What Is The Gluten Sensitivity? Is The Gluten-Free Diet Necessary?

First of all, “gluten” is a protein complex found in most grains such as wheat, rye and barley. Gluten does not cause a problem in individuals with normal and healthy intestines. In individuals with Celiac Disease, gluten taken into the body has an inflammation-triggering effect on the intestines and damage the structure of the cells responsible for absorption. Therefore, gluten-free diet is a “medical nutrition therapy” in individuals with Celiac Disease and its efficacy has been proven. On the other hand, “Non-Celiac Gluten Sensitivity” is different from Celiac Disease as its name implies. There is no inflammatory response and definite dietary recommendation for Non-Celiac Gluten Sensitivity. Individuals who say they have this sensitivity report that they experience some digestive symptoms when they eat gluten-containing foods. Some of these symptoms are bloating, flatulence, abdominal pain. However, it is difficult to diagnose an individual with gluten sensitivity as there is no explicit mechanism or biomarkers to explain this.
 
The popular arguments about Gluten Free Diets like “If a food contains gluten, it is harmful.” are false and over-generalizing. Here, it is necessary to fully evaluate the source of gluten. For example, bulgur is a whole grain containing gluten, while white rice is gluten-free but refined grain. In terms of dietary fiber, bulgur is a healthier option than rice, and gluten does not change it. On the other hand, gluten is a common ingredient in the food industry and many ultra-processed packaged foods such as chocolate, biscuits, crackers contain gluten. If an individual removes such packaged products with gluten-free diet, it is not surprisingly to benefit because they will also reduce the intake of high calories, sugar, salt and saturated fat. In other words, it is not correct to generalize each source of gluten as equally harmful.
 
Another issue that needs to be considered in individuals who say that their digestive problems decrease or disappear with gluten-free diet is that gluten-containing foods also contain other compounds that can cause digestive problems. For instance, it is now known that foods containing FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides and polyols) also cause digestive symptoms. Especially in Irritable Bowel Syndrome, intestines do not function as desired and individuals with this syndrome suffer from gas, bloating, constipation or diarrhea. Following a gluten-free diet is common in these individuals.
 
In a study published in the Journal of Gastroenterology in 2018, researchers investigated whether the symptoms of Non-Celiac Gluten Sensitivity were caused by gluten or, as we mentioned above, from other compounds called FODMAPs. In this study, 59 Gluten Sensitive individuals were divided into three groups and given a muesli bar containing gluten or fructane (a FODMAP compound thought to trigger symptoms). Surprisingly, digestive symptoms were significantly more in individuals consuming bars containing fructane, rather than gluten. Therefore, individuals should find the triggers that cause symptoms rather than restrict gluten directly as it can be unnecessary and useless.  Furthermore, the findings of this study raise doubts about the definition of "Non-Celiac Gluten Sensitivity". Not all individuals with digestive problems need to follow a gluten-free diet, the source of the symptoms may be anything other than gluten (like fructane).
 
In conclusion, while gluten restriction is indisputably medical nutrition therapy in Celiac Disease; gluten restriction for other conditions like “gluten sensitivity” is controversial. In individuals with self-reported Gluten Sensitivity, the cause of related digestive problems may be caused by other non-gluten triggers. Particularly in recent years, studies on FODMAP-containing foods and their restrictions have been increasing. The important point here is to find the relevant food that triggers the symptoms in consultation with a dietitian and to remove it from the diet. Briefly, dietary approaches that are common in general population and have no scientific basis should be avoided and Gluten Free Diet should not be considered as a solution for every disease.