Advice · benefits · Blog · caffeine · coffee · dangers · risks

caffeine – what’s going on in that cup of coffee?

Ask people their thoughts on coffee and you’ll get mixed reactions.

Ask one person, and they might think it’s great.
The next person might claim it’ll kill you.

Myself? I am a self-proclaimed coffee aficionado.

As are my nearest and dearest.

My mum, for example, goes beyond the realm of aficionado, and both encompasses and embraces the role of the superfan (that’s a nice way of saying she’s a bit of an addict).

This, for example, is her two-day supply of Nespresso coffee pots.

Each one of them is one cup.

There’s 14 there.


Two days.

But its not just my family that seem so enamoured by coffee…

All you need to do is unlock your phone and there’s Instagram-perfected Starbucks cups (complete 34ACZSYTOFwith misspelt name), masterpieces drawn in coffee foam, and mason jars filled with delightfully creamy iced coffees.

Why is this?

Is it now in our culture to want, or need, that injection of caffeine each morning?

And if so many people love it, then why do others still dislike or even distrust it?

Does anyone even know what caffeine does?

I’ve spent some time looking into our well-loved friend caffeine, and along the way I’ve found out plenty of things that have surprised me.

So, read on, and you might be wanting that Nespresso machine after all…

So, what is caffeine?


There’s loads of buzz words that are associated with caffeine: stimulant, drug, excited, coffee, soft drinks, energy, to name a few.

Caffeine is a naturally occurring chemical, and can be found in more than 60 plants, such as coffee beans, tea leaves, and cacao beans.

Its role in these plants is to act as a pesticide, paralyzing and killing insects that try and feed on the plants.


In its purified form, caffeine is an intensely bitter white powder – pretty unpleasant, and pretty potent.

Caffeine can also be man-made, and is sometimes added to different foods, drinks, and medicine.

To give you a brief idea of doses, one cup of coffee contains about 100-200mg of caffeine, a cup of tea contains around 60-90mg of caffeine, and a can of Coca-Cola contains 34mg of caffeine.

What does caffeine do, exactly?

When caffeine enters the body, it affects the way your body works, ultimately changing how you feel and behave.

It acts as a stimulant to the central nervous system (the brain, spinal cord, and other nerves in the body).

The main (and most desired) effect of caffeine is a temporary increased sense of wakefulness, and alertness.

Caffeine is that magic wand that gives you the lift of energy at the beginning (or middle) (or end) of your day.

How does it do that?

Imagine caffeine as a person – what do you think their main characteristics would be?

Before I started reading into what caffeine does, I thought caffeine was like an army drill sergeant, screaming up to your bunk at 5am to get your butt moving.

But really, caffeine acts more like a secret undercover agent, its strength found in stealth.

Before I go on, let’s get our learning caps on – caffeine needs a little biological introduction.

Throughout the day, our neurons are firing away, sending all sorts of signals to all sorts of body parts – it’s what keeps our bodies ticking.

As our neurons fire, a neurochemical (a chemical that affects the nervous system) builds up in our bodies.

This neurochemical is called adenosine.

On a normal day, our neurons keep on firing, and the nervous system uses its special receptors to monitor this adenosine.

As the day goes on, more and more adenosine goes through these receptors, and this is what makes us feel sleepy!

Simply put, adenosine = tired.

So, more time spent awake = more adenosine = more tired.

So, where does caffeine fit into all this?

Caffeine is a master of disguise. He’s top dog of MI5.

Caffeine is the same size and shape of adenosine.

So, to the adenosine receptors in the nervous system, caffeine looks just like the chemical they’re meant to be monitoring.

Caffeine, acting and looking like adenosine, walks nonchalantly up to the receptor, and binds to it, just as adenosine would.

But once caffeine’s bound, actual adenosine molecules can’t enter, creating a sort of traffic jam, and ultimately preventing you from getting tired!

Is that where you get the caffeine “boost” from?

Not really – the kick you get from caffeine is a result of caffeine blocking off the adenosine receptors.

Once the receptors are blocked, other neurotransmitters such as dopamine and glutamate can get ahead of the game.

Dopamine levels rise, your energy rises with it, and you get that you that familiar energy kick.

A great way to think of it is that caffeine is acting like a bouncer to a club – it blocks the door, keeping the tired adenosine molecules out, while the energy-peaking stimulators throw a party inside.

Other than being an epic party planner, does caffeine have any other benefits?

It’s worth noting here that coffee is not just caffeine. There’s loads more things found in coffee that could lead to their own benefits – it’s full of antioxidants, and other nutrients that act to benefit the body.

But there are loads of studies out there that shed more and more light on the possible benefits of caffeine on the body. Here are some that I thought are notable:

Weight loss: Yup. I’m going there. While no conclusive results have been drawn from long-term weight loss, there are theories that suggest that caffeine suppresses appetite (leading to decreased food intake), and that it may stimulate thermogenesis – a method your body uses to get heat & energy from food.

Sports performance: many a study have shown that caffeine can increase endurance performance, including reducing your perceived exertion (meaning caffeine makes your body feel like it’s doing less than it is). affeine can also relieve post-exercise muscle pain by up to 48%. However, studies looking at the relationship between caffeine and short-term, high-intensity exercise remain inconclusive. So, a cup of joe before a 10k might be a better idea than a caffeine shot before your deadlifts!

Cognitive decline: several studies show that regular, moderate, lifelong consumption of caffeine may slow down age-related cognitive decline (loss of memory and thinking skills), especially in women over 80. This included diseases such as Alzheimer’s and Parkinson’s disease.

Men’s… nether-regions: you read that right… I’ve read some interesting studies that show caffeine could lead to a lower incidence of erectile dysfunction, and improve the quality of the sperm produced (increased semen volume, better motility, and less sperm DNA fragmentation). Huh.

Protection against type-2 diabetes: a meta-analyses spread over 20 years showed that people who increased their caffeine intake by more than one cup a day over a 4-year period had an 11% lower risk of type-2 diabetes than those who did not increase their intake. However keep in mind that a lot of coffee consumed nowadays has an inordinate amount of sugar in it (Starbucks caramel frappes, I’m lookin’ at you!). So remember, if you drink sugary coffees, the results of this study might not apply.

Survival from colon cancer: there was a study published last month that show patients with colon cancer who are heavy coffee drinkers have a lower death rate than those that don’t drink, or drink less, coffee. The relationship between the two, though, may not be causative.

Life expectancy: this is a bomb-shell! According to a long-term study on the life expectancy of men and women who consume more than 6 cups of coffee a day, coffee has a positive association with life expectancy. Over the span of 14 years, it was found that men that drank more than 6 cups of coffee had a 10% lower risk of death, and women with the same factors had a 15% lower risk of death.

So why do some people think its bad?

This is a huge question to answer – there are so many ways you could look at it.

I think a big part of the reason behind why some people believe caffeine is bad for you is because of the drug-like, addictive side to caffeine.

Bodies can build up a tolerance to the effects of caffeine, meaning they need more of it to feel the desired effects.

When a person skips their morning coffee, the brain is flooded with adenosine, and dopamine levels fall – knocking the brain’s balance out of wack.

This ultimately leads to the withdrawal symptoms lots of caffeine-detoxers experience: headaches, sleepiness, constipation, irritability, insomnia.

There’s also a stereotype of the kind of person who drinks lots of coffee… High-strung, stressful, agitated people.

There’s also been some evidence of negative effects of caffeine…

Hypertension: caffeine can cause a short and dramatic spike in your blood pressure. This could have many risks, such as damaging your heart, arteries, or even your brain.

Blood sugar: I just mentioned that caffeine could protect you against type-2 diabetes, however for those already with type-2 diabetes, it’s worth noting that a small increase in blood sugar can be detected after caffeine consumption, particularly after meals.

Pregnancy: could caffeine affect your pregnancy? Some studies have shown that this could be the case. Caffeine can cross the placenta in the blood and affect the baby’s heart rate, and some studies have even linked caffeine consumption with increased risk of miscarriage when a woman drinks more than 300mg a day (that’s about 3 cups of coffee).

Breast-feeding: the same concept goes for breast-feeding – caffeine could pass into the breast milk, where it will be ingested by the baby. This could make the baby jittery and cause them to have trouble sleeping.

Fertility in women: while caffeine could possibly improve a man’s little soldiers, caffeine has been shown to affect a woman’s Fallopian tubes – altering and disrupting the natural movement of the egg into the uterus. Caffeine could reduce a woman’s chance of getting pregnant by about 27%.

Looks like as good as caffeine looks for men’s bits, the same may not be said for women’s!

Insomnia: caffeine drank 3 or even 6 hours before sleep can really effect not only the amount of time taken to fall asleep, but also the quality of sleep you get. There’s a myriad of problems that are associated with not getting enough sleep at night, including difficulty with weight management, and lowered cognitive function.

So, with that mixed bag of good and bad, is there a happy middle-ground?

Everyone is different.

I personally know of plenty of people who take a sip of coffee and go wild, whereas others could drink 2 or 3 cups just to feel a buzz.

From what I’ve read (and by no means take what I say as gospel – I’ve done my reading purely through interest and your doctors, GPs, and other professionals will know much better) it seems like 3-5 cups of coffee hits that ‘middle-ground’, where you can reap some of the possible benefits discussed above.

However keep in mind that this depends on many personal factors, such as your body’s own caffeine tolerance, the effects you feel after a cup of coffee…

Do what feels right for you.

Great, so where’s my cappuccino?

My thoughts exactly.


So there you have it – my try at compiling a comprehensive guide to all things coffee.

Remember though, it’s worth taking away what I said above about coffee not just being caffeine.

I hope it’s shed some light on what caffeine does to your body, and that it’s got you to a place where you can make a *semi* educated decision on how you want to incorporate caffeine into your life.

That’s all for now…
the active grazer x


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