As dietitians, we are familiar with the top eight food allergens: wheat, soy, eggs, cow’s milk, fish, shellfish, peanuts, and tree nuts. What about…red meat? Meet the alpha-gal allergy. It’s a rare condition that is becoming more common. Because of the obvious nutrition implications, dietitians are often called upon to educate patients, clients, families, foodservice staff, and other healthcare providers how to navigate this unique condition.
What is alpha-gal allergy?
Alpha-gal is short for galactose-α-1,3-galactose, a sugar molecule. This molecule differs from most food allergies because the allergen is a carbohydrate rather than a protein molecule. The alpha-gal molecule is found within the saliva of the Lone Star tick, as well as other potential arthropods after they have been feeding on mammalian blood. However, within the United States, the Lone Star tick is the primary cause. This sugar molecule exists in most mammalian meat (beef, pork, lamb, venison, goat, and bison). It can also be found in mammalian by-products, like cow’s milk, gelatin, and the cancer treatment medication, cetuximab. On the other hand, animal by-products obtained from chicken, turkey, and fish do not contain alpha-gal.
The best way to diagnose alpha-gal allergy is with a blood test measuring alpha-gal antibodies. Other pertinent history includes recent outdoor activity, exposure to ticks, and any known or suspected reaction after consuming mammalian meats. Alpha-gal allergic reaction symptoms are similar to those of any food allergy with one notable exception: alpha-gal reaction symptoms can be delayed by two to six hours after exposure to mammalian meats. If symptoms are delayed, it can confuse patients, family members, and clinicians when attempting to track the cause of the allergic reaction. The most common symptom reported is typically skin reactions, but reactions can be as severe as anaphylaxis. Adults appear to have more severe reactions than children do.
Nutrition implications of alpha-gal allergy
When it comes right down to it, alpha-gal allergy is a food allergy. In theory, the treatment of alpha-gal allergy is simple—avoid offending foods. In practice, however, this can present a challenge. Once alpha-gal allergy is diagnosed, all mammalian meats and by-products should be avoided. Again, this includes, beef, pork, lamb, venison, mutton, goat, and bison, plus any food that contains red meat extracts. Some individuals with alpha-gal allergy must also avoid dairy products made from cow’s, sheep’s or goat’s milk. The good news is that all fruits, vegetables, grains, nuts, legumes, poultry, and seafood are appropriate for alpha-gal allergies.
How dietitians can help
Just like any food allergy, the long list of “no” foods can be daunting and discouraging for patients and their families. Dietitians should be equipped with an even longer list of “yes” foods that are appropriate for an alpha-gal allergy. Encourage all family members to support their loved one as they cope with their new diet restrictions. Teach clients and families how to read food labels, especially for “unsuspecting” foods like gelatin, broths, and gravies. Make sure your client’s diet is still nutritionally complete, recommending vitamin or mineral supplements, if needed. And educate the foodservice team that a red meat allergy is, indeed, a thing and what alternative food options they can safely offer.
We are still learning more about alpha-gal allergy. Research is optimistic, indicating that some individuals may be able to reintroduce mammalian meats back into their diets after a period of abstinence, as long as no additional tick bites have occurred.
Sara Glanz, MS, RD, LD, CNSC worked as a traveling dietitian for Dietitians On Demand for two years before joining the team as the corporate dietitian. In this role, she has championed the continuing education program to empower dietitians everywhere to achieve their professional goals.
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Centers for Disease Control and Prevention. Alpha-gal allergy. https://www.cdc.gov/ticks/alpha-gal/index.html. Updated March 28, 2019. Accessed May 28, 2019.
Mabelane T, Ogunbanjo GA. Ingestion of mammalian meat and alpha-gal allergy: Clinical relevance in primary care. Afr J Prim Health Care Fam Med. 2019;11(1):e1-e5. Published 2019 Apr 29. doi:10.4102/phcfm.v11i1.1901
Platts-Mills TAE, Li RC, Keshavarz B, Smith AR, Wilson JM. Diagnosis and Management of Patients with the α-Gal Syndrome. J Allergy Clin Immunol Pract. 2020;8(1):15-23.e1. doi:10.1016/j.jaip.2019.09.017
Wilson JM, Schuyler AJ, Workman L, et al. Investigation into the α-Gal Syndrome: Characteristics of 261 Children and Adults Reporting Red Meat Allergy. J Allergy Clin Immunol Pract. 2019;7(7):2348-2358.e4. doi:10.1016/j.jaip.2019.03.031