Systematic review demonstrates that the probability of IgE-mediated allergic reactions to food proteins in human breast milk is low
Published: February 1, 2022
It is well established that food proteins can be excreted into human breast milk. The presence of food proteins in human breast milk have been linked with the exacerbation of symptoms (e.g. eczema, wheeze, vomiting, infant colic, diarrhea) in children with allergic conditions. These observations have sometimes resulted in inappropriate restriction of maternal diets or breastfeeding cessation in routine clinical practice although systematic reviews on colic and eczema did not show a benefit of maternal dietary exclusions. Existing evidence has never been reviewed systematically making development of evidence-based clinical guidelines on the treatment of breastfed children with food allergy very challenging.
In a recent article in The Journal of Allergy and Clinical Immunology: In Practice, Gamirova, Berbenyuk, Levina, et al. assessed the probability that food proteins in human breast milk could trigger allergic reactions in infants with IgE-mediated food allergy. Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, this systematic review searched MEDLINE and EMBASE until November 2021. Authors extracted data regarding the levels of food proteins detected in human breast milk and compared with data
from the Voluntary Incidental Trace Allergen Labelling (VITAL 3.0) guide to assess the probability of food-allergic individuals to experience IgE-mediated reactions on ingesting human breast milk.
The authors identified 32 studies meeting inclusion criteria. Concentrations of cow’s milk, egg, peanut, and wheat proteins were measured in human breast milk in the available literature. Levels of food proteins across the studies were much lower than the eliciting dose for 1% of allergic individuals in most of the samples. The estimated probability of an IgE-mediated allergic reaction in a food-allergic infant breastfed by a woman consuming the relevant food was estimated as ≤1:1000 for four foods evaluated (cow’s milk, egg, peanut, and wheat). Outcomes of this systematic review demonstrate that although reactions may occur in a small number of children due to ingestion of human breast milk containing relevant food proteins, the probability of an IgE-mediated allergic reaction is low. Future research would benefit from identifying women who excrete high quantities of food proteins into breast milk and assessment of both IgE-mediated and non-IgE-mediated allergic reactions in children during breastfeeding.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.