Pollo's Revenge

August 11, 2007 2:40 PM

Why do I get sick when I eat meat?

I've been vegetarian for 14 years. Last week I was served a burrito. I became violently ill shortly afterwards, and after examining the leftovers, there definitely was chicken in this food.

posted by Homeskillet Freshy Fresh to health & fitness (30 comments total)

Because the enzymes and bacteria that you'd use to digest meat are dwindling in your system after 14 years of no meat digestion?
posted by mikeh at 2:45 PM on August 11, 2007

You body simply isn't used to digesting meat. Basically, you don't have the enzymes to properly digest the meat and you body doesn't know what to do with the food. It's why when people go from being a vegetarian to a meat-eater, it's highly suggested to slowly reintroduce meat back into their diet instead of gorging on a 24oz NY strip.
posted by jmd82 at 2:49 PM on August 11, 2007

It really depends on what you mean by sick.
posted by 517 at 2:55 PM on August 11, 2007

Occams razor folks - maybe it was just food poisoning, and nothing to do with the meat per se?
posted by i_am_joe's_spleen at 3:01 PM on August 11, 2007 [1 favorite]

Is food poisoning really more likely than the commonly observed sensitivity longtime vegetarians have to meat?
posted by zixyer at 3:08 PM on August 11, 2007

Vomit. Dry heaving, specifically. Thanks for the science, guys.
posted by Homeskillet Freshy Fresh at 3:21 PM on August 11, 2007

I don't see any science. I see some supposition. Can anyone actually post a better explanation than "this is what it seems like might be happening?" The best thing I can find with google is this, which seems to support more the food poisoning theory (did you really not notice the chicken when you were eating it?). Anyway, I'm not a vegetarian, but very curious about the truth of the matter.
posted by ch1x0r at 3:31 PM on August 11, 2007

Any long-time vegetarian will tell you that they often discover they've been served meat by becoming violently ill. It's what happens when you don't have it for a long time.

It's weeks of fun if you're a long-term vegetarian who has to start eating meat again for health reasons.
posted by Jairus at 3:39 PM on August 11, 2007

I was strictly vegetarian for nine years. Then I started eating meat. I never experienced any ill effects or sickness. I used to tell people when I was vegetarian "if I start eating meat I'll get sick" but I was just making that up to sound pure. Wasn't true, at least in my case.
posted by Nelson at 3:49 PM on August 11, 2007 [1 favorite]

vegetarian who has to start eating meat again for health reasons

An imaginary creature, to be sure...

The sick-after-meat thing has happened to every ex-veg I've ever met. I have no explanation -- sorry -- but for what an anecdote's worth, it's not rare.
posted by kmennie at 3:51 PM on August 11, 2007

I know that with milk, even the sensitive can build up tolerance. Studies have shown that sensitive individuals can tolerate it if they add it to their diet slowly. The same sort of treatment is used for other food sensitivities.
link

The digestive system is a funny place, full of god knows how many species of bacteria and different enzymes. All the information points to the flora population being geared towards your current diet.

I transitioned from vegetarianism and had to do it slowly with supplemental probiotics.

Most cases of food poisoning are accompanied by other symptoms. I'd say one case of vomiting does not usually mean food poisoning. If you had a fever or multiple episodes...maybe.
posted by melissam at 3:57 PM on August 11, 2007

Any long-time vegetarian will tell you that they often discover they've been served meat by becoming violently ill.

Not in my case -- I was able to restart eating meat with no physical effects whatsoever; I've known other people with the same ease of moving between meat and veg. Similarly, two meat-eating friends who were working in India and eating about 99% vegetarian for that year returned home to cheeseburgers and t-bones with no ill effects, except perhaps on their cholesterol levels. And, when I was in the Peace Corps, several long-term vegetarians in the group decided to start eating meat for convenience and social reasons; they found it yucky and weird and morally ambivalent, but none of them had any stomach problems. So it is not guaranteed that eating meat after not eating it for years will cause problems, although anecdotally many people seem to have that issue.

The symptoms you describe -- heaving until there is nothing left inside -- sound an awful like the times I've had food poisoning, honestly. If you started feeling better once you were totally emptied out (rather than that days-long misery of the stomach flu), I'd guess food poisoning.
posted by Forktine at 3:57 PM on August 11, 2007

I like joe's_spleen's explanation. As far as I know, you don't shut off your proteolytic enzymes after years of vegetarianism. You probably don't want to -- it would make digesting all of that plant protein difficult.

Perhaps it's supratentorial in nature.
posted by scblackman at 3:57 PM on August 11, 2007

I found this via google: Vegetarian got sick after eating meat

It does indeed sound like you don't have the enzymes up to speed yet, but apparently this only takes a short while.

I suppose after eating no meat for a long time, the taste alone could make you ill.
posted by Deathalicious at 4:09 PM on August 11, 2007

I vote for food poisoning. Eat a fresh piece of broiled chicken and get back to us if you'd like to test your theory. If you get sick from something you're certain is fresh, then there's more of a question there. I've served chicken to vegetarians (not spitefully, mind you) and haven't seen them manifest any sickness.
posted by StrikeTheViol at 4:09 PM on August 11, 2007

Also, I think it's highly possible that you might react positively to well cooked and "safe" meat, but might be more sensitive than the average meat-eater to slightly undercooked or poorly cooked meat.
posted by Deathalicious at 4:13 PM on August 11, 2007

Lots of vegetarians have a problem eating meat, more than I'd expect from food poisoning. I've assumed that one's intestinal flora adapt to live off whatever you're eating, and if you're a longtime vegetarian, maybe you don't have bugs that can deal well with meat (or you do, but not as many of them as a meat-eater would, and there's a little population explosion, or something). This explains the "gas, diarrhea" reaction more than the "vomiting" reaction though, which does sound more food-poisoning-like.

Given the way we all share intestinal flora, your reaction might have to do not only with whether you ever eat meat, but also with how much time you spend near people who eat meat.
posted by hattifattener at 4:26 PM on August 11, 2007

I remember reading an interview with Sylvester Stallone that asked about his choice to be a vegetarian. I believe he said he tried being a strict vegetarian would get violently ill if he accidentally ate meat. I believe he stated he ate some type of meat about once a month so this would not happen.
posted by Yorrick at 4:32 PM on August 11, 2007

Here's what I think happened, assuming no one else got sick and it wasn't food poisoning.

The pancreas has several specialized enzymes that are used to break apart proteins into polypeptides and amino acids. Each enzyme degrades protein in a different manner, some cleaving the protein in half, other peeling amino acids away from the ends of the chain and some only breaking a protein at specific amino acid pairings. For whatever reason, you were deficient in one of these enzymes and a whole bunch of odd polypeptides ended up in your small intestine and triggered your vomiting reflex. Since the food was already out of your stomach, all you got were the dry heaves instead of the wet heaves(?).

If you wanted to add meat back to your diet it would just be a matter of introducing it back in more slowly so your pancreas would have a chance to respond to the increased demand for whatever you were deficient in.
posted by 517 at 4:53 PM on August 11, 2007

My friend started eating meat after almost 20 years by having beef and suffered no ill effects.
posted by loiseau at 5:58 PM on August 11, 2007

While eating meat voluntarily is not an option, it seems food poisoning and enzyme deficiencies are. Many thanks to the MeFiSci crowd.
posted by Homeskillet Freshy Fresh at 6:15 PM on August 11, 2007

did you really not notice the chicken when you were eating it

No, I really did not notice the chicken until I dissected the burrito. I had eaten a few hours before, only had a few bites of the burrito, and asked it to be boxed up. It wasn't a great amount of chicken -- I had 3/4 of the burrito left, and only found three strips of chicken, about 1/2 an inch long each -- and I must confess that I didn't really look at the food.

As far as it being supratentorial or psychosomatic, I didn't know of the chicken until after I was sick.
posted by Homeskillet Freshy Fresh at 6:24 PM on August 11, 2007

i dove, head first, into a bacon cheeseburger or something like that as i flipped the bird to my four years of veg-dom. i didn't get sick. but i was fully braced for it after hearing that it happened to everyone else.
posted by tremspeed at 7:29 PM on August 11, 2007

vegetarian who has to start eating meat again for health reasons

An imaginary creature, to be sure...

FWIW - I used to eat vegetarian for about 7 years. I transitioned into a diet with a small amount of meat in it. Crohn's disease surfaced, and let me tell you that there is no way I could conceivably go back to being vegetarian at the present time without spending 1/2 my life on a toilet and the rest of the time cleaning up afterwards. So, yeah, not so imaginary.
posted by plinth at 7:51 PM on August 11, 2007 [1 favorite]

vegetarian who has to start eating meat again for health reasons

An imaginary creature, to be sure...

FWIW - I used to eat vegetarian for about 7 years. I transitioned into a diet with a small amount of meat in it. Crohn's disease surfaced, and let me tell you that there is no way I could conceivably go back to being vegetarian at the present time without spending 1/2 my life on a toilet and the rest of the time cleaning up afterwards. So, yeah, not so imaginary.

Same here, the transition was worth it. I have a stomach disorder too and it makes a big difference. The transition involved small amounts and was slightly iffy, but the end result is so much better. Soy is evil for stomach disorders, so is seitan and many of the other foods veggies rely on. I'm really tired of VeggieJerks making out like their diet is the best and makes everything better.
posted by melissam at 8:12 PM on August 11, 2007

For what it's worth, most cases of food poisoning do not involve eating meat (though sometimes meat is involved - such as the industrial equivalent of the salad prepared after the cutting board was insufficiently cleaned after cutting infected chicken), and the symptoms described here sound more like a short period of illness, rather than salmonella, which is more in the realm of taking many hours to develop and knocks you down for a few days.
So I think Occam's razor points to the differing vegetarian enzyme balance.

I believe you can buy bacteria to re-populate your gut (for example, to take after a course of antibiotics has stripped you out), and I've heard of vegetarians using those to help with initial meat digestion, but I can't vouch if that stuff is genuine or health-store snake-oil pills, I've just heard people talk about them.
posted by -harlequin- at 6:17 AM on August 12, 2007

I've been a vegetarian for over 25 years. Believe me, I can tell you when that "vegetarian" soup was made with chicken stock or beef broth; I'll get quite ill shortly after eating.
posted by belladonna at 6:35 AM on August 12, 2007

I've been veggie for 9 years and have a similar reaction to even trace amounts of animal product. I don't even think the veg time served has much to do with it. About 8 1/2 years ago, I ordered a taco pizza and forgot to order no beef. It was covered in lettuce and cheese so it took me a few bites before I realized it, and I guess I figured the harm was already done so I ate the rest of the slice. Absolute misery for hours!

Nowadays, 2 years into veganism, I will know if I ate dairy even if I had no idea at the time.

Sorry, no science, just more anecdotal evidence.
posted by Drew_Blood at 7:28 AM on August 12, 2007

Most likely because, uh.......... Its like a punch solarplexes. Shock to your system I get the same feeling from greasy foods .
posted by Bon Joey at 11:44 AM on September 20, 2007

From my own experience transitioning from vegetarianism to meat-eating (no ill effects at all), and from talking with other vegetarians, I have concluded that the fabled sickness is akin to "the vapors."
posted by jayder at 7:22 PM on May 1, 2008