UK dietitians release 1st nutrition-focused guide for alpha-gal syndrome

A tick-borne food allergy that was almost unheard of years ago is now so common in Kentucky that many residents know someone living with it. To help patients, families, clinicians and the community make sense of it, registered dietitians at the University of Kentucky Martin-Gatton College of Agriculture, Food and Environment (CAFE) have published one of the first nutrition-focused guides to the condition.

The paper, “Nutritional considerations for alpha-gal syndrome: a mini-review,” appeared in Frontiers in Allergy and was supported with funding from The Bill Gatton Foundation. Heather Norman-Burgdolf, Ph.D., assistant UK Extension director for Family and Consumer Sciences (FCS) and part of FCS Extension, and Anna Cason, also from FCS, played roles as second authors.

“Not only is it a new syndrome, it’s also just one of a kind,” said Abbigail Pace, Ph.D., UK Department of Dietetics and Human Nutrition assistant professor, one of The Bill Gatton Foundation Early-Career Professors and the paper’s lead author. “That’s why it’s been challenging to really characterize it and get the information out there broadly.”

Alpha-gal syndrome (AGS) is triggered by bites from certain ticks, most commonly the Lone Star tick in Kentucky. The bite sensitizes the body to a sugar called galactose-alpha-1,3-galactose, or "alpha-gal," found in the meat of most mammals — beef, pork, lamb, venison, rabbit and squirrel among them — and in dairy products, gelatin, some medications and a long list of food additives.

“Unlike most food allergies, which are reactions to proteins, alpha-gal syndrome is a reaction to a carbohydrate,” Pace said. “That distinction is part of what makes it so difficult to diagnose and manage.”

An estimated 15,000 new cases are identified in the United States each year, according to the review, with many more believed to go undiagnosed. Kentucky, sitting in the heart of Lone Star tick range, is among the hardest-hit states.

“We’re seeing such an explosion of it right now,” Pace said. “You can ask a group of people, and several of them will say, ‘Yes, I know someone with alpha-gal syndrome,’ especially in rural areas. Kentucky is just inundated with it.”

Reactions typically appear two to eight hours after exposure, a delay that separates AGS from most food allergies and often leaves patients waking in the middle of the night with hives, swelling or, in severe cases, anaphylaxis. The severity of a person’s reaction can also be pushed higher by factors such as exercise, alcohol consumption, dietary fat intake, and use of nonsteroidal anti-inflammatory drugs like ibuprofen.

AGS guidance

Rather than a blanket recommendation to avoid all mammal products, the paper lays out a tiered elimination approach.

The first tier targets the highest-risk foods for someone with AGS: mammalian meats, especially fatty cuts. The second tier includes dairy, broths, gelatin, lard and other mammalian-derived ingredients. The third covers additives such as carrageenan, glycerin and magnesium stearate, which may or may not be sourced from mammals depending on the product. Highly sensitive patients may need to eliminate all three tiers; others can stop after one.

“There are people who have alpha-gal syndrome who don’t necessarily react to dairy and other mammalian-based food ingredients,” Pace said. “That gives people more options and a little more autonomy to create a diet that is reasonable for them in their lifestyle.”

The safest protein sources include poultry, eggs, fish, seafood, beans, lentils, nuts and seeds. Some individuals with alpha-gal syndrome turn to less common proteins such as emu, ostrich and duck.

The review devotes substantial attention to label reading, an area where alpha-gal syndrome patients face unusual challenges. For example, chicken sausage may be packed in pork casing. “Plant-based” and “vegan” claims are not always reliable safety nets. Mammalian-derived ingredients also show up in everything from gel caps to gravy. The paper includes a reference table of common food additives that may contain alpha-gal.

Pace’s core advice for anyone newly diagnosed is short: be prepared, not scared.

“Do your research, communicate that you have a food allergy and that it’s very serious, and bring your medication,” Pace said. “Keep your EpiPen and antihistamine on you.”

Because the syndrome touches diet, gastroenterology, dermatology and mental health — and because tick prevention is central to keeping it from worsening — the authors recommend a team-based approach that includes an allergist, a registered dietitian, a mental health provider and a tick-prevention expert. There is also hopeful evidence in the literature that, without additional tick bites, alpha-gal antibody levels can decline over time, and a small group of patients has been able to reintroduce mammalian products under medical supervision.

Kentucky is currently in peak tick season, and every life stage of the Lone Star tick, from larva to adult, can transmit alpha-gal sensitization.

To learn more about FCS Extension at Martin-Gatton CAFE, visit fcs.mgcafe.uky.edu.