
- Weakening of the bones, known as osteoporosis
- Iron-deficiency anemia
- Vitamin B12 or folate deficiency anemia
- Malnutrition and nutritional deficiencies
Untreated coeliac disease in children can have particularly serious effects, including growth and development delays. In adults, malnutrition has many serious side effects that can affect overall health and quality of life[4][13].
Less common but more serious complications include some types of cancers, such as bowel cancer or lymphoma of the small bowel, though the increased risk is small. Problems affecting pregnancy can also occur, such as babies having low birth weight or miscarriages[5][7].
It is important to note that complications generally only affect people who continue to eat gluten or those who have not yet been diagnosed. Even if symptoms are mild, damage and inflammation can still occur without noticeable symptoms[5][15].
Who Is More Likely to Develop Coeliac Disease?
Coeliac disease can affect children and adults in all parts of the world. In the United States, the condition is more common among white Americans than among other racial or ethnic groups. A coeliac disease diagnosis is also more common in females than in males[3].
You are more likely to develop coeliac disease if you[3][4][5]:
- Have a family member who has the disease, particularly first-degree relatives such as parents, brothers, sisters, or children
- Have certain other conditions, including type 1 diabetes, autoimmune thyroid disease, Down’s syndrome, Turner syndrome, or Williams syndrome
- Have certain genetic changes (HLA-DQ2 or HLA-DQ8 genes)
Because coeliac disease runs in families, first-degree relatives of people with coeliac disease should be tested even if they do not have symptoms[5][3].
How Is Coeliac Disease Diagnosed?
Diagnosing coeliac disease involves several steps. It is important to note that you should not eliminate gluten from your diet before being tested, as this might make the test results appear normal and lead to an incorrect diagnosis[8].
If you have symptoms of coeliac disease or have an increased risk of developing the condition, your healthcare provider will start by reviewing your medical and family history and performing a physical exam[6].
The diagnostic process typically includes[8][6]:
Blood tests: These are the first step in diagnosis. Serology testing looks for specific antibodies in your blood. Elevated levels of certain antibody proteins indicate an immune reaction to gluten. Genetic testing can also be done to check for the HLA-DQ2 and HLA-DQ8 genes, which can help rule out coeliac disease[8].
Endoscopy with biopsy: If blood tests indicate coeliac disease, an endoscopy is usually performed. This procedure uses a tiny camera on the end of a flexible tube to examine the upper digestive system. During the endoscopy, the healthcare provider can view your small intestine and take a small tissue sample, called a biopsy, to check for damage to the villi[8].
About 10% of the time, the antibodies in the blood are negative, and many people have only minor intestinal changes with normal villi, which can make diagnosis challenging. This is why multiple tests may be needed[7].
In some cases, a capsule endoscopy may be used. This test involves swallowing a tiny wireless camera about the size of a large vitamin pill to take pictures of the entire small intestine[8].
Treatment and Management
There is currently no cure for coeliac disease. However, the condition can be successfully managed through a strict, lifelong gluten-free diet. This is the only effective treatment available[2][5][10].
Following a gluten-free diet means completely avoiding all foods and products that contain gluten from wheat, barley, and rye. This includes obvious sources like bread, pasta, cereals, biscuits, crackers, cakes, pastries, and beer. However, gluten can also be hidden in many processed foods, sauces, soups, packaged foods, and even some non-food products like medicines, vitamins, supplements, lip balms, and toothpaste[9][10].
When you are first diagnosed with coeliac disease, you will typically be referred to a registered dietitian who specializes in treating people with this condition. The dietitian will help you adjust to your new gluten-free diet, ensure your diet is balanced and contains all the nutrients you need, and teach you how to identify which foods are safe to eat[9][10].
Many foods are naturally gluten-free and can still be included in your diet, such as meat, fish, vegetables, fruits, cheese, potatoes, and rice. Additionally, many gluten-free versions of common foods like pasta, pizza bases, and bread are now available in supermarkets and health food shops. In some places, doctors may provide gluten-free bread and flour mixes on prescription[9].
For most people with coeliac disease, symptoms should improve considerably within weeks of starting a gluten-free diet. The small intestine can begin to heal, and the healing process may take up to a few years for the digestive system to recover completely[9][10].
Even if you only eat a small amount of gluten, such as a spoonful of pasta, you may experience very unpleasant intestinal symptoms. If you continue eating gluten regularly, you will be at greater risk of developing complications such as osteoporosis and some types of cancer in later life[9].
Your healthcare provider will typically offer you an annual review to monitor your progress. During this review, your height and weight will be measured, your symptoms will be reviewed, and your diet will be assessed to determine whether you need any further help or specialist nutritional advice[9].
Living with Coeliac Disease
Adjusting to life with coeliac disease requires significant lifestyle changes, but with proper management, people with the condition can live healthy, active lives. Making the transition to a gluten-free diet is one of the first steps in restoring health[16].
One of the most important things to understand is the risk of cross-contamination. This occurs when gluten-free foods come into contact with foods containing gluten, or when the same utensils or cooking equipment are used for both. Even small amounts of gluten can cause damage to the small intestine. If you are the only person in your household going gluten-free, make sure you have your own utensils and cooking equipment to avoid cross-contamination[9][21].
It is essential to always check food labels carefully. Many processed foods include additives that contain gluten, such as malt flavoring and modified food starch. By law, food labeled as gluten-free can contain no more than 20 parts per million of gluten, which should not cause problems for most people with coeliac disease[9][10].
A special note about oats: While oats do not naturally contain gluten, many people with coeliac disease avoid eating them because they can become contaminated with other cereals that contain gluten. Some people may also be sensitive to a protein in oats called avenin. If you want to include oats in your diet, make sure they are labeled as gluten-free and discuss this with your healthcare professional first[9][19].
Telling your friends and family about your condition is important so they can offer support and understand the importance of avoiding gluten. It can also help to connect with support organizations like Coeliac UK or the Celiac Disease Foundation, which provide useful resources, information about living gluten-free, local support groups, and access to the latest research and treatment developments[5][16].
With planning, creativity, and support, following a gluten-free diet becomes easier to manage over time. A sustainable gluten-free diet, combined with regular medical monitoring, allows most people with coeliac disease to manage their symptoms effectively and prevent long-term complications[18][21].
