Are you like me in that some days you just can’t get going? I feel as though I’m dragging my proverbial and this usually is as a result of coffee deprivation. I need at least two cups of cappuccino to kick start me into action. Do you empathize with me? So why is it we need this caffeine fix to perk us up in order to face the day?
All we need to do is to tweak our neuro-chemistry. Our brains are incredibly amazing and some of our neuro-impluses are faster than the fastest computer you can find. Maybe one day the computers may catch up. Within our brains there are many different chemicals known as neurotransmitters. Examples of some of these neurotransmitters are: adrenaline, histamine, dopamine, etc. These are the ‘languages’ of the nervous system along with electrical signals sent down the neurons. In other words, they are the means by which each neuron communicates with others to process and send messages to the rest of the body.
In addition, there are specialized areas on cells and neurons known as receptors. Each neurotransmitter has a specific receptor site. It is on this receptor site that a neurotransmitter can bind to and produce a specific response. It is a bit like a key that fits into a lock and unlocks it. However, sometimes a key can fit a lock but it cannot unlock it. This is how caffeine has its effect. Let me explain a bit more.
Forget the coffee for the time being and lets see the normal state of mind. In the brain there is a neurotransmitter known as adenosine, which will bind with adenosine receptors and produce an inhibitory effect on the central nervous system (CNS). It tries to slow and calm you down. The longer you are awake, the more adenosine becomes available to bind to these receptors. You are now so chilled out that eventually you fall asleep!
But the uncanny thing is that caffeine can also bind with these adenosine receptors. Because caffeine is sitting at the adenosine receptors and blocking it, adenosine cannot get to its own receptors to do its work. So this disrupts the natural monitoring of the adenosine activity by the nervous system. This is because the chemical structure of caffeine is quite similar to adenosine structure but not similar enough to cause the same effect. It is the key that can fit into a lock but can’t unlock it. While the false key is in the lock, you can’t put the actual key in. Similarly, the caffeine will block the adenosine receptors so that adenosine cannot get to the receptors. So the adenosine is unable to carry out its normal function of inhibiting the nerve activity. The opposite happens. Since there is no adenosine on the receptor, the nerve activity is speeded up. This in turn improves your reaction time. Now, because adenosine is blocked, it also activates the release of our natural stimulants like dopamine and glutamate, which are normally kept in check by adenosine. This sounds great, but the reality is that it has a knock on effect on other neurotransmitters and organs within our bodies. At the base of the brain, there is a small gland, about the size of a pea, known as the pituitary gland. Although tiny, it is hugely important. It acts as a sensor and controls many of the activities in the body. It releases many hormones to keep everything functioning properly.
The pituitary gland will sense the extra activity due to caffeine and will assume that there is something going on, maybe there is some danger! So it responds by releasing adrenaline. You have heard of adrenaline rush when you are scared, excited or performing a demanding activity like Bradley Wiggins has been during Tour de France! The adrenaline release will dilate your pupils; you start breathing deeper to take in more oxygen and the heart beat increases to circulate this extra oxygen. At the same time, the liver starts to release more glucose to raise your energy levels to meet the demands of extra activity.
At a neuro-chemical level, another neurotransmitter called dopamine is released in response to things like caffeine, food, sex etc. Dopamine creates a feeling of pleasure, very similar to that of amphetamine, cocaine or even heroin but to a lesser extent. Hey, you are on a natural high!! Similar to cocaine, caffeine can be addictive, but obviously not to the same extent as these drugs. Scary eh? The more pleasure or satisfaction you get due to dopamine, the more you desire it. To satisfy that desire the person will repeat behaviors that cause the release of dopamine. However, your body becomes tolerant to these pleasure-giving stimulants and so more and more caffeine is needed to produce the same effect of stimulation from your excitatory neurotransmitters. In other words, you have formed a ‘tolerance’ to caffeine.
I think if coffee was invented today, there is a great possibility that it could be a banned substance! So, this is how coffee makes us feel alert and ready to take on the day and why we crave that caffeine fix. We get withdrawal symptoms if we stop drinking coffee, which manifests itself as headaches, fatigue and irritability. This is why it is so hard to give up coffee and takes about 10 to 14 days before you stop feeling absolutely rotten without it!