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caffeine; drug; stimulant; coffee; tea; chocolate ;


What is caffeine?

Caffeine is a chemical.

caffeineCaffeine is a  drug because it has an effect on the body.  It acts as a stimulant - that means the brain and nervous system speed up.

It is found in many plants from all over the world. Here are a few that you probably have already come across.

  • Coffee beans.
  • Tea leaves.
  • Kola (cola) nut.
  • Cocoa beans (used to make chocolate)

What caffeine does

Caffeine stimulates the central nervous system.

Small amounts lead to:

  • feeling more awake
  • your heart beating faster
  • your blood pressure going up
  • making more urine (wee)
  • having more stomach acid.

caffeineLarger amounts lead to:

  • feeling restless and anxious
  • having trouble getting to sleep
  • not getting enough deep sleep and dream sleep (if you have caffeine before going to bed).

Having a lot of caffeine every day can lead to sleeping problems, stomach problems, feeling worried or depressed.

Stopping drinking coffee

Some people get dependant on coffee and they can have withdrawal symptoms like headaches and feeling sick if they stop having caffeine. These symptoms last only a few days.

Where you get caffeine

Most adults drink tea or coffee. These are the amounts of caffeine in average cup sizes (there are two amounts because it depends how strong you make it).


  • Filtered coffee             200-250mg of caffeine.
  • Percolated coffee:         100-150mg of caffeine.
  • Instant coffee:             60-100mg of caffeine.
  • Decaffeinated coffee:     2-4mg of caffeine.


  • Tea: 8-90mg of caffeine, but could be more depending on the type of tea.
  • Iced tea: 12-28mg of caffeine.

Other drinks

  • Cola drinks: 30-72 mg of caffeine.
  • Hot chocolate: 10mg of caffeine.

Energy drinks

  • Energy drinks: 150mg or more of caffeine. This is too much for kids.

Even your favourite Chocolate bar (100gm size) has about 10-30mg of caffeine.

Did you know?

  • Caffeine takes between 5 and 30 minutes to start affecting your body and brain.
  • Caffeine has been used by people since the Stone Age.
  • People were drinking tea in 2700 BC, that is 2700 years before the birth of Christ. 
  • People in Central America were making drinks from the cocoa nut for many centuries before Europeans went there.
  • People in Europe started drinking coffee around 1600 AD.
  • People in North America started eating chocolate bars in 1876.
  • For about 300 years doctors and scientists have been studying the health effects of caffeine in our diet. They have found that caffeine does not cause damage to the body and does not cause cancer. But drinking too much does cause problems such difficulty getting to sleep and irritability.
  • Many young people drink cola and energy drinks - but be aware that these drinks contain lots of sugar too and often too much caffeine.
  • Caffeine is found in the leaves, seeds or fruit of more that 60 plants. Some people still chew the leaves of plants that have caffeine in them just as people did thousands of years ago.

Dr Kate says:

Dr KateHas someone in your family ever said to you, "You're too young to have a coffee."  Well, now you know why.

It's a good idea to avoid caffeine when you are young, then your body can do its best job of helping you grow, making sure that you get the best sleep and keeping you healthy.

Maybe someone in your family is getting a bit tired and grumpy because they are not sleeping well? Check up on their caffeine intake. You could be doing them a favour.

Caffeine makes you "hyper",
It makes blood pressure high
It will make you stay awake
Your sleep time it will take
You can make this stop
Don't have caffeine after 2 o'clock

Caffeine, caffeine, it's everywhere
It's over here it's over there.
In chocolate bars and chocolate cake
And choc chip cookies that you bake.

In tea and coffee, cola too.
I drink it and eat it but do you?
Mums and dads have it every day.
If you have too much your body will pay.



If you would like to know more about caffeine visit the Reachout site: How to cut down on caffeine  

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We've provided this information to help you to understand important things about staying healthy and happy. However, if you feel sick or unhappy, it is important to tell your mum or dad, a teacher or another grown-up.


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