All about caffeine

Caffeine, the world’s most popular stimulant, is found in half the beverages we drink. Whether you can’t get enough of the stuff, or barely touch it, it’s important to know how it works, and how it can affect you. There are a couple of things to remember, including the fact that caffeine can have withdrawal effects and impact on your health if you have too much.

You should keep reading if:

  • You drink coffee or tea
  • You drink energy or soft drinks
  • You eat chocolate
  • Anyone close to you does any of the above
three teen girls relaxing and drinking coffee

What is caffeine?

Though many people start their day with a coffee, or drink cola with their lunch, very few know exactly what caffeine is. Caffeine is actually a stimulant drug which makes the central nervous system in your body speed up the messages to and from the brain. It is a substance found in the leaves, seeds or fruit of a number of plants, such as coffee and tea plants. A wide range of food and drinks contain caffeine, including chocolate, soft drinks, energy drinks, tea and coffee. It can also be taken in capsules, tablets, or powder form. 

How much caffeine is in popular beverages?

The approximate amount of caffeine found in coffee, tea, chocolate, cola, energy drinks, and caffeine tablets is listed below. How much caffeine is in your favourite beverage?

 Product  Caffeine content
 Typical tablet  100mg
 Cup of instant coffee*  60-80mg
 Cup of brewed coffee  60-120mg
 Cup of black tea  10-50mg
 Can of cola 375ml  80mg
 Red bull 250ml  80mg
 'V' 250 ml      80mg

*amount of caffeine depends on the type of coffee bean and size of cup

Caffeine Effects

The effects of caffeine differ from person to person, depending on your age, body size and general health. If you are pregnant, consuming caffeine might effect your pregnancy, so talk to your doctor about how much caffeine you consume. There are short and long term effects on caffeine consumption, but if you regularly have caffeine you might have different reactions than if you have caffeine only occasionally.

Short-term effects

Caffeine takes 5-30 minutes to circulate around the body. Small to medium amounts of caffeine, up to 300mg, can speed up the brain and the central nervous system so that you feel more awake. It also increases your concentration and alertness. However, caffeine isn't a substitute for sleep.

Long-term effects

Some research has shown links between heavy use (more than 350mg) of caffeine and high blood pressure, heart disease, heartburn, ulcers, severe insomnia and infertility. 

Can you overdose on caffeine?

If you consume too much caffeine it is possible that you might have serious health consequences. Consuming a huge amount of caffeine can even be fatal in extreme circumstances however, this is very rare. A person would have to consume 5-10 grams of caffeine (or 80 cups of strong coffee, one after the other) to have an overdose.

Caffeine addiction and withdrawal

Caffeine is considered addictive. It causes withdrawal symptoms after you stop after having it regularly (most commonly headaches) and you can experience cravings when you stop having it. Regular users can also become emotionally and mentally dependent upon their daily caffeine (coffee, energy drinks, etc). Withdrawal usually last for only a few days and is minimal if you reduce caffeine gradually.

Things to remember

Often caffeine pills or energy drinks such as No Doz or Red Bull are taken by people during exam or study periods in an effort to stay awake and alert to study more. But it's important to remember that caffeine isn't a substitute for a proper nights sleep and really doesn't help you in the long run. At the end of a study period if you've had heaps of coffee you might find you have difficulty sleeping or that you are moody and irritable. You may also experience headaches.

What can I do now?

  • Keep track of how much caffeine you consume in a day.
  • If you want to cut down, reduce your intake slowly.
  • Avoid consuming caffeine at night time to prevent it from affecting your sleep.
Last reviewed: 06 August, 2015
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