fbpx Skip to main content

As a medical student at University I must have consumed the equivalent of a small lake of instant coffee.
Battling the demands of essays to be written and information to be memorised, I kept myself going with my trusty kettle and large jar of instant coffee.

By the time I graduated I was so sick of the stuff I couldn’t drink it any more and switched to tea.

It has only been in recent years that I have actually started to enjoy coffee again. But, I still can’t drink the instant sort. It has to be real coffee.

And I have to say; I look forward to my daily mid morning cup. I love the wonderful aroma and savour every last drop.

But does it do anything for our brain in terms of mental performance?

Caffeine has been described as the world’s most widely consumed psycho-stimulant.
How many of us start our day with that cup “just to get us going”?
Apparently 90% of Americans do.

Caffeine is a stimulant. In much the same way as amphetamines, cocaine and heroin are and no I am definitely not recommending those to start your day.
It works on our brain by speeding it up.
So yes, we are more alert when we consume caffeine.

The peak effect on our brain occurs 15 to 45 minutes after drinking the coffee and the total effect lasts around two hours.

How this works, is that in the brain we have receptors for a brain chemical called adenosine. Now, these receptors are unable to distinguish between adenosine and caffeine. So when we have that cup of coffee, the caffeine locks onto the adenosine receptors and blocks the adenosine from being able to exert it’s normal effect of slowing down brain cell activity. So, our brain cells speed up their rate of firing.

The trouble starts when the pituitary gland detects the increased rate of brain cell activity and presumes there is an emergency happening somewhere. This results in the flight or fight response being initiated, with the adrenal glands pumping out adrenaline to fire us up.

So yes we are alert and ready, but not necessarily in terms of improved mental performance.

Once the effect of the caffeine and the adrenaline has worn off we are likely to be feeling more tired and a bit flat.
Time for another cup of coffee to get us going again….. Leading to a vicious cycle being set up. We become addicted to that quick fix we appear to get from drinking coffee. Drinking a lot of coffee will actually make you feel more tired.
We need to remember too that caffeine is also found in tea and cocoa.

Can’t sleep at night? It could be the coffee.

Many people find that they can’t drink coffee late at night as it keeps them awake.
Caffeine has a half-life of 6 hours That cup of coffee you have mid afternoon will leave you still with around 50% of the caffeine in your system when you are going to bed that night. That in itself it not a huge problem. Many of us can get to sleep even with a significant amount of caffeine still in our system.
But remember that the caffeine blocks your adenosine receptors?
We need the adenosine to slow our brain cells down when we want to sleep. The caffeine interferes with your ability to have good quality sleep by reducing deep sleep, which we need for good brain function.

There is some good news about the caffeine though.
It increases our dopamine levels in our brain.
Dopamine is the neurotransmitter, which makes us feel good and happy.
So when I have my mid morning coffee, I am alert and happy too.

Does quitting coffee really give you a headache?

Want to quit or cut down your coffee consumption? That’s fine. Just be prepared for the withdrawals.
You may have heard of people telling you they get a caffeine withdrawal headache if they miss their coffee or try to cut down. That’s because the caffeine causes blood vessels to dilate. Remove the caffeine and the blood vessels constrict, which can cause a nasty headache.
That’s why people who suffer from vascular headaches (caused by blood vessel constriction) use caffeine tablets to take away the headache.
Plus you may suffer from aches and pains, extreme tiredness and depression during the period of withdrawal. But the worst is only for a couple of days.

Researchers at the University of Vermont and John Hopkins School of Medicine published a paper in 2009 demonstrating the physiological effect on our brain of quitting caffeine.
Caffeine withdrawal produced EEG changes, associated with the feeling of fatigue. Cerebral blood flow on ultrasound was also shown to increase. Subjectively those on the study reported feeling sluggish, tired and weary.

So yes it can take several days to get over the worst with reduced alertness and slower reaction times.
But by day 6 or 7 your body will have recovered, your blood pressure is like to be lower, you may have less anxiety, be sleeping better and be functioning mentally just as well as when you had been drinking coffee.

The study revealed that those people who drink coffee regularly have no mental benefit or advantage over those that don’t, despite those of us who like to think it helps give us the edge.

Oh well.

Maybe we should just enjoy coffee and its caffeine for what it is. A stimulant that will give us short term increased alertness and happiness.
We just need to make sure we don’t have so much that we impair our brain fitness and mental performance.

Want to Use This Article?
You can as long as you cite the author Dr Jenny Brockis and the source www.drjennybrockis.com

Dr Jenny Brockis

Dr Jenny Brockis is a medical practitioner and internationally board-certified lifestyle medicine physician, workplace health and wellbeing consultant, podcaster, keynote speaker and best-selling author. Her new book 'Thriving Mind: How to Cultivate a Good Life' (Wiley) is available online and at all good bookstores.

Leave a Reply