The multifactorial nature of food allergy

Approximately 12% of the Dutch adults and adolescents reports to have food allergy. However, only one-third reports characteristics which are, from a medical point of view, consistent with food allergy. This thesis describes genetic and environmental risk factors for food allergy. A lower risk of food allergy was associated with a longer duration of breastfeeding, growing up at a farm and having no family history of eczema. In multiple studies, gene variants were associated with food allergy. Firstly, the filaggrin gene, important for the skin-barrier function, was associated with food allergy in children. Other recent studies showed that improving the skin-barrier leads to a lower risk of eczema and it may potentially lead to a lower risk of food allergy. Secondly, the Signal Transducer and Activator of Transcription 6 (STAT6) gene was associated with the presence of specific Immunoglobulin E to foods in blood and food allergy in children. Thirdly, specific Human Leukocyte Antigen class II gene variants were specifically associated with peanut allergy in both children and adults. These genes encode molecules that present antigens, including food antigens, to immune cells which mediate food allergic reactions. From this thesis we can conclude that in the pathophysiology of food allergy the following is likely to be true “Genes load the gun but environment pulls the trigger”