Caffeine: workings, overdose, withdrawal
The Espresso Diaries, chapter 2
Every morning, I wake begrudgingly to the beautiful Davis sunrise, ready to begin my hopefully productive day with my favorite routine: ingesting hard psychoactive drugs.
OH SHI- I MEAN CAFFEINE
Yes, caffeine is a drug. Specifically, it is a stimulant (in the same category as amphetamines and cocaine). But hey! Before you point the finger at me saying I have an addiction and I need to dial back my intake, keep in mind that 90% of North Americans have caffeine daily1. Our collective addiction to this drug is fascinatingly normalized. But I think it’s about time I figure out exactly what I am putting in my body, and I invite you along for the ride!
Caffeine: How it works
Caffeine occurs naturally in almost 60 different types of plants (tea leaves, cacao beans, yerba mate, the list goes on). It has an evolutionary purpose: when present in high concentrations, it’ll be toxic to the insects, acting as repellent. In smaller doses, it’ll purposefully do the opposite: give bugs a buzz and lure them into revisiting that plant, spreading its pollen23.
For us, caffeine is a stimulant, targeting our central nervous system. It enters the bloodstream through the lining of your mouth, throat, and stomach. 30-60 minutes after you drink it, you will be at peak jitteriness, and the half-life is 5 hours, so it stays in your system for a hot minute4.
Once in your body, caffeine works to give us all the wonderful things we associate with our daily brew: increased energy, better memory, and improved cognitive functioning to name a few. But how does it do this? Let’s ask science.
Okay, hey I’m back. I asked science. Apparently, caffeine, once ingested, blocks the adenosine receptors in the body; adenosine is a ribonucleoside that triggers the receptors and produces some good ol’ relaxation and sleepy feelings. Caffeine is called an “adenosine receptor antagonist,” as it wedges into the receptors, blocks adenosine and the feeling of sleepiness and relaxation5.
How much is too much?
It’s recommended that adults drink under 400 milligrams of caffeine a day. Not to rat myself out, but I’ve most certainly gone over that threshold from time to time. Let’s do the math:
One shot of espresso: 64-75 milligrams
One cup of coffee: up to 96 milligrams
Grande latte from Starbucks: two shots of espresso (128 milligrams)6
Now, what did I do yesterday? Well, I woke up, had a hydroflasks worth of black coffee in the morning (two cups), got a grande latte in the afternoon, and had another cup of black coffee in the evening. If my math is correct, that puts me over the recommended intake- about 416 mg. So what does this mean?
Fear not! I’m still alive and kicking. As I said, 400 mg a day is a generalized cutoff point for adults, but this is hardly a fine line. The ways in which caffeine affects a person depends on way too many variables for us to declare any hard cutoff; generally speaking, staying below this level ensures you get only the desirable effects of caffeine, like wakefulness and better cognitive functioning, leaving out the undesirable effects.
It is possible to overdose on caffeine, but not orally, and not accidently. It would take about 10 grams- or 78 lattes- to get close to this level of danger, and you would have to ingest this quickly, out-running the caffeine’s half-life7. Does that mean you should drink 77 lattes?
…No.
The more you drink, the more those favorable effects will be replaced with negative ones: headaches, anxiety, insomnia, higher blood pressure, and fatigue can all happen when you drink too much coffee8. Some of my friends don’t drink coffee because they claim it adversely affects them, only succeeding at making them anxious. Luckily, coffee only makes me do a little dancey-dance, but keep in mind it affects everyone differently.
Withdrawal: Is caffeine addictive?
Is caffeine a drug? Yes. Is it addictive? Eh… kinda?
Well, it doesn’t really fit the criteria of an addictive substance. Since it mostly works to block adenosine receptors, it doesn’t activate the same reward circuits in our brain that genuinely addictive drugs do9.
Not only that, but the withdrawal symptoms are mild at best. You may get a headache, but you won’t be subject to the more serious symptoms that would result from alcohol or cocaine withdrawal.
It mostly comes down to tiredness: when caffeine wears off, adenosine embraces its long-lost receptor, and we get an onrush of fatigue. This is most likely the “crash” we experience and associate with withdrawal10. It would be more accurate to say we keep coming back for more only so we can stave off the feelings of fatigue. If you stop consuming caffeine for a few days, your body quickly becomes readjusted. So let’s just call caffeine what it is: a psychoactive habit, not necessarily a physiological addiction.
At least that’s what I tell my parents.
Jokes! Jokes!
Welp, I hope you learned as much as I did with this little learning detour. If you have any suggestions for future endeavors, do let me know!
Stay caffeinated,
Cass
Gregg, Boston. “Caffeine: The Good, The Bad, and The Ugly” OrthoNeuro. https://orthoneuro.com/caffeine-the-good-the-bad-the-ugly/
How Does Caffeine Keep Us Awake? Ted-Ed. Youtube.
Stephenson, Tristan. The Curious Barista's Guide To Coffee. Ryland Peters & Small, 2019.
Cherny, Kristeen. “How Long Does Caffeine Stay in Your System?” Healthline. https://www.healthline.com/health/how-long-does-caffeine-last
Ribeiro, Joaquim A, and Ana M Sebastião. “Caffeine and adenosine.” Journal of Alzheimer's disease : JAD vol. 20 Suppl 1 (2010): S3-15. doi:10.3233/JAD-2010-1379
W, Amanda. “Starbucks Drink Guide: Lattes” Delishably. https://delishably.com/dining-out/Starbucks-Drink-Guide-Lattes
Murray A, Traylor J. “Caffeine Toxicity.” StatPearls. June 29 2021. https://www.ncbi.nlm.nih.gov/books/NBK532910/
Garduno, Pablo. “What Are the Negative Effects of Caffeine?” San Diego Health. July 18 2020. https://sandiegohealth.org/what-are-the-negative-effects-of-caffeine/
“Caffeine Withdrawal Anxiety (A 3 Point Guide)” Optimist Minds. January 27 2022. https://optimistminds.com/caffeine-withdrawal-anxiety/#:~:text=Though%20caffeine%2C%20like%20other%20addictive%20drugs%2C%20does%20enhance,withdrawal%20can%20sometimes%20be%20iatrogenic.%20Understanding%20caffeine%20better
Caffeine! Hank Green. Youtube.