How does caffeine keep us awake? - Hanan Qasim

Translator: Klavdija Cernilogar Reviewer: Nika Kotnik

Over 100,000 metric tons of caffeine are consumed

Vsako leto ljudje zaužijemo

around the world every year.

za več kot sto tisoč ton kofeina.

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

To je toliko, kot znaša teža 14 Eifflovih stolpov skupaj.

Most of this caffeine is consumed in coffee and tea,

Večino kofeina spijemo v kavi in čaju

but it's also ingested in some sodas,

pa tudi v nekaterih gaziranih pijačah,

chocolate,

čokoladi

caffeine pills,

kofeinskih tabletah

and even beverages labeled decaf.

ter celo v pijačah z oznako "brez kofeina".

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

S pomočjo kofeina ostanemo pozorni, zbrani, veseli in energetični

even if we haven't had enough sleep.

tudi če nismo dovolj spali.

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

Lahko pa tudi dvigne krvni pritisk in povzroči anksioznost.

It's the world most widely used drug.

Je najbolj razširjena droga na svetu.

So how does it keep us awake?

Kako nam pomaga, da ostanemo budni?

Caffeine evolved in plants where it serves a few purposes.

Kofein se je v rastlinah razvil z razlogom.

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

V visokih dozah, v listih in semenih nekaterih sort,

it's toxic to insects.

je strupen za žuželke.

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

Če pa ga užijejo v manjših dozah, kot recimo v nektarju,

it can actually help them remember and revisit flowers.

jim lahko pomaga, da si rastlino zapomnijo in se tja vrnejo.

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

V človeškem telesu kofein deluje kot spodbuda centralnemu živčevju.

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

Ohranja nas budne, saj blokira eno od temeljnih molekul za spanje,

a substance called adenosine.

ki se imenuje adenozin.

Your body needs a constant supply of energy,

Telo potrebuje stalen dotok energije,

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

kar dobi z razgraditvijo visokoenergetske molekule z imenom ATP.

In the process,

V tem postopku

it liberates adenosine, ATP's chemical backbone.

se sprosti adenozin, kemična osnova ATP-ja.

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

Nevroni v možganih imajo receptorje, ki so kot nalašč za to molekulo.

When adenosine docks to these receptors,

Ko se adenozin priklopi na te receptorje,

it activates a cascade of biochemical reactions

sproži biokemične reakcije,

that cause neurons to fire more sluggishly

ki upočasnijo nevrone

and slow the release of important brain-signaling molecules.

in sproščanje pomembnih molekul, ki pošiljajo možganom signale.

In other words, you get sleepy.

Z drugimi besedami: postanemo zaspani.

Caffeine is what's called an adenosine receptor antagonist.

Kofeinu pravijo tudi antagonist receptorjev adenozina.

That means it derails this process of slowing your neurons down

To pomeni, da ustavlja proces, saj upočasnjuje nevrone tako,

by blocking adenosine receptors.

da blokira receptorje adenozina.

Caffeine and adenosine have a similar molecular structure,

Kofein in adenozin imata podobno molekularno strukturo,

close enough that caffeine can wedge into the adenosine receptors,

zato se kofein lahko vrine v receptorje adenozina,

but not close enough to activate them.

a jih ne more aktivirati.

To summarize, adenosine inhibits your neurons.

Skratka, adenozin zaustavlja nevrone.

Caffeine inhibits the inhibitor, so it stimulates you.

Kofein ustavlja ta inhibitor, zato nas stimulira.

Caffeine can also boost positive feelings.

Kofein lahko tudi sproža pozitivne občutke.

In some neurons, the adenosine receptors

V nekaterih nevronih so receptorji adenozina

are linked to receptors for another molecule called dopamine.

povezani z receptorji za molekulo, ki ji pravimo dopamin.

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

Vloga dopamina v možganih je med drugim, da spodbuja občutek užitka.

When adenosine docks in one of these paired receptors,

Ko se adenozin naveže na enega od teh povezanih receptorjev,

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

dopamin težje najde svoje mesto,

interrupting its mood-lifting work.

zato ne more pomagati pri boljšem počutju.

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

Če pa kofein prevzame mesto adenozina, ne pride do enakega učinka,

and dopamine can slide in.

zato lahko dopamin zdrsne k receptorju.

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

Dokazano je, da lahko vpliv kofeina na receptorje adenozina in dopamina

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

prinese tudi dolgoročne koristi, zmanjša tveganje za bolezni,

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

kot so Parkinsonova, Alzheimerjeva ali vrste raka.

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

Kofein lahko telesu tudi pomaga hitreje kuriti maščobe.

In fact, some sports organizations think

Nekatere športne organizacije mislijo,

that caffeine gives athletes an unfair advantage

da kofein daje športnikom nepošteno prednost,

and have placed limits on its consumption.

zato so omejile njegovo uživanje.

From 1972 until 2004,

Med letoma 1972 in 2004

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

so morali olimpijci imeti v sebi manj od mejne količine kofeina,

to compete.

da so smeli tekmovati.

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

Seveda pa niso vsi učinki kofeina tako koristni.

It might make you feel better and more alert,

Morda se počutite bolje in ste bolj budni,

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

a morda vam srce bije hitreje in se dvigne krvni pritisk,

cause increased urination or diarrhea,

večkrat morate na stran, lahko dobite drisko,

and contribute to insomnia and anxiety.

lahko postanete nespečni in anksiozni.

Plus, the foods and beverages caffeine is found in

Poleg tega imata hrana in pijača, ki vsebujeta kofein,

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

tudi čisto svoj vpliv na telo, ki ga ne gre zanemariti.

Your brain can adapt to regular consumption of caffeine.

Možgani se privadijo rednega uživanja kofeina.

If your adenosine receptors are perpetually clogged,

Če so receptorji adenozina stalno blokirani,

your body will manufacture extra ones.

bo telo proizvedlo nove.

That way, even with caffeine around,

Tako lahko adenozin kljub kofeinu

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

opravlja svoje delo in možganom signalizira, naj upočasnijo tempo.

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

Zato se kdaj zdi, da moramo vase spraviti vedno več kofeina,

to feel as alert.

da bi ostali budni.

There are more and more adenosine receptors to block.

Vedno več receptorjev adenozina je treba blokirati.

It's also why if you suddenly quit caffeine,

Če se naenkrat odrečete kofeinu,

you may experience an unpleasant withdrawal.

zato lahko pride do neprijetnih učinkov.

With plenty of receptors and no competition,

Ogromno receptorjev brez konkurence povzroči,

adenosine can work overtime,

da adenozin prekomerno deluje,

causing symptoms like headaches,

kar povzroči glavobole,

tiredness,

utrujenost

and depressed moods.

in depresijo.

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

A v nekaj dneh dodatni receptorji adenozina izginejo,

your body will readjust,

telo se prilagodi

and you'll feel just as alert as ever,

in postane budno kot prej,

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

celo brez doze najbolj popularnega stimulanta na svetu.