To Eat Or Not to Eat Gluten: Your DNA May Tell

For a majority of individuals, the term gluten is directly associated with wheat. Indeed, gluten constitutes the main storage protein found in wheat, but it's also present in rye, barley, and oats [1].

Wheat kernels are composed of 8 - 15% protein, with gluten making up approximately 85 - 90% of this protein content [1]. The unique properties of gluten are crucial for successful baking, making it a common ingredient in cakes, biscuits, pastries, and pasta [1].

Gluten is also added to many processed foods to enhance texture, flavor, and moisture retention, even in products that do not contain wheat [1].

In recent times, gluten has been increasingly viewed in a negative light, with recommendations to reduce its consumption due to the difficulty some individuals have in digesting certain components of this protein [1]. These components can lead to gluten intolerance, including conditions such as coeliac disease, non-coeliac gluten sensitivity, and wheat allergy [2, 3]. It's important to recognize that being allergic to wheat or sensitive to gluten does not necessarily mean one has coeliac disease [1].

Symptoms common to gluten-related conditions, Crohn’s disease, and irritable bowel syndrome include nausea, constipation, bloating, irregular bowel habits, abdominal discomfort, pain, and diarrhea [3].

Coeliac disease, an autoimmune disorder, affects those genetically predisposed and is characterized by specific immune antibodies [3, 4]. It affects about 1% of Western and American populations, with a lower prevalence reported in Sub-Saharan Africa [1, 5].

Wheat allergy involves an immune response to wheat products, distinct from the autoimmune response of coeliac disease. Gluten sensitivity, on the other hand, does not trigger an immune response or inflammation [3].

Additional symptoms of coeliac disease can include weight loss, malabsorption, poor growth, short stature, anemia and iron deficiency, delayed puberty, decreased bone density, and dermatitis [4, 5].

For those with coeliac disease, ingesting gluten can trigger an immune response that damages the intestine's lining [1, 4]. This damage can impair nutrient absorption, leading to long-term health issues [6].

The symptoms of coeliac disease can vary widely, and some individuals may not exhibit any symptoms at all. Despite this, the intestines can still be damaged [5, 7]. Diagnosis of coeliac disease typically requires a biopsy of the intestines along with antibody testing [5, 6]. The presence of the IgA-TG2 antibody is a significant marker for this condition [6].

The only effective treatment for coeliac disease is a lifelong gluten-free diet [8]. However, this diet should be adopted under professional guidance to ensure nutritional needs are met [7, 9].

Removing gluten and wheat from the diet without a medical need can have negative impacts on gut bacteria and lead to deficiencies in micronutrients and fiber [9, 10]. These deficiencies often include calcium, iron, folate, and several B vitamins [10].

Coeliac disease is highly hereditary and more prevalent in women than men. The HLA DNA gene plays a crucial role in the development of this condition [1, 4, 5, 6]. Most individuals with coeliac disease possess either the HLA-DQ2 or HLA-DQ8 gene [11].

Before eliminating gluten and wheat from your diet, it's advisable to undergo genetic testing to assess your risk for gluten intolerance. This approach allows individuals to make informed decisions about adopting a gluten-free diet based on their specific genetic predispositions [11, 12].

References:

[1] Biesiekierski, J. R. (2017). What is gluten? Journal of Gastroenterology and Hepatology (Australia), 32, 78–81. 

[2] Cabanillas, B. (2020). Gluten-related disorders: Celiac disease, wheat allergy, and nonceliac gluten sensitivity. Critical Reviews in Food Science and Nutrition, 60(15), 2606–2621.

[3] Roszkowska, A., Pawlicka, M., Mroczek, A., Bałabuszek, K., & Nieradko-Iwanicka, B. (2019). Non-celiac gluten sensitivity: A review. Medicina (Lithuania), 55(6), 1–19.

[4] Tye-Din, J. A., Galipeau, H. J., & Agardh, D. (2018). Celiac disease: A review of current concepts in pathogenesis, prevention, and novel therapies. Frontiers in Pediatrics, 6(November), 1–19.

[5] Caio, G., Volta, U., Sapone, A., Leffler, D. A., De Giorgio, R., Catassi, C., & Fasano, A. (2019). Celiac disease: A comprehensive current review. BMC Medicine, 17(1), 1–20.

[6] Al-Toma, A., Volta, U., Auricchio, R., Castillejo, G., Sanders, D. S., Cellier, C., Mulder, C. J., & Lundin, K. E. A. (2019). European Society for the Study of Coeliac Disease (ESsCD) guideline for coeliac disease and other gluten-related disorders. United European Gastroenterology Journal, 7(5), 583–613.

[7] Sharma, N., Bhatia, S., Chunduri, V., Kaur, S., Sharma, S., Kapoor, P., Kumari, A., & Garg, M. (2020). Pathogenesis of Celiac Disease and Other Gluten Related Disorders in Wheat and Strategies for Mitigating Them. Frontiers in Nutrition, 7(February), 1–26.

[8] Melini, V., & Melini, F. (2019). Gluten-free diet: Gaps and needs for a healthier diet. Nutrients, 11(1).

[9] Diez-Sampedro, A., Olenick, M., Maltseva, T., & Flowers, M. (2019). A Gluten-Free Diet, Not an Appropriate Choice without a Medical Diagnosis. Journal of Nutrition and Metabolism, 2019.

[10] Niland, B., & Cash, B. D. (2018). Health benefits and adverse effects of a gluten-free diet in non-celiac disease patients. Gastroenterology and Hepatology, 14(2), 82–91.

[11] Van Heel, D. A., Franke, L., Hunt, K. A., Gwilliam, R., Zhernakova, A., Inouye, M., Wapenaar, M. C., Barnardo, M. C. N. M., Bethel, G., Holmes, G. K. T., Feighery, C., Jewell, D., Kelleher, D., Kumar, P., Travis, S., Walters, J. R. F., Sanders, D. S., Howdle, P., Swift, J., … Wijmenga, C. (2007).

[12] Dubois, P. C. A., Trynka, G., Franke, L., Hunt, K. A., Romanos, J., Curtotti, A., Zhernakova, A., Heap, G. A. R., Ádány, R., Aromaa, A., Bardella, M. T., Van Den Berg, L. H., Bockett, N. A., De La Concha, E. G., Dema, B., Fehrmann, R. S. N., Fernández-Arquero, M., Fiatal, S., Grandone, E., … Van Heel, D. A. (2010).