Chia Seed Allergy: Emerging Clinical Evidence, Molecular Allergens, and the Unresolved Question of Cross-Reactivity

Chia seed (Salvia hispanica L.) is increasingly incorporated into contemporary foods, yet its allergenic potential remains poorly characterized. Published clinical evidence is limited to a small number of case reports, conference reports, and one case series describing immediate IgE-mediated reactions, cutaneous manifestations, and anaphylaxis. Molecular studies have identified candidate allergenic protein families, including 2S albumins, 7S vicilin-like globulins, 11S legumin-like globulins, and oleosins, and have demonstrated IgE recognition and potential cross-reactivity, particularly with sesame. However, molecular cross-recognition does not establish clinically relevant cross-allergy. This structured narrative review synthesizes the available clinical and molecular evidence regarding chia seed allergy, with emphasis on clinical manifestations, candidate allergens, chia–sesame cross-reactivity, diagnosis, and major knowledge gaps. Current evidence supports chia as a potential emerging food allergen but is insufficient to determine prevalence, natural history, reaction thresholds, or individual risk. Standardized diagnostic extracts, validated specific IgE thresholds, component-resolved diagnostics, and chia-specific oral food challenge protocols are currently lacking. Prospective clinical studies and further molecular characterization are required to establish the true clinical significance of chia seed allergy.