Even if the Sun is out fog and rain still smother your sleepy soul or not maybe you're more of a morning person but it's an obvious fact that many of us do need some coffee or tea to prepare us for workers school
Coffee and tea are some of the most widely consumed beverages on the planet but how does caffeine affect your body and mind throughout the day and is it bad for you or addictive
what is caffeine?
Caffeine is a stimulant of the central nervous system and is classified as a methylxanthine
Methylxanthines are a subclass of a class of chemicals called xanthi the methyl part of its name tells you that it includes a compound similar to methane called a methyl group xanthines are very common in many organisms including the tissues of humans so it's no surprise that coffee and tea to different plants that are only distantly related develop the ability to synthesize caffeine
But why would they do that?
Well like all plants coffee and tea have to deal with insects that want to eat their leaves and fruit so their leaves and seeds produce caffeine
Juvenile coffee plants in particular also leach caffeine into the surrounding soil they do this to stop the growth of other plants nearby that way there's less competition
Meanwhile tea plants produce caffeine in two places cellular vacuoles which are a type of organelle containing organic compounds and around the vascular bundles which are like the veins and arteries of a plant the first is thought to discourage plant eating animals from munching the leaves and the second is thought to fight off fungi that also want to bite
Other plants like Kola nuts contain caffeine as well in fact around 60 plant species produce the stuff by now you must be tempted to spit out your latte in disgust who wants to drink insecticide even if it comes from a plant
Don't worry the chemical is only lethal for bugs because bugs are much smaller plants use caffeine to an use the effects we associate with a caffeine buzz but they're applying it to a tiny organism that just can't take it
The lethal dosage for a human being is about seventy-five to a hundred cups in a day for a 154 pound adult caffeine's ld50 the dosage at which half of a mad scientist unlucky test victims fatally overdosed is about 150 to 200 milligrams for every 2.2 pounds in an adult body
There's no way you're getting that much caffeine inside of you even the most ridiculous energy sports drink has no more than about 300 milligrams of caffeine in total
So what are those effects? how does caffeine stimulate you?
We all know that caffeine is a central nervous system stimulant and that it has effect on your brain
Caffeine targets many parts of your brain including the cerebral cortex the region of the brain devoted to memory consciousness and language
that might explain why you're a little more articulate and aware after a glass or mug of your favorite caffeinated beverage but more generally and more importantly it eliminates drowsiness that drowsiness that you want to eliminate with coffee goes away when caffeine binds to the adenosine receptors which prevents adenosine from working and that makes way for the brains natural stimulants
But caffeine also stimulates the medulla oblongata the upper part of your brainstem that part of your brain controls vital involuntary functions like the beating of your heart breathing vomiting and the dilation and contraction of major blood vessels
That's why a strong cup of coffee and tea also raises your heart rate and increases blood flow or restricts it see that's where things get a little complicated one of the ways caffeine works is by inhibiting a cellular enzyme called phosphodiesterase and phosphodiesterase is how your body puts the brakes on your cells favorite party drug cyclic adenosine monophosphate or camp camp promotes activity in your cells so when caffeine blocks at phosphodiesterase yourself go into overdrive thing is overdrive is a relative term since you're different cells serve different functions when caffeine binds with the cells that make up your blood vessels the overload of camp causes those vessel to dilate
Which is why coffee can have different physical effects depending on the dosage or the individual drinking it?
It will definitely make you think and talk faster but it may or may not raise or lower your heart rate that is at normal doses
We should probably start talking about higher doses the doses that won't kill you but might give you some unwanted side effects one unpleasant side effect caffeine fans know is that it can give you a vicious need to go to the bathroom at normal doses like those you find in a single cup of coffee or a few cups of tea this won't happen so fast but what if you have two to three cups of coffee or five to eight cups of tea now you're talking around 250 to 300 milligrams of caffeine at that point caffeine acts as a short-term diuretic it stimulates your urine output which is a nice way of saying it makes you pee like a racehorse but caffeine can do other bad things you've probably heard of the coffee jitters those are real it's bad enough if you're a mentally healthy individual with no anxiety issues but if you suffer from anxiety caffeine can absolutely make your condition worse of course if you're reasing this and have anxiety we recommend you talk to your doctor about drinking caffeine before you toss out all of your coffee and tea but one of the most burning questions people have about caffeine is
Whether or not it's addictive?
Well not exactly remember those adenosine receptors if you drink coffee or tea every day your brain can sense that those receptors are getting blocked by caffeine after a while it will make more adenosine receptors to compensate and as we've already discussed those receptors induce drowsiness when adenosine binds to them so if you skip your daily caffeine for the first time in forever you'll be more drowsy than normal and there are other withdrawal effects of caffeine headaches irritability etc
But the important point here is that caffeine although it is a stimulant doesn't work like other stimulants stimulants like illicit substances and amphetamines work by blocking dopamine transporters these transporters remove the neurotransmitter dopamine from your synapses but illicit substances don't block dopamine receptors so when illicit substances or amphetamines block those transporters dopamine accumulates in the synapse dopamine is highly implicated in the reward system in your brain this system trains your brain to learn that certain actions will pay off with a desired effect illicit substances and a fetta means therefore trick your brain into thinking it's always accomplishing something the brain then rewards itself with a sense of euphoria and success and just as your brain will increase adenosine receptors to try to outfox caffeine your brain will also reduce dopamine receptors if you do too many stimulants that's why illicit substances are so addictive with so little dopamine your body and brain cry out because they need that accomplishment feeling it feels like some action vital to survival is needed and so you feel like you need it
Caffeine withdrawal doesn't tell your brain you need caffeine in exactly the same way it just tells you it's tired and if it's a lazy Sunday afternoon and you have nothing to do most people are fine with that you may like being picked up by caffeine but you can do without it there are many more specific effects caffeine has on our bodies and brain and it would take forever to get through all of them but there's one we really can skip that's
Caffeine's half-life
don't worry caffeine isn't radioactive we're talking about caffeine's biological half-life that's the time it takes for half of a substance to disappear in a healthy adult that's about 6 hours however smoking birth control and some antidepressants can extend that half-life to several days but even after half of the caffeine is metabolized or removed the other half is still there and while it may have stopped keeping you alert and awake it can still impact the quality of your sleep so let's assume you have an average physiology and body weight you don't smoke take birth control or antidepressants if you have coffee at 8 a.m. 25% will remain by 8 p.m. if you drink it in the afternoon it might still be at half-strength by bedtime and if it isn't enough to keep you up it can limit the time you spend in REM sleep REM sleep or rapid eye movement is literally the stuff of dreams it's when our brains reorganize our thoughts to prepare our minds for the coming day ahead
Depriving yourself of REM sleep can lead to irritability and a sense that you didn't rest at all the previous night you feel tired and you end up needing more caffeine to get through the day
That's why experts recommend that you limit caffeine intake to the mornings they suggest a cutoff time of 2 p.m. for most adults what does this all mean for you your morning and your coffee maker or tea pot by now you should be pretty confident that caffeine isn't fatal unless you drink an impossible amount you can't get addicted to it like other stimulants at worst it makes you a little dependent it makes you go to the bathroom a lot if you drink more than a few cups and well that's it