Coffee and the Brain

If you are reading this, there’s a high chance you drink coffee. According to the National Coffee Association, about 64% of Americans ages 18 or older drink a cup of coffee every day. Why?

Most Americans drink a cup of Joe to wake themselves up, or to resist laziness, headaches, or boredom. Coffee’s magical power has led us to become dependent on it daily, so it begs the question: Is coffee good for us? 

To answer this question, we must travel to the brain, and understand coffee’s effects on our behavior. 

If you have taken Biology, you will know that adenosine is a molecule that binds to 3 phosphate groups to create ATP, a primary molecule for energy. When we consume energy, we break the bonds between adenosine and phosphate, creating lots of unbounded adenosine wandering around the brain. This wandering adenosine binds to receptors in the brain, making us feel drowsy.

This effect is why, after running a marathon, we feel very tired. Running the marathon has forced our body to consume large amounts of ATP, leaving lots of unbounded adenosine molecules to bind to receptors, making us very drowsy and tired. 


This is where the drug caffeine, a molecule heavily present in coffee, comes into play. The caffeine molecule blocks the adenosine receptors so that adenosine can’t bind to them, reducing the drowsiness effect. This type of drug is known as an antagonist, meaning it reduces the effects of a neurotransmitter. This is the opposite of agonists like cocaine, which increase the effect of a neurotransmitter in the brain. Therefore, caffeine is generally known as an Adenosine Receptor Antagonist. 

Chemical Structure of the Caffeine Molecule | Download Scientific Diagram
Molecular structure of caffeine

So now you know why we feel the way we do after we drink coffee. It isn’t because coffee magically heightens our mood, but it is because it has a distinct neurological effect. So is this good for us? 

The biggest problem with coffee and caffeine is addiction, and this has a legitimate neurological basis as well. When we build up a tolerance to caffeine, the body ‘up regulates’ the number of adenosine receptors, so that the caffeine cannot stop adenosine from binding to them and causing drowsiness. After this happens, we need more caffeine to feel the same way as we did before. More receptors present = more caffeine required. This is a hallmark of addiction. If we go a few days without caffeine or coffee, many people tend to notice irritability, anxiety, headaches, and more. 

However, the way we consume coffee can prevent this. The best way to prevent addiction is to only use caffeine occasionally or to cycle coffee intake by taking periodic breaks to prevent tolerance. From this, we can start to use coffee in a healthy way, and prevent dependence. 

If you have any questions about caffeine and its effects on your body specifically, I recommend you contact your doctor. 

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