Why do regular coffee drinkers seem to need more and more coffee to maintain the buzz? Can coffee actually kill you?
On the chemical level, caffeine is structurally similar to adenosine, a chemical that makes us sleepy. When we drink coffee, caffeine binds to our brain’s adenosine receptors, preventing the chemical from binding with the receptors and making us tired. For those of us who regularly drink coffee in copious amounts, our brains develop more adenosine receptors, so it takes more coffee to keep us awake. That also helps explain why we turn into exhausted monsters when we try to wean ourselves off of coffee, as having more adenosine receptors means more adenosine makes its way into our brains.
Caffeine also builds up the adrenaline supply, which increases heart rate, gets blood pumping, and opens up airways. And, caffeine prevents dopamine from getting reabsorbed into your system, leaving the feel-good chemical hanging around in your brain longer. On the downside, this dopamine effect is also what makes coffee so addictive, so keep that in mind the next time you’re eyeing that 2nd (or 10th) cup of joe.
Check out the video at the top of this post to learn more about the effect caffeine has on your brain, and whether too much caffeine can kill you.