Alpha-gal syndrome (AGS) is an allergic condition where individuals develop an allergy to alpha-gal, a sugar molecule found in most mammals but not in humans and other primates. This allergy often results from specific tick bites, which can transfer alpha-gal from the tick’s saliva into a person’s bloodstream, triggering an immune response. When people with AGS are exposed to alpha-gal through food or other products, they can experience allergic reactions ranging from mild symptoms like rashes, nausea, and stomach pain to severe, life-threatening anaphylaxis.
Mammalian Meats
Mammalian meats are primary sources of alpha-gal, often triggering allergic reactions in individuals with Alpha-gal Syndrome. Common examples include beef, pork, lamb, venison, goat, rabbit, and bison. Organ meats such as liver, kidneys, and heart can contain higher concentrations of alpha-gal than muscle meat. Even small amounts of these meats can cause a reaction in sensitive individuals, with symptoms typically appearing several hours after ingestion. In contrast, poultry like chicken and turkey, along with various types of fish, do not naturally contain alpha-gal and are generally considered safe for individuals with AGS.
Dairy, Gelatin, and Other Food Additives
Alpha-gal can also be present in less obvious food sources, requiring careful label scrutiny. Dairy products, derived from mammals like cows and goats, contain alpha-gal. While the alpha-gal content in dairy might be lower than in meat, it can still trigger reactions in sensitive individuals, including to products like milk, cheese, yogurt, and butter.
Gelatin is often made from collagen found in mammalian bones, skin, and connective tissues. This mammalian-derived ingredient is common in various foods, including gummy candies, marshmallows, some desserts, and certain processed foods.
Other mammalian-derived ingredients and food additives may also contain alpha-gal. These include natural flavors (sourced from beef or pork), fats like lard, tallow, and suet, and certain emulsifiers, thickeners, and byproducts such as glycerin, magnesium stearate, and mono- and diglycerides, if derived from mammals. Even carrageenan, a common thickener derived from red seaweed, contains the alpha-gal epitope and can cause reactions in some people with AGS.
Medications and Personal Care Items
Alpha-gal can also be found in certain medications and personal care items. Some medications, particularly those in capsule form, often use gelatin as a primary component. Gelatin-containing vaccines, such as some for measles, mumps, rubella (MMR), varicella, and yellow fever, may also pose a risk. Additionally, antivenoms, often derived from venom-immunized non-primate mammals, contain alpha-gal and can cause reactions. Individuals with AGS should discuss all medications with their healthcare providers or pharmacists to identify potential alpha-gal sources. Personal care products like cosmetics, lotions, soaps, and shampoos may also contain animal-derived ingredients such as lanolin (from sheep’s wool), collagen, glycerin, and stearic acid, which may contain alpha-gal.
Identifying Alpha-Gal Ingredients on Labels
Navigating product labels requires careful attention for individuals managing alpha-gal syndrome, as “alpha-gal” itself is rarely listed. Instead, look for terms indicating mammalian-derived ingredients. These include “gelatin,” “bovine,” “porcine,” “animal-derived,” “lard,” “tallow,” “suet,” and “collagen.” Other terms like “lanolin,” “magnesium stearate,” and “glycerin,” when sourced from mammals, also indicate potential alpha-gal content.
If an ingredient’s source is unclear, contact the manufacturer directly for clarification. Beyond packaged goods, cross-contamination is a concern, particularly in shared kitchens or when food is prepared on surfaces or with utensils previously used for mammalian products. For instance, using a grill for non-mammalian meats that was also used for red meats can transfer alpha-gal.