Epidemiology of wheat allergy
The reported prevalence of adverse reactions to wheat and gluten has escalated in recent years. While this rise may be associated with the change in our diet from a hunter/gather focus on meat, fruits, and vegetables to a more agrarian life which domesticated grasses and grains, and therefore increased the consumption of grains markedly there is no definitive link. We do know that wheat is ubiquitous in most industrialized diets. 
Studies utilizing the food challenge method of diagnosis estimate a wheat allergy prevalence of 0.1 – 0.6% in Europe [1-8]. However, in the US wheat is reported as one of the eight most common IgE mediated food allergens. A recent study indicated a worldwide prevalence of 0.5 – 9% of the population . In a recent study 0.4% of US adults reported an allergy to wheat diagnosed via a doctor . The prevalence of wheat allergy is high amongst children in the US, ranging from 0.4% to 1.0% of the population. Most children “grow out of” or have their wheat allergy resolve over time with 29% resolution at age four and up to 65% by age twelve .
Wheat – a complex grainWheat is a complex food containing cross-reacting proteins to both other cereals and pollens. Wheat and cereals are composed of four classes of proteins; the water/salt soluble albumins and globulins and the water/salt insoluble gliadins and glutenins, which together are known as prolamins / gluten. Of these, there are two major proteins considered linked to adverse reactions, the lipid transfer protein (LTP) and the omega-5 gliadins (both considered to be prolamins or seed storage proteins) . It is important to take these factors into account when performing tests to confirm a wheat allergy: Wheat is a grass and the profilins in wheat are likely to cross-react with grass; not indicating the likelihood of reaction to consumption of wheat [7,10-12]. Wheat also contains a number of proteins that may cross-react with rye and barley and allergies to these should therefore be ruled out before diagnosing a wheat allergy.
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- Zuberbier, T., Edenharter, G., Worm, M., Ehlers, I., Reimann, S., Hantke, T., Roehr, C. C., Bergmann, K. E. and Niggemann, B. (2004) 'Prevalence of adverse reactions to food in Germany - a population study', Allergy, 59(3), 338-45.
- Venter, C., Pereira, B., Grundy, J., Clayton, C. B., Arshad, S. H. and Dean, T. (2006) 'Prevalence of sensitization reported and objectively assessed food hypersensitivity amongst six-year-old children: a population-based study', Pediatr Allergy Immunol, 17(5), 356-63.
- Venter, C., Pereira, B., Voigt, K., Grundy, J., Clayton, C. B., Higgins, B., Arshad, S. H. and Dean, T. (2008) 'Prevalence and cumulative incidence of food hypersensitivity in the first 3 years of life', Allergy, 63(3), 354-9.
- Ronchetti, R., Jesenak, M., Trubacova, D., Pohanka, V. and Villa, M. P. (2008) 'Epidemiology of atopy patch tests with food and inhalant allergens in an unselected population of children', Pediatr Allergy Immunol, 19(7), 599-604.
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