Age at introduction to complementary solid food and food allergy and sensitization: A systematic review and meta-analysis.

Abstract

An infant's age at introduction of complementary solids may contribute to food allergy. We aimed to synthesize the literature on the association between age at introduction of complementary solids, excluding milk products, and food allergy and sensitization. We searched the electronic databases PubMed and EMBASE (January 1946-February 2017) using solid food, allergy and sensitization terms. Two authors selected papers according to inclusion criteria, identifying 16 cohort studies, 1 case-control study and 8 randomized controlled trials (RCTs). Pooled effects across studies were estimated using random-effects meta-analysis. Cohort studies-Introducing complementary solids at age≥4months vs <4months was not associated with food allergy (OR 1.22; 95% CI, 0.76-1.96) but was associated with food sensitization (OR 1.93; 95% CI 1.57-2.38). First exposure from age 4 to 6months vs <4months was not associated with food allergy (OR 1.01; 95% CI, 0.64-1.60) but was associated with food sensitization (OR 2.46; 95% CI 1.55-3.86). Randomized controlled trials-Egg exposure from age 4months was associated with reduced egg allergy (OR 0.63, 95% CI, 0.44-0.90) and sensitization (OR 0.76, 95% CI, 0.51-0.95). Peanut exposure from age 4months compared to delayed exposure was associated with reduced peanut allergy (OR 0.28, 95% CI 0.14-0.57). We found no evidence from observational studies that introducing solids before 4months protected against food allergy, but there was evidence for protection against food sensitization. From RCTs, introducing egg from 4 to 6months and peanut from 4 to 11months reduced the risk of egg allergy, peanut allergy and egg sensitization. PROSPERO systematic review registry (CRD42016033473).