Only people with specific gluten-related conditions—such as celiac disease, wheat allergy, or non-celiac gluten sensitivity—experience adverse reactions to gluten consumption.
Myth: Gluten is harmful.
“Gluten” is a generic term referring to a group of proteins found in cereals such as wheat, barley, and rye. Gluten is present in bread and baked goods, pastries, pasta, breakfast cereals (including oats, which are frequently contaminated with gluten), malt (derived from barley), certain food colourings made from cereals, and beer (when brewed from grains). Most people tolerate gluten well, but there is a minority—about 1 in 20 individuals (Taraghikhah, Ashtari et al., 2020)—who experience symptoms related to gluten intake. Gluten-related disorders may be autoimmune (celiac disease), allergic (wheat allergy), or non-allergic and non-immune (non-celiac gluten sensitivity).
Celiac disease
This is the most extensively studied gluten-related condition. It affects approximately 1% of the population and has an autoimmune basis: the body’s immune system attacks small structures in the intestine called microvilli, which are essential for nutrient absorption. The result is impaired nutrient uptake.
Testing for celiac disease is recommended for individuals who have a first-degree relative diagnosed with the condition, as well as for those presenting associated symptoms, including abdominal pain, bloating, diarrhea or constipation, steatorrhea, nausea and vomiting, cognitive changes, anxiety or depression, marked fatigue, migraines, skin rashes or itching, joint pain, dysmenorrhea, recurrent mouth ulcers, symptoms of peripheral neuropathy, or significant weight fluctuations. These symptoms, however, are non-specific and may indicate either malabsorption (impaired intestinal nutrient absorption) or other conditions with no clear symptom pattern, which may manifest silently or intermittently.
To diagnose celiac disease, blood tests can be performed to measure specific antibodies. Confirmation may be obtained through a duodenal biopsy or genetic testing for HLA DQ2 or DQ8, which is particularly useful when there are discrepancies between antibody test results and biopsy findings. Treatment involves adopting a strict gluten-free diet and avoiding cross-contamination in kitchens where both gluten-containing and gluten-free foods are prepared.
Wheat allergy
Wheat allergy occurs when a person consumes or inhales wheat flour. In this case, the immune system overreacts to proteins found in wheat, and the reaction may be intensified by physical activity. Symptoms may include swelling or itching of the mouth or throat, hives, skin rashes, nasal congestion, headaches, breathing difficulties, abdominal cramps, nausea, vomiting, diarrhea, and, in severe cases, anaphylaxis—a serious, rapidly progressing allergic reaction that can be life-threatening. A distinguishing feature of wheat allergy, compared with celiac disease, is the speed with which symptoms appear after gluten consumption, often within just a few minutes. Diagnosis can be established through skin prick tests or blood tests.
Non-celiac gluten sensitivity
Non-celiac gluten sensitivity affects around 10% of the population, causes symptoms similar to those of irritable bowel syndrome, and is characterised by reactions that may occur anywhere from a few hours to several days after the consumption of gluten-containing foods. The most common symptoms include bloating, diarrhea, abdominal pain, nausea, gastroesophageal reflux, fatigue, headaches, joint pain, skin rashes or eczema, and depressive symptoms (Barbaro, Cremon et al. 2018).
Because there is no specific diagnostic marker for this condition, physicians primarily identify it by excluding other possible causes. Although avoiding gluten can reduce symptoms, the Low-FODMAP diet has produced similar results. This diet limits easily fermentable carbohydrates such as lactose (found in dairy products), fructose (from fruit, honey, or syrups), fructans (such as those found in wheat, including inulin), galactans (present in legumes), and polyols (sweeteners such as sorbitol, mannitol, and xylitol).
An increasing overlap has been observed between non-celiac gluten sensitivity and irritable bowel syndrome. For this reason, in selected cases, physicians may also recommend a gluten-free diet.
In conclusion, for celiac disease and wheat allergy, a gluten-free diet is absolutely essential. In non-celiac gluten sensitivity, adherence to a gluten-free diet is important for symptom control but not decisive. For irritable bowel syndrome, reducing gluten intake within a Low-FODMAP diet is sufficient.
Bibliography
- Barbaro, M. R., Cremon, C., et al. (2018), “Recent advances in understanding non-celiac gluten sensitivity”, in F1000 Research, vol. 7, art. no. F1000 Faculty Rev-1631.
• Taraghikhah, N., Ashtari, S., et al. (2020), “An updated overview of spectrum of gluten-related disorders: clinical and diagnostic aspects”, in BMC Gastroenterology, vol. 20, art. no. 258.
