What is Gluten?
Gluten is a protein found in grains like wheat, rye and barley.
Why is Gluten Important?
There are various disorders that can be related to this protein. We will discuss wheat allergy, celiac disease and gluten sensitivity below.
What is Wheat Allergy?
Normally, your immune system generates antibodies (substances in the blood produced by your immune system) to protect your body against foreign invaders. If you have wheat allergy, your body creates an allergy-causing antibody that targets one of the proteins found in wheat. So, whenever you eat wheat, your immune system mounts an attack and you can have a range of symptoms that could be mild or severe. A severe allergic reaction may include a potentially life-threatening reaction called anaphylaxis. Some of the symptoms of wheat allergy include: itching, hives, swelling, sneezing, runny or stuffy nose, difficulty swallowing, shortness of breath, cough, wheezing, vomiting, diarrhea, abdominal cramps, and lightheadedness.
Wheat is one of the top 8 foods that are responsible for ~90% of food allergies. Wheat allergy is more common in children, but can occur in adults. Many children are able to outgrow this allergy.
What is Celiac Disease?
The biggest misconception is that celiac disease is due to an allergy; however that is not the case. It is actually an autoimmune disease. When people with celiac disease eat gluten, their bodies have an immune response and produce a different kind of antibody than the type produced in allergy; this celiac antibody attacks and damages the lining of the small intestine. As a result, nutrients pass through the digestive system without being absorbed. This often leads to symptoms such as diarrhea, gas, bloating and eventually, malnutrition.
Other symptoms of celiac disease may include nausea or vomiting, constipation which may alternate with diarrhea, itchy skin; since absorption of nutrients is poor, there may also be unexplained weight loss, anemia, weakness or muscle cramps, and more rarely neurological complaints including seizures, migraine headaches, or concentration and memory problems.
Patients with celiac disease will not lose their sensitivity to gluten -- unlike gluten or wheat allergy, one does not "grow out of" celiac disease. However, symptoms can be well controlled with a gluten-free diet, which allows the intestinal lining to heal and once again absorb nutrients as it should.
What is Gluten Intolerance?
People who fall into this group have the classic symptoms of celiac disease mentioned above, but have no detectable intestinal damage, and test negative for certain key autoimmune (celiac) antibodies. They also do not have wheat allergy. Gluten intolerance is a diagnosis by default for those who don't have celiac disease or wheat allergy, but feel better on a gluten-free diet.
Research is being conducted to see if there may be special blood tests that could help diagnose this condition, however at this time there are no such tests available.
How are these Disorders Diagnosed?
If you think you may have a gluten-related disorder, you should discuss your symptoms with an allergist, which is a physician specializing in allergic and immunologic disorders. Based on your history and physical exam, the doctor will advise you on the proper tests needed to identify the source of your problem.
To diagnose wheat allergy, your doctor may perform allergy skin tests (a scratch test using a drop of liquid extract placed on the skin), with results in about 20 minutes. Alternatively, a blood test may be ordered to look for the allergy-causing antibodies.
To evaluate for celiac disease and gluten intolerance, blood tests may be done to look for the autoimmune antibodies that can cause celiac disease. If these are positive, a small intestine biopsy may be needed to confirm the diagnosis of celiac disease. If these tests are negative you may be diagnosed with gluten intolerance.
What are the Treatment Options?
For all 3 disorders, strict avoidance of gluten is the mainstay of treatment. If you have wheat allergy you must be sure to avoid all wheat proteins, not just gluten. Your allergist can tell you what these include.
At this point there are no medications that are effective in treating these disorders.
What is a Gluten-free Diet?
Many foods can have hidden sources of gluten (such as sauces, processed meats and even beer). In addition, many grains are enriched with vitamins. Avoiding grains with a gluten-free diet may mean eating fewer of these enriched products. Speak with your allergist, gastroenterologist, and/or a dietitian to ensure that you understand which products to avoid. It is important that you get enough of the vitamins and nutrients that wheat products provide, such as iron, vitamin B12, vitamin D, magnesium, and fiber.
If you are on a gluten-free diet, you will likely eat more fruits, vegetables, and lean meat, and more naturally gluten-free grains like brown rice, quinoa, and buckwheat. Many stores also offer a wide selection of gluten free products. Be sure to read labels and only buy the packages with the gluten-free symbol on them (see link to video). Some products say "gluten free", but do not have the symbol -- you can call the manufacturer to ensure that these products do not contain gluten before purchasing them.