Whether it’s from tea, coffee, energy drinks, or a square of chocolate, just about everyone gets their morning pick me up from caffeine. But caffeine isn’t entirely benign. I missed my morning coffee today and already feel a host of the normal withdrawal symptoms that go along with physical dependence, which include restlessness, headaches, and fatigue. According to the National Coffee Association’s 2013 survey, 83 percent of Americans drink coffee. This is a conservative estimate for caffeine intake, because it doesn’t include people who get their fix from tea or energy drinks. Caffeine is the drug of choice for our 24/7 working society.
Caffeine wakes you up by affecting the binding of adenosine to receptors in the brain. When adenosine is created in the brain, it binds to adenosine receptors, which slow down neural activity and make you tired. However, caffeine molecules bind to all of the adenosine receptors, stopping adenosine from slowing your brain down. Your body notices all this activity going on and releases adrenaline, expecting a fight or flight situation. This explains why you feel both awake and a bit on edge when you have a strong cup of joe.
The history of caffeine is just as interesting as its biochemistry. Coffee beans grew in the wild and were eaten by Ethiopian tribes for their energising effect, but it wasn’t till people started brewing coffee in the 1400s that it spread from Ethiopia to Yemen, where Sufi mystics used it to keep themselves awake during their night-time prayer. All over the Middle East, Islamic cultures took notice of the Sufi practice and adopted coffee themselves, which was controversial because some conservative Imams up in Mecca thought it should be forbidden.
From the Middle East coffee was imported to Malta and Italy and then to the rest of Europe. In Europe it became the go to drink for the intellectuals of the time, who eschewed beer and taverns to get wired and talk ideas with other scholars in coffeehouses. A coffee house in Cambridge was the original meeting place for Edmund Halley and Isaac Newton when they were discussing the mathematics that would eventually turn into Newton’s theory of gravity. So in the end, despite the negatives of physical dependency, I have to thank caffeine for helping provide scientists and artists alike with the mental energy to discover and make cool things. As the saying goes, “A mathematician is a machine for turning coffee into theorems.”