Celiac Disease, Non-Celiac Gluten Sensitivity, and Food Allergy: How are they different?
Celiac disease, an autoimmune disease of the small intestine triggered by gluten, is a frequent condition affecting 1-4% of the world population. (1) Celiac disease can develop across the lifespan, and is a chronic disease caused by a food-induced delayed hypersensitivity immune response.
In those with celiac disease, ingestion of gluten (a protein fraction found in wheat, rye, and barley) causes inflammation in the small intestine, manifesting as chronic diarrhea, difficulty absorbing food, weight loss or failure to thrive. Celiac disease may lead to a variety of non-intestinal symptoms including anemia, chronic fatigue, osteoporosis, impaired spleen, infertility, neurologic disorders, skin rashes and cancer, especially if left untreated. Celiac disease is also associated with other autoimmune conditions, such as diabetes, Addison’s disease, rheumatologic, thyroid and liver disorders. A diagnosis of celiac disease is associated with increased overall mortality.
A blood test is available for celiac disease but, like any test, it is not 100% accurate. This test evaluates the immune system’s response to gluten. Most patients with celiac disease have certain genes called HLA-DQ2 or DQ8, and this test can also be used for diagnosis.(2) If blood tests are negative and there is still a high suspicion or family history of celiac disease, a gastroenterologist may need to perform an endoscopy and biopsy. This procedure is done under sedation as a tube is inserted through the mouth and passed into the small intestine for observation and biopsy. Both the blood tests and the endoscopy need to be done while the patient is eating gluten.
Those who are diagnosed with celiac disease need to completely and permanently avoid any form of gluten in their diets. Getting help from a dietitian or nutritionist is recommended.
There is research that shows a possible decreased risk of celiac disease with breast feeding and continued breast feeding when gluten is introduced into the child’s diet. A previous history of intestinal infections and the state of natural bacteria in the gut may influence the development of celiac disease. Additionally, wheat has been modified to contain higher amounts of gluten and this, along with the increased ingestion of wheat (breads) in developed countries, may contribute to the increasing incidence of celiac disease.
What is non-celiac gluten sensitivity (NCGS)?
NCGS is a syndrome of symptomatic response to gluten ingestion in patients without evidence of celiac disease when looking in the blood or at tissue under a microscope. (3) The most common complaints are abdominal pain, bloating, and/or change in bowel patterns, but some patients complain of other symptoms that don’t involve the intestines, such as foggy mind, or feeling sluggish or tired. The onset occurs typically within hours or a few days of ingesting gluten. This timing distinguishes NCGS from the rapid onset of symptoms in wheat allergy (minutes to hours), but can overlap with the delayed onset of symptoms in celiac disease (days to weeks). In many patients, gluten is probably not the specific trigger. The symptoms are not reproduced in studies when patients and their examiners don’t know if the food they are eating contains gluten (these are called double-blind food challenge), suggesting a placebo or non-gluten-related physiologic effect. This effect may be potentially attributable to other components such as fermentable, poorly absorbed short-chain carbohydrates (fermentable oligo-, di-, and monosaccharides and polyols ["FODMAP"]).
How is celiac disease different from cereal grain allergy?
Celiac disease and NCGS are different from wheat, rye or barley allergy. Cereal grain allergy is more common in children and is usually outgrown with age. With a food allergy, the immune system overreacts to one or several food proteins (including gluten as well as other proteins in cereal grains) and causes rapid symptoms that can be serious or even life-threatening (anaphylaxis).(4) In a classic, IgE-mediated wheat allergy, symptoms usually begin shortly after ingestion of the food (a few minutes to an hour or so) and include hives, shortness of breath, lightheadedness or vomiting. In a non-IgE-mediated food allergy, ingestion of wheat may lead to chronic allergic inflammation, for example, eosinophilic esophagitis or to violent vomiting within 1-4 hours of eating, e.g., food protein-induced enterocolitis syndrome (FPIES). (5, 6)
Since allergic reactions to foods can be life-threatening, food allergic people must be very careful to avoid their food triggers. If you have severe allergies to food, be sure to complete an Anaphylaxis Action Plan and carry your autoinjectable epinephrine with you at all times. Use this medication in the event of an anaphylactic reaction, seek medical care, and then see an allergist/immunologist for follow-up care.
If you believe you may have a food allergy, see an allergist / immunologist.
If you believe you may have celiac disease, see a gastroenterologist.
1. Wessels M, Auricchio R, Dolinsek J, Donat E, Gillett P, Mårild K, et al. Review on pediatric coeliac disease from a clinical perspective. European journal of pediatrics. 2022.
2. Husby S, Murray JA, Katzka DA. AGA Clinical Practice Update on Diagnosis and Monitoring of Celiac Disease-Changing Utility of Serology and Histologic Measures: Expert Review. Gastroenterology. 2019;156(4):885-9.
3. Mumolo MG, Rettura F, Melissari S, Costa F, Ricchiuti A, Ceccarelli L, et al. Is Gluten the Only Culprit for Non-Celiac Gluten/Wheat Sensitivity? Nutrients. 2020;12(12).
4. Kraft M, Dölle-Bierke S, Renaudin JM, Ruëff F, Scherer Hofmeier K, Treudler R, et al. Wheat Anaphylaxis in Adults Differs from Reactions to Other Types of Food. The journal of allergy and clinical immunology In practice. 2021;9(7):2844-52.e5.
5. Molina-Infante J, Lucendo AJ. Approaches to diet therapy for eosinophilic esophagitis. Current opinion in gastroenterology. 2020;36(4):359-63.
6. Cianferoni A. Food protein-induced enterocolitis syndrome epidemiology. Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology. 2021;126(5):469-77.