There are two types of allergic reactions that occur in the population related to wheat intolerance:

1. Individuals with the coeliac disease react mainly to the complex protein gliadin that is part of a larger protein group called ‘gluten'. Similar forms of gluten are also present in other grains such as Spelt, Rye , Barley, and Oats. The gliadin protein binds to a specific site on T-cells. These cells are a part of the immune system that recognise and respond to particular microbes and foreign molecules. These T cells induce an inflammatory response which causes damage to the small intestine, resulting in virtually no digestion at all, in the worst cases.

Scientists believe that the gliadins in Spelt will still be toxic to coeliacs, as the differences in the amino acid sequences of wheat gliadins and spelt gliadins appear minor (sequence identity of 98.5%)

2. Individuals that are allergic to wheat react to one or more of the other proteins in wheat. The most common reactant fractions are albumin and globulin; and only in rare cases the gluten proteins gliadin and glutenin. These adverse reactions are mediated by immuno-globulin E antibodies which cause our normal allergic responses and are manifested in wheat intolerant individuals in a number of forms; involving: the skin (hives, atopic eczema), the gastrointestinal tract (abdominal cramps, nausea and vomiting) as well as the respiratory tract (asthma or allergic rhinitis).

It appears that the differences in the protein make up of Spelt compared to Wheat are sufficient to allow most wheat intolerant people to eat Spelt. Spelt is an alternative to wheat for a large proportion of the wheat intolerant population.