More Information on Background: Assessing Food Allergens

In addition, relatively few people have food allergies.  In the U.S., approximately 1-2.5 % of the adults and 6–8 % of the children are affected by food allergies.   Many children outgrow these allergies by three years of age (Sampson, 1992, 1995, 2000).  People with food allergies are usually allergic to a few specific proteins within one or two foods (Metcalfe et al., 1996).   Within a group that is allergic to a specific food, there is variation in the amount of an allergen required to trigger the reaction as well as the severity of the response in each individual.   It is often not possible to differentiate the allergenic protein (s) from the thousands of proteins present in a given food that is identified as causing allergies.   In addition, the exact protein responsible can vary among the different people allergic to a given food. Finally, the allergenicity of a food or protein may vary across different societies and cultures due to differences in exposure.   For example, peanut allergies are more common in North America, and rice allergies are more common in Japan.