Caffeine is a stimulant drug found in varying quantities in the seeds, leaves and fruits of some plants. In this state, it acts as a natural pesticide by paralysing insects that feed on the plants.
It is the world's most widely consumed psychoactive drug.
Humans consume it in large quantities through tea, coffee, soft drinks and energy drinks, and also in chocolate. It takes about 20 minutes for caffeine to enter your system, and the effects can last up to five hours.
Reasonable amounts can affect you by acting as a central nervous system stimulant. It can restore alertness and reduce drowsiness for a limited period of time. It can also produce faster and clearer flow of thought, increased focus, and good body coordination. While this is a positive effect, if taken close to your regular bedtime, the stimulant action may affect your sleep. It is also a diuretic, so you will pee more when using it.
Caffeine is very addictive. Regular use leads to increased tolerance, which means that over time you will get less effect from the same quantity. Addicts will experience withdrawal effects when they stop drinking it – irritability, nervousness, restlessness and sleepiness. Ordinary consumption can have low health risks.
So why is this addictive psychoactive drug freely available?
The US Food and Drug Administration has classified caffeine as ‘generally recognised as safe’. Part of their reasoning is that toxic doses of over 1 gram, for an average adult, are much higher than typically used doses (less than 500 mg).
Can I use caffeine to help keep me awake?
Most people don’t use caffeine as effectively as they could. We tend to drink it when we are not really tired, which means the stimulating effect doesn’t have the impact we need.
A good example is when instructors take a coffee break between appointments; often as a habit but may be the early signs of caffeine addiction.
To use caffeine effectively, we need to be strategic about when we drink it. Here are a few tips that might give you an advantage:
- Avoid drinking caffeinated drinks when you are not tired. You could be building a tolerance to it.
- Avoid drinking caffeinated drinks in the morning. You should be more alert and active when you wake up and caffeine at this point could increase the risk of tolerance. One exception may be if you have a really early start in the morning.
- As we mentioned, avoid caffeine as you head to bed. The stimulant action can make falling asleep and staying asleep more difficult.
- If you do drink caffeinated drinks, increase your water intake to counter the caffeine’s diuretic effect. You might have noticed that you need to pee more when you drink caffeinated drinks?
- Be aware of how much caffeine is in different foods and drinks. See the table below.
Level of caffeine in common substances (typical dosage approximately 500 mg)
Coffee (250 ml)
- Instant 65 – 100 mg
- Brewed 115 – 175 mg
- Espresso 100 mg
Tea (250 ml)
- Green tea 8 – 30 mg
- Normal 50 – 70 mg
Caffeinated beverages (250 ml)
- Coke 50 mg
- Red Bull 80 mg
Most chocolate bars
- Approximately 20 – 40 mg
Simply put, the less caffeine you take, the more effective it will be when you need to use it to help you stay awake.