Gluten has been a topic of significant interest and research recently. It has become a media darling over the past few years for a variety of medical and non-medical reasons, and interest has led to a vast body of literature and information that is occasionally confusing and misleading. This review categorizes the diseases associated with gluten based on confirmed medical facts.

Gluten (from Latin gluten, meaning glue) is a composite of storage proteins termed prolamins and glutelins that are stored together with starch in various cereal (grass) grains. It is found in wheat, barley, rye, oat, related species, hybrids (such as spelled Khorasan and emmer, among others), and their products, such as malt. Gluten gives elasticity to dough, allowing for the puffy and chewy texture. About 80% of the protein in bread wheat is gluten. Pasta has a lesser degree of gluten. Imitation meats, beer, soy sauce, and occasionally, ice cream and ketchup have gluten from the included stabilizing agents. Contamination of other food products with gluten is also a common problem. Hair products and cosmetics sometimes contain gluten, as well.

Gluten is significant for physicians since it has a spectrum of illnesses associated with it, for example, gluten-sensitive enteropathy or celiac disease (CD), non-celiac gluten sensitivity (NCGS), wheat or grain allergy, gluten ataxia, and dermatitis herpetiformis (DH).

History

Aretaeus Cappadocia described a non-specific entity termed koiliakos in 250 AD. Koelia is Greek for the abdomen. Francis Adams translated this to English in 1856, using the term Coeliacs or celiacs. Samuel Gee famously said in 1888 that "to regulate the food is the main part of the treatment" and that "if the patient can be cured at all, it must be by means of diet."

Carnegie Brown published a book in 1908 that described peripheral neuritis in patients with CD. The book also discussed "sprue" and ataxia, but this was hard to prove since the actual diagnosis could not be confirmed with certainty.

Second World War II led to devastation and famine across the world. Most people suffered from malnutrition and illnesses, but the subgroup with celiac improved and felt better. Dutch Pediatrician Willem-Karel Dicke noted that mortality from the disease decreased from 30% pre-war to a lesser figure, which was reversed after the war. His papers were some of the first that mentioned the effect of a wheat-free diet on children.

Eventually, small bowel biopsy methods were developed in the 1950s and 1960s, and diagnosis could be confirmed. In 1961, Taylor published an immunological study and linked the disease to circulating antibodies. Although it was initially thought to be a food allergy, the autoimmune theory was accepted, and HLA-DQ2 was linked to it. In 1966, enteropathy was noted in 9 of 12 patients with dermatitis herpetiformis. In the same year, it was noted that CD was associated with many neurological disorders.

In the 1980s, the journal Gastroenterology coined “non-celiac gluten sensitivity.” This disease was very prevalent in Europe but not so much in the United States. Alessio Fasano, who treated celiac patients in Europe, moved to Boston to work at Massachusetts General Hospital and found that it was a prevalent disease in the United States as well. His 2003 article in the Journal of American Medical Association started a process of recognizing the disease and paved the way for many more studies on the subject.

Studies in the 2000s and 2010s linked the disease to almost everything. Gluten was quickly vilified. The Food and Drug Administration (FDA) started requiring the labeling of gluten-free products in 2013. Gluten-free mania ballooned the related global industry to a $3.5 billion per year figure with a forecast of $4.7 billion in 2020. Gluten-free pizza, cookbooks, apps, and restaurants have mushroomed rapidly since.