22 Comments

Baffling N=1 personal anecdote: I started taking creatine and supplementing whey protein about three months ago. I am apparently an outlier in creatine response; I've been regularly setting lifetime personal best records for weight lifted (at age 63). But also my visible body fat has significantly decreased while I have increased my calorie intake by >>500 kcal/day and I've done only my usual amount of aerobic exercise.

Maybe my liver will start bulging out of my belly soon? And then explode?

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I assume you're also gaining muscle. Congrats!

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Thank you! It's a lot of fun. Although really puzzling! Creatine does not have this effect size for most people. My best guess is that I have some mutation that made me creatine deficient all my life. Now somewhat wistfully imagining the body I might have had if I'd started taking it when I was 23 instead of 63.

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You have been on fire the last two weeks. I know a little about this and the cancer stuff. First class work. Please keep it up

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I would be interested in what happens with living liver (node) donors. Unfortunately they’re sufficiently rare that it would be hard to get a decent sample.

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It makes sense from an adaptive perspective, athletes benefit from the larger glycogen storage.

Which has two questions spring to mind :

- is the effect larger in endurance athletes?

- do athletes get larger livers, or are larger livers a necessary condition to become an elite athlete?

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Wait, so what's the reason to want a bigger liver? It doesn't seem like the post explains this. Do we generally expect bigger livers to work better if they don't develop the problems listed above?

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It’d certainly be easier if you wanted a smaller liver:

> “Most drugs are metabolized by the liver. By manipulating liver size, we can tailor the metabolic rate to any level that we want.”

>

> “Manipulating liver size?” Hermes didn’t like the sound of this.

[...]

> The eagle gave a voracious shriek.

<https://slatestarcodex.com/2017/02/27/a-modern-myth/>.

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To increase REE, right?

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yep

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What does the larger liver actually do with all the extra energy that it's using?

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Process more food, basically. So keeping the rest of the body "topped up" faster than it could otherwise, and filtering blood faster, helping keep toxin levels lower.

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Oh, cool, so it sounds like it's directly good for body function as well as just wasting more calories for those who have trouble with energy balance?

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Well in principle yes. I'm not sure it is an absolute good though, I imagine that one needs some kind of proportionality to be respected.

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I'm a bit worried about your male athletes though... 200lbs is not exactly what I would call a "large" male athlete!!

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the study was in Japan

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Ah ok! Makes more sense.

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See, they're big in Japan!

(oh, the eastern sea's so blue...)

There's a joke here about sumo wrestlers, but I can't think of it.

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Citing the big LPS or IL-6 liver as an example of better liver function is essentially a biology example of Goodhart's law: it's responding to a stress that is more dangerous than whatever benefit (if any) the larger liver is providing, it's not actually doing a better job. Similarly, lots of organs may increase in size and weight due to edema (water getting trapped in there), infiltration by metabolic products or cancer cells, or other things--cardiomegaly (a big heart) is famously a good index of *poor* cardiac function (the thing doesn't pump the blood as well so it hangs around, most of the time).

Most likely the big athlete livers are actually full of more or better-functioning liver cells doing what they do physiologically, but more of it. You want to look at some index of liver *function*, not just the overall size of the organ.

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Does that mean it's better for health to have big organs? Intuitively it seems beneficial for them to have extra capacity, but I don't know

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No.

If it's small and not working, that's bad, but usually if it's big that means it's not working well either. Livers and spleens can be full of crap like amyloid or infiltrating cancer cells, big hearts are usually not doing a good job pumping blood out, and in general anything that starts growing in the body is assumed to be cancer until proven otherwise.

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So what?

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