>2x ultra-marathons >26 miles, or at least 5 marathons completed
Yes, and it seems like it's really a 7.5x risk increase. Still pretty spectacular, though!
I really wonder what could cause that. Randomly throwing out possible causes: 1) blood redirected away from gut, 2) overuse of NSAIDS, 3) ultraprocessed foods (gels etc), 4) strange microbiome issues (gels + stress in gut from extreme exertion = altered gut flora?)
The study that found the result is DOI: 10.1200/JCO.2025.43.16_suppl.3619
Which is way more than what original hunters and gatherers ever clock. They do move a lot, but not so much, and they alternate their activities a lot too (running, walking, resting, taking entire days off and just guarding their village).
We're not really optimized for this sort of extreme endurance and long-term development of serious pathologies is unsuprising.
You shouldn't so offhandedly assume a hunter-gatherer lifestyle couldn't lead to issues like increased risk of CRC, or that activities which lead to increased risk of CRC couldn't be what hunter-gatherers did. Evolution is neither fast nor perfectly precise. Plenty of animal populations have common health problems that simply weren't harmful enough to reproduction to be selected out, much less something rare and late-onset like CRC.
I don't assume anything. From what we know about health of the last surviving hunter-gatherers, they suffer significantly less from "diseases of civilization" when taken in proportion to their settled neighbours. Some of those diseases (such as high blood pressure or diabetes 2nd type) seem to be totally absent in them. Cancers do happen, but not as often.
This pattern is quite old. Already ancient Egyptians suffered from civilizational diseases much more than hunter-gatherers, especially the richer ones (heart attacks, gout, cancer).
I won't bother checking or disputing the accuracy of your factual claims, because it does not matter.
Colorectal cancer is not the same thing as high blood pressure, or type 2 diabetes, or any other cancer that isn't colorectal cancer. Diseases are not a monolith and you cannot assume low risk of some diseases means low risk of others. That is wild guesswork passed off as logic, like measuring the shadow your testicles cast on the wall and announcing it is 24.1 degrees Celsius. Ultra-marathon runners also have low risk of type 2 diabetes!
Do you have specific evidence that modern hunter-gatherers have low rates of colorectal cancer that cannot be explained by survivorship bias, screening, genetic differences, and all other confounders, and that they are representative of historical hunter-gatherers? No? Then you cannot confidently conclude that hunter-gatherers didn't experience elevated rates of CRC.
Absolutely, we may have a depressed rate of CRC where ultramarathoners just get back up to the historical baseline. Who knows, but we don’t know it isn’t that.
"Diseases are not a monolith and you cannot assume low risk of some diseases means low risk of others. That is wild guesswork passed off as logic..."
Diseases are not a monolith, but they do tend to arise and fall in some specific clusters, and that is not "logic", good or bad (too many computer-minded people drag logic into the chaos that is biology), but rather a long-time empirical observation, albeit with some exceptions.
You are really obsessed with my testicles. That is a weird comparison, but at least you know that you're not a bot. This would be too weird for a LLM to produce.
In general, I don't think your irony is as strong as you think. Shrinkage of various materials in the cold is the original basis for a thermometer.
Of course it is better to use something better-observable like mercury. But in absence of an industrial civilization, you don't have mercury to measure.
Sigh. Sure, if you had a gun to your head and you knew nothing else, it would be better to guess that a given population (hunter-gatherers) with low rates of some illnesses (T2D, HBP) also had low rates of another illness (CRC) than the reverse. Okay. That's a slightly better-than-chance guess, not anywhere near a solid basis for speculation.
"Anyways, it makes sense that marathoners get CRC because hunter-gatherers probably don't run that much" is bongcloud lalaland tier guesswork.
"makes sense that marathoners get CRC because hunter-gatherers probably don't run that much"
That is a misinterpretation of what I wrote. Let me reformulate.
"Marathons are so much more extreme than what we used to do in the Stone Age, that some pathologies resulting from such long-term physical overload are to be expected." I don't see anything lala about that. You do extreme things, you reap some consequences, sooner or later.
I would say that marathons go beyond our design parameters, but my experience in HN is that the "design" metaphor always conjures some people who consider it a dog-whistle for intelligent design (as opposed to evolution), not just an imprecise metaphor, as metaphors usually are. So I avoid it in order not to attract a senseless fight.
