Nutritional considerations for alpha-gal syndrome: a mini-review

Alpha-gal syndrome (AGS) is an immunoglobulin E-mediated sensitivity to galactose-alpha-1,3-galactose ("alpha-gal"), an oligosaccharide found in non-primate, mammalian-derived foods and products as well as some plant-based ingredients. Sensitization to alpha-gal is most commonly caused by a tick bite. Once sensitized, individuals experience delayed allergic reactions, typically 2-8 h after exposure to mammalian foods and other alpha-gal containing products. Symptoms range from urticaria to anaphylaxis and differ from exposure to exposure in the same individual, distinguishing AGS from other IgE-mediated food allergies. Recognition of AGS has grown since 2008, when patients receiving the anticancer drug, cetuximab, experienced severe reactions later linked to alpha-gal. In 2009, 24 cases were documented when patients endorsed anaphylaxis and urticaria several hours after eating meat. Today, an estimated 15,000 new cases occur annually in the United States, with many more suspected due to testing limitations and limited awareness among affected individuals and healthcare professionals. AGS has been diagnosed on every continent except Antarctica though there is not a global estimate of AGS prevalence at this time. Given the varying types and severities of sensitivity of this IgE-mediated food allergy, registered dietitian nutritionists (RDNs) are vital members of the care team. This mini review provides an overview of AGS for nutrition professionals that are responsible for delivering medical nutrition therapy, nutrition education, and nutrition counseling across clinical, community, and food service settings.