Galactose-alpha-1,3-galactose, commonly known as Alpha-gal, is a carbohydrate molecule found in the tissues of nearly all non-primate mammals. Humans, apes, and Old World monkeys naturally lack this sugar, and our immune systems may recognize it as a foreign substance. Alpha-gal Syndrome (AGS) is an acquired allergic reaction where the body develops specific immunoglobulin E (IgE) antibodies to this sugar, often after a bite from a specific type of tick, such as the Lone Star tick in the United States. This sensitization causes allergic symptoms, which can range from hives and gastrointestinal distress to life-threatening anaphylaxis. Reactions typically occur 2 to 10 hours after ingesting the molecule, and managing AGS requires strict avoidance of foods, products, and medical items that contain Alpha-gal.
Mammalian Muscle Meats
The most common trigger for Alpha-gal Syndrome is the muscle meat of mammals, which contains high concentrations of the Alpha-gal molecule. Meats to avoid include common sources like beef, pork, and lamb, which are all derived from mammals. The restriction extends to other mammalian species frequently consumed, such as bison, goat, and venison. Even meats that may not be traditionally classified as “red meat,” such as rabbit, are derived from mammals and contain the Alpha-gal epitope. Organ meats, including liver, kidneys, and heart, can contain higher amounts of Alpha-gal than muscle meat, making them especially risky for AGS sufferers.
Dairy Products and Rendered Fats
Alpha-gal is present in products derived from mammalian secretions and fat tissue. Dairy products such as milk, cheese, yogurt, butter, and cream, whether from cows, goats, or sheep, all contain Alpha-gal. While many individuals with AGS can tolerate dairy, a portion remains sensitive to these products and must avoid them.
Rendered fats, which are fat tissues processed for cooking, represent another significant source of Alpha-gal. These include lard (derived from pork) and tallow (derived from beef). These fats are often used in commercial food preparation and can be hidden ingredients in items like baked goods, refried beans, or frying oils.
Gelatin and Other Processed Derivatives
Gelatin is a major source of Alpha-gal, produced by boiling the collagen and connective tissues, such as bones and hides, of mammals like cattle and pigs. This product is used extensively as a gelling agent or stabilizer in foods. Gelatin is also frequently used to make the coatings for capsule-form medications and nutritional supplements.
Common food items containing gelatin include:
- Gummy candies
- Marshmallows
- Desserts
- Ice creams and yogurts
Processed ingredients like meat stocks, broths, bouillon, and gravies made from mammalian bones are high-risk sources of Alpha-gal. These derivatives are often “hidden” on ingredient labels under general terms like “natural flavorings” or “extracts,” requiring careful scrutiny by those with AGS.
Medications, Vaccines, and Medical Devices
Alpha-gal is found in components of non-food products, making avoidance a complex challenge for those with AGS.
Pharmaceuticals and Biologics
One recognized pharmaceutical risk is the anticoagulant Heparin, which is derived from the intestines of pigs or the lungs of cattle. Although most patients tolerate Heparin, severe allergic reactions have been documented, especially with intravenous administration. Certain vaccines and biologics may also contain Alpha-gal due to the use of bovine or porcine materials in their production or as stabilizers like gelatin.
Medical Devices and Personal Care
Biological medical devices, such as bioprosthetic heart valves derived from pig or cow tissue, contain Alpha-gal and can pose a risk of allergic reaction. Personal care products can also contain the carbohydrate, including cosmetics that use lanolin (a fat derived from sheep’s wool) or glycerin when it is sourced from mammals.