Alpha-gal syndrome: Mechanisms, global epidemiology, and implications for meat science

Galactose-α-1,3-galactose (α-Gal) is a carbohydrate epitope conjugated to glycoproteins and glycolipids and ubiquitously expressed in non-primate mammalian tissues. α-Gal has emerged as the causative antigen of alpha-gal syndrome (AGS), a delayed IgE-mediated food allergy to mammalian-derived products, including red meat. Clinical symptoms are highly variable among AGS patients and influenced by factors such as α-Gal content and structure, molecular carrier, and host-specific immune responses. Emerging evidence indicates that α-Gal content and structure may vary across tissues and product types, with higher concentrations frequently reported in organ meats and lipid-rich fractions. Additionally, α-Gal epitopes exhibit notable thermal stability, suggesting that conventional cooking and processing methods may not effectively reduce allergenicity. Current analytical approaches have improved detection and characterization of α-Gal; however, methodological standardization and functional assays linking molecular presence to clinical reactivity remain limited. Epidemiological data indicate that AGS is a globally emerging condition, with geographic variation driven by tick distribution, environmental factors, and differences in surveillance and clinical recognition. Despite increasing recognition, knowledge gaps persist regarding α-Gal occurrence in food systems, the impact of processing on allergenicity, and effective mitigation strategies. Therefore, the objective of this review is to synthesize current knowledge on the biochemical basis, immunological mechanisms, and global epidemiology of AGS, and to evaluate the occurrence, distribution, and stability of α-Gal in meat systems. In particular, meat scientists are uniquely positioned to advance understanding of α-Gal distribution, stability, and mitigation in food systems, thereby contributing to improved risk assessment and management of AGS.