COW’S MILK allergy (CMA) is one of the most common food allergies in infancy, even among exclusively breastfed babies. Although breast milk is the recommended sole source of nutrition for the first six months of life, small amounts of cow’s milk proteins such as β-lactoglobulin can pass into breast milk from the maternal diet. This can lead to allergic reactions in sensitive infants, but many aspects of CMA in breastfed babies remain unclear.
A recent review has explored the immunological mechanisms, diagnostic challenges, and maternal dietary considerations related to CMA in breastfed infants. The study outlines the different types of immune responses involved, IgE-mediated, non-IgE-mediated, and mixed reactions, and highlights that standard IgE tests may not detect all cases. Diagnosis often relies on maternal elimination of cow’s milk followed by symptom monitoring and reintroduction.
One of the most debated aspects is whether breastfeeding mothers should follow cow’s milk-free diets. While elimination may reduce symptoms in some infants, it can pose nutritional risks to both mother and child. Therefore, such diets should only be considered after a thorough evaluation. The review also notes the limited evidence linking allergen levels in breast milk to the development of CMA, pointing to the need for further research.
Moreover, the infant’s gut microbiota may play a role in both allergy development and tolerance. Future research should aim to identify non-invasive diagnostic tools and biomarkers for non-IgE-mediated allergies, and explore how factors like maternal microbiome and genetics influence allergen transfer through breast milk.
Ultimately, accurate diagnosis and personalised management plans are essential. Overdiagnosis can lead to unnecessary dietary restrictions, impacting infant growth, maternal nutrition, and family life. This study encourages a balanced, evidence-based approach to CMA in breastfed infants, supporting breastfeeding while ensuring effective allergy management and promoting long-term health.
Reference
Caffarelli C et al. Cow’s milk allergy in breastfed infants: what we need to know about mechanisms, management, and maternal role. Nutrients. 2025;17(11):1787.
