The accumulation of adenosine tells your brain it is time for a nap. Caffeine stops the adenosine message so your brain doesn’t realize you’re really tired.
How caffeine hacks your brain so you keep GOING and GOING
The accumulation of adenosine tells your brain it is time for a nap. Caffeine stops the adenosine message so your brain doesn’t realize you’re really tired.
You got to finish the report for your boss. You’re future depends on it, but you’re exhausted.
To keep going you reach for a little pharmacological assistance.
And in a couple of minutes you get your second wind and you’re firing on all four cylinders.
Caffeine to the rescue.
Every wondered, how caffeine can take you from bored and tired, to with it, in such a short space of time ?
The pharmacology of caffeine
Officially caffeine acts as an antagonist at the adenosine receptors, there are 4 known variants of the receptor, caffeine primarily interacts with the A2A receptor.
Unless you’re into pharmacology, antagonist at the adenosine receptor means nothing – so let me try to explain how caffeine works in more familiar terms.
ATP the currency of the body
We all know that money makes the world go round. It turns out, the substance that is the “equivalent” of money in your body is ATP (adenosine triphosphate).
Your body takes the food you eat and turns it into ATP, in a process known as respiration.
NOTE : Respiration is not the same as breathing, breathing supplies the oxygen needed for the chemical reactions of respiration.
ATP is the “currency” used to “pay” for all the transactions (reactions) in your body.
The ATP molecule is a big spender
It releases energy in a complex chemical reaction.
This energy drives all the reactions in your body from muscle contractions to moving molecules from one place to the other etc. etc. etc.
From riches to rags
Unfortunately Mr Money Bags doesn’t save for a rainy day, so when the energy has been consumed, he is left penniless in the form of a substance known as adenosine.
If any of you have been in this financial predicament, then you will know how demoralizing this is. You really aren’t able to go out on the town, so the best thing to do is to head for “bed”.
This is what happens in your body.
A day in the life….
You start the day (hopefully) full of energy, but as the day wears on, and you do all the things you need to do, that energy is used up. Eventually there isn’t a lot of energy left and your body is full of adenosine.
The penniless adenosine then goes to his “bed”.
The “bed” is the ADORA2A receptor, a special molecule located on membranes throughout your brain. Once adenosine hops on the receptor/bed this signals your body that you should do the same. And in no time at all, you’re knocking on the door of dreamland.
A quick recap…
Tiredness is an adenosine PROBLEM
The more adenosine molecules circulating, the more tired you’re body feels, as your energy levels drop off. Certainly your get up and go has got up and went. Your sunny disposition has also left the building so you become increasingly grouchy and aggressive.
Time to catch a few Zeeeeees
The superwise use this signal to have a snooze. However, unfortunately your boss / teacher or other slave driver, may not be willing for you to take the much needed rest.
So you reach of your caffeine fix
The caffeine fix may be in the form of coffee, cola or an energy drink. If you are hard core – a caffeine pill.
The caffeine comes along and tricks the signaling system.
The reason this trickery works is because chemically speaking, caffeine looks a lot like adenosine. The resemblance is enough to allow caffeine to hop on adenosine’s bed (ADORA2A receptor), but the “fit” is not perfect.
NOTE : Obviously this is not the case in cartoon world. Did you notice, I always depict drugs as a square and neurotransmitters are oval.
The not so comfy bed
In fact, truth betold, he doesn’t find the bed uber comfy at all. Adenosine’s intention are too hunker down and sleep. Caffeine is a STIMULANT, when caffeine hops on the bed, he’s not thinking sleep. But he does his best to hunker down.
And this leaves adenosine on standing on the side lines, unable to keep adrenaline and company in check.
In this moment, the GO SIDE of your autonomic nervous system is triggered.
“Fighting” BIG WOOLLY MAMMOTHS and things
You’re firing on all four cylinders you’re primed to deal with a BIG WOOLLY MAMMOTH or some other horrible. You can opt to stand your ground and FIGHT, or take FLIGHT and make a quick get away. Whatever you decide – you’ll make the “RIGHT” decision because you’re thinking will be sharp as a pin and as an added bonus you’ll feel GOOD doing it. Lol.
It takes approx 10 – 15 minutes to begin to feel a little perky and the effect will usually last 4 – 6 hours.
GO CAFFEINE !
But ADORA2A receptors are not all created equal.
ADORA2A variations
Genetic variations impact how well caffeine binds to the receptor and consequently, the magnitude of the stimulant effects experienced.
Two gene versions are connected with caffeine sensitivity.
- rs5751876
- rs2298383
For the record, there are other ADORA2A versions, some of which have been associated with Parkinson’s disease and autism. The most studied ADORA2A SNP is rs5751876 SNP – there are two possibilities, a “T” allele and a “C” allele.
The T beds are seriously UNCOMFORTABLE for caffeine.
Caffeine ninjas
People with two copies of the TT version would be caffeine “ninjas”, because caffeine struggles to settle in. These are the people who will proudly declare that they can drink a cup of coffee before bed and sleep like a baby. Of course, this is not 100 % true, ninjas are not IMMUNE to the effects of caffeine – it can still cause sleep disturbances, but the effect is not obvious.
Stats suggest approx. 17 % of Europeans carry this gene combo, the incidence of the gene is a little higher in other ethnicities.
Caffeine sensitives
If you have a T and a C allele, or worse 2 C versions of the gene, caffeine is really able to hunker down and keep adenosine out, so caffeine tends to hit harder, making you more likely to feel wired or restless.
More caffeine genes
What your ADORA2A recptors LOOK LIKE, is not the only thing contributing to caffeine sensitivity. How efficient your liver is at “dealing” with caffeine is also very important. It’s a topic I’ll cover in a different video.
The take home message…….
Caffeine is a tool.
When used wisely, caffeine can power you through life’s challenges without derailing your overall health.
In an ideal world, you want to use caffeine alongside optimized body chemistry. Sign up for my email list today, to stay in the loop about what’s coming next and get practical, science-backed tips delivered straight to your inbox.
Further reading
Caffeine makes you genuinely smarter
Everyone knows caffeine keeps you going – which helps you focus for longer and thus makes you smarter, but caffeine is also helping you to remember
Caffeine is the ultimate party killjoy
The alcohol turns your brain off. Caffeine turns the circuits on. Discover what is going on in the brain when alcohol and caffeine are mixed.
Why elves and other smallish people shouldn’t drink too much coffee
Elves, like human children are small containers. Pouring a cup of coffee or a can of coke, into a small container magnifies the effect, leaving BIG results