The Effects of Caffeine on the Brain

Just as you want to know what your food does to your body when you eat it, knowledge of what coffee does to the brain matters. In this article, we’ll take a closer look at the effects of caffeine on the brain.  You probably want to know, then, why you should be wary of drinking coffee to excess. When you drink a coffee, you will notice yourself that enriching lift that it gives you. You feel more alert: things that normally need pointed out to you become obviously apparent. The work that you need to do becomes much easier to focus on, as you have something in our system that boosts your alertness. 

The effect of coffee on the brain, though, comes from the binding of our adenosine receptors.  Think of caffeine as a Trojan horse of sorts. Instead of sending the adenosine receptors through the body, it sends caffeine instead. This mimics the adenosine receptors, but never sends the “lights out” moment that makes us feel tired. It essentially stops the body from being able to make us go “OK, that’s enough for just now!” – it gives us extra energy because your body cannot understand that it feels tired (temporarily).

What does that mean? It’s simple. It means that your brain is no longer capable of producing the chemical that makes us feel tired. Therefore, our body is literally unable to feel fatigued or drained of energy. You will be able to go at 100% as your body can no longer read the signs that would normally see us put down our tools and just stop. That added alertness and buzz allows us to get though tasks that might feel like too much of a strain. If you keep on drinking coffee, then, you can work through the stress barrier and get the job done.

That isn’t all, though. You’re also going to find that caffeine can free up dopamine and glutamine levels so that we can avoid what we call ‘rollercoaster thinking’: the peaks and troughs of the mind that can negatively damage performance. Our mind can therefore stay on the task at hand. This helps us to retain concentration and level-headedness, just as we need it most. 

Does your mind ever develop a resistance to coffee?

This is the challenging part. Coffee has many effects on the mind – one effect being the brains need to develop more adenosine receptors. What are presently blocked off will be replaced, and that means that you need more coffee to block these new receptors. This gives you that same lift all over again, making it easy for you to start feeling the various benefits of coffee on the mind. For one, you’ll be far less likely to miss out on that deadline – you don’t feel tired, so why stop?

This, though, is only the start of the mental effects of coffee. There is much more to come. Let’s look at some of the other issues that can come up when you keep on drinking coffee. 

Now that you can appreciate what coffee does to begin with, what about ‘stage two’ of the process?

Coffee and the mind: does caffeine have an impact on our memory?

The first thing that we need to look at then is what caffeine does to the brain. As you will no doubt know by now, coffee tends to contain anything from 70-140mg of caffeine in a single 8oz cup. Depending on the kind of coffee that you drink and the strength of the coffee, it’s likely to be higher than 100mg. Keep in mind, too, that the human body can safely take in around 400mg of caffeine. Therefore, four cups of 100mg strength coffee per day would be unlikely to cause long-term detrimental issues.

Caffeine does have numerous effects on the mind, though, including your memory. However, it’s not a bad impact: your brain is likely to work better in terms of memory recollection due to caffeine intake. Caffeine has a positive impact on the mind, with long-term memory likely to improve with caffeine intake. So, if you are worried that drinking too much coffee might be making you forgetful, fear not: that’s not one of the effects of caffeine on the mind.

There is a reason, after all, why so many students drink coffee. Yes, it’s to make up for those last night gaming sessions and midweek nights out. But it’s also to help them improve the standard of their studying. If you are a student and you want to make your learning more methodical, you should drink a cup of coffee after a study session.

Why? Because caffeine helps to open the mind and allow the information that you just learned to plant its own seed. Now, all those figures and studies that you just learned for your big exam might be more likely to stick around in the mind.

Does caffeine have a long-term impact on the mind, though?

Since caffeine is a stimulant, many of us worry that it might have a long-term and negative impact. It does have an impact on our mood, but it often lasts only as long as a few hours – unless taken in excess. 

Of course, there are some who will tell you that, while caffeine is good for the brain today, it might not be next week. However, there are presently no studies whatsoever that show long-term memory damage through caffeine intake. The energy crash that you feel when the caffeine wears off is your body producing new adenosine receptors. Therefore, the crash comes not from your mind faltering, but your body being able to feel tired again. Given you skipped a period of the day where you would have felt naturally fatigued, it can feel a touch more extreme.

So, if you are worried that drinking a lot of coffee is going to make it harder for you to learn and study, fear not. As it stands, there’s only good things to be said about the positive impact on memory. 


Sadly, there is always a but when it comes to something with no drawbacks. Earlier, we mentioned that you have a 400mg limit per day of how much caffeine you can take in. While that is still a lot of caffeine, you will find that exceeding this dosage on a regular basis will have problems for the body and mind.

One of the most common problems that you might feel is a sense of foggy mindedness. When you are exceeding that 400mg level, your body is now entering a state of mild flux. Therefore, while it will help you to perform at a higher level until the coffee wears off, when it does you will pay for it. Often, something that you could easily remember amid your coffee rush will become very hard to pinpoint. It can make you feel incredibly frustrated, as you are unable to tap into the knowledge that you need and want.

If you get used to exceeding that 400mg level, then you will start to suffer from regular coffee withdrawals. Only when you start to go over the recommended level, though, will you suffer from this negative side-effect of coffee on the brain.

So, will I lose my memory if I keep drinking too much coffee?

Oh no, that isn’t the cast at all!

You will, though, find it harder to pluck the answer that you need from your mind. When you feel foggy minded, too, you can start making mistakes, conflating one thing with another. This problem, though, is a temporary affliction. You will be able to recover from that – either with another coffee or a prolonged rest.

As ever, it’s recommended that you take it easy with your coffee intake. We don’t recommend that you push your coffee intake beyond 400mg and recommend that you try to stay under that limit. This can help to limit the effects of coffee on the mind, such as a short-term lack of clarity in your thinking once the excess wears-off.


Paul Mason

coffee blogger

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How long does caffeine stay in my system?

Typically, the coffee that you take won’t kick in right away – though it might feel as if it does. Instead, you can find that it takes around 45-minutes to an hour. However, that caffeine intake will last for many hours – with some caffeine hits lasting as long as six hours!

If you keep on drinking coffee throughout the day, you will start to feel the impact on your body and mind. It will mean that you are topping up the hours that the caffeine has to work on our body. Try and balance out when you drink your coffees then; some of us can have two in an hour. That’s not good!

Also, try and put in a regiment to ban drinking coffee after dinnertime. If you do this, you are far less likely to feel wired as it comes towards your bed-time. If you do need to have a coffee, then try and switch to something a bit more easy-going for a coffee drink at night or try to get a decaffeinated brand that you like the taste of. This helps you to enjoy the idea of having a coffee without the caffeine.

The long-term impact of coffee on the brain

Now, we’ve warned you so far about what can happen if you overdo it with coffee. While a foggy mind can become a common trait in the short-term, constant excessive coffee intake without pause will eventually lead to some worrying long-term problems. The body needs rest, and with the effect of coffee on the mind halting that rest, you can certainly pay for that. Here, then, are some of the long-term side effects that coffee could have on your system when consumed in excess:

  • A sense of anxiety and uneasiness cause by the up and down nature of your mind-set when drinking large amounts of coffee.
  • High blood pressure caused in part by the inability to get rest and that sense of anxiety that you feel.
  • Poor sleeping standards and an unregulated sleeping pattern, further reducing your chances of being able to rest and recuperate accordingly.
  • Indigestion and heart burn can become a common problem for coffee drinkers in excess, too, so keep that in mind if you suffer from these issues.

As ever, if you suffer from any of these issues then you should look for medical assistance. More importantly, you should try to cut down on your coffee intake – at least temporarily.

Does coffee influence my mood?

One thing that you will likely notice is that when you drink coffee, you tend to have a change in your mood. Why? Because you feel more alert, you feel more alive, and you feel more energised. You’ll start being more productive and you’ll be able to really make a big change to the kind of tasks you can complete on any given day.

However, given what coffee does to our body – essentially closing down our ability to feel tired – we often feel quite nervous. Some of these feelings, though, are a minor placebo. We read that this is how coffee should make you feel, so we allow ourselves to feel that way. Caffeine will normally give you that nice kick and lift – but only when you need it.

For example, ‘stacking’ caffeine benefits is hard work. You can’t just drink two, three cups of coffee in a short space of time and get a triple lift. When you feel fatigued and low on energy, you are much more likely to need the rush. When you are already buzzing from a cup of coffee, though? You likely won’t feel anything like the difference you would expect.

If you continue to drink coffee when you already feel energetic, you are merely delaying the withdrawal symptoms that you would feel – prolonging the inevitable, basically. You should always look to keep this in mind, as it can have a big impact on your day-to-day mood and performance. The bottom line, then, is if you already feel anxious, a coffee will not settle that!

Why does coffee lift my performance levels?

You will have noticed yourself how coffee can lift your spirits and boost performance in many ways. You will be likely to be more alert, more likely to take in details and be quicker to respond to information and actions that need your response. The problem is, though, that many people make the same mistake mentioned above.

Studies in the past have shown that, after that first 100mg of coffee in the day (which kicks your performance levels much higher), the future performance boosts afterwards tend to be minimal. As such, if you want a consistent boost during the day, it’s better to space out your coffee intake by several hours. The interesting paradox, too, is that, since coffee is a drug, you might merely be staving off your addiction and cravings.

Many of us see drinking 3-4+ cups of coffee in a day as a way of improving performance. However, it might merely be levelling you out to avoid the performance recession you would feel by going through withdrawal. Therefore, instead of boosting performance, your addictive side might merely be performing at what you would if you never drank coffee at all!

These small but significant factors need to be considered. For many people, the effects of coffee on the mind and performance are subjective. If you were to evaluate your performance with and without coffee (prior to being addicted, where you now need coffee to work to your normal capacity), you’d likely find some very interesting disparities.

Coffee and brain entropy

When we hear the word entropy, we often associate it with chaos and disorder. So, when you hear that coffee could cause something known as ‘brain entropy’, it can feel quite worrying. What you should do, then, is read this quick section.

Brain entropy is a good thing, not a negative. We all assume that our mind should be like the ideal filing cabinet: compartmentalised, incredibly organised and arranged into the most studious format possible. However, a chaotic mind is often a more powerful mind. A 2018 study found that, in a study of 892 people, that higher levels of brain entropy produced what was defend as ‘higher intelligence’. This entropy was found in major parts of the brain, like the inferior temporal lobes.

This means that our brains can work with unique thought patterns and allows us to come up with new solutions. If we all have the same organised mind, we’d come to the same conclusions. This would stifle innovation and limit our ability to create better, safer ways to enjoy our lives. In fact, the study showed that the minds with the least entropy tend to belong to those who are in deepest, longest sleeps. Who wants to think like they are in a deep sleep?

So, when you hear someone say that coffee and caffeine can cause brain entropy, don’t panic. By improving blood flow to parts of the brain, including the lateral prefrontal cortex, we boost our ability to come up with new ideas, to innovate and to think outside of the box. Free from being stuck with only conventional solutions, you can come up with more radical and impressive ideas.

Don’t panic when you hear that your cups of coffee create entropy. Still, don’t try and push your mind to some new level of zen by drinking multiple cups of coffee. Like any other part of the relationship between caffeine and the mind, it can only do so much: and most of the good work comes from that first cup!


What are the effects of caffeine on the body?

Since you can now relate to the impact of coffee on the mind, let’s take a brief look at what you might feel physically. While your mind is whirring, you might start to notice a few common symptoms – especially if you overdo it with the coffee. Some issues you might feel include:

  • A sense of alertness that leaves you able to react faster to physical issues i.e. dropping items, opening doors.
  • Improved pace of operation, allowing you to get through the working day with more efficiency and clearer results.
  • However, you might also begin to feel like your muscles are aching and you have general aches and pains throughout the body. This comes from the coffee crash.
  • An increased heartrate is common, too – you might find that your heart feels like it is racing. If this continues for a prolonged period, seek medical assistance.

A warning about coffee and bone health

There is, though, one major red flag that we want to address. When you drink coffee, your body is no longer capable of absorbing calcium into the bones to the same level. This would naturally increase your chances of bone damage, fractures and breaks. It would also increase the chances of osteoporosis.

If you are suffering from excessive bone aches and pains, we recommend making an appointment with your doctor. They can check your calcium intake and recommend lifestyle changes to improve on this problem.

So, should I get rid of my kettle?

No, of course not! The effects of coffee on the mind (and body) aren’t as damaging as they are made to sound. In fact, it offers us the kind of lift and boost that we need to give it 100% and really attack the day. Like anything else in life, though, too much is going to have long-term negative impacts on our health.

Your body and your mind deserve to be treated correctly. Given the fact that coffee is the most commonly consumed drug in the world, then, it’s not something you need to worry about. When taken in moderation, the effects of coffee on the brain can be very rewarding. Just try to limit your coffee intake – quality over quantity is essential.

Coffee, due to the ease in which we can get hold of it, is often treated as harmless. Coffee has many benefits, but the drawbacks we’ve mentioned above are real indeed. Keep that in mind, and you’ll be much, much more likely to enjoy your coffee and benefit from its rewards. Drink too much of it, though, and you’ll feel the consequences long-term.

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