How Caffeine Affects Your Brain

As we approach finals, it’s extremely likely that you will consume the most widely used drug in the world—caffeine. Whether it’s through coffee, tea, soda or even chocolate, caffeine has a huge presence in the diet of many college students. If you’re like me, you might find yourself reaching for a second, third or even fourth cup of coffee per day, but what exactly makes this magical elixir so effective? What is it doing to our brains? How does it work and why am I now suddenly craving a trip to Starbucks?

To understand how caffeine works, we first have to look at a chemical called adenosine. Adenosine is a sleep-inducing chemical that is produced in our brains. In order for adenosine to work, it needs to find its comparative receptor. Like two pieces of a molecular puzzle, adenosine locks with its receptor and creates a sensation of tiredness within the brain. Caffeine, when introduced to your system, mimics adenosine and blocks it from matching with its receptor. Caffeine isn’t a perfect swap with adenosine, so it fits enough to block adenosine without inducing feelings of sleepiness. Therefore, caffeine doesn’t actually give you more energy, but rather blocks the neurological process that makes you tired. 

Over time, our brains will adapt to the regular addition of caffeine and create more adenosine receptors. Like any other drug, our bodies will build up a tolerance to caffeine. Caffeine works fast, but the effects don’t last long. The half-life for caffeine is 3-5 hours, so after about six hours, your body will retain less than half of the caffeine that you originally consumed. This is a large reason that people will crave an afternoon cup of coffee. The relatively short lifespan of caffeine contributes to its addictive quality, however, there are several other factors that contribute to the addictiveness of caffeine. Some of these include the release of dopamine after drinking coffee—which is similar yet milder to the release of dopamine created by cocaine—and your brain’s reliance upon caffeine to block the extra adenosine receptors.

Caffeine is going to have different effects on everyone depending on a multitude of factors, but understanding the basic mechanisms of how it operates can only be beneficial. Caffeine has a dominant role in college culture, and students are constantly surrounded by ways to access it. I’m not saying to drop caffeine altogether—I know I won’t be anytime soon—but understanding that everything (even coffee) in moderation is always a good idea.