Gluten-related disorders is the term for the diseases triggered by gluten, including celiac disease (CD), non-celiac gluten sensitivity (NCGS), gluten ataxia, dermatitis herpetiformis (DH) and wheat allergy. The umbrella category has also been referred to as gluten intolerance, though a multi-disciplinary physician-led study, based in part on the 2011 International Coeliac Disease Symposium, concluded that the use of this term should be avoided due to a lack of specificity.
Gluten is a group of proteins, such as prolamins and glutelins, stored with starch in the endosperm of various cereal (grass) grains.
As of 2017, gluten-related disorders were increasing in frequency in different geographic areas. The increase might be explained by the popularity of the Western diet, the expanded reach of the Mediterranean diet (which also includes grains with gluten), the growing replacement of rice by wheat in many countries, the development in recent years of new types of wheat with a higher amount of cytotoxic gluten peptides, and the higher content of gluten in bread and bakery products, due to the reduction of dough fermentation time. However, a 2020 study by the Leibniz-Institute for Food Systems Biology casts doubt on the idea that modern wheat has higher gluten levels. From a seed bank, they grew and analyzed 60 wheat cultivars from between 1891 and 2010 and found no changes in albumin/globulin and gluten contents over time. "Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat."