Mankind has existed for 2·5 million years but only in the last 10 000 years have we been exposed to wheat. Wheat was first cultivated in the Fertile Crescent (South Western Asia) with a farming expansion that lasted from about 9000BC to 4000BC. Thus it could be considered that wheat (and gluten) is a novel introduction to man's diet! Prior to 1939 the rationing system had already been devised. This led to an imperative to try to increase agricultural production. Thus it was agreed in 1941 that there was a need to establish a Nutrition Society. The very roots of the society were geared towards necessarily increasing the production of wheat. This goal was achieved and by the end of the 20th century, global wheat output had expanded 5-fold. Perhaps as a result the epidemiology of coeliac disease (CD) or gluten sensitive enteropathy has changed. CD is a state of heightened immunological responsiveness to ingested gluten in genetically susceptible individuals. CD now affects 1 % or more of all adults, for which the treatment is a strict lifelong gluten-free diet. However, there is a growing body of evidence to show that a far greater proportion of individuals without coeliac disease are taking a gluten-free diet of their own volition. This clinical entity has been termed non-coeliac gluten sensitivity (NCGS), although the condition is fraught with complexities due to overlap with other gluten-based constituents that can also trigger similar clinical symptoms. This review will explore the relationship between gluten, the rising prevalence of modern coeliac disease, and the new entity of NCGS along with its associated uncertainties.

The rise in gluten consumption over time has led to the increasing recognition of coeliac disease (CD) with associated complications. However, only recently has there been an appreciation that the spectrum of gluten-related disorders is greater than just CD, which may explain the growing global popularity in gluten-free products. Current literature suggests that a newly recognised clinical entity in the form of non-coeliac gluten sensitivity (NCGS) may be the most common gluten-related disorder encountered by healthcare professionals, although its exact prevalence is as yet unknown. This article will review the historical relationship between mankind and gluten as well as the progressive recognition that it is possible for gluten to have a deleterious effect on our health. To this effect we discuss the prevalence, diagnosis and complications of CD including the benefits derived from a gluten-free diet (GFD). Finally, we discuss our current understanding of NCGS, in addition to highlighting the need for further research to determine the extent, clinicopathological features and serological biomarkers to help recognise this emerging condition in clinical practice.