Gluten is being blamed for nu­merous health problems, and recent claims suggest that by eliminating gluten from our diet we can cure diabetes, obesity, rheumatic illnesses, and cataracts. Wheat, and gluten in particular, has been given pariah status by the millions who are on the low-carb diet bandwagon, particularly those who believe they are allergic or sensitive to gluten. Since most of the evidence against wheat or gluten is unsubstantiated by science, there is no need for patients to avoid gluten unless they have celiac disease, or to avoid wheat unless they have IgE antibody-mediated wheat allergy. 

In patients with celiac disease, the consumption of gluten provokes an autoimmune response that damages the small intestine and can cause symp­toms of bloating, diarrhea, cramps, abdominal pain, weight loss, malabsorption of nutrients, and long-term increased risk of gastrointestinal malig­nancies. Among the general population this occurs in 1 in 133 patients. If there is a family history the incidence jumps to 1 in 22. Treatment of celiac disease requires strict adherence to a gluten-free diet. 

Untreated celiac disease, even in those patients with minimal symptoma­tology, results in increased risk of gastrointestinal malignancy and low bone density. Several studies have sug­­gested an increased risk of other auto­immune illnesses such as hypo­thyroid­ism, type 1 diabetes, connective tissue diseases, and also preterm delivery and intrauterine growth retardation if celiac disease is left untreated. 

The probability of diagnosing celiac disease is over 5% in those persons with a family history of celiac disease who otherwise have unexplained iron deficiency anemia, steatorrhea, type 1 diabetes, or a failure to thrive in children. IgA antitissue transglutaminase and IgA endomysial antibody are equiv­alent in diagnostic accuracy, but antigliadin antibody tests are no long­er used routinely as they have lower sensitivity and specificity. Small bow­el biopsy should be performed in pa­tients with positive serology to confirm diagnosis. Ensure the patient has consumed gluten for 2 months prior to testing and is not IgA deficient to prevent missing the diagnosis. 

How should physicians respond to patients who say they feel better since they have cut out gluten?
Many people say that they feel better after eliminating gluten from their diet, but it is usually because the gluten-laden processed food removed from their diet has been replaced with basic, nutrient-dense, whole foods. Some patients with irritable bowel syndrome will see an improvement in symptoms with a lower carbohydrate diet, however this may not be due to the absence of gluten but rather as a result of an overall improvement in diet.

Physicians need to give patients guidance in the form of evidence-based advice about their diets, and encourage them to make overall healthy food choices instead of simply eliminating gluten. Patients influenced by fad diets may follow unnecessary elimination processes that result in nutrient res­trictions—and possibly significant expense. 

Celiac patients need guidance and nutritional advice from a registered dietitian on healthy eating that includes gluten-free grains. Physicians should also be aware that true celiac disease sufferers are entitled to claim the incremental costs associated with the purchase of gluten-free products as an eligible medical expense on their income tax returns. 

HealthLink BC online (www.healthlinkbc.ca [11]) or by phone (8-1-1) is a useful reference for further information on healthy eating and therapeutic dietary interventions. Celiac-specific information can be found at the Canadian Celiac Association (www.celiac.ca [12]). 

The majority of our patients are perfectly fine continuing to eat wheat and this should be encouraged. Whole grains and cereals are essential parts of a healthy, balanced diet and provide energy, fibre, and B vitamins. 
—Kathleen Cadenhead, MD
—Margo Sweeny, MD
Nutrition Committee

Acknowledgment
Special thanks to Dr Paul Martiquet, Medical Health Officer for Rural Vancouver Coastal Health.

This article is the opinion of the Council on Health Promotion and has not been peer reviewed by the BCMJ Editorial Board.

Suggested reading
Alberta Society of Gastroenterologists and the Toward Optimized Practice Program. A summary of the NASPGHAN, AGA and WGO guidelines: Diagnosis of Gluten-Sensitive Enteropathy (Celiac Disease). 2006. Accessed 4 March 2013. www.celiac.ca/pdfs/CeliacGuidelines_CanadaFeb2008.pdf [13].

Cosnes J, Cellier C, Viola S, et al. Incidence of autoimmune diseases in celiac disease: Protective effect of the gluten-free diet. Clin Gastroenterol Hepatol 2008;6:753. Accessed 4 March 2013. www.uptodate.com/contents/management-of-celiac-disease-in-adults/abstrac... [14].

Ludvigsson JF, Montgomery SM, Ekbom A. Celiac disease and risk of adverse fetal outcome: A population-based cohort study. Gastroenterology 2005;129:454. Accessed 4 March 2013. www.ncbi.nlm.nih.gov/pubmed/16083702 [15].

Nørgård B, Fonager K, Sørensen HT, et al. Birth outcomes of women with celiac disease: A nationwide historical cohort study. Am J Gastroenterol 1999;94:2435. www.uptodate.com/contents/management-of-celiac-disease-in-adults/abstrac... [16].

US Department of Health & Human Services. Agency for Healthcare Research and Quality. Recognition and assessment of coeliac disease: Dietary considerations before testing for coeliac disease. Ac­cessed 4 March 2013. http://guideline.gov/content.aspx?id=15438#Section424 [17].

Ventura A, Magazzù G, Greco L. Duration of exposure to gluten and risk for autoimmune disorders in patients with celiac disease. SIGEP Study Group for Autoimmune Disorders in Celiac Disease. Gastroenterology 1999;117:297. Accessed 4 March 2013. http://www.ncbi.nlm.nih.gov/pubmed/10419909 [18].