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refurb · 3 years ago
Genetic differences can alter caffeine metabolism significantly, reducing half-life by up to 80% (which has a huge impact since it’s typically 5-6 half-lives to “flush” a drug out of your system).

Basically it may take some individuals 48 hours to metabolize all caffeine while others may do it in 10 hours.

https://jamanetwork.com/journals/jamanetworkopen/fullarticle...

coreyh14444 · 3 years ago
I'm in this camp and it sucks. If I have a full size cup of coffee at 5am, my sleep will suffer. Otherwise fit, healthy dude in my 40s, but have the caffeine tolerance of a toddler.
sschueller · 3 years ago
Working out seems to also affect this. The days I workout I can "tolerate" more than when not.
red-iron-pine · 3 years ago
same. a hard workout beats me up and gets me sleeping like a baby.

i'd imagine the blood pumping, sweat, lots of water intake, and boost to metabolism probably doesn't hurt either.

icouldntresist · 3 years ago
I've actually been cutting out caffeine after listening to Michael Pollan talk about drugs and society on NPR.

Turns out the half life is typically long enough that using caffeine every day long term will lead to cognitive decline because of sleep deprivation. It's good for an occasional boost, but you're really burning the candle at both ends.

cainxinth · 3 years ago
I'm off caffeine after many years of daily consumption. Took a few weeks, but my energy level is now about the same as it was before I quit and I no longer feel tired without it. I do quite miss the taste and ritual of tea and coffee, though.
seeknotfind · 3 years ago
I stopped caffeine for 2 years and never felt the same. Happy for you.
staticman2 · 3 years ago
80% of adults have caffeine intake in a given day. So what's more plausible, that 80% of adults have cognitive decline, or the author in question is full of crap?
red-iron-pine · 3 years ago
given the state of society, why do you think everyone is thinking well?

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TedDoesntTalk · 3 years ago
I don’t get it. If you only consume caffeine in the morning, every morning, how does it affect your sleep? By bedtime it is all metabolized.
icouldntresist · 3 years ago
> By bedtime it is all metabolized.

According to Pollan, for most people, there's still enough in your system to disrupt your natural sleep; your brain doesn't shut down enough to get a good rest. IIRC, he was discussing monitoring brain activity during sleep and you can see the difference between people who drank coffee that morning, and people who didn't. Caffeine has just about left your system completely around the time you wake up and start drinking it again, which usually isn't too long before you start getting caffeine withdrawal symptoms.

edit: half life for caffeine is 2-12[1] hours (most sources claim ~5), depending on the person. For a half life of 6 hours (using this because it's close to 5 and divides evenly into 24), you still have >1/8 of what you drank that morning in your system when you go to bed, and 1/16 when you wake up. Over the course of a lifetime, it's not hard to imagine that having a cumulative effect.

1: https://www.sleepfoundation.org/nutrition/how-long-does-it-t...

_aavaa_ · 3 years ago
icouldntresist · 3 years ago
That looks like it, but I heard it in 2022 or 2023, might have been a re-run.

I can't listen to it right now, but I remember in the program he was talking about publishing some of his books describing his experiences with illegal substances and he had his publisher agree to pay all potential legal costs on top of paying his regular salary to his wife in case of incarceration.

sschueller · 3 years ago
Yes, this calculator doesn't show how you end up a week later when your base level isn't zero. Taking a 2 day break from coffee can help a lot.
SirMaster · 3 years ago
Yeah, I have no caffeine on weekends and that just seemed like a good idea to me without any evidence.

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hirundo · 3 years ago
I stop caffeine intake around noon, and was just disillusioned about it being out of my system by bed time nine hours later.
biugbkifcjk · 3 years ago
I'm the same, 1pm is an absolute cut off otherwise it'll be a restless night
archerx · 3 years ago
I build tolerance to caffeine very quickly for some reason. One night I drank two redbulls so I could finish a project (I had been drinking a lot of coffee and energy drinks during that period) and decided to take a quick nap before going into crunch mode and ended up sleeping the entire night.

I had a redbull yesterday at 17:30 and fell asleep with no problem at 22:30.

If I want the true effects of the energy drinks I have to use them sparingly or else my tolerance ramps up and it doesn’t give me the energy buzz but kinda makes me sleepy...

smcl · 3 years ago
If anyone's not sure what values to input, it looks like the values provided (67mg and 130mg) are for roughly one 40-50ml serving of espresso followed by 2x that (a double espresso).

I usually have one espresso (or lungo) after breakfast and another after lunch. So this means that this extra shot at ~13:00 means I have over 2.4x the caffeine in my system at 22:00 than if I'd only had the morning coffee (3.6mg vs 8.83mg). Not sure whether I expected any different since twice the coffee works out to roughly twice the caffeine (since I go to bed a little later) :-)

tulio_ribeiro · 3 years ago
A lot of people don’t realize that caffeine is not the only substance that affects our body when we drink coffee.

There is also paraxanthine, which is a metabolite of caffeine that has a similar half-life and similar effects.

Paraxanthine can increase lipolysis, which means it breaks down fat and releases fatty acids into the bloodstream. It can also enhance alertness, mood, and cognitive performance.

So, even when the caffeine levels in your blood start to drop, the paraxanthine levels are still high and keep you stimulated. That’s why the effects of coffee can last much longer than you think.

Frummy · 3 years ago
I used to be a hardcore caffeine aficionado. I learned that if I took it after lunch, my sleep would be impacted, not noticeably on one day but the effect stacks since it's a daily habit and that long term rejuvenation is worse. Eventually my father listened to some podcast and became opinionated about artificial caffeine and didn't want me to drink energy drinks.
Projectiboga · 3 years ago
I wonder what different effects tea has? I saw a study once that the boost you feel from coffee is only getting you to where you'd be if you never drank it. It's an illusory stimulation where you're just erasing withdrawal symptoms.
FounderBurr · 3 years ago
Actual stimulation is much more limited than the half life of the substance would suggest, as it is with most other stimulant drugs.

Even if much of the substance remains unchanged by the liver the stimulation effect is front loaded. After a short time, typically 2-3 hours, physiological stimulation decreases rapidly unless even more stimulant is added.