Considerations on Developing Criteria to Determine Whether a Food Allergen is of Public Health Importance

Food allergy is the result of a particular type of immune response against one or more food components, usually proteins. The food allergy reactions that are the focus of regulatory measures are mediated by antibodies of the IgE class. Importantly, food allergy is a two-step process. The first step, the sensitisation phase, consists of an immune response resulting in production of IgE antibodies specific for the allergen. The second step, the provocation phase, is the triggering of a symptomatic allergic reaction as a result of exposure to the allergen after sensitisation has been established. For reasons not well understood, a majority of sensitised individuals never will experience clinical reactions. Determining the number of sensitised individuals (test positives) in a population will therefore grossly overestimate the prevalence of food allergy. The term ‘allergy’ should be used only if clinical reactions occur. For triggering a food allergic reaction in a sensitised individual, only the ‘acute’ food intake and not the intake over time is of importance, and food allergy in this aspect resembles acute poisoning. Because of the cultural, agricultural, economic and nutritional importance of the foods, society accepts that a small fraction of the population develops allergies to traditional food products. Prevention of allergic reactions is then sought by means of education and by labelling of the most important allergenic foods. However, some 200 allergenic foods have been described, but only a small minority of these appears to be of importance in terms of frequency and severity of reactions triggered in the population. When it comes to management of the allergens, however, there is a lack of clear criteria at two levels: at the level of defining what documentation should be required to enter a proposed new food allergen into one of the large allergen databases, as well as at the level of determining which food allergens are of sufficient public health importance to require special regulatory attention in terms of labelling. With the aim of increasing transparency and predictability of decision-making processes and obtaining more consistency between labelling of different allergens as well as between labelling of allergens in different food regulatory jurisdictions, ILSI Europe has taken an initiative to establish clear criteria and a framework to determine the public health importance of a given food allergen. These criteria will consist of factors relating to food properties, population factors, and exposure factors.