The coffee world is full of myths, misconceptions and is muddied by marketing. No more true than this is the murky understanding of caffeine.

Let us correct our first issue. Decaf coffee is not caffeine free. Decaf coffee has gone through the process of decaffeination which LOWERS the amount of caffeine although it can retain up to 30% of its original levels. Three decaf flat whites could be almost the same as one normal one. People sensitive to caffeine should not drink decaf before bed.

We all know caffeine can keep you awake, but do we know why? And how long will it affect me?

Adenosine is a central nervous system neuromodulator with specific receptors in the brain. Throughout the day adenosine is produced and delivered to receptors, this creates a natural feeling of sleepiness and starts from the moment you wake up. It is an important tool in the normal function of the sleep process. When the chemically similar caffeine reaches the brain it blocks some of those adenosine receptors. Adenosine has fewer available receptors which reduces the signal to the brain that you are sleepy and slows the rate at which neural activity decreases, keeping you feeling more alert for longer.

Once the caffeine is metabolised you still have those now significant levels of adenosine and they still have a job to do. The now available receptors are bound to by the adenosine and a wave of sleepiness occurs. You know this as a coffee crash.

Caffeine slows the reuptake of dopamine which ignites the pleasure circuits of the brain. This boost of dopamine improves mood but can lead to dependency. Caffeine has the similar effect of cocaine on dopamine, both in fact are classed as psychoactive stimulants. A few squares of dark chocolate contains noticeable levels of caffeine, studies have shown that a significant portion of adults ‘Crave’ chocolate and a higher portion again crave coffee.

Caffeine also stimulates the adrenal gland to produce more adrenaline. This again makes you feel alert but large amounts can create anxiety.

The metabolism of caffeine is dependent on the individual but typically 50% of caffeine consumed is still within the body's system after six hours, 25% is still present after twelve hours. Two flat whites at midday can have the same effect as a single espresso at midnight.

The presence of caffeine at night can have an effect on sleep quality by reducing the amount of time spent in stages 3 and 4 of non REM sleep, the sleep you do have has less restorative effects leading to a heightened sense of sleepiness the next day and of course that leads back to more coffee.

In short, small amounts of caffeine can have helpful effects such as mood enhancement, prolonged alertness, sustained attention and for a short period of time it can reduce feelings of fatigue. It is however important to consider how much caffeine we take on and indeed when in the day we take it on. Having a coffee when you are already nervous or anxious may compound those feelings or it could be just the ticket to keep you going through that boring meeting.

As an unregulated and legal psychoactive stimulant caffeine is often used in the sporting world, especially in high intensity short term events such as sprinting.

Everyone is different and tolerance and the metabolization of caffeine is individual, you can reduce caffeine intake by changing drink choices (speak to us in the shop for helpful info) or swapping to decaf (which we now know doesn't mean caffeine free.

Now when you notice our staff twitching you know why.