07/09/2025
What is Alpha-gal Syndrome?
Alpha-gal syndrome (AGS) is a type of food allergy to mammalian meat and products (such as beef, pork, lamb, venison, and sometimes dairy or gelatin). It is caused by an immune reaction to galactose-alpha-1,3-galactose (alpha-gal), a sugar molecule found in most mammals but not in humans and other Old World primates (apes and monkeys from Africa and Asia).
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How does it develop?
Tick bites are the primary cause.
In the U.S., the Lone Star tick is most strongly linked, but other tick species in different regions can also trigger the condition.
When a tick carrying alpha-gal bites, it introduces the sugar molecule into the body. The immune system then creates antibodies against alpha-gal.
Later, when the person eats red meat or mammalian products, the immune system reacts, causing an allergic response.
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Symptoms
Unlike many food allergies, AGS reactions are delayed, usually appearing 3–6 hours after eating.
Common symptoms include:
Hives, itching, or skin rash
Swelling of lips, tongue, throat, or eyelids
Nausea, vomiting, diarrhea, or indigestion
Coughing, shortness of breath, or chest tightness
Drop in blood pressure, dizziness, or fainting
In severe cases, anaphylaxis
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Foods and Products to Avoid
Red meat: beef, pork, lamb, venison, rabbit, goat
Dairy products (for some people)
Gelatin (found in candies, marshmallows, some medicines, and vaccines)
Certain medications derived from mammals (e.g., some capsules, heart valves, or vaccines stabilized with gelatin)
Poultry (chicken, turkey) and fish are generally safe, as they do not contain alpha-gal.
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Diagnosis
Blood test to check for alpha-gal–specific IgE antibodies
Skin prick or food challenge tests in some cases
Medical history, especially tick exposure, is key for diagnosis
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Management
Strict avoidance of mammalian products is currently the only reliable treatment.
Epinephrine auto-injectors (e.g., EpiPen) may be prescribed for those at risk of severe reactions.
Some people’s sensitivity decreases over time if they avoid new tick bites, but re-exposure can restart the allergy.
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👉 Alpha-gal syndrome is still a relatively newly recognized condition, and awareness is growing. If someone experiences delayed allergic reactions after eating red meat, they should consult an allergist and get tested for alpha-gal antibodies.
