Alpha-Gal is Bad, Especially for Farmed Animals

Disclaimer: I’m not vegan. I’m not even vegetarian. I eat meat all the time. I’ve been a firm critic of efforts to objectively quantify the difference in suffering across very different species. That said, I cannot help but agree that eating meat is probably the morally worst thing I do, and I also have to agree that eating different kinds of meat are different levels of bad. Eating 1 kg of chicken basically entails eating an entire chicken, which most likely lived in truly awful conditions, while 1 kg of beef is less than 1% of a cow, and which probably did not live in quite as awful conditions.

That said, let’s talk Alpha-Gal. Suppose you get bitten by this unsavoury little bugger:

Via Wikimedia

It’s a Lone Star Tick. This tick has recently ingested some animal blood, containing galactose-alpha-1,3-galactose (alpha-gal). The tick’s bite spits a little bit of alpha-gal into you, and your immune system freaks out about it. The mechanism is a little hazy, but the result is well-documented: you can’t eat anything with the alpha-gal molecule in it. This includes beef, pork, venison, basically any mammalian meat source, even cows’ milk.

While the Lone Star tick is the poster-child, alpha-gal syndrome has been linked to other kinds of ticks as well, though at much lower rates. It seems like some ticks are better at sensitising their hosts to alpha-gal than others. Since alpha-gal isn’t caused by a pathogen which can spread or evolve, the increase in frequency of alpha-gal syndrome is probably just due to there being more ticks around, which is in turn probably due to climate change.

The Ethics

Crutchfield and Hereth (2025) argue that alpha-gal syndrome is, in some sense good: eating cows and pigs is morally bad, and if you get alpha-gal syndrome, you can’t eat them anymore. They go on to make the (deliberately provocative) claim that preventing the spread of alpha-gal is morally bad, because if fewer people get alpha-gal syndrome, then more people eat meat. This caused a bit of a moral debate.

Anyway, they’re wrong. Regardless of their ethical reasoning, they’re wrong for boring technical reasons. Remember how alpha-gal is a sugar found in mammal meat? That means that people with alpha-gal syndrome can still eat non-mammal animal products.^[1] This includes shrimp, fish, and chicken, which I have listed in increasing order of how much I expect animal-welfare normies to care about them. This ordering is also, perhaps not coincidentally, in decreasing order of how bad EAs think it is to eat them.

I’m not the first person to point this out: Ebert and Koeder (2026) got there before I did! As well as going after the ethics of using tick bites to force people to stop eating meat, they point out that Crutchfield and Hereth made the bizarre claim that people who get alpha-gal usually go vegetarian, which they based on a single case study.

This is almost certainly not true. Existing studies recommend people to eat more poultry and seafood. I suspect it would become less true the more people get alpha-gal syndrome. Some people might hear “allergic to red meat” and give up all meat out of safety, or confusion. The more people with alpha-gal, the stronger the cultural transmission of the knowledge that you can eat seafood and poultry.

Can We Do Anything?

Hopefully at this point we’re all on board with the fact that treating alpha-gal syndrome would be good on basically every axis. Unfortunately, allergies are pretty difficult to treat! The mechanism is (most likely, according to Román-Carrasco et al (2021)) a population of mast cells and basophils which hang around in the lymphatic system. When you eat red meat, it gets digested over the course of a few hours, and then its components are taken up and transported around the body. Some of those components have alpha-gal molecules as part of them. When those hit the lymphatic system, the waiting immune cells sound the war-trumpets and rally the troops, leading to a systemic allergic reaction which includes potentially fatal swelling of the airways.

Unlike other chronic diseases like infections, or even cancers, the problematic agents are just normal cells in the immune system. They’re hard to target with drugs. Ideally, we’d have some kind of drug which kills off just the immune cells which are responding to the alpha-gal, but that drug hasn’t been invented yet.

There are a couple of groups working on it though, and one is short on funding. The main method seems to be to use human-serum albumin conjugated to alpha-gal. I think the theory is that a low dose of mildly-immunogenic alpha-gal-HSA conjugate will overall produce tolerance. I’m suspicious that they’re only publishing in Frontiers, a somewhat dodgy journal of AI-generated rat balls fame, and immunology is absolutely not my speciality, so I can’t really assess the methods very well. One is also working on sublingual nanoparticle formulations (i.e. you just put them under your tongue, no need for IV delivery) which would be extremely cool to have in general.

How Much Should We Care?

This section is going to be rather uted up. Apologies. If you don’t really care about shrimp and chicken, then you should just care about the people affected, and for them, it seems to really suck!

If you do care about shrimp and chicken, then consider that it would cost somewhere around $7-9 to offset the total increase in shrimp and chicken suffering caused by one alpha-gal sufferer in one year, by donating that money to a campaign for cage-free eggs, or to a shrimp stunning project. At the current prevalence of alpha-gal, this means somewhere under $1M/year’s worth of harm caused by alpha-gal syndrome to animals. If there is a way to turn $1M into a cure for alpha-gal arriving 1 year sooner, then it might be on par with other animal welfare interventions, but that would require you to have a lot of confidence in the ability of grantees to turn money into clinical results (a famously difficult thing to do).

This would change if the prevalence of alpha-gal syndrome went up by a lot, which isn’t impossible: at least 5% (!!!) of the residents of Martha’s Vineyard are testing positive for alpha-gal, having reported their first case in 2020! Extrapolated across the US, that would mean 17 million individuals (though this is very unlikely) which would mean that bringing forward a cure by 1 year might easily be worth $100M. For now, though, this seems like an inefficient way to help factory farmed animals.

I Clauded up a calculator here if you want to screw around with the numbers yourself.

1. ^{^}

   Now if you were wondering why humans can be allergic to a component of our own flesh, the answer is that primates, for some reason, do not produce alpha-gal. This means that people with alpha-gal can also eat monkey. I expect most people in the west would rather eat chicken and shrimp.