What’s the big deal with gluten? - William D. Chey

Gluten is an insoluble protein composite consisting of two proteins: gliadin and glutenin.

Gluten is found in certain grains such as wheat, rye and barley. It is responsible for the elastic consistency of dough and the chewiness of foods made from wheat flour, such as bread and pasta.

These foods cause problems for some people, like wheat allergy, celiac disease and non-celiac gluten sensitivity.

• Wheat allergy is uncommon and occurs when a person's immune system reacts to wheat proteins leading to mild problems. However, in rare cases, it can lead to anaphylaxis.
• Celiac disease is inherited. Eating foods with gluten leads to inflammation and damage to the lining of the small intestine, which impairs intestinal function.
• People with non-celiac gluten sensitivity experience painful gut symptoms and suffer from fatigue, brain fog, joint pain or skin rash.

Diagnoses of gluten sensitivity are based on the development of symptoms, the absence of wheat allergy and celiac disease, and subsequent improvement on a gluten-free diet.

There's no reliable blood or tissue test because gluten sensitivity isn't a single disease but has several possible causes.

The problems people develop when they eat wheat and other grains aren't exclusively due to gluten.

• Some people claim gluten sensitivity but are really sensitive to the sugars found in wheat and other foods, called fructans. The intestine can't break down or absorb fructans, so they are fermented by bacteria in the large intestine or colon, causing unpleasant symptoms in people with bowel problems.
• Another possible explanation is the nocebo effect. A person believes something will cause problems, and because of that belief, it does.