If there’s one thing I know for certain in this life, it’s that I will never be able to make it through my Monday morning lecture without having a cup of coffee well beforehand. Rarely do I consider the fact that I’m stimulating my brain with a drug when I do so, but that’s what’s really happening when you have any caffeine.
Your Brain Without Caffeine
Caffeine is considered a drug because it acts on the central nervous system. It can be made naturally in plants or artificially and added to foods.
It works the way it works because of its chemical structures. Caffeine molecules look a lot like adenosine molecules to the brain. Adenosine is a natural substance in your nervous system that regulates your sleep cycle.
Adenosine binds to neuron receptors in the brain. This binding allows adenosine to do what it’s meant to do, which is make you feel drowsy. The longer you’re awake, the more your adenosine levels rise. Their accumulation throughout the day is what makes you want to hit the hay at night.
How It Wakes You Up
Since caffeine molecules have a similar structure to adenosine, your brain can’t tell them apart. The receptors will bind to anything it thinks is adenosine.
Whenever you have caffeine in your system, the molecules will bind to those receptors. Even if you have high levels of adenosine, the caffeine blocks all the receptors by binding to them first. If adenosine doesn’t bind to its receptors, you don’t feel drowsy.
If caffeine and adenosine were siblings, caffeine would be the one that screams louder so more people listen to it. Poor adenosine is left floating around with no receptors to listen.
How It Keeps You Awake
In addition to blocking adenosine, caffeine also influences the glands in your body to secrete hormones. It mainly influences the adrenal gland to secrete more adrenalin.
Adrenalin is commonly referred to as the “fight or flight” hormone. Your body secretes high levels of this stuff when you’re put in stressful situations. Our ancestors used it to survive in the wild, but your body is more likely to produce it when you’re in the middle of a big exam.
This hormone causes a lot of changes in the body that lead to more blood getting to your muscles and more oxygen getting to your brain. It increases the overall energy levels in your body and makes you feel more awake and aware.
Since caffeine is a drug, prolonged consumption can make the brain associate the habit with waking up. While addiction to the caffeine molecule has been long studied, scientists now believe that the habit of drinking your morning cup of coffee may play a role in waking you up just as much as the chemical reactions themselves.
Some people like to stay away from caffeine since it causes all these chemical reactions and may lead to dependency. For me, as long as it keeps blocking those adenosine receptors, I’ll keep brewing a magical cup of coffee every morning.