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With it’s stimulating effects, it’s easy
to understand why coffee is the second most
traded commodity on Earth after oil. For many,
it keeps us awake and moving through our busy
days. But how does it work? What exactly does
coffee do to your brain?
Whenever you’re awake, a chemical called
adenosine slowly accumulates in your brain.
And this adenosine binds to receptors which
slow down brain activity - ultimately, the
more adenosine there is, the more tired your
brain feels. Which makes sense, as the longer
you’re awake, the more fatigued you become.
Conversely, while you sleep, the concentration
of adenosine declines, gradually promoting
But it turns out that the caffeine in your
coffee is incredibly similar to adenosine
in structure. The caffeine works it’s way
through your bloodstream and into the brain,
where it starts to compete and binds with
adenosine receptors. But because it’s not
adenosine, the ‘sleepiness’ effect isn’t
felt. Adenosine can no longer bind, meaning
it’s calming properties are diminished.
Which is great for you when you’re feeling
tired! However, with long term use of caffeine,
your brain responds by creating more adenosine
receptors - which means more caffeine is required
to elicit the same response. It also means
that when you try to quit drinking coffee
or miss your daily intake, you might experience
some withdrawal symptoms and feel more tired
than you would have before you ever drank
But the caffeine doesn’t stop there! It
also stimulates the production of adrenaline
- you know, the Fight or Flight hormone? This
increases your heart rate, gets your blood
pumping, and even opens up your airways. Furthermore,
it affects Dopamine levels by preventing its
reabsorption in the brain, which makes you
feel happy! In fact, this is the exact same
thing that cocaine does, just to a lesser
degree. It’s a drug, afterall! This dopamine
stimulation is also the aspect of coffee that
makes it moderately addictive.
So can you drink too much coffee? It turns
out there is a lethal dose of caffeine which
is somewhere around 150mg of caffeine per
kilogram of your body. This means if you weigh
70kg you would require 14,000mg of caffeine
to overdose. Put into perspective, an average
cup of coffee contains roughly 150mg of caffeine,
meaning if you are 70kg, approximately 70
cups of coffee would kill you. However, you’d
have to drink those cups all at once making
it effectively impossible to overdose on caffeine
from coffee, since you wouldn’t be able
to physically fit that much in your stomach.
You’d also start experiencing mania and
hallucinations before getting to this point.
Caffeine also has a halflife of around 6 hours
-so if you drank a standard coffee with around
150mg of caffeine, after about 6 hours there
will only be 75mg left in your system and
you’ll be feeling half of the effect. And
6 hours after that, you’ll have 37.5mg - leaving
more room for adenosine to jump back into
action. Which is why you may reach for another
cup throughout the day, to maintain that glorious,
alert and energetic feeling.
So drink up! And enjoy the buzz...while it
And for all of you in school, while we know
caffeine is key, so are good deals on textbooks!
So we’ve teamed up with SlugBooks.com to
get you the cheapest prices for the books
you need. All you have to do is head to SlugBooks.com/AsapSCIENCE
and search the ISBN number of the books your
looking for. SlugBooks will then compare prices
from all across the net. Seriously, we know
how expensive textbooks can be, so hopefully
this will save you some money! Special thanks
to SlugBooks for supporting AsapSCIENCE.
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