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Your Brain On Coffee with English subtitles  

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 wakefulness.

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 lasts :)

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 to get you the cheapest prices for the books

you need. All you have to do is head to 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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