Early exposure to cow’s milk protein is associated with a reduced risk of milk allergies

Published online: September 26, 2018

There has been a recent paradigm shift for food allergy prevention with recent infant feeding guidelines around the world advising parents to introduce allergenic solid foods into the infant’s diet in the first year of life. Historically, food allergy prevention strategies were aimed at allergen avoidance in early life. Evidence to inform these guideline changes are largely based on randomized controlled trials for peanut and egg allergy. Less is known about whether the timing of introduction of cow’s milk protein into the infant’s diet is associated with the risk of developing cow’s milk allergy, or whether the window of opportunity for early allergen exposure to prevent food allergy differs for common food allergens.

Using data from the population-based HealthNuts study, a study recently published in The Journal of Allergy and Clinical Immunology: In Practice, examined whether there was an association between the timing of introduction to cow’s milk protein through the use of a cow’s milk based infant formula, and the risk of cow’s milk allergy. Peters et al reported that exposure to cow’s milk protein in the first 3 months of life was associated with a reduced risk of cow’s milk sensitization (odds ratio 0.44), parent reported reactions to cow’s milk consistent with IgE-mediated allergy (odds ratio 0.44), and cow’s milk allergy (odds ratio 0.31). There was no evidence of a difference in risk between infant’s who were exposed to only a partially hydrolyzed infant formula, compared to a standard cow’s milk based infant formula. Early exposure to cow’s milk protein was not associated with the development of other IgE-mediated food allergies including egg and peanut, which indicates that early exposure to cow’s milk does not prevent food allergies per se, but that early exposure to the allergen is important for inducing oral tolerance to that allergen only.

This study is one of the largest population-based studies to assess the relationship between early exposure to cow’s milk protein and the risk of cow’s milk allergy, using objective measures of food allergy. These findings are from an observational study and clinical trials are warranted to further assess this association before any recommendations to infant feeding guidelines are made.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.