What Coffee Does to Your Brain and Body
Many of us rely on coffee every single day in order to wake ourselves up and feel invigorated for whatever tasks lie ahead. Some of us will even refuse to speak to anyone until we’ve had our first cup!
But although we’re happy to guzzle gallons of the stuff, we often aren’t all that sure as to what it is actually doing to our bodies and brains. Coffee gets its kick from caffeine, and caffeine is a drug. So the question you really need to be asking yourself, is whether this is actually good for you. What is this stuff doing to your brain?
Because coffee actually has a profound effect on your brain and body – some of it good, and some of it bad.
Here’s what you need to know.
How Caffeine Works
Caffeine acts on the brain by blocking the action of a neurotransmitters known as adenosine. Neurotransmitters are chemicals like hormones that are released in the brain1, altering things like mood, alertness, and memory.
Adenosine is an interesting neurotransmitter because it is created as a by-product of other processes. Specifically, adenosine is generated during the creation of energy and electrical charges across brain cells. The more we use our brains, the more adenosine builds up. This has the effect of making us feel groggy and tired, acting in unison with external cues such as sunlight to tell our bodies that it is time to go to sleep.
Sleep then goes about clearing out all of that adenosine, which allows the brain to return to optimum performance upon waking.
What gives caffeine its power, is that it has a similar chemical structure to adenosine – so much so that the brain actually mistakes it for adenosine! Caffeine therefore gets attached to the adenosine “receptors,” which them blocks them and prevents them from being affected by the adenosine as normal.
In short, the adenosine stops having any effect in the brain, and you therefore feel far less tired and “groggy.” Your brain fog disappears, you can remember more, and you generally start to function more optimally. Other benefits include improved attention, verbal memory, and better mood2. One study showed that drinking caffeine after studying could even help to consolidate memory! 3
Tolerance and Addiction – The Dark Side of Caffeine
If caffeine is starting to sound like the real “Limitless pill” though, hold your horses! Although caffeine can certainly increase cognitive performance in the short term, it can also have deleterious effects over time.
That’s because caffeine can profoundly alter the structure of your brain.
With repeated use, the brain will react to what it perceives as an increasein adenosine by producing even more adenosine receptors – it’s supply and demand! Thus you start to feel tireder when you haven’thad your morning coffee than you previously would have. Not only that, but it will now take a lot more caffeine in order to have the desired effect.
This is caffeine tolerance, and it’s something that many of us live with on a daily basis. In fact, it has been suggested that the reasonmany of us feel so groggy in the morning, is actually that we are experiencing caffeine withdrawal. That also explains why that first cup of coffee goes down so well!
Coffee = Stress in a Mug?
There are other chemical changes that occur across the body in response to caffeine as well.
One of these is the release of stress hormones such as cortisol and adrenaline.
When you consume caffeine, this causes the brain to become more active in the absence of adenosine. This increased excitability is read by the rest of the body as being a sign that something “big” is happening. Usually, when the brain becomes more active in this manner, it is because we are highly focused on a task, or because we are scared for our lives or stressed about something.
This then triggers a sympathetic nervous response.
To understand this, it helps to think about the autonomic nervous system. This is the part of the nervous system that we have no conscious control over (hence the “auto” in the name). It is responsible for regulating arousal in response to outside events, and this is achieved through two “branches.” Those branches are the “sympathetic nervous system” and the “parasympathetic nervous system.” 5
The sympathetic nervous system is what creates the “fight or flight” response to stress. This triggers the release of cortisol, norepinephrine, and adrenaline from the adrenal glands. That in turn causes the heartrate to speed up, breathing to become faster, blood to become thicker, and vision to become narrower. Blood is also redirected away from the immune system and digestive system, and toward the muscles and the brain. These adaptations are designed to help us survive a confrontation with a predator or competitor. The adaptations are also intended to be short-lived.
The parasympathetic nervous system on the other hand places us in a state of “rest and digest.” This is associated with feelings of contentment and relaxation, triggered by chemicals like serotonin, melatonin, and GABA.
In short then, drinking caffeine has the same effect as seeing a lion in your path, and that’s why you feel shaky, stressed, and excitable. Over-reliance on caffeine might lead to digestive issues, malnutrition, and even a predisposition for getting sick often.
Then there is the issue of sleep. Thanks to the inert adenosine and heightened arousal, it is much more difficult to sleep with caffeine still in your system. Caffeine has a half-life of 5-6 hours, meaning that it takes about 10 hours to pass entirely through the system (though this varies from person to person). Generally, if you consume a mug of coffee at 2pm in the afternoon, then you won’t be able to sleep easily until 12am. Even if you get to sleep, the quality will be disturbed and you won’t feel as refreshed in the morning.
Of course, this can lead to further caffeine use, which can develop into a vicious cycle leading to tolerance and addiction.
And on top of ALL that, stress actually blunts creativity. So while you might be more productive and focused thanks to caffeine, the quality of your work could still suffer!
It’s Not All Bad – The Surprising, and Amazing Benefits of Caffeine
At this point, you might be considering throwing out your coffee supplies!
Before you do that though, keep in mind that caffeine also has a number of very beneficial effects – and is actually very good for you in a large number of ways:
- Caffeine is a powerful antioxidant, meaning that it can protect the cells from oxidative damage and thereby reduce your cancer risk.
- Caffeine has been shown in numerous studies to be neuroprotective – meaning that it can reduce your likelihood of suffering with dementia or Alzheimer’s. 5
- Caffeine increases the metabolism and blunts appetite, helping to support weight loss.
- Caffeine is a popular ingredient in pre-workouts, because it can increase muscle fiber recruitment and max strength.
- Caffeine may permanently enhance mood, motivation, focus, and memory. Why? Because by using your brain repeatedly in a specific way, you can bring about plastic changes that will alter its very structure.
- Caffeine raises gene expression, which means that your entire DNA becomes slightly more “plastic” and can respond better to exercise, learning, and more.
- Caffeine has also been shown to lower the risk
of numerous illnesses and conditions:
- Type 2 Diabetes
- Erectile dysfunction
- Liver disease
What to Do With All This Information
So, coffee isn’t entirely good or bad. What it is though, is a huge factor that influences the way you feel and think every single day. The most important thing then, is that you be conscious with your choices when using caffeine, and that you understand precisely what it is doing to you.
We all respond to caffeine differently. If you notice that you are struggling to get to sleep, that you feel groggy in the morning, and that you keep getting sick… now might be the time to consider cutting back! If you aren’t noticing any of these side effects, then carry on.
Aim to drink all your coffee before mid-day in order to enjoy a restful night of sleep, and take the occasional day off. If you find that difficult, then you might want to reconsider your relationship with the drink.
Remember too, that there are a large number of ways you can get caffeine in your diet. Green tea is a particularly healthy option for increasing your intake of caffeine, for example.
And consider other lifestyle factors too. If you are relying on caffeine every day to function as a normal human being, chances are that you are taking on too much work, or that you aren’t getting enough sleep. Try to address these issues before you start drinking coffee by the gallon.
Ultimately, this is a case of everything in moderation. With a little common sense, coffee can be a brilliant pick-me-up, and a delicious start to the day.
- A Detailed Guide to Your Brain – So You Can Start Hacking It
- Effects of caffeine and glucose, alone and combined, on cognitive performance
- Post-study caffeine administration enhances memory consolidation in humans
- Overview of the Autonomic Nervous System
- Caffeine as a protective factor in dementia and Alzheimer’s disease