7 surprising facts about caffeine and sleep

As I sit typing I am slurping on my favourite tipple. Along with millions of people worldwide one of the first things I do in the mornings is pour a steaming cup of coffee. Just the aroma alone makes me feel in a better state to face the day, and I couldn't imagine lasting a whole 24 hours without at least one mug of Joe. Over recent years coffee drinking has exploded in this country and it's estimated that we spend over £900 million per annum on the stuff. But do you ever consider what is lurking in that smooth brown liquid you are guzzling? What is it about coffee that makes it so appealing?

Modern life is increasingly hectic and we all seem to be in a permanent state of semi-exhaustion. One way many of us try to cheat the system is by perking ourselves up with a cheeky coffee. Caffeine is a natural substance found in coffee beans (as well as tea and cocoa beans) and its ability to help keep us awake is well known. However have you ever stopped to think how this happens and what other effects it might be having on our internal clock?

Here are a few facts about caffeine that may make you ponder over your next Americano.

Fact 1: Caffeine stops us feeling sleepy. This happens because caffeine is able to mimic the behaviour of a brain chemical called adenosine. Normally adenosine molecules will bind to adenosine receptors, causing drowsiness and inducing sleep. Caffeine is able to trump the adenosine molecules and fix onto the receptors instead. When the caffeine molecules block the adenosine receptors, the feeling of drowsiness is prevented and we remain feeling alert and awake.

Fact 2: Caffeine has also been show to make you faster at completing certain tasks, especially when tired. However the effects of this wear off if you are a frequent coffee drinker as tolerance to caffeine quickly sets in.

Fact 3: The effects of caffeine start after 30-40 minutes after it's been drunk, but can last for over six hours.

Fact 4: Although caffeine can be useful in keeping us awake, there is a payback. Studies have show that after drinking caffeine our sleep is both shortened and more disrupted. Researchers have also found that the ratio of deep sleep to light sleep is disordered; so not only is our sleep briefer and more fitful but also of poorer quality.

Fact 5: These effects are felt more strongly in middle age than in your 20s. That may explain why once people hit 30 they seem to stop drinking coffee after dinner!

Fact 6: Some of us are definitely more susceptible to the effects of caffeine than others. People who don't usually drink caffeinated drinks will notice more obvious effects from it, and recently a gene has been identified which makes certain individuals more sensitive to the powers of caffeine.

Fact 7: Just this week a study was published which shows that caffeine not only keeps us awake but also can reset our internal clock by up to 40 minutes. It is thought that this new information may prove useful in the future for dealing with jet lag as well as other sleep disorders.