Alpha-gal syndrome: Foods to Avoid


Alpha-gal syndrome is an emerging allergy caused by ingesting red meat. The allergic reaction, which can occur one to several hours after eating red meat, can cause anaphylaxis, gastrointestinal symptoms, and skin changes.


Alpha-gal syndrome typically presents with abdominal pain, diarrhea, nausea or vomiting. But it can also lead to swelling of the face or throat, voice changes, difficulty breathing, hives, or fainting, according to recent article “AGA Clinical Practice Update on Alpha-Gal Syndrome for the GI Clinician: Commentary,” by McGill and colleagues.¹

According to the authors, the syndrome is an IgE-mediated reaction that can occur hours after eating beef, pork, other mammalian meat, or mammalian-derived products.
“A history of awakening at night from sleep with GI distress may suggest alpha-gal given the typical hours in delay from alpha-gal ingestion to reaction.”

Investigators believe alpha-gal syndrome occurs after an individual is bitten by an infected tick or develops a parasitic infection. “In the United States, the Lone Star tick, an ectoparasite whose principal host is deer, is strongly implicated,” the authors write.

Individuals with alpha-gal syndrome should take preventative measures to avoid further tick bites because “additional tick bites may worsen the allergy.”

McGill and colleague summarized the proposed pathophysiology. “When the sensitized human eats mammalian meat or mammalian-derived products, the antigen alpha-gal is absorbed by the GI tract bound to fat in a glycolipid, and incorporated into chylomicrons, which enter the circulation in roughly 2 hours.”

“When the antigen alpha-gal then binds to IgE antibodies present on mast cells that richly populate the GI tract, these mast cells degranulate and release their abundant supplies of histamine and other mediators,” the authors explain.

“These mediators in turn can act on sensory nerve endings to cause pain on intestinal smooth muscles to cause contractions, and on mucous glands to secrete mucous,” the authors write.

Food to avoid for alpha-gal syndrome patients

The American Gastroenterological Association has offered guidance on foods to avoid for patients with alpha-gal syndrome. They include:

  • Pork, beef, venison, and other mammalian meat – in essence, any animal with hair;
  • Products made from these mammals, such as lard, butter, milk, and others should be avoided;
  • Aerosolized alpha-gal (i.e., from frying bacon or beef products);
  • Gelatin derived from the collagen in pig or cow bones such marshmallows, gummy bears, gelatin candies, and desserts also may be problematic.

Fish, seafood, turkey, chicken, and other fowl are acceptable for patients with alpha-gal syndrome.

In cases of accidental exposure, patients can take diphenhydramine, 25 milligram tablets. Self-injectable epinephrine might help if respiratory compromised.

The authors suggest, “Gastroenterology clinicians should be aware of the diagnosis and management of alpha-gal syndrome because a subset of alpha-gal allergic patients show GI symptoms such as abdominal pain, diarrhea, nausea, or vomiting without skin changes or anaphylaxis.”

  1. McGill SK, Hashash JG, Platts-Mills TA. AGA Clinical Practice Update on Alpha-Gal Syndrome for the GI Clinician: Commentary. Clin Gastroenterol Hepatol. Apr 2023;21(4):891-896. doi:10.1016/j.cgh.2022.12.035

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3 months ago

My name is Edward I have problems with my gut for the last 6 years. I’ve been to more doctor appointments that I can count and I’ve had severe stomach pain and nausea and here lately a lot of brain fog problems remembering and a rash that will pop up at any time I’ve heard such severe stomach pain or gut pain that I just have to lay down put my feet up and just breathe focus on my breathing because I’ll scream if I don’t this condition has caused me to be mean to the people that love me the very ones trying to help me I’ve only known that I’ve had an alpha gal for 2 days and I’m trying to adjust to eating only only one I’m supposed to you no meat at all except for chicken and fish I’m seeing what works for me but right now I’m in a lot of pain I don’t know why what is caused from I don’t to my knowledge have not had beef or pork or anything and I’m haven’t been exposed to anything at all I’m having severe stomach pain where I’m having to lay down and I’m having trouble I’m only talk texting this out cuz I can’t remember to keep texting and everyone’s really focusing on trying to get this little paragraph written and I’m going to go walk for a minute and try to get this pain to go away the pain I have is like waves of pain I can feel it coming on and I can tell when it’s going to be really bad all I can do like I said is lay down and hope it goes away quick I have the trouble passing gas and my testicles have been pulled up because of this severe pain the pain right now is like severe it is causing me to be hard and starting to sweat oh man I’m hoping it goes away pretty quick and I got chills and I’m almost certain that I’m peeking out on the pain right now I also hurts around to the back side where my kidneys are not right above my kidneys and my head will hurt here lately I’ve had a rash a company with bad headaches and the other day my hands and feet were burning like crazy I don’t have any of this… Read more »

3 months ago
Reply to  Edward

The pain is starting to go away and I feel a little bit better I can tell I’m going to be better and feel it comes in waves and I feel no pain at all after it’s gone I’ve been living with this for years and it’s sad but I’m almost used to this it exhaust me to have this pain and I know that I’m going to be fatigued and unable to do the things I want to do but I’m glad it’s gone and I’m glad I finally figured out what this is I just want no want to go through I’ve been through and hope that if you have Alpha gal that I hope you have diagnosed it pretty quick I heard there’s people that was when 10 years without having and diagnosis I’m still hurting now but I thought that I would write this just to pass time and hope that it helps somebody please if you notice somebody with irritable bowel please tell him to get tested for it I forgot because a lot of times I think that they misdiagnosed people

1 month ago
Reply to  Edward

I am sad you had to go through all of that and for so long. There’s plenty of information on the Internet. I had just heard about alpha gal and about 2 weeks later, I got bitten! I have been diagnosed for 2 months now and I MISS dairy (cheeses, sour cream, ricotta, ice cream) soooooo much!!!! I used to enjoy cooking…not so much anymore. The plant-based things are decent, but the real thing is so much better)…not to mention you have to pay through the nose for them. Best wishes on your AG journey!

Last edited 1 month ago by Karen