Aside from giving us enough energy to take over the world (or day), breakfast mostly focuses on our stomachs. We eat to fill our bellies with glorious morning meals. But when it comes to caffeinated beverages like coffee and tea, the game totally changes. Of course, many of us guzzle these drinks because we enjoy them. Yet, it’s not uncommon to have secret motives in mind. Think about it: We turn to these drinks to fuel our brains. The way caffeine wakes you up is an art in itself, helping so many of us function as normal human beings. And it’s all thanks to wonderful world of science.
It starts with the brain’s nerve cells. Also known as neurons, these cells communicate with each other by sending substances called neurotransmitters. This exchange jumpstarts biological processes on the cellular level. Think of neurotransmitters like the text messages sent between cell phones, planning the game plan for tomorrow’s brunch.
And then there’s a chemical called adenosine. This naturally occurring substance regulates your sleep cycle by promoting drowsiness. Adenosine brain levels are lowest while you sleep. They also increase the longer you stay awake. It’s your body’s way of making sure that you get that much-needed beauty rest.
In order to encourage sleepiness, adenosine needs to bind to specific brain receptors. But here’s the thing: Caffeine molecules look like adenosine. They’re so similar in structure that nerve cells can’t tell the difference. As a result, adenosine can’t connect with those receptors and make you sleepy. Basically, caffeine is adenosine’s evil twin that forces it to play hooky.
Aside from influencing neurons, caffeine also gets the hormones involved. It increases the production of adrenaline, the “flight or fight” hormone that gives you a rush of energy and heightened awareness. It helps you stay on your toes during stressful situations. In this case, that situation might be something like an early start on a Monday morning.
Caffeine’s superpowers can also manifest through psychological dependency. Board-certified nutrition specialist Jason Boehm explained to me that years of drinking coffee (or tea) can easily make your brain connect the habit to waking up.
Together, these concepts make your beloved wake-up call possible. Science can be something crazy, after all. And sometimes, it just happens to be disguised as a cup of coffee.