Prevention of food allergy

Development of a food allergy appears to depend on both genetic factors and exposure-especially in early infancy-to food proteins. In prospective studies, the effect of dietary allergy prevention programmes has only been demonstrated in high-risk infants, i.e. infants with at least one first degree relative with documented atopic disease. High-risk infants feeding exclusively on breast milk and/or extensively hydrolysed formula (eHF) combined with avoidance of cow's milk proteins and solid foods during at least the first 4 months of life are found to have a significant reduction in the cumulative incidence of food allergy, especially cow's milk protein allergy/intolerance (CMPA/CMPI), in the first 4 years of life. As no studies have been conducted pertaining to the preventive effect of avoidance of milk and other foods after the age of 4-6 months, recommendation of preventive elimination diets beyond this age is empirically based. In order to reduce costs and to minimize the risks of stigmatisation and malnutrition, it is important to avoid unnecessary restrictive and prolonged diets. A diet period of 4-6 months appears to be sufficient in the majority of infants. At present, eHF are recommended as a substitute for cow's milk. A few high risk infants may benefit from a maternal diet during lactation, but there is no documented beneficial effect of maternal dieting during pregnancy.