Food allergy: only a pediatric disease?

Epidemiologic studies report an increase in food allergies in industrialized countries, but mainly focus on children and young adults. This leads to the impression that food allergies do not occur in the older population. However, age-related changes dramatically affect both the innate as well as the adaptive immune system - a phenomenon known as immunosenescence. Deficiencies in micronutrients, especially zinc and iron, as well as vitamin D, in the elderly may also contribute to the development of allergies. A further risk factor of the elderly in developing food allergies could also be the decreased digestive ability of the stomach due to atrophic gastritis or anti-ulcer medication. In these settings, undigested proteins may persist and become allergenic. In fact, mouse models indicate that these pharmaceuticals support the induction of Th2 responses not only in young adult, but also in aged animals. Previous reports have already suggested that allergies are underdiagnosed among the elderly. Based on our own recent study conducted in a geriatric nursing home, we also suggest that food allergies may be underestimated.