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taw comments on Coffee: When it helps, when it hurts - Less Wrong

44 Post author: JustinShovelain 10 March 2010 06:14AM

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Comment author: taw 10 March 2010 08:12:22AM 1 point [-]

I don't trust a single one of these findings, as I don't trust their proxies to be of any real use, I don't trust their methodology to be representative of the real world, and frankly I'm extremely skeptical that any result I see is not classical statistics shenanigans before I at least see it confirmed by a meta-analysis based on large number of trials.

Comment author: AngryParsley 10 March 2010 09:17:06AM *  13 points [-]

Do you also distrust neurochemistry? Caffeine has a known mechanism of action. It's not poorly understood like modafinil. Caffeine binds to certain types of adenosine receptors, but it doesn't activate them. This prevents adenosine from binding to and activating the receptors. Adenosine does a lot of things, but one thing it causes is sleepiness. If you increase the amount of adenosine in someone's brain, they get sleepy. The amount of adenosine in the brain naturally increases over the day until you fall asleep. So if adenosine makes you slow and sleepy, blocking it should make you sharper and more alert. It's no surprise that most people report caffeine having that effect on them.

So, there are a bunch of studies. There's a known mechanism of action. There are lots of caffeine users who can confirm the effects predicted by the studies and the neurochemistry. You can even get firsthand evidence if you try the drug yourself. What more do you want?

Comment author: taw 10 March 2010 10:49:22AM 1 point [-]

Do you also distrust neurochemistry? [...]

Basically yes. Brain are evolved complex homeostatic systems, not engineered systems with neat subsystems in which chemicals are control knobs; randomly changing various things in brains will not get you clean results. Findings that something interacts with some enzyme has almost no relevance to question of influence over real world effects.

By the way caffeine doesn't even make you not sleepy. Modafinil and amphetamines do, in different ways.

Comment author: AngryParsley 10 March 2010 11:05:12AM 4 points [-]

By the way caffeine doesn't even make you not sleepy. Modafinil and amphetamines do, in different ways.

In the paragraph before that, you said you didn't trust neurochemistry to explain how drugs work. Why do you then accept amphetamine's mechanism of action (or at least accept that it differs from modafinil's), but not caffeine's?

And I'm pretty sure caffeine makes people less sleepy. It's not as powerful as modafinil or amphetamines, but it's effective.

Comment author: RichardKennaway 10 March 2010 11:47:34AM 4 points [-]

And I'm pretty sure caffeine makes people less sleepy.

Which people, though? Not all of them, every time, because as a heavy user, I have noticed that coffee sometimes seems to bring on drowsiness instead of dispelling it. I say "seems to" because I've not done any experiments, but I've heard it happens to other coffee drinkers as well.

Comment author: wedrifid 10 March 2010 01:45:22PM 4 points [-]

By messing with adenosine receptors caffeine reduces one of the mechanisms behind 'sleepiness', that is, the sleepiness you get from having been awake too much.

Because caffeine also has general stimulant effects, particularly at large doses it can also produce the seemingly paradoxical effects that stimulants have on some people. Sure, take enough caffeine and amphetamine and you can stay up and remain approximately functional. But sometimes taking stimulants makes people tired. For example, if I drink a red bull and take a couple of Ritalin tablets I can either fall straight to sleep or stay up for another 36 hours, depending on whether there is task that latches on to the ensuing over-focused attention control systems and overrides the sleepiness impulse.

(Thus goes the typical explanation that I hear from various sources. I take it with a grain of salt. I trust the actual results of experiments somewhat more than the stories that get told in the accompanying discussion.)

Comment author: MichaelGR 10 March 2010 04:01:41PM 2 points [-]

My parents drink coffee before going to bed. I've always assumed that it was because withdrawal during the night would be worse than the "stay awake" effect, but maybe there's another explanation.

Comment author: RobinZ 10 March 2010 04:06:41PM 7 points [-]

That sounded more interesting out of context than it should have.

Comment author: MichaelGR 11 March 2010 01:52:48AM 1 point [-]

Ha! And totally unintentional, I assure you :)

Comment author: loqi 10 March 2010 11:48:10PM 2 points [-]

I've found that caffeinated sleep tends to be fairly satisfying and invigorating. The trick (for me, anyway) is to fall asleep before full onset. 100mg caffeine pills do the job nicely, assuming I'm sleepy enough to nod off in time. The penalty for failure is pretty stiff though - I've lost half a night's sleep that way.

Comment author: RichardKennaway 10 March 2010 04:04:24PM 1 point [-]

Curiously, I've never experienced any sort of withdrawal symptoms from caffeine. When I've had a reason to stop drinking coffee and tea for a week, I've simply done so with no discomfort.

Comment author: h-H 12 March 2010 01:12:55AM *  1 point [-]

true, I usually feel sleepy after drinking coffee-but I rarely if ever drink it anyway.

Comment author: taw 11 March 2010 10:44:12AM 1 point [-]

Caffeine might increase energy levels, and do other things, but it is ridiculously inaccurate to say "caffeine makes you less sleepy" as its main effect. Try modafinil/caffeine double blind test - modafinil is not "stronger caffeine", it's completely different, by actually reducing sleepiness without any energy boost. Amphetamines are even more complicates.

Comment author: ciphergoth 10 March 2010 10:53:51AM 12 points [-]

What better sources of information should we be updating on?