[high-speed] by now we've gotten to know each other. you may have noticed i'm kinda high energy guy. i can be [loudly] loud. i've been known to talk a little too fast. ireally excited about nerdy things and you're probably thinking to yourself "ah, that hank, he must have to drink a bunch of rockstar, coffee, red bull, diet coke,
crash diet headache, other coke and coffee and rockstar andcoffee... i already did coffee! ...to keep himself so peppy all the time." [normal speed] and you would be wrong about that. this machine does not require caffeineto operate! [theme music]
i have been known to have a coke everyonce in a while, but in general i tend to avoid the world's most popularpsychoactive drug. this make me something of an aberration in a world that is caffeine crazy. and by crazy i mean that today millions have you willpay more for 12 ounces of this then for a gallon of this. and i don'teven want to talk about what happens to my friends when they go a couple days without the caffeine. holy anxious,irritable, headachy people! this stuff's powerful. despite all the sweet tasting things that we tend to put into caffeinated beverages caffeine itself
is a bitter, white, powdery alkaloid. socaffeine does have taste which is why caffeine-free coke and coke tastedifferent. world consumes over 260 million pounds of caffeine every yearand while most if it is extracted either from coffee or tea, there's a bunch ofdifferent natural sources. these include two south african plants: yerba matte andguarana, the latter you probably have heard of as anadditive in some energy drinks. and there's also something called the kolanut, which is native to western and central africa, which a lot of people chew on for its stimulating properties. and once upon a time it was used as flavoring for thepopular caffeinated beverages
that still bear its name today. but sinceyou, my dear viewer, have an active, analytical,science-y mind, you're wondering right now "why is it so stimulating? how does itwork?" basically it tricks your brain intothinking that you're not tired. caffeine, known to chemists as 1,3,7-trimethylxanthine, is actually similar in structure tonaturally-occurring molecules in our in our body called adenosines. adenosine bonds to receptor cells in thebrain, which in turn has a calming effect [slowing] on the entire nervous system and that
makes you [slowly] sleepy. what caffeine does is it blocks those receptors in thebrain before adenosine can get in there and do its thing. instead of calming the nerve cells, caffeine stimulates them causing increases in the heart rate andthe blood pressure, increasing alertness and delaying the onset of fatigue. peoplewho love their caffeine love that feeling of alertness, that artificial brain chemistry bond iscreating. caffeine peaks in your bloodstream about 30 minutes after you first take it in,
and then it has a half-life in yourbody about six hours. so six hours after you drink it, you're feeling half the effects, which is why people have to keep drinking throughout the day in order to maintainthe feeling of alertness that that initial cup gave them. and this raises thequestion of whether or not caffeine is addictive. and it sort of is buttechnically, it isn't. caffeine can cause some physical dependence but going cold turkey isn't gonna give you anything like the withdrawal symptoms of nicotine or cocaine. you'll have a headache, you'll be cranky, but you'll feel better in a day or two, ipromise. caffeine may feel pretty addictive
but it's more about dedicated habit. it doesn't mean the scientific definitionof what an addictive substance is. unlike cocaine, scientists say, caffeine doesn'tpose a threat to society and it doesn't activate these brain reward circuitsthat are kinda the key to actual physical addiction. so going back to this friend of mine who has like twoliters of mountain dew a day, and he mixes it up with espresso shots... should i be worried about that guy actually overdosing oncaffeine? the answer, thankfully, is no. doctors recommend thatthe average person keep his or her
caffeine intake below 300 milligrams perday that's roughly the amount of caffeine in two12-ounce cups of coffee. by comparison a red bull contains about 80 milligrams of caffeine, while pillslike nodoz contain two hundred milligrams perpill. but here's the deal: depending on your weight, you would needto consume between six and seven grams have caffeine per day, which would bereally hard to do unless you were dedicated to the cause and had, youknow, a jar full of caffeine. so unless my friend can slam fifty to ahundred cups of coffee in the day
which i don't think anyone's stomach couldactually be big enough to handle, he'll be okay. so good news: we can allstop being so nervous. and just relax a little bit.thank you for watching this episode of scishow i'm gonna have a coke now. if you i wanna learn more about caffeine, there's links in the description. if you wanna ask questions or suggest topics you canhook up with us on facebook or twitter or of course in the youtube comments below.
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