Caffeine is the world's most widely consumed psychoactive drug. It can be found in a whole host of drinks, but it's most popular form is coffee, with the UK drinking approximately 95 million cups per day! So in honour of this king of beverages, we decided to collate a collection of caffeine facts for you to enjoy.
Caffeine acts a stimulant to the nervous system, therefore it can make you feel more awake, help you think faster and more clearly and improve your co-ordination.
120,000 tonnes of caffeine is consumed around the world every year.
Finland is the most caffeinated country in the world, where the average adult consumes 400mg or about four cups of coffee a day - that's our recommended maximum daily limit according to the UK Food Standards Agency.
93% of people at work in the UK drink at least one drink with caffeine in it a day.
A cup of instant coffee can contain about 100mg of caffeine while a cup of filtered coffee can contain about 140mg.
The average mug of tea can contain about 75mg of caffeine. Even though tea contains more caffeine than coffee by dry weight, tea is usually brewed much weaker than coffee so a cup of tea contains less caffeine than a cup of coffee.
Some decaffeinated coffee does, despite what it says on the tin, contain caffeine. One study discovered that some brands of decaf coffee contained about 10mg of caffeine per cup.
A cup of green tea can contain about 25mg of caffeine, depending on the brand and how it's brewed.
Cocoa has about 20mg of caffeine in an average cup.
Chocolate made from cocoa beans contains a small amount of caffeine. A typical 50g bar of milk chocolate can contain about 25mg of caffeine. A 50g bar of plain chocolate can contain up to 50mg of caffeine.
Caffeine is present in some fizzy drinks and energy drinks such as cola (40mg a can) and Red Bull (80mg a can).
Caffeine can be a weak diuretic (although this varies from person to person) - meaning that it could make you go to pee more, which can lead to mild dehydration. Caffeine's diuretic effects seem to be less with those who drink lots of it.
If you drink lots of caffeine then be sure to help counteract any negative effects by also drinking plenty of water.
Drinking up to about three or four cups of instant coffee or a couple of cups of filtered coffee in a day (depending on how strong they are) shouldn't cause most healthy adults any harm, but some people are more sensitive to caffeine than others. Caffeine can cause a slight, temporary rise in heart rate and blood pressure and large doses (over three or four cups of coffee) can increase your stress levels and cause lapses in concentration.
On average, it takes about four to five hours for your body to eliminate 50% of the caffeine you consume. 75% of the caffeine will be gone after about eight to ten hours.
Caffeine can interfere with your sleep. Its effects can vary depending on your metabolism and how much you normally consume but, for most people, if you stay off the caffeine from about six hours before bedtime then you won't be affected. If you drink it just before bedtime or throughout the day then the quality of your sleep may be reduced.
Drinking caffeine may make you feel more sober after you've been drinking alcohol but your body's reaction time and your judgement could still be impaired - so don't think it's safe to drive after drinking even if you've had a coffee.
There's no such thing as caffeine addiction, apparently. Addiction to it would mean that you compulsively consume it against your better judgement, rather than chose to have it by your own free will.
But caffeine dependence is a real thing - meaning that you could experience headaches, drowsiness, irritability or lack of concentration if you were to stop drinking it after regularly drinking a couple of cups of coffee or a few or more cups of tea a day (235mg on average).
Caffeinism is a condition where you can experience restlessness, headaches, insomnia, irritability, nervousness and palpitations when drinking too much of it.
Caffeine intoxication can occur if you overdose, causing your nervous system to become over-stimulated.
The Food Standards Agency advises pregnant women not to drink more than 200mg (a couple of cups of coffee) of caffeine a day as it can increase the risk of miscarriage or a baby with low birth weight.
While studies say that up to 300mg of caffeine a day is safe for children, many are sensitive to it and can experience anxiety or irritability. Seeing as most of the caffeine kids consume is from energy drinks or fizzy drinks they also contain large amounts of added sugar - they're definitely not going to be good for children's health anyway.
Caffeine mostly comes from the bean of the coffee plant, tea bush leaves or kola nuts, but it's also found in Amazonian maple guarana berries, South American holly yerba mate leaves and around fifty-five other plants.
Caffeine is a natural pesticide in plants that contain it - killing insects trying to feed off of them.
Chinese legend has it that the emperor Shennong discovered tea around 3000BC when the appropriate bush's leaves accidentally fell in to boiling water. What luck.
Actual evidence of the earliest awareness of the coffee plant and the drink it can produce dates back to Yemen monasteries in the middle of the fifteenth century.
Even though studies have shown that caffeine can stimulate hair follicle growth and improve the condition of hair, these studies were only conducted in the test tube - not on anyone's actual head. Despite this, you can buy shampoos that contain caffeine but it's debatable as to whether this will actually help you grow a full head of thick hair.
There is such a thing as a Spazzstick - a caffeinated lip balm.
It's spelt with an 'ei' not an 'ie'. We always get that wrong (thank heavens for spellcheck).