The effects of caffeine on last minute revision

Now the dissertation dash may be over but there are unfortunates among us who still have to deal with exams. As a result you’ve traded writing your essays for the constant and repetitive task of revision, spending so much time in the library you actually have an assigned seat and overdosing on coffee. So how does coffee get you through these hard times? As you pop the next Pro-Plus and contemplate buying your fourth Red Bull of the day, here’s how it works.

The essential ingredient in all these products is caffeine. Discovered in 1819 by Friedrich Ferdinand Runge, it is essentially a Central Nervous System stimulant. Caffeine can promote alertness and wakefulness which makes it such a great ingredient to give us the top up of energy needed to read through those last lectures. Caffeine is metabolised by enzymes in the liver and creates alkaloids (compounds with basic nitrogen atoms) which can have different effects on the body. One of these – Paraxanthine – increases the breakdown of fat (which is why caffeine is often used in diet pills) thus elevating glycerol and fatty acids in blood which can give us more energy. Theobromine dilates blood vessels while Theophylline relaxes the smooth muscle of lungs and is used to treat asthma.

More to the point, caffeine can cross the blood brain barrier. This means it can directly act upon cells in the brain when ingested. Primarily, it acts as an antagonist of adenosine receptors. Adenosine is composed of an adenine molecule attached to a ribose sugar molecule. It plays an important role in energy transfer and is also believed to promote sleep. By and large, adenosine has an inhibitory effect on the nervous system. It acts to protect the brain by stopping neuronal activity and increasing blood flow. As an antagonist, caffeine counteracts this defence. Although we are not exactly sure yet how this mechanism creates attentiveness, it definitely hinders neuronal rest. Interestingly, caffeine can also act on adenosine receptors in other tissues than the brain, effectively blocking the production of energy in the body. It could be said that caffeine is keeping our mind awake whilst blocking energy production in our bodies. Is that really effective?

There are obviously counter indications to large amounts of caffeine ingestion. Overuse can create an addiction as well as conditions such as nervousness, insomnia, headaches and heart palpitations. In extreme cases, a caffeine overdose can lead to extremely severe biological conditions and sleep disorders. But it has been shown to decrease the risk of developing Parkinson’s disease in men.

Overall, a moderate consumption (around 300 mg per day) of your favourite caffeine fix won’t hurt but beware of overdoing it! Necessary amounts to induce a reaction vary according to size and height but usually, caffeine takes less than one hour to start working and should last in your body up to four hours.

Caffeine content:

Cup of drip coffee = 115-175 mg

Espresso = 60 mg

Instant coffee = 65-100 mg

Can of Red Bull = 80 mg

Can of Coca-Cola = 34 mg

ProPlus tablet = 50 mg


One thought on “The effects of caffeine on last minute revision

  1. Thanks for this article.I am unfortunate to not being able to drink anything with Caffeine in it, just a sip of decaf makes me feel dizzy and my heart palpitate, my symptoms with normal coffee and coke range from breathing difficulty to fainting!!!But I'm fine with reasonable amounts of chocolate 🙂 Thank God!!!(Found your blog on bloglovin', I am the only other General Science blog!!lol)www.sciencesosexy.blogspot.comI am following you via GFC

    Posted by Esmeralda | December 19, 2011, 1:27 pm

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About me

Natacha is a research scientist and a lover of all things science! She love finding out interesting facts about all aspects of life, whether it’s how genetic engineering works or what the difference between crimped and straight hair is. There’s a bit of science behind every mystery and the Science Informant will help find the clues for everyone to enjoy and understand the amazing world of science!

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