PURPOSE OF THE STUDY.
To determine whether the timing of allergenic food introduction influences the risk of development of allergic or autoimmune disease.
Meta-analysis of studies evaluating the timing of allergenic food introduction in the first year of life and reported allergy, allergic sensitization, or autoimmune disease.
A comprehensive literature search from January 1, 1946, to March 8, 2016, was performed. Participants were enrolled within 6 months of life, and outcomes were evaluated between 7 months and 6 years of age. Across the 146 studies evaluated, the age of allergenic food introduction and associated allergic or autoimmune outcomes were compared in 24 interventional/69 observational studies and in 6 interventional/48 observational studies, respectively. Bias and statistical heterogeneity were quantified by using validated methodology. A post hoc trial sequential analysis quantified the statistical reliability of the moderate- to high-certainty findings with egg introduction and gluten introduction. The certainty of evidence score was determined by using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.
The meta-analysis of 5 trials with 1915 participants found a decreased risk of developing an egg allergy with egg introduction at 4 to 6 months (RR 0.56; 95% CI, 0.36–0.87). Meta-analysis of 2 trials with 1550 participants found a lower risk of developing a peanut allergy when peanut was introduced at age 4 to 11 months (RR 0.29; 95% CI, 0.11–0.74). There was no association with the timing of introduction of other allergenic foods (milk, wheat, soy, tree nuts, and shellfish) and the risk of allergic sensitization or food allergy. There was conflicting evidence about the early introduction of fish and the associated risk of allergic sensitization. No association was found between the timing of gluten introduction and celiac disease, inflammatory bowel disease, or type I diabetes mellitus or between the timing of milk introduction and type 1 diabetes mellitus.
There is moderate-certainty evidence that the introduction of egg between 4–6 months of age and peanut between 4–11 months of age is associated with a reduced risk of egg and peanut allergy, respectively. There is low- to very-low-certainty evidence that fish introduction between 6–12 months of age is associated with decreased allergic sensitization or rhinitis. There is high-certainty evidence that the timing of gluten introduction has no association with celiac disease.
This large-scale meta-analysis and systematic review concludes that the early ingestion of egg and peanut is associated with antigen-specific oral tolerance, a heartening finding with significant implications for families wondering about the right age to introduce these potentially allergenic foods. There was no consistent evidence, however, that the introduction of 1 food influences the development of a different food allergy. Reassuringly, there was no consistent evidence that the timing of food introduction impacts autoimmune diseases, including celiac disease, type I diabetes mellitus, or inflammatory bowel disease.
- Copyright © 2017 by the American Academy of Pediatrics