Today we’re gonna talk about caffeine
It’s the most widely consumed psychoactive drug in the world, most commonly consumed as coffee. And we’re all familiar with the effects of caffeine, but what exactly is caffeine?
Why do plants produce it?
What does it do to our bodies and is it good for you? Now, from a chemical perspective,
caffeine can be described as both a methylxanthine and an alkaloid.
The first name refers to the shape and composition of the caffeine molecule while alkaloids as a whole are a broader group of naturally occurring organic compounds, defined by having at least one nitrogen atom.
Alkaloids have many functions and effects but almost all are bitter in taste. Caffeine occurs naturally in more than 60 different plants, but more surprising then that is that those plants each develop different biochemical mechanisms and pathways to create caffeine.
This is a phenomenon known as convergent evolution.
Most people associate caffeine with coffee and it is named for coffee, but it also occurs in tea,
chocolate, kola nuts, guarana seeds and even the flowers of citrus plants.
Plants produce caffeine primarily as a pesticide
It deters insects from attacking or eating the plant, in part with its bitter taste, but caffeine is also toxic to some herbivore insects. It does also have one super interesting function.
Studies have shown that caffeine can improve the memory of bees, helping them create a stronger association between the smell of a coffee flower and its sweet nectar.
This might be why caffeine exists in very low concentrations in the nectar of certain flowers, like the citrus flowers we mentioned before. It gives those plants a competitive advantage in the world of pollination.
Human consumption of caffeine
Human consumption of caffeine likely starts back in 3,000 B.C. with the consumption of tea.
And tea, gram for gram, has more caffeine than coffee, but we just use more coffee when we make a cup.
The beginning of coffee consumption is a little bit harder to pinpoint, but by the middle of the 15th century, we’re pretty confident that coffee drinking had taken hold in Yemen and the surrounding areas. With both tea and coffee, very early records show that people liked it for the stimulating properties of caffeine.
Credit for the discovery of caffeine is not quite clear cut.
In 1819, a German chemist named Friedlieb Ferdinand Runge
isolated what he called kaffebase, a nearly pure caffeine extract.
He did this work apparently at the suggestion of the famous writer, Johann Wolfgang von Goethe.
Runge is also notable for having been the first to isolate quinine and also for the invention of paper chromatography. In 1821, it was discovered independently by French chemist Pierre Jean Robiquet
to whom caffeine’s discovery had traditionally, historically been credited.
It was also discovered at the same time by two other French chemists working together, Pierre-Joseph Pelletier and Joseph Bienaime Caventou. Pelletier was the first to use the word caffeine in print, though Robiquet was the first to isolate and describe the properties of pure caffeine.
A white, crystalline powder
In that pure form, caffeine is a white, crystalline powder that has a pretty bitter taste. If you take a large enough dose, it’s toxic but in lower doses, if you look at how it affects humans, you start to understand its enduring popularity.
Now, most people consume caffeine by drinking coffee and it’s absorbed initially through the gastrointestinal tract and then 30 to 60 minutes after consumption, that’s when it reaches peak concentrations in the body.
Let’s get into some biology here. Now, caffeine affects the body with three different mechanisms.
Firstly, caffeine blocks the receptors in the body for a compound called adenosine.
Under normal circumstances, adenosine triggers these receptors and it produces a feeling of relaxation and even drowsiness for some people. And so caffeine prevents this from happening,
while also causing the body to increase production of dopamine and noradrenaline.
This is the mechanism behind most of the effects that we all experience with caffeine, this inhibition of adenosine. It happens at relatively low doses and gives us that feeling of wakefulness
or alertness that we associate with a cup of coffee. This mechanisms might also explain the kind
of caffeine crash that many people experience with a sudden feeling of tiredness and exhaustion.
It might be that once the body metabolizes all of the caffeine, then the adenosine is finally able to trigger those receptors and really, really make us feel tired and drowsy.
Caffeine also causes the release of calcium inside of muscle cells and it can prevent or slow its reuptake. This increased availability of calcium increases the power output of the muscles but it does require a pretty large dose to occur, around 500 milligrams for an average person.
Caffeine can inhibit what are called phosphodiesterase, now, if you stop these enzymes working properly, then you can actually cause the body to burn more fat.
But for this to work, it also requires a much larger dose than people would typically get from drinking a few cups of coffee in a day. Caffeine affects the central nervous system.
Caffeine makes us feel more alert
Caffeine makes us feel more alert, more awake and has been shown to improve memory. However, the beneficial effects of caffeine aren’t as clear cut as we would like.
Several studies have now shown that that improved mental clarity that we get when we drink coffee in the morning, well, that comes from alleviating our withdrawal symptoms, rather than actually improving our cognitive functions.
One positive impact is the increasing evidence for caffeine’s ability to act as both a treatment
for some aspects of Alzheimer’s and Parkinson’s, as well as having some preventative properties as well. Now, caffeine could be said to be the last legal performance-enhancing drug, but it wasn’t always this way.
Between 1984 and 2004, caffeine was actually on the Olympic Committee’s banned list. If they tested your urine and you were at a higher concentration than 12 micrograms per milliliter, you were out. And to hit that level, you could do it with just five to eight cups of coffee in the morning. And because people metabolize caffeine differently, this was ultimately an unfair thing to police and after 2004, it was off the banned list.
Now, as we talked about before, caffeine does affect the muscles, it does affect power output
but it does seem less effective with habitual users of caffeine. Though it does impact the perception of exertion and fatigue, which is kind of interesting.
For people using caffeine for sport, they’re typically dosing three to five milligrams per kilo of body weight. Now, not everyone has a positive experience with caffeine and we do need to talk about that.
Symptoms like mild anxiety, jitteriness, insomnia, reduced coordination, these are all symptoms people can suffer with even mild caffeine consumption. Caffeine can have a negative effect on anxiety disorders and doses above 300 milligrams can worsen someone’s anxiety.
However, lower, more moderate doses have been shown to be associated with reduced symptoms of depression.
Consuming coffee regulation does leave you susceptible to experiencing caffeine withdrawal if you stop suddenly.
Now, most people can experience a big headache that can last a little while. They can become irritable, fatigued, some can get flu-like symptoms or struggle to concentrate.
Typically these symptoms will last for up to 24 hours, though occasionally, it can go on for longer
and people have experienced caffeine withdrawal for up to three days.
So how much caffeine exactly is considered healthy?
Recommendations are quite broad because people respond to and metabolize caffeine a little bit differently but current guidelines are for an adult, it’s no more than 400 milligrams of caffeine per day.
And that’s 200 milligrams if you’re pregnant or breastfeeding. Soft drinks, energy drinks, tea are all popular sources of caffeine, but coffee is by far the most popular.
But with soft drinks and energy drinks, there is typically a fixed and known amount of caffeine in them. You can look up on the internet how much coffee is in a can of Coca-Cola. With coffee, you can’t. A cup of coffee will have quite a dramatic variance in its caffeine content, depending on a number of factors.
The coffee itself will play a role. Arabica has half the caffeine content of Robusta, but the recipe or the way that it was brewed, these will all have an impact.
They’ve gone and done tes and bought coffees from different cafes and there’s been a pretty wide range reported, anywhere from around 65 up to over 300 milligrams in a single cup.
Various governments and governing bodies have tried a few times to legislate coffee companies
to have them tell you exactly how much caffeine is in your coffee-related product, but so far, that’s never happened. It’s always been successfully lobbied against.
Excessive caffeine consumption
It can be quite unpleasant and actually, it can be fatal. To reach caffeine toxicity, you’d have to ingest around 10 grams of pure caffeine in a day.
To do that, you’d have to drink between 50 and 100 cups of coffee. So it’s actually pretty rare
that anyone reaches that from drinking coffee. More often, people have died from caffeine intoxication from consuming too many caffeine pills or other medications that may contain caffeine.
I think for those of us who drink and enjoy coffee all the time, it’s really important to understand a bit more about caffeine. This is a psychoactive drug that we’re taking every single day.
We should understand what it is and how it affects us. Now, I know you’ll probably have questions
about decaf and decaffeination and I promise, I’ll answer them all in a future post.
And if you wanna know more about caffeine, I’ve left you some reading down in the description below.
But for now, I’ll say thank you so much for reading and hope you have a great day.