Gluten and its genetic traces

BiogeniQ, Health, Nutrition

24 June 2019

What exactly is gluten?

Gluten is a protein found in some cereals, including wheat, rye and barley. It is what gives bakery products their shape and elasticity. In general, gluten is ubiquitous in the diet of Canadians given its presence in wheat products and many processed foods.


What illnesses are caused by gluten?

Celiac disease is an autoimmune condition that involves a severe reaction to gluten. In those suffering from the disease, the consumption of gluten causes significant long-term damage to the lining of the digestive system. A wide range of symptoms can be observed in people with celiac disease, including weight loss, abdominal pain, skin lesions or dietary deficiencies. There is no treatment for this condition. The only way to eliminate symptoms is to completely eliminate gluten from the diet. Only 1% of Canadians have celiac disease.[1]

Gluten intolerance, or non-celiac gluten sensitivity, is a very different condition that can also have a wide range of symptoms, from digestive disorders (e.g. bloating, cramps or nausea) to extra-intestinal problems such as joint pain, rashes, general fatigue and headaches. The main factor that distinguishes non-celiac gluten sensitivity from celiac disease is the absence of an immune system response. It is estimated that 6% of Canadians have non-celiac gluten sensitivity. It should be noted, however, that this condition is difficult to diagnose and is often self-reported, therefore the statistics are likely approximate.[2]

There are other conditions associated with gluten, but they are quite rare.


Careful, gluten is not always involved! 

Wheat products, all of which contain gluten, can also cause digestive discomfort due to a completely different nutrient in these products. Fructans are a type of carbohydrate found in wheat products, among others. In some people, fructans can cause symptoms of digestive intolerance when consumed in large quantities.


How is a diagnosis made?

A diagnosis of celiac disease is made in several stages. At least four of the following factors must be observed to confirm such a diagnosis:[1]

  • Presence of antibodies in the blood associated with an immune response to gluten
  • Presence of symptoms associated with celiac disease
  • Presence of genetic markers associated with celiac disease
  • Biopsy of the small intestine showing damage to the intestinal wall or the presence of immune system cells
  • Improvement in blood antibody levels or symptoms when a gluten-free diet is adopted

Celiac disease can develop at any time in a person’s life. For most people, the diagnosis occurs between the ages of 40 and 60.[3]

Gluten intolerance, on the other hand, is diagnosed through a combination of negative tests for celiac disease and a significant improvement in symptoms when gluten is removed from the diet.


Why do a genetic test?

Specific genetic variations, namely genes HLA-DQ2 or HLA-DQ8, are present in almost all individuals with celiac disease. In the absence of these two genetic variations, the risk of celiac disease is so low that it can be virtually eliminated.[1] People with a first-degree family member who has celiac disease, Down syndrome or an autoimmune disorder have a significantly higher risk of celiac disease. This is when genetic testing can be particularly useful in alleviating any concerns.

To be valid, blood antibody assays used for diagnosis require a significant quantity of gluten to be consumed in the weeks prior to the assay. For individuals who have already eliminated gluten from their diet to improve their quality of life, it can be discouraging to reintroduce gluten (from half a slice to five slices of bread a day for a few weeks, or even months!) and experience symptoms of the disease all over again simply to prepare for a blood test.

Since the effects of celiac disease vary greatly from one individual to another and symptoms often appear similar to those of other conditions, the average time frame for a diagnosis is 12 years.[4,5] This entails several years of discomfort and the risk of developing complications associated with the disease, such as dietary deficiencies. The information provided by a genetic test can help guide a doctor’s diagnosis in the event that symptoms appear. 


Should gluten be banned?

Absolutely not. Unless you have a condition associated with gluten consumption, it is not recommended to eliminate gluten from your diet. This would involve restricting several foods, which could increase the risk of dietary deficiencies. This is why a gluten-free diet, when necessary, is usually adopted under the supervision of a health care professional. 


Catherine Vézina


A proud representative of the new generation of nutritionists, Catherine uses her theoretical and practical knowledge to judiciously counsel BiogeniQ’s patients. In particular, she ensures that patients understand their nutrigenomics test result, taking care to place it in perspective with their lifestyle habits. She also writes articles and other content on nutrition.



[1] Fondation québécoise de la maladie cœliaque. Diagnostic, [online], 2015 (in French) [] (Consulted on May 15, 2019) 

[2] Cranney A., Zarkadas M., Graham I. et al. “The Canadian Celiac Health Survey,” Digestive diseases and science, vol. 87, February 2007, p. 1087-1095 []

[3] Agriculture and Agri-Food Canada.   “Gluten Free” Claims in the Marketplace, [online], updated November 10, 2017 [] (Consulted on May 15, 2019) 

[4] Canadian Society of Intestinal Research. Celiac Disease: Still Vastly Under-Diagnosed, [online], 2009 [] (Consulted on May 15, 2019) 

[5] Health Canada. Celiac Disease – The Gluten Connection, ­[online], 2009 [] (Consulted on May 15, 2019)