Alpha-Gal Syndrome and Meat Allergy

a man suffering abdominal pain lays in fetal position on a couch while holding his stomach

Can you be allergic to meat? The answer is yes, and it can be life-threatening. This allergy is known as alpha-gal syndrome, commonly called red meat allergy. It can affect people who eat beef, pork, bison, lamb, venison and/or goat.

How does this happen? You get bitten by a tick (usually the lone star tick) and that bite transfers alpha gal, a type of sugar molecule found in your body. Your immune system then develops a response to this molecule. When you eat products that contain alpha gal, you have an allergic reaction.

Foods that contain alpha gal are red meat or meat from mammals, and products that are made with them (including milk and gelatin). Alpha gal is not found in fish, birds (including chicken) or humans.

You can be allergic to meat – specifically red meat – but only under certain conditions. Commonly called red meat allergy, or alpha-gal syndrome (AGS) after the blood carbohydrate involved in the allergy, the condition is connected to a recent tick bite.

You may hear red meat allergy also referred to as mammalian meat allergy, lone star tick disease or tick bite meat allergy.

Geographic distribution of suspected alpha-gal syndrome cases* per 1 million population per year — United States, 2017–2022

* A suspected case of alpha-gal syndrome was defined as being in a person who had confirmatory laboratory evidence (serum or plasma alpha-gal–specific IgE ≥0.1 IU/mL or ≥0.1 kU/L) with no clinical information available.

Abbreviations: IgE = immunoglobulin E; IU = international unit; kU = kilounit. Source CDC

A U.S. map shows suspected case frequencies by county. Dark blue indicates over 87 cases, medium blue 11-87, light blue 1-11, and gray shows no suspected cases. The highest concentrations are in the South and East regions.

Alpha-gal syndrome cases have risen steadily since the condition was first identified in 2009. A recent study by the U.S. Centers for Disease Control and Prevention (CDC) found that between 2010 and 2022, there were 110,000 suspected alpha-gal cases. CDC also estimates that up to 450,000 people in the United States may have AGS, but many may not know they have it. AGS is not unique the the U.S. – cases have also been discovered in Europe, Asia and Australia.

What is alpha-gal syndrome?

AGS is a red meat allergy caused by a tick bite. The alpha gal sugar molecule is found in a tick’s saliva. Soon after the tick bites you, it causes an immune system response that increases your sensitivity to red meat. The allergic reaction usually occurs hours after eating a meal with red meat.

Is alpha-gal syndrome also lone star tick disease?

Some refer to the condition as the lone star tick disease. It is thought that AGS is caused by a bite from the lone star tick, but species of ticks in other parts of the world can also cause the condition.

The lone star tick is most prevalent in the eastern and southeastern regions of the United States. It can be found as far west as Texas and New Mexico and as far north as Maine. Alpha-gal syndrome cases have also been reported in Australia, Germany, Sweden, Japan, and South Africa.

a woman sitting at her desk at work holds her stomach due to nausea

What are alpha-gal symptoms and meat allergy symptoms?

First you must identify the tick bite. This can be hard because these critters are small and difficult to find. They often attach themselves to the leg, groin, back of the neck or the scalp. Many people only experience a rash that itches longer than normal. There may also be a small, hard bump under the skin where the tick bit you.

Ticks that transfer alpha-gal sugar molecule can cause red meat allergy. AGS allergy symptoms are similar to other food allergy symptoms, but with more gastrointestinal distress. Signs of an AGS allergic reaction may include:

  • Hives or itchy rash
  • Gastrointestinal problems (GI symptoms)
  • Nausea or vomiting
  • Heartburn or indigestion
  • Diarrhea
  • Severe abdominal pain
  • Cough, shortness of breath, or trouble breathing
  • Swelling of the lips, throat, tongue or eyelids
  • Dizziness or fainting
  • Low blood pressure

The allergy can cause anaphylaxis – a potentially life-threatening allergic reaction involving more than one organ system at a time. But this is rare.

doctor consulting woman in her office

How is alpha-gal syndrome diagnosed?

Alpha-gal syndrome can be diagnosed by a board-certified allergist or other healthcare provider trained in the condition. When evaluating you for AGS, the doctor will…

  • take a thorough health history;
  • perform a physical exam;
  • order a blood test to check to see if your immune system has developed antibodies to alpha-gal;
  • consider a skin test to determine if other allergies are causing symptoms.

The doctor will also ask:

  • what symptoms you’re experiencing;
  • when the symptoms started;
  • what foods you have recently eaten;
  • if you know of any recent tick bites or have been in an area with lots of ticks.

If the symptoms and testing are consistent with AGS, you will be then given instructions on dietary avoidance.

AGS is sometimes hard to diagnose because symptoms are often delayed 2-6 hours. (Most food-allergic reactions occur within a few minutes of consuming an allergen, but with AGS, it’s often delayed.) You may eat a steak for dinner but not develop symptoms until nearly midnight.

Talk with your doctor if you think you have alpha-gal syndrome. Print out and bring information about the disease with you to the doctor appointment. A recent CDC studyfound that 42% of healthcare providers had not heard of AGS. And of those who had heard of AGS, less than a third knew how to diagnose it. It’s best to see a board-certified allergist who is trained in diagnosing the condition.

Alpha-gal allergy treatment

People with AGS should always carry epinephrine in case of a severe or life-threatening allergic reaction, also called anaphylaxis. Epinephrine should be given first and fast to treat anaphylaxis. It’s important to carry two doses of epinephrine in case symptoms worsen or return.

Like other food allergies, avoidance of the trigger food is the key to preventing symptoms. It is critical for people with AGS to avoid eating red meat and any other meat products that contain the alpha-gal sugar molecule.

Alpha-gal syndrome prevention

The best thing you can do to avoid AGS is prevent tick bites. Here are some strategies to avoid tick bites:

  • Know your environment. Do your best to avoid ticks. They like bushy, grassy and wooded areas. If you frequent these areas in your yard, on walks or hikes, or through your work, you are at higher risk for tick bites.
  • Cover your skin. Wear long sleeves and pants so you don’t have exposed skin. To be extra cautious, tuck your socks onto your pants.
  • Tick proof your clothing and gear. Products with 0.5% permethrin can be used to pre-treat clothing and gear.
  • Use EPA-recommended insect repellents or a bug spray.
  • Do a regular tick check. After being outside, check yourself and your pets for ticks – particularly in dark crevices such as behind ears, in the belly button, in underarms, and the groin.
  • Shower and wash your clothes after being outside.
  • Keep your pets indoors and away from wooded areas as much as possible during tick season. Pets can bring ticks into your house. They may jump from your pet to you and your family. Pets can also get tick-borne diseases and possibly AGS themselves. Consider giving your pets tick prevention medications

The more often you are bitten by ticks, the higher your risk for developing AGS. Preventing tick bites can also help protect you from other tick-borne diseases like Lyme disease and Rocky mountain spotted fever.

close-up of a cooked steak topped with rosemary and peppercorns

Are there alpha-gal foods to avoid?

Since trigger avoidance is key with AGS, it is important to avoid foods containing alpha-gal. These foods include most types of red meat and related meat products:

  • Red meat from mammals (including beef, pork, lamb, venison, rabbit, bison, buffalo and other meats); organ meats such as livers, hearts, brains and intestines contain the highest amounts of alpha gal
  • Cow’s milk or cow’s milk products (ice cream, yogurt, etc.)
  • Gelatin made from beef or pork
  • Products made from or cooked with mammalian fat (such as lard, tallow or suet)
  • Meat broth, bouillon, stock and gravy
  • Gummy candies, marshmallows and some other candies that may contain derivatives of alpha gal

Just because a food contains alpha-gal doesn’t mean you will have an allergic reaction. Some people with AGS are able to tolerate milk and other products.

Alpha-gal may also be found in non-food items, including medications and medical products. So it is important to work together with a board-certified allergist. Come up with a plan to avoid accidental exposure.

What’s a good alpha-gal allergy diet?

If you’re living with AGS, you likely require dietary restrictions to avoid symptoms. That doesn’t mean you need to become vegan or vegetarian. You just need to be aware of and avoid foods that contain alpha-gal.

You can still eat poultry (chicken, turkey), eggs or fish as part of your diet. Fresh fruits and vegetables are safe and a great source of nutrients.

Can you eat eggs with alpha-gal allergy?

Yes, you can eat eggs with AGS. Eggs come from poultry such as chicken or ducks. Poultry does not contain alpha-gal, so it is safe to eat eggs if you have AGS.

What about alpha-gal and alcohol?

Alcohol does not contain alpha-gal. However, people with AGS who eat red meat (or other alpha-gal foods) and also recently consumed alcohol may develop more severe symptoms.

Is there a cure for alpha-gal syndrome?

There is no cure for alpha-gal syndrome. If you’re diagnosed with AGS, the best way to avoid an allergic reaction is to not eat red meat. People with AGS who accidentally eat red meat should carry an epinephrine auto-injector, the best treatment for severe allergic reactions. The good news is that AGS is not a lifelong condition.

Questions & Answers (Q&A) on Meat Allergy

You may have specific questions about alpha-gal syndrome. Here’s a Q&A with some common questions about this condition. If there’s a topic you’d like to see answered in this Q&A, please email Gary Fitzgerald, Senior Editor Food allergy management at home can be a challenge at first. A new food allergy diagnosis may require a complete clean-out of your pantry and refrigerator to get rid of foods containing your allergens.

People tend not to develop AGS soon after the tick bite. They may notice that the skin around the tick bite itches longer than normal – 10 days or so. But it can take up to 3 months for alpha-gal syndrome to develop.

This is a another reason why diagnosis is challenging – you may not even remember having a tick bite.

Cases of alpha-gal syndrome have risen steadily since it was first discovered in 2009. In a recent CDC study, researchers found more than 110,000 suspected cases of AGS since 2010. There were approximately 15,000 suspected new AGS cases every year between 2017 and 2021.

The highest prevalence was found in Oklahoma, Kansas, Arkansas, Missouri, Mississippi, Tennessee, Kentucky, Illinois, Indiana, North Carolina, Virginia, Maryland and Delaware. Remarkably, 4% of all suspected AGS cases were found in one county – Suffolk County, New York.

CDC also estimates that the AGS prevalence could be much higher. It may affect as many as 450,000 people in the United States. Some people may gave AGS and not know it.

Children and adults develop the same symptoms of AGS. The most common symptoms involve hives and gastrointestinal problems. Adults are more likely to have an anaphylactic reaction to alpha gal than children.

No, there are no home remedies for AGS. The best action to prevent a meat allergy is to avoid tick bites. If you already have the condition, then avoid eating any meat products containing alpha gal.

Red meat allergy is only caused by the introduction of the sugar molecule alpha gal into your body. It is not caused by an infection. Other tick-borne diseases such as Lyme disease and Rocky Mountain spotted fever do not cause a sensitivity to meat.

Alpha-gal syndrome is a delayed reaction: symptoms can happen hours after eating meat. People often don’t think it’s a food-allergic reaction. This is very different from a typical food allergy in which symptoms usually occur immediately after eating a food allergen.

No. The chances of getting red meat allergy are still quite low. Studies have identified the groups at highest risk. Largely it’s hunters, gardeners and others who spend a lot of time outdoors in tick areas.

Watch for AGS symptoms if you get a tick bite. If you experience an itchy rash or hives and/or stomach problems, then you may want to hold off on eating red meat until you can get tested.

Most people with AGS experience symptoms only after eating a major cut of meat. They do not typically develop allergy symptoms due to cross contact with other foods or utensils; or casual contact with someone who is consuming red meat.

AGS does not appear to last forever. However, additional tick bites can boost your level of sensitivity, so if you’re someone who goes outdoors and gets tick bites 4-5 times a year, it may be hard for the meat allergy to go away. Others may be fine within 20-24 months. However, the allergy could return with another tick bite.

Other conditions that may look like food allergies or co-exist with food allergies?

There are other conditions that are different than food allergies but the symptoms, diagnosis and treatment vary depending upon the condition. Here are some of them.

Food Intolerance
Oral Allergy
Syndrome (OAS)
Celiac Disease
Eosinophilic
Esophagitis (EOE)
FPIES
GERD

Reviewed by:
Jacqueline Eghrari-Sabet, MD, FACAAI, is board-certified in allergy, immunology and pediatrics. She is the Medical Director of Telehealth for Allergy & Asthma Network. Dr. Eghrari-Sabet is the founder of Family Allergy & Asthma Care and the FAAR Institute in the Washington, DC area, where she has been in private practice since 1994. Dr. Eghrari-Sabet is Assistant Clinical Professor at George Washington University School of Medicine and Health Sciences where she mentors the next generation of doctors. She is also President of White Coat Resources, a health education consulting service.