Revisiting the Role of Soy Formula for Infants With IgE-Mediated Cow's Milk Allergy

Cow's milk allergy is one of the most commonly reported food allergies in infancy and early childhood. Although extensively hydrolyzed formulas and then amino acid-based formulas are the current standard of care, soy-based formula represents a less costly and more palatable alternative. Some cited concerns about soy-based formula include potential phytoestrogen-related effects and coallergy with cow's milk. However, recent data challenge these concerns, demonstrating minimal evidence of cross-reactivity between cow's milk and soy, and a favorable long-term safety profile in healthy term infants. This review critically examines the historical context, current guidelines, coallergy data, safety evidence, and nutritional adequacy of soy-based formula.