I'm a contrarian in a number of ways.
One of them is that I don't drink caffeine.
It's the most widely used drug in the world. If you go and Google the health benefits of it you will quickly find a plethora of benefits of both coffee beans and tea leaves.
If those were the only sources today, that would be one thing. But now energy drinks are a staple for people all over the world.
I think more of us than we would care to admit are using caffeine as a crutch for poor sleep and low energy, we use it to mask that we don't naturally possess within us the energy to meet the demands of the day. Yes for some of us it's ritual, but that's not the majority anymore.
My top reasons are:
1 - I don't want to depend on anything to feel my baseline normal
2 - I don't want to do anything that could jeopardize my sleep
3 - I'm hesitant about anything deemed a stimulating substance that manipulates the normal function of my body and nervous system.
4 - I want my brain to have optimal blood flow at all times
Blood Flow Drops
Not forever but in the short term: roughly a quarter drop. In a randomized, blinded, placebo-controlled perfusion MRI study of 20 adults, 250 mg of caffeine cut cerebral blood flow by 23% in gray matter and 18% in white matter. A second Wake Forest study in 45 people put the average gray matter reduction at 27%.
Three days
What I object to has nothing to do with disease. It's that I'm all in on agency and against addiction. I'm about optimizing rhythms to align with nature. I know too many people who 'need' caffeine to function normally. That doesn't make sense to me.
At Johns Hopkins, researchers gave people caffeine in capsules instead of coffee, then swapped the capsules for a dummy pill without telling them. Three days of 300 milligrams a day was enough to produce measurable withdrawal. Not headaches yet, those showed up around day seven. At three days it was fatigue, low mood, feeling flu-ish. And it happened at maintenance doses as low as 100 milligrams a day, which is about one cup.
Then another study - Researchers took 87 regular coffee drinkers and secretly switched them to decaf. Same drink. Same mug. Same morning. Some were told it was decaf and some weren't.
Withdrawal showed up either way, and so did the dip in their thinking. Being told changed how much they craved it. It changed nothing about how they felt or how they performed.
Believing had nothing to do with it.
None of this is exotic or fringe. Caffeine withdrawal is a diagnosis in the DSM-5, and roughly half of people who stop get a headache, with about one in eight feeling bad enough that it interferes with their day.
But my favorite detail is buried in the international headache classification, which is the document neurologists use to name what's happening in your skull. To qualify for a caffeine withdrawal headache, your usual dose has to have been "interrupted or delayed."
Delayed. Not skipped. Late.
The world's headache authority accepts that a normal dose arriving two hours behind schedule can bring on a headache. That's not a description of a beverage. That's a description of a schedule your body is now dependent upon.
Back to Baseline
The usual answer here is that you build a tolerance, and it stops mattering.
Peter Rogers at Bristol has spent years on this question, and his summary got my attention. When habitual caffeine drinkers go without overnight and then have their coffee, yes, they get sharper. But their alertness and their performance never exceed people who don't use caffeine at all, or people who used to and quit.
They come back up to where those people already were.
Caffeine Timing and Sleep
Last year a team ran 23 men through seven different conditions, varying both dose and timing, with sleep measured rather than guessed. Four hundred milligrams four hours before bed, which is a pre-workout scoop or a big energy drink, cost 50 minutes of total sleep and half an hour of deep sleep. The same dose taken twelve hours before bed still cut deep sleep by 20 minutes. A 9 a.m. dose, still collecting at 3 a.m.
But interestingly enough at least in this study, 100 milligrams, about one cup, did nothing measurable at any timing they tested. Including four hours before bed.
But notice a zoomed out look at a number of studies and you see a pattern. Pooling 24 controlled studies, the thresholds for losing no sleep at all come out at roughly 9 hours before bed for a normal cup and over 13 hours for a pre-workout serving.
The average American adult takes in about 186 milligrams a day and roughly 89 percent of us take in some.
So what does that all mean? Mostly that when you drink it matters more than how much. Nine hours before bed is the cutoff for one normal cup. If you're asleep by 10, last call was 1pm. Your morning coffee may not be a problem for sleep – though as we have discussed there are other effects through the day. But the 3pm one is, and that's the cup nobody thinks twice about.
How to Flourish
Ask which exposure the study measured. Coffee and caffeine are not the same subject.
Run the two-week test on yourself. Taper down over a couple of weeks rather than quitting cold, since stepping down gradually produced far less trouble than stopping outright. Then see what you feel like at a baseline that isn't borrowed.
Count milligrams, not cups. The evidence is about dose. Eight ounces of drip coffee is around 100. A pre-workout scoop can be 300 or more.
Put a curfew on it before you put a limit on it. If you keep one thing, keep this: measure back from when you go to bed, not forward from when you wake up.
-Jared
P.S. - My wife Baddie Crocker has a beautiful newsletter where she shares her perspectives on tending the land, recipes, women’s health and more.
I’d love to hear from you. 👋
P.S. - This newsletter does not provide medical advice. The content, such as graphics, images, text, and all other materials, are provided for reference and educational purposes only. The content is not meant to be complete or exhaustive or to be applicable to any specific individual’s medical condition.
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Whoop - Track your HRV and REM Sleep
Function Health - Optimize Your Health via 160+ BioMarkers
Here are a few topics I think you’ll love if you haven’t checked them out before:
