Early nutritional strategies for preventing allergic disease.

The rising number of children and adults with allergic disorders worldwide has prompted interest in strategies to prevent or reduce the risk of allergy. This article discusses the role of early nutritional strategies in the prenatal/ postnatal periods that potentially may modify disease risk. Exclusive breastfeeding may help to prevent allergic disease by decreasing exposure to exogenous antigens, protecting against infections, promoting gastrointestinal mucosal maturation and the development of gut microbiota, and conferring immunomodulatory and anti-inflammatory benefits. However, the results of the studies are inconsistent, showing a protective effect, no effect, or even a predisposing effect. Still, breastfeeding should be promoted for its nutritional, immunological and psychological benefits. For infants with a documented hereditary risk of allergy (i.e., an affected parent and/or sibling) who cannot be breastfed exclusively, dietary products with confirmed reduced allergenicity are recommended. Previously, for complementary feeding, early exposure to solid foods during infancy was associated with the development of allergic diseases, particularly eczema. Currently, the guidelines downplaythe role of solid foods in the development of allergies, stating that there is no convincing scientific evidence that the avoidance or delayed introduction of potentially allergenic foods beyond 4-6 months reduces allergies in infants considered to be at increased risk for the development of allergic diseases or in those not considered to be at increased risk. Evidence from some trials with probiotics or prebiotic oligosaccharides suggests some benefits, but at present there is insufficient evidence to support their routine use. Neither can specific recommendations be made for the use of long-chain polyunsaturated fatty acids, antioxidants, folate, and vitamin D.