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Comment by Gatsky | Hacker News Reader

Unfortunately meat is clearly bad for you in at least one but probably many ways. The most compelling evidence to me is that carnivorous animals have higher rates of death from cancer, see fig 2 of this fascinating study: https://www.nature.com/articles/s41586-021-04224-5

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"Carnivorous animals have higher rates of death from cancer"

Say hello to Crocodiles :)

https://www.cell.com/heliyon/fulltext/S2405-8440(21)02697-9

The study I cited was of mammals. We aren't going to learn anything useful from the lifestyle of cold-blooded reptiles. For one, their metabolic rate is much lower.

Likewise comparing ourselves to obligate carnivores, or obligate herbivores is also less useful. Ideally you'd want omnivores that for one reason or another excluded meat from the diet, or did not. Right?

Not really. The key question is whether meat is carcinogenic or not. If you eat less of it, sure it will be less carcinogenic, but it won't be suddenly good for you.

There seems to be a lot of people who want to eat meat and also deny that it has various adverse health effects. The evidence is pretty clear, that's all I'm saying. What one does with that information is up to the individual. I don't do anything with it.

but you can't blanket say meat is carcinogenic. If we acknowledge that meat has no link to cancer in alligators or sharks, then we need to question if it is because of animal, the meat, or both. Likewise, if mountain lions have higher rates of cancer than deer, is it the animal or the food? Likewise deer are eating acorns which are very high in antioxidants. So its another variable. Do mountain lions have higher cancer rates than a wild hog? That is an interesting question. As far as my bias from what I want to do. I want to eat ice cream and drink scotch all day, but I won't argue either are healthy. Alcohol is generally listed second after tobacco as a cause for cancer in humans. I really just don't think the link between meat and health is well established in humans, or even if it is the same across human variation.

This is only a study of raw meat consumption, which is comparatively rare among humans. If it turns out — and this study acknowledges this limitation — that the predominant causal agent here is cancer-casing viruses, that would have pretty irrelevant impact for humans.

There are so many confounds here that it’s hard to draw conclusions for humans except maybe what’s worth future study.

FWIW, I have no horse in this race either.

The 2012 plenary session in the biggest cancer conference in the world was about cancer causing viruses in red meat that wasn’t cooked to a certain temperature. It hasn’t really panned out since. In any case, the bottom line remains that red meat can cause cancer. Preparing it a certain way might reduce the risk but not to zero. Humans still eat a lot of non-virally sterile meat. Yes we can spend the next 100 years studying it, but what should one have for dinner tonight? The answer it seems is probably not red meat.

I mean…maybe? But it depends on the effect size, really. And the virus thing is just one possibility among many.

Even if red meat increases your lifetime chance of cancer even by a few percentage points, then one should probably spend more effort reducing other risks, like moving further away from the highway, filtering your air, etc. Definitely don’t fry anything, and probably stay away from grilling too?

Likely depends what else is in your diet too.

Does that study only look at zoo animals? I would assume carnivorous animals get far more exercise when they have to hunt, chase, and kill their food than when it’s given to them. That confounding factor alone might be large. I’ve been wondering about the relation between nutritional excess and cancer, can’t recall ever seeing this studied.

Yes, they are animals in human care. But the fact is there is a difference between carnivores and herbivores across various species and animal lifestyles, which is strong proof that meat is carcinogenic. What factors mitigate this in the wild are largely irrelevant. You can smoke and exercise and be a bit better off, but that doesn't change the carcinogenic potential of cigarettes.

> What factors mitigate this in the wild are largely irrelevant

Why? If we find a link indicating exercise reduces or eliminates the cancer risk associated with eating meat, then it would just show another option for behavioral change to produce positive outcome. More options is not a bad thing.

It’s a bit like studying how to reduce your chance of lung cancer from smoking if you want to keep smoking. No mitigating factor will eliminate the risks from red meat, except not eating it. Also lifestyle or nutritional mitigation factors are difficult to study, and it’s never clear if they apply to a given person with a particular genotype and environment.

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