Randomized Trial of Introduction of Allergenic Foods in Breast-Fed Infants

TLDR

The optimal timing for introducing allergenic foods to breast‑fed infants remains unclear. The study aimed to determine if early introduction of allergenic foods protects breast‑fed infants from developing food allergy. A randomized trial of 1,303 breast‑fed infants at 3 months assigned them to early introduction of six allergenic foods versus standard exclusive breastfeeding until about 6 months, with food allergy assessed between ages 1 and 3 years. Intention‑to‑treat analysis showed no significant benefit, but per‑protocol analysis revealed a lower prevalence of any food allergy (2.4% vs 7.3%) and of peanut (0% vs 2.5%) and egg (1.4% vs 5.5%) allergies in the early‑introduction group; higher weekly intake of peanut or egg protein was linked to reduced allergy risk, though early introduction was difficult to implement and overall efficacy was not confirmed in the primary analysis. Trial funded by the Food Standards Agency and others; registered as ISRCTN14254740.

Abstract

The age at which allergenic foods should be introduced into the diet of breast-fed infants is uncertain. We evaluated whether the early introduction of allergenic foods in the diet of breast-fed infants would protect against the development of food allergy.We recruited, from the general population, 1303 exclusively breast-fed infants who were 3 months of age and randomly assigned them to the early introduction of six allergenic foods (peanut, cooked egg, cow's milk, sesame, whitefish, and wheat; early-introduction group) or to the current practice recommended in the United Kingdom of exclusive breast-feeding to approximately 6 months of age (standard-introduction group). The primary outcome was food allergy to one or more of the six foods between 1 year and 3 years of age.In the intention-to-treat analysis, food allergy to one or more of the six intervention foods developed in 7.1% of the participants in the standard-introduction group (42 of 595 participants) and in 5.6% of those in the early-introduction group (32 of 567) (P=0.32). In the per-protocol analysis, the prevalence of any food allergy was significantly lower in the early-introduction group than in the standard-introduction group (2.4% vs. 7.3%, P=0.01), as was the prevalence of peanut allergy (0% vs. 2.5%, P=0.003) and egg allergy (1.4% vs. 5.5%, P=0.009); there were no significant effects with respect to milk, sesame, fish, or wheat. The consumption of 2 g per week of peanut or egg-white protein was associated with a significantly lower prevalence of these respective allergies than was less consumption. The early introduction of all six foods was not easily achieved but was safe.The trial did not show the efficacy of early introduction of allergenic foods in an intention-to-treat analysis. Further analysis raised the question of whether the prevention of food allergy by means of early introduction of multiple allergenic foods was dose-dependent. (Funded by the Food Standards Agency and others; EAT Current Controlled Trials number, ISRCTN14254740.).