How does caffeine keep us awake? - Hanan Qasim

Kako nas kofein drži budnim? - Hanan Qasim

Prevoditelj: Irma Komljenović Recezent: Ivan Stamenković

Over 100,000 metric tons of caffeine are consumed

Više od 100,000 tona kofeina konzumirano je

around the world every year.

u svijetu svake godine.

That's equivalent to the weight of 14 Eiffel Towers.

To je ekvivalent težini 14 Eiffelovih tornjeva.

Most of this caffeine is consumed in coffee and tea,

Većina kofeina unešena je u kavi i čaju,

but it's also ingested in some sodas,

no on se nalazi i u nekim sokovima,

chocolate,

čokoladi,

caffeine pills,

kofeinskim tabletama,

and even beverages labeled decaf.

čak i u nekim bezkofeinskim pićima.

Caffeine helps us feel alert, focused, happy, and energetic,

Zbog kofeina se osjećamo oprezno, usredotočeno, sretno i energično,

even if we haven't had enough sleep.

čak i ako se nismo dovoljno naspavali.

But it can also raise our blood pressure, and make us feel anxious.

No može nam povisiti krvni tlak, a zbog njega se možemo osjećati anksiozno.

It's the world most widely used drug.

To je najšire upotrebljavana droga na svijetu.

So how does it keep us awake?

Kako nas onda drži budnima?

Caffeine evolved in plants where it serves a few purposes.

Kofein se razvio u biljkama u kojima služi nekim svrhama.

In high doses, as it's found in the leaves and seeds of certain species,

U velikim dozama, na primjer u lišću i sjemenkama određenih vrsta,

it's toxic to insects.

otrovan je za kukce.

But when they consume it in lower doses, as it's found in nectar,

Ipak, kad ga unose u manjim dozama, kao u nektaru,

it can actually help them remember and revisit flowers.

može im pomoći zapamtiti cvijeće koje će ponovno posjetiti.

In the human body, caffeine acts as a stimulant for the central nervous system.

U ljudskom tijelu kofein se ponaša kao stimulans središnjeg živčanog sustava

It keeps us awake by blocking one of the body's key sleep-inducing molecules,

Drži nas budnima tako što zaustavlja ključnu molekulu za izazivanje sna,

a substance called adenosine.

tvar koja se zove adenozin.

Your body needs a constant supply of energy,

Tvoje tijelo treba stalnu zalihu energije

which it gets by breaking down a high-energy molecule called ATP.

koju dobiva razgradnjom ATP-a, molekule bogate energijom.

In the process,

U tom procesu

it liberates adenosine, ATP's chemical backbone.

otpušta adenozin, glavnu sastavnicu ATP-a.

Neurons in your brain have receptors perfectly tailored to this molecule.

Neuroni u tvom mozgu imaju receptore baš za tu molekulu.

When adenosine docks to these receptors,

Kad adenozin uđe u te receptore,

it activates a cascade of biochemical reactions

započinje lanac biokemijskih reakcija

that cause neurons to fire more sluggishly

koje uzrokuju sporije djelovanje neurona

and slow the release of important brain-signaling molecules.

i usporavaju otpuštanje važnih signalizirajućih molekula.

In other words, you get sleepy.

Drugim riječima, pospan si.

Caffeine is what's called an adenosine receptor antagonist.

Kofein je takozvani antagonist receptora za adenozin.

That means it derails this process of slowing your neurons down

On otkazuje proces usporavanja tvojih neurona

by blocking adenosine receptors.

blokiranjem receptora za adenozin.

Caffeine and adenosine have a similar molecular structure,

Kofein i adenozin imaju sličnu molekularnu strukturu,

close enough that caffeine can wedge into the adenosine receptors,

dovoljno sličnu da se kofein može ugurati u receptore za adenozin,

but not close enough to activate them.

ali ne toliko da bi ih i aktivirao.

To summarize, adenosine inhibits your neurons.

Ukratko, adenozin je inhibitor tvojih neurona.

Caffeine inhibits the inhibitor, so it stimulates you.

Kofein usporava samog inhibitora, usput te stimulirajući.

Caffeine can also boost positive feelings.

Kofein ti može i pojačati pozitivne osjećaje.

In some neurons, the adenosine receptors

U nekim su neuronima receptori za adenozin

are linked to receptors for another molecule called dopamine.

povezani s receptorima druge molekule: dopamina.

One of dopamine's roles in the brain is to promote feelings of pleasure.

Jedna od uloga dopamina u mozgu je proizvodnja osjećaja zadovoljstva.

When adenosine docks in one of these paired receptors,

Kad se adenozin spoji s jednim od tih receptora,

that can make it harder for dopamine to fit in its own spot,

otežava ulazak dopamina u svoje mjesto,

interrupting its mood-lifting work.

prekidajući njegov posao podizanja raspoloženja.

But when caffeine takes adenosine's place, it doesn't have the same effect,

No kad kofein zauzme mjesto adenozinu, više nema isti učinak,

and dopamine can slide in.

i dopamin može ući.

There's evidence that caffeine's effects on adenosine and dopamine receptors

Postoje dokazi da učinci kofeina na receptore za adenozin i dopamin

can have long-term benefits, too, reducing the risk of diseases

mogu imati i dugotrajne prednosti, poput smanjenja rizika

like Parkinson's, Alzheimer's, and some types of cancer.

Parkinsonove i Alzheimerove bolesti, te nekih vrsta raka.

Caffeine can also ramp up the body's ability to burn fat.

Kofein može i povećati mogućnost tijela da sagorijeva mast.

In fact, some sports organizations think

I doista, neke sportske organizacije vjeruju

that caffeine gives athletes an unfair advantage

da kofein sportašima daje prednost,

and have placed limits on its consumption.

pa su postavili granice njegova konzumiranja.

From 1972 until 2004,

Od 1972. do 2004.,

Olympic athletes had to stay below a certain blood-caffeine concentration

Olimpijci su morali imati određenu koncentraciju kofeina u krvi

to compete.

kako bi se natjecali.

Of course, not all of caffeine's effects are so helpful.

Naravno, nisu svi učinci kofeina tako korisni.

It might make you feel better and more alert,

Možda se zbog njega osjećaš bolje i opreznije,

but it can also raise your heart rate and blood pressure,

no može ti povećati brzinu otkucaja srca i krvni tlak,

cause increased urination or diarrhea,

uzrokovati pojačano mokrenje ili proljev,

and contribute to insomnia and anxiety.

te pridonijeti nesanici i anksioznosti.

Plus, the foods and beverages caffeine is found in

Čak i hrana i pića koji sadrže kofein

have their own impacts on your body that have to be taken into account.

imaju utjecaj na tvoje tijelo koji se mora uzeti u obzir.

Your brain can adapt to regular consumption of caffeine.

Tvoj se mozak može prilagoditi redovnom unošenju kofeina.

If your adenosine receptors are perpetually clogged,

Ako su ti receptori za adenozin neprestano začepljeni,

your body will manufacture extra ones.

tvoje će tijelo proizvesti nove.

That way, even with caffeine around,

Tako, čak i s kofeinom,

adenosine can still do its job of signaling the brain to power down.

adenozin može obaviti svoj posao i signalizirati mozgu da se isključi.

That's why you may find you need to consume more and more caffeine

Zato trebaš unositi sve više i više kofeina

to feel as alert.

kako bi se osjećao jednako usredotočeno.

There are more and more adenosine receptors to block.

Nastaje sve više receptora za adenozin koje treba začepiti.

It's also why if you suddenly quit caffeine,

Ako onda iznenada prestaneš unositi kofein,

you may experience an unpleasant withdrawal.

možeš doživjeti neugodne simptome povlačenja

With plenty of receptors and no competition,

S puno receptora i bez ikakve konkurencije,

adenosine can work overtime,

adenozin će raditi prekovremeno,

causing symptoms like headaches,

što će uzrokovati simptome poput glavobolje,

tiredness,

umora,

and depressed moods.

i depresivnih raspoloženja.

But in a few days, the extra adenosine receptors will disappear,

Ipak, za par će dana dodatni receptori za adenozin nestati,

your body will readjust,

tvoje će se tijelo ponovno prilagoditi,

and you'll feel just as alert as ever,

i osjećat ćeš se budno i usredotočeno kao i prije,

even without an infusion of the world's most popular stimulant.

čak i bez doze najpopularnijeg stimulansa na svijetu.