In a previous article we discussed the risks of caffeine, but what about the benefits? On the whole, we drink a lot of coffee. Mostly we drink it in the morning because we think it helps us wake up for the day. Or, we drink it ahead of an important assignment because we think it improves our cognition. But where does coffee come from? How does it work? Does it make us smarter? What is the evidence for either of these claims? We know we work harder and faster, but have you ever wondered why? Put the kettle on.
The early history of coffee is as murky and unclear as a strong cup of Americano. Coffee beans come from the berries of a plant native to East Africa. Ethiopian herders are thought to have first started to cultivate the bush about a thousand years ago. They might have noticed that the berries gave them a boost to their energy. They did not brew the cherries, but put them into balls of animal fat and chewed them. Eventually, the plant reached the Arab Peninsula via trade with, the Mamluk and Ottoman Caliphates prior to the 15th century. Further trade a century later introduced it to Europe via Italy at which point we also began to cultivate it, breaking the Arab monopoly.
Chemistry of Caffeine
Coffee contains caffeine, a plant-derived chemical originally synthesised as a pesticide; its effects and those in the same group (xanthines) kill, paralyse or otherwise poison insects and small mammals. Fortunately, the effects in humans are scaled down (unless you drink 4 cans of Monster in 24 hours). Nowadays we drink coffee because the caffeine it contains acts as a stimulant and so it is supposed to be accordingly performance-enhancing.
With this in mind, coffee might be the most widely consumed psychoactive drug with 55 million cups consumed in the UK per day. Up until 2004, the International Olympic Committee had caffeine on its proscribed substance list . Caffeine affects a broad set of areas within the body. In your cardiovascular system, it speeds up your heart rate and makes it beat for forcefully. It impacts your central nervous system by increasing stress and lowering the threshold at which your motor system (which governs bodily movement) generates impulses to produce movements. These may not sound like good or desirable effects, but let’s examine what this means more closely.
Does coffee make you smarter?
These stimulating effects of coffee have clearly been known for a while, hence its deep-seated popularity. After it is absorbed in the stomach, it quickly passes into most bodily tissues, including the brain. From here, it activates a series of nervous system chemicals and reactions within cells which exert its effects. Those acting on the heart and producing anxiety are well documented in both humans and animals. Those allegedly enhancing cognition are harder to prove on paper and are as such more controversial.
So how does coffee exert brilliance? The bottom up evidence of this is that caffeine improves performance on simple tasks, especially those based on attention and reaction times. In addition to this, it increases alertness and attention by blocking certain chemicals (adenosine for example) which produce sleepiness. What isn’t clear, as with most mechanisms involving the brain, is where this cognitive improvement evidence meets with the theory of those neurochemical signalling pathways.
Stress, to an extent, improves performance. I say to an extent because after a point, the improving factor drops off. This bell curve was noticed early on in the history of experimental psychology and is termed the Yerkes-Dodson Law. Stress improves performance until the subject reaches the top of the curve, after which point, the increasing levels of stress negatively hit the performance instead. Too much of a good thing… Positive stress is termed ‘eustress’ and negative stress ‘distress’. You may have experienced this in hazardous situations involving looming deadlines or spur of the moment reactions. Caffeine increases stress, by minorly depriving tissues of the heart and brain of oxygen at the same time as activating stress chemicals in those systems. This may be responsible for its potentiating your ability to focus and prioritise your attentions.
And so that is our journey through caffeine. In writing these words, I have experienced its slight effects myself. If you want to give it a try, all you have to do is put the kettle on. It is certain that coffee wakes you up; it beats back chemicals which put you to sleep as well as powering up your heart for action. It may also help you concentrate and study more effectively, though too much will tip you over the edge into anxiety and the jitters. This is just an examination in the short term. The long term use of coffee produces all sorts of strange powers; by prolonged use, it may prevent diseases of the nervous system such as Alzheimer’s or Parkinson’s, cause hypertension and cardiovascular disease, and of course, it produces tolerance. As before, you can have too much of a good thing. Keeping within safe and sensible limits, I wish you a productive percolated future!
A note from the Editor
Picks up coffee.
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Any opinions above are the author’s alone and may not represent those of his/her affiliations. Any comment is based on the best available evidence at the time of writing. All data is based on externally validated studies unless expressed otherwise. Novel data is representative of the sample surveyed. An online recommendation is no substitute for seeing your own doctor and should not be taken as medical advice. Article proofed and edited for publication by Dr. BM Janaway.
Sources and Further Reading
- Cappelletti S, Daria P, Sani G and Aromatario M. Caffeine: Cognitive and Physical Performance Enhancer or Psychoactive Drug? 2015. Curr Neuropharmacol. 13 (1) 71-88.
- Allegra Project Café UK 2016 Report, December 2015
- Porciúncula LO, Sallaberry C, Mioranzza S, Botton PH Rosemberg DB. The Janus face of caffeine. 2013. Neurochem Int. 63(6). 594–609.
- Einother SJ, Giesbrecht T. Caffeine as an attention enhancer: reviewing existing assumptions. 2013. Psychopharmacology. 225(2). 251-74.
- Yerkes RM, Dodson JB. The relation of strength of stimulus to rapidity of habit-formation. 1908. Comparative Neurology and Psychology. 18 459-82.
- Nathanson JA. Caffeine and related methylxanthines: possible naturally occurring pesticides. 1984. Science. 226 (4671): 184–7
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