How does that tasty cup of coffee or tea wake you up in the morning? The tea and coffee industries make up nearly $100 billion of the global market. The average coffee drinker (me included), drinks more than 2 cups a day. Altogether there are more than 9.5 billion kg of coffee and 2.6 billion kg of tea produced per year! So… how does caffeine work?
Caffeine affects your body in the following steps:
Your brain has more than 100 billion neurons that fine throughout the day. These carry signals throughout your body and assist in things like moving muscles and communication. The wear and tear of the day cause a molecule called adenosine to build up in your body. Because caffeine is both water and lipid-soluble (dissolves in water and fat), it can cross the blood-brain barrier into the interior portion of the brain.
Inside the brain, caffeine prevents the molecule adenosine from binding to its receptors. Normally, without coffee, adenosine’s job is to tell your body when it’s tired or sleepy. As you go throughout your day, more and more Adenosine builds up and binds to adenosine receptors. This buildup tells your body it’s tired and needs a nap. If you drink coffee, this is where caffeine steps in.
Caffeine, which looks like adenosine, fits into the adenosine receptor but doesn’t send any signals. It blocks adenosine from binding, stopping that dreaded tired feeling. This creates an adenosine traffic jam, keeping you awake and alert.
Caffeine blocking adenosine increases your respiration, breathing, and constriction of your blood vessels
Caffeine also indirectly causes the release of dopamine in certain parts of the brain. Better known as the pleasure molecule, dopamine’s release provides perceived desirability towards its associated outcome.
Sadly, eventually comes the crash 🙁 … With all of these adenosine molecules being blocked from binding, they sit waiting for the caffeine to leave. When the caffeine party is over, adenosine rushes in, hitting you with all of the extra tiredness all at once. This is where the grogginess or the cliff, as many call it, comes in.
And that’s how caffeine works!
Random Fact: Even though a standard dose is around 100 mg, more than half of American coffee drinkers consume more than 300mg of this stimulant daily!
