Javascript is not enabled.

Javascript must be enabled to use this site. Please enable Javascript in your browser and try again.

Skip to content
Content starts here
CLOSE ×
Search
Leaving AARP.org Website

You are now leaving AARP.org and going to a website that is not operated by AARP. A different privacy policy and terms of service will apply.

Alpha-Gal: What You Need to Know About the Red Meat Allergy Caused by Ticks

A bite from the little bugs could take beef and pork off the menu


spinner image Lone Star Tick
Bob Balestri / Getty Images

When temperatures warm and foliage blooms, doctors and public health experts urge people to take proper tick precautions before heading outdoors. A bite from one of the little bugs could result in a disease, like Lyme or babesiosis. It could also lead to a strange but serious food allergy that, for meat-eaters, could sideline summer barbecue plans.

Alpha-gal syndrome is an allergy to red meat that can be triggered weeks after a bite from the lone star tick and possibly other varieties. And like tick-borne diseases, which are on the rise in the U.S., so are cases of alpha-gal.

member card

AARP Membership — $12 for your first year when you sign up for Automatic Renewal

Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP The Magazine.

Join Now

“We’re continuing to identify new patients every week in allergy clinics across the Southeast and East who’ve had essentially brand-new reactions,” says Scott Commins, M.D., an associate professor of medicine at the University of North Carolina and a leading expert on alpha-gal syndrome. “And that has been a big change over the past, say, 10 years.”

More than 34,000 people in the U.S. have tested positive for alpha-gal syndrome, according to research published by Commins and his colleagues in 2021.

What is alpha-gal?

Alpha-gal is a sugar molecule — many mammals have it, including cows and pigs, and Commins says researchers have come to understand that some ticks do too. But it’s not found in people, so when a person gets a bite from a tick that has alpha-gal in its saliva, the body creates an immune response to the molecule, and some people create a strong allergic response.

Symptoms of alpha-gal syndrome

Reactions can range from mild to severe and may include:

• Hives or itchy rash

• Nausea or vomiting

• Heartburn or indigestion

• Diarrhea

• Cough, shortness of breath or difficulty breathing

• Drop in blood pressure

• Swelling of the lips, throat, tongue or eyelids

• Dizziness or faintness

• Severe stomach pain

Source: Centers for Disease Control and Prevention 

“So then when we eat a hamburger, hotdog, etc., we have an allergic reaction to the meat, and it’s specifically to that alpha-gal that’s in pigs and cows,” Commins says. This is the case even if a person has been able to eat red meat their whole lives without issue. 

Recognizing the symptoms of alpha-gal

Unlike other food allergies, symptoms of alpha-gal syndrome don’t come on right away. “If you have a peanut allergy and you go out to a restaurant and you get an accidental exposure, you know you’re in trouble before you leave the restaurant,” says Jeffrey Wilson, M.D., an allergist and immunologist and assistant professor of medicine at the University of Virginia.

With alpha-gal, however, it could be hours — three to six, or more — before hives or a rash develop, or you start to feel lightheaded and short of breath. Other common warning signs include indigestion, nausea, vomiting, diarrhea and severe stomach pain.

This delay can make it difficult for people to make the connection between what they ate and their symptoms, Commins says. To complicate matters even more, some people experience only gastrointestinal (GI) symptoms, which is easy to blame on food poisoning or a stomach bug.

The American Gastroenterological Association recently updated its guidance for physicians to consider alpha-gal syndrome in patients with “unexplained GI symptoms of abdominal pain, diarrhea, nausea and vomiting” — especially if they live in an area where ticks and the allergy are prevalent (the Southeast, mid-Atlantic, Midwest and East Central regions). The group also notes that a history of waking up at night with GI distress may also signal the syndrome.

Another possible warning sign is redness or irritation that is slow to heal in the spot where the tick latched on. “Some folks would say it even felt like a knot under the skin,” Commins says.

Health & Wellness

AARP Members Only Access to Special Health Content

Access AARP health Smart Guides, articles and special content

See more Health & Wellness offers >

If you notice these symptoms after eating mammalian meat (beef, pork, lamb, venison, etc.), talk to your primary care provider or an allergist. A blood test, alongside an exam and patient history, is often used to diagnose the allergy; your doctor may also order an allergy skin test.

One thing to note: If you’re getting a routine allergy test but don’t have symptoms of alpha-gal syndrome, know that some people produce antibodies for molecule, but don’t have a full-blown allergy. “So, a positive test does not automatically mean you have a red-meat allergy,” Wilson says.

There is no treatment for alpha-gal syndrome, though experts say it’s possible the allergy fades over time, especially if you’re able to dodge additional tick bites. Those with the allergy — which can range from minor to severe — have to avoid red meat and often other products containing alpha-gal, like meat broth or stock and gelatin made from beef or pork. Some people are unable to eat dairy. 

Ticks on the move

Pinning down a reason for the rise in alpha-gal syndrome is tricky, experts say. Food allergies, in general, are increasing, Wilson notes. There’s also more recognition and awareness around alpha-gal.

And because tickborne diseases are increasing overall, Commins says “it kind of makes an argument that people are just coming in contact [with ticks] and being bitten more frequently.”

Interestingly, the tick population fluctuates on a yearly basis, says entomologist Michael Raupp. But one thing that has grown is their reach. With warmer temperatures, ticks have been expanding further north.

“This is a phenomenon that’s going on with lots and lots of different kinds of insects and arthropods, including ticks,” says Raupp, professor emeritus at the University of Maryland. “And because the tick is now moving into these areas, you’re going to have cases of the red meat allergy and [other tickborne diseases] in these areas where they haven’t been before.”

membership-card-w-shadow-192x134

LEARN MORE ABOUT AARP MEMBERSHIP.

Get instant access to members-only products and hundreds of discounts, a free second membership, and a subscription to AARP the Magazine.

To avoid ticks and any allergies or ailments they transmit, Raupp has a few tips:

• Stick to a paved surface or the center of the trail when walking or hiking. Ticks are most often lurking in the lush vegetation.

• Tuck your pant legs into your socks if you’re going to be out in grasses and plants.

• Too hot for pants? Reach for a spray repellent. The CDC recommends using an Environmental Protection Agency (EPA)-registered insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-Menthane-diol (PMD) or 2-Undecanone.

• You can also treat your clothing and boots — not your skin — with products containing 0.5 percent permethrin. The CDC has more information on how to do that. Or you can buy clothing that has already been treated.

• Put your garments either directly in the wash or even just the dryer when you get home. “And if you spin that on a medium to high cycle for about 30 minutes, you’ll kill any ticks that might have come home with you,” Raupp says. Also, take your shoes off outside so you don’t bring any ticks in the house, and examine pets and any gear outside as well, such as backpacks.

If you notice a tick on your body — and it’s important to check routinely — make sure you:

• Remove it as soon as possible. It takes the tick about 36 to 48 hours to transmit diseases like Lyme, according to the Centers for Disease Control and Prevention. “So, if you can get that tick off in the first 24 hours, it’s going to greatly decrease your chances of contracting a tickborne illness,” Raupp says.

• When you do get the tick off, don’t flush it. Identifying the tick can help you understand your risks. “If it’s a black-legged tick, that puts Lyme disease in the picture,” Raupp says. The primary tick associated with a red meat allergy is the lone star tick. Many universities and health departments offer tick identification services, including the University of Maryland and the University of Rhode Island. 

Video: Top 5 Tips for Preventing Tick-Borne Disease
Even more strategies to help protect yourself from disease-carrying tick bites.

Join AARP to continue reading

Find exclusive interviews, smart advice, free novels, full documentaries, fun daily features and much more — all a benefit of your AARP membership — on Members Only Access.

Join AARP for Members Only Access

Already a Member?