What is Celiac Disease?
Celiac disease (CD) is an autoimmune disorder in which the body has a toxic reaction to gluten, the storage protein in the cereal grains wheat, rye, and barley. CD is present in about 1 out of every 133 Americans (some scientists believe it may be closer to 1 in every 100). Common symptoms of celiac disease include diarrhea, abdominal pain and gas, weight loss, unexplained infertility, neurologic conditions, unusual bleeding or anemia (due to vitamin/mineral deficiencies), and osteoporosis. There are at least 300 symptoms associated with celiac disease!
How Do You Get Celiac Disease?
There are three factors in the development of celiac disease: genetic, environmental, and immunologic. First, a person must inherit specific genetic markers. Next, the person with these genes experiences an environmental trigger or physical stressor. Some examples of environmental or physical stressors I have observed with my patients include:
- Emotional events—divorce, loss of a family member or close friend.
- Stress—at work, school, or home.
- Surgery or severe infection, especially if the infection required powerful antibiotics.
- Severe gastroenteritis (viral illness accompanied by vomiting and/or diarrhea) or “traveler’s diarrhea” which never completely clears up.
Genetics + Environmental/Physical Stressor + Gluten in the Diet =
Interestingly, not everyone who has the genetic markers develops celiac disease after a stressor event. One leading theory is that stressor events elicit a change in bacteria population in the gut, leading to intestinal permeability or leaky gut syndrome. When a protein such as gluten leaks from the inside the intestine into the tissue, it activates the immune response. Once the switch in the immune system is flipped “on,” it changes how the body perceives gluten. So the next time the person ingests gluten, the body sees it as an invader.
After the disease has been triggered, the immune system attacks the finger-like absorptive lining (called villi) in the small intestine. Eating gluten causes the villi in the small intestine to flatten, called villous atrophy. Normal villi look like peaks and valleys, while the villi of someone with celiac disease looks more like low rolling hills. The villi constitute the main site of absorption in the small intestine. If they are damaged, the body is unable to absorb key macro and micronutrients, causing malnutrition.
Testing for Celiac Disease
A physician should diagnose celiac disease. He or she may begin with a screening blood test for CD, such as tissue transglutaminase antibodies (tTg IgA) and/or endomysial antibody (EMA). Both of these tests are highly sensitive and specific for celiac disease.
However, there can be false positive or negatives with blood tests. Therefore, experts in the celiac field recommend the “gold standard” method of diagnosis: an endoscopy with a small bowel biopsy.
What Is an Endoscopy with Biopsy?
After the patient is sedated, an endoscope, a small camera at the end of a flexible tube, is inserted through the mouth. As the endoscope is advanced through the esophagus, stomach, and duodenum, the gastroenterologist looks for abnormalities in the function and tissue of the digestive tract. Once the camera is in the duodenum, the doctor may biopsy, or remove, tissue samples with a small pincher, especially if the villi look abnormal.
Biopsy samples are sent to the lab and reviewed under the microscope by a pathologist. They are looking for flattened villi, as mentioned above, as well as specific inflammatory cells. Once a diagnosis of celiac disease is confirmed, the patient should meet with a registered dietitian to learn the principles of a strict, life-long, gluten-free (GF) diet.
Should I Try a Gluten-Free Diet Before Diagnosis?
Physicians and dietitians specializing in the treatment of CD recommend that people do not start the gluten-free diet until they have the small bowel biopsy. If you start this diet and choose to get tested later, you will likely have a false negative result. The small bowel will have healed up and blood tests may be in the normal range. In addition, villi will look at least somewhat healthy during endoscopy and on the pathology report.
Treatment for Celiac Disease
At the present time, the only medical treatment for celiac disease is a life-long 100 percent gluten-free diet. No wheat, rye, barley, kamut, spelt, triticale, malt, or contaminated grains. Only certified gluten-free grains are recommended; they are tested to be sure they contain less than 20 parts per million (ppm) of gluten. Certified GF grains are free from gluten contamination growing in the field, during transportation, storage, and in processing.
What Is Gluten?
Gluten is the storage protein that gives bread its structure and elasticity, or stretchiness. Bread containing gluten has a distinct texture when you chew it.
Why Follow the GF Diet for Celiac Disease?
If you took normal intestinal villi and spread them out flat, they would cover an area roughly the size of a tennis court. If you have untreated celiac disease (or are not following the GF diet closely), and the villi lose all their peaks and valleys, this can decrease the surface area to about the size of a table top! Your body may be unable to absorb all the nutrients it needs to maintain health.
Over time, malabsorption of nutrients leads to poor nutritional status and vitamin and mineral deficiencies. In addition, those with CD who still eat gluten have a higher risk of developing osteoporosis, other autoimmune diseases, and even some types of intestinal cancers. The GF diet is one diet where there is no cheating allowed. How much is considered cheating? Consuming enough wheat to cover your pinky fingernail each day is enough to result in ongoing intestinal damage.
Following a gluten-free diet can be challenging. Enlisting the help of a registered dietitian, your family, friends, and a local support group is essential. They can give you dos and don’ts on how to follow the GF diet at home, in restaurants, and when traveling. Gluten contamination can easily happen in restaurants with inappropriate food choices, and even in your own kitchen, sabotaging even the best of intentions.
Non-Celiac Gluten Sensitivity
For many years, when someone had a negative blood test and a negative small intestinal biopsy, that would confirm that this patient did not have celiac disease. They were advised to eat a regular balanced diet, including gluten.
However, these same patients would often continue to have intestinal complaints for months or years. Some decided to follow a gluten-free diet on their own, and their symptoms drastically improved. In recent years, scientists studied these patients more closely and determined there is a diagnosis separate from celiac disease. They coined a new term: non-celiac gluten sensitivity. Since the knowledge base of gluten sensitivity is in its infancy, much is still unknown. For example, we do not yet know the long-term prognosis or progression, if there is one. The good news is that gluten sensitivity does not seem to affect the villi in the intestine, cause malabsorption, or increase risk of other autoimmune diseases. We anticipate new research in the future that will improve the diagnosis and treatment of this newly-identified disorder.
Diagnosing Non-Celiac Gluten Sensitivity
Currently, testing for gluten sensitivity is a diagnosis of exclusion. The physician usually begins with the same blood tests used for celiac disease. Virtually all patients with celiac disease have the same genetic markers. In patients with non-celiac gluten sensitivity, only about 50% have those same genetic markers. When AGA blood-testing is conducted, about 50% of patients with gluten sensitivity have a positive blood test for AGA-antibodies.
In patients with gluten sensitivity, intestinal biopsies are (virtually) normal. If celiac disease and IgE wheat allergy can be excluded, but symptoms are alleviated with a gluten-free diet, gluten sensitivity is suspected.
Treatment for Gluten Sensitivity
The treatment for non-celiac gluten sensitivity is a 100 percent gluten-free diet. An interesting observation by experts in the field is that minutes or hours after gluten exposure, those with gluten sensitivity often report more intense symptoms (abdominal pain or diarrhea) than those with celiac disease. In fact, these negative reactions sometimes make it easier for those with gluten sensitivity to fully adhere to the gluten-free diet.
Books and Research
There are many excellent publications on the subject of celiac disease and the gluten-free diet. Some are well written and have accurate information, while others record more of a personal journey. One book I highly recommend is: Celiac Disease: A Hidden Epidemic by Peter H. R. Green and Rory Jones. I jokingly call it the “Bible of Celiac Disease.” Author Dr. Peter Green is a well-respected researcher and physician, who has published numerous studies and also founded The Celiac Disease Center at Columbia University. He is dedicated to researching celiac disease, and is involved in direct patient care as well.
Several other books I recommend:
- Gluten-Free Diet: A Comprehensive Resource Guide—Expanded and Revised Edition by Shelley Case, RD
- Real Life with Celiac Disease by Melinda Dennis, MS, RD, LDN and Daniel Leffler, MD, MS
- The Ultimate Guide to Gluten-Free Living by Celiac Disease Center at Columbia University
There are numerous organizations which support the celiac community in the United States.
- Gluten Intolerance Group (GIG) www.gluten.net
- Celiac Sprue Association www.csaceliacs.org
- Celiac Disease Foundation (CDF) www.celiac.org
- The University of Maryland Center for Celiac Research www.celiaccenter.org
- Beth Israel Deaconess Medical Center, a teaching hospital of Harvard Medical School www.celiacnow.org
Get tested for celiac disease before you start the gluten free diet. The most compelling reason? Since CD is considered an auto-immune disease, you need to be followed closely by a physician long-term (for vitamin/mineral deficiencies, adequate bone density, risks of intestinal cancers, etc). However, if you have non-celiac gluten sensitivity, it is not associated with other auto-immune conditions, so long-term MD follow-up is not as critical.