The Stuff You Need To Know About Caffeine

Caffeine. The world’s most popular drug, and by a long way.

Literally billions of people wake up each morning and the first thing they do is brew a coffee. So, it can’t be bad for you, can it?

Caffeine has often been in the headlines for it’s negative effects, but are there any benefits?

We’ve lifted the curtain on the misnomer that caffeine is bad for you.

So let’s take a look at what caffeine is, what effect it has on you, and how much is too much.

What Is Caffeine?

Caffeine is in a lot of products that we consume. We know what it does and how it feels, but what actually is it?

Caffeine is a naturally found stimulant that’s most commonly found in tea, coffee, and cacao plants.

There is also a synthetic version, which is added to some medicines, foods, and drinks. For example, some kinds of pain relievers and medicines or alertness. It’s also added to energy drinks and snacks or gum that advertise themselves as energy boosting.

Caffeine is thought to have been first drunk more than 4500 years ago, when people first brewed tea. Coffee is thought to have been discovered many years later, in the 14th or 15th century, by a goat herder in Ethiopia.

Today, 90% of the world’s population drink or eat products containing caffeine, everyday.

what is caffeine infographic

How Does Caffeine Work?

After you’ve consumed the food or drink containing caffeine, it quickly enters your bloodstream once broken down in your gut. After that, it makes its way into your liver, where it’s broken down into compounds.

The compounds it’s broken down into can affect different organs in different ways. The biggest effect being on your brain.

This is where we’re introduced to adenosine. A neurotransmitter that’s levels build up throughout the day from the moment you wake. The higher the amount of adenosine you have in your brain, the more sleepy you feel, until you have enough built up that you could fall asleep.

What caffeine does, is block the receptors of adenosine, therefore stopping that feeling of tiredness. It can also increase the levels of adrenaline in your blood, and increase the dopamine and norepinephrine levels in your brain. These two chemicals make us feel good, and mobilise the brain and body for action.

All of these effects combined give you the perceived feeling of alertness and focus. You can focus on the task in front of you with more intensity, and makes you more productive.

Caffeine works very quickly, you can feel the effects after 20 minutes of consuming it. It also takes a long time to completely exit your body, with a half life of around 6 hours.

What Are The Effects On The Body?

The first thing we should note when talking about the effects of caffeine on your body, is that there are variables. Caffeine’s effect each individual changes based on these things:

  • The amount consumed
  • Size, weight and health
  • Quantity of consumption over long periods of time
  • If you’re taking other drugs at the same time

With all of these considered, you can feel a range of different effects once you’ve consumed caffeine. These can include:

  • Feeling more alert and focused
  • Restless and excitable
  • Dehydration
  • Faster heart rate and breathing
  • Stomach cramps
  • Headache
  • Higher body temperature

Some of these may seem bad, and they are, but they’re not all that common. Some of these effects you will only feel if you have too much caffeine, or if you have any underlying conditions that might compound the effects of caffeine.

There are many benefits of drinking caffeine over a prolonged period of time, but in low quantity. The more caffeine you consume at any one time, the more of a tolerance you build it, and the less effect it will have on you. So you drink more to have the desired effect, and your tolerance level will build up so you don’t feel anything, so you drink more, and so on.

Drinking too much caffeine can have a lot of negative effects, and if you don’t get your caffeine fix for the day, that can lead to caffeine withdrawal.

coffee beans in cupped hands

Overdose Effects

Unless you were to drink a ridiculous amount of espressos in a short period of time, it’s hard to overdose.

If you do have lots of caffeine, or witness someone having a lot of caffeine, then there are signs to look out for as to determine whether they have had too much.

If you start to vomit, or begin to seizure, then that is a definite sign that you’re had more than what’s recommended as a healthy dosage. Developing tremors, having a panic attack, being confused, or noticing a very fast heart heart rate are also signs that you need to call for help straight away.

It is possible to die from having too much caffeine, just like it’s possible to die from eating too many bananas. It’s super rare, and would take an insane amount of coffee for it to get to that point.

Long Term Effects

Drinking caffeine over a long period of time can have it’s benefits, if drunk in moderation. Regular, heavy use of caffeine can cause some negative side effects, such as:

  • Sleeping difficulty
  • Constant headaches
  • Irregular heart rate or rhythm
  • Low blood pressure
  • Poor appetite
  • Restlessness
  • Weakness and fatigue

If you’re drinking 4 or 5 cups of coffee a day, chances are you’re drinking too much caffeine. Try coming off caffeine for a couple of weeks, and going on a caffeine detox. If you don’t think you need to, still try coming off the drink for a while. If you crave a coffee, or can’t help but brew one, then you probably should do a detox.

Caffeine should be treated like any other drug we deal with. Consume in moderation, and know when you’re having too much of it.


Giving up caffeine after consuming it for a very long time can be hard, just like giving up any other drug. The body has to get used to functioning without it, which is challenging because it’s adapted to living with it for so long.

After 24 hours since your last caffeine fix, you’ll start noticing symptoms of withdrawal. These can include:

  • Headaches
  • Fatigue
  • Irritability
  • Difficulty concentrating
  • Flu-like symptoms (fever, achiness, vomiting)

Who Should Avoid or Limit Their Caffeine Intake?

For the majority of people reading this, you’re going to be just fine drinking a couple of cups of coffee a day. Caffeine consumption is widely considered safe, but you should always consult with a medical advisor if you’re concerned.

For example, caffeine can have some complications or negative effects if you:

  • Are pregnant, as caffeine can pass through the placenta to your baby
  • Have anxiety
  • Have high blood pressure
  • Often suffer from migraines or other chronic headache conditions
  • Have sleep disorders, like insomnia
  • Have GERD
  • Are under 18 (children and teenagers can be sensitive to the effects of caffeine)

If you’re pregnant, you should be limiting the amount of caffeine you have each day to around 200mg.

High levels of caffeine during pregnancy can result in many complications. For example having a low birthweight, which can also increase the risk of health problems in later life. Too much caffeine has also been found to increase the risk of a miscarriage. 

Caffeine can of course affect your sleep, especially if you’re consuming coffee during the later hours of the afternoon or evening, or in high quantities (six 8oz cups a day or more). Therefore, people who already have difficulty with sleep, should definitely limit their caffeine intake.

A common sleep disorder called Sleep Apnea, can often go undiagnosed and therefore untreated. A symptom of this disorder is high levels of daytime sleepiness, and so people who suffer from Sleep Apnea can mask their sleepiness with caffeine.

There are many ongoing studies at the moment that are researching the link between caffeine use and sleep.

coffee beans spilling out of a bag

Are There Any Benefits Of Caffeine?

Yes! It’s not all doom and gloom, but knowing how to avoid the negative effects is important to understand before focusing on how caffeine is good for you.

Protection Against Heart Disease and Type 2 Diabetes

It’s been shown in several studies that caffeine does not increase the risk of heart disease, but in fact decreases it.

Evidence in one recent study showed that men and women that drink between one and four cups of coffee each day have a 16 – 18% lower risk of heart disease.

There is also evidence to suggest that caffeine lowers your risk of developing type 2 diabetes. They found that your risk drops by about 14% for every 200mg of caffeine intake per day. It was also found that decaffeinated coffee has the same effect, showing coffee on its own could actually have some beneficial properties when it comes to preventing type 2 diabetes.

Caffeine with Co-Workers

Research suggests that drinking a moderate amount of coffee in the workplace, before participating in a group task, actually increases the productivity of that person.

Not only that, but people who drank coffee before the task actually had a more positive look on their co-workers productivity too.

We could put this down to the fact that caffeine increases the individual’s alertness, and can therefore allow you to pay more attention to what’s going on around you.

Caffeine May Improve Brain Function and Mood

Like we said earlier, caffeine blocks the build up of adenosine, while increasing production of dopamine and norepinephrine.

This is thought to have a positive effect on your mood and perceptions.

So much so, that studies have shown a link between increased amounts of coffee consumption, and a lower risk of suicide. Drinking between two to three cups of coffee a day can lower your risk of suicide by 45%.

Even when looking at depression, caffeine seems to lower the risks by a considerable amount, but bigger studies need to be conducted to conclude anything.

Alzheimer’s and Parkinson’s Disease

Research has also found that lifelong caffeine consumption may reduce the risk of Alzheimer’s disease. There have also been studies that reported people with a higher coffee consumption have a lower risk of Parkinson’s disease.

what is caffeine infographic

What Products Have Caffeine?


The most obvious beverage to be on this list is coffee. The amount of caffeine in each cup depends on what coffee beans you’ve used. On average you get 95 milligrams of caffeine in one cup of coffee.

Decaffeinated Coffee

While you’d be under the impression from the name that there would be no caffeine in it, there actually is. Decaf means exactly that, decaf coffee, less caffeine. If there was no caffeine in it, I guess it would be called ‘no-caf’?

Anyway, decaf coffee contains around 10% of caffeine as a regular coffee, about 2-13 milligrams.

If you think that decaf has a low enough amount of caffeine to have just before bed, you’d also be wrong. It certainly contains enough caffeine to disrupt your sleep if you have it in the hours leading up to bedtime.


Caffeine is naturally found in tea, coffee and cocoa trees, so most chocolate contains at least some caffeine. It’s hard to give a general amount though, as the caffeine content varies depending on the chocolate and whether it’s blended with other ingredients.

The darker the chocolate, the more caffeine is generally the rule of thumb. Milk chocolate can have around 14 milligrams, whereas a very dark chocolate bar can have more than 30 milligrams.

Breakfast Cereals

With the fact that chocolate contains caffeine in mind, it comes at no surprise that your breakfast cereal that has chocolate in it includes some caffeine.

Some cereals can have up to 11 milligrams of caffeine, which is about as much as your standard decaf coffee.

Headache Medicine

If you get a headache, it can be very tempting to pop a painkiller to relieve some of the pain. Maybe think twice if you’re heading to bed. Caffeine is a very common additive in painkillers as it can help the other ingredients speed up relief from headache pain. It can make up to 40% of the pill.

Getting a good night’s sleep is going to be better for your headache than a painkiller will be. So if you’re off to bed with a headache, try giving the medicine a miss.

How Much Caffeine Is Okay?

The European Food Safety Authority (EFSA) and the US Department of Agriculture (USDA) both agree that a daily intake of 400mg of caffeine is safe. If you consider that in an average cup of coffee there’s 95 milligrams, then you can have 3 or 4 cups a day.

There are some side notes with this number though. It is definitely not recommended that you drink all 400mg in one go. Fatal doses have been recorded when 500 milligrams have been consumed in one go.

It’s recommended that you stick to 200 milligrams of caffeine for every dose. For pregnant women, it’s recommended that up to 200 milligrams of caffeine a day is safe.

It’s also worth noting that if you have 3 or 4 cups of coffee a day, then you need to make sure that no other food or beverage that you’re consuming contains much caffeine. You don’t want to be going over the recommended safe limit every day.

Final Thoughts

Caffeine is not an unhealthy part of your diet, infact, it can actually have beneficial effects.

It is important to consume it in moderation (like with all things), and follow the recommended daily intake guidelines.

You don’t need to feel guilty when you’re thinking about brewing that second cuppa. But if you’re already on your fifth for the day, maybe think about cutting down, or switching to decaf after your first cup.

If you’re not drinking amazing coffee yet, check out our reviews to help you fix that!

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Tom Bolland

Tom Bolland

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