Lots of people enjoy drinking coffee or tea as part of their daily routine. Often used to drive away tiredness or increase concentration ahead of a long revision session, caffeine is incredibly popular. But what is caffeine and what should you know about how it works?
Caffeine has been with us since the first use of tea and coffee. As far back as 2737 B.C., legends detailed the first discovery of tea by the Chinese emperor, Shennong. Coffee came on to the scene a while later, in 575 A.D. Coffee beans in Africa were used both as money and food. In the 11th Century, A.D. coffee was consumed by the Arabians.
Caffeine is a naturally-occurring drug, found in the leaves and fruits of over 60 plants. Present in coffee, energy drinks, tea and cold medicines, caffeine is a stimulant. As a stimulant, caffeine increases the activity in both your brain and nervous system. In small amounts, it can make a person feel focused and refreshed. However, in large doses, caffeine causes difficulty sleeping and can make you feel anxious and uncomfortable.
Like other drugs, people can quickly develop a tolerance to caffeine. Tolerance means that your body adapts to the drug, requiring more of it to get the same effect. People who have developed large tolerances to caffeine may experience some nasty symptoms when trying to wean themselves off. These symptoms can include restlessness, headaches, tiredness and irritability.
How caffeine affects the body
The short-term effects of caffeine are felt after 5-30 minutes of consuming it. Some of the effects include an increased heart rate, more energy and greater mental awareness. Every person is different in how quickly they can metabolise (break down) caffeine. Still, the effects typically last up to 12 hours.
Having too much caffeine can leave you feeling very uncomfortable. Some of the symptoms associated with too much caffeine include:
- Dehydration
- Rapid heartbeat
- Anxiety
- Irritability
- Trembling hands
- Rising body temperature
- Dizziness
- Headaches
How much caffeine is ok?
Caffeine can affect you differently to others, depending on a few factors. Your age, body mass, metabolism and health are all factors that affect how much you can safely consume. Current research recommends that adults consume 400mg or less per day. A 250ml instant coffee contains between 80-120mg caffeine and a 250ml cup of tea contains between 65-105mg. Energy drinks can contain 80mg of caffeine per 250ml, but remember that some energy drinks come in cans bigger than 250ml.
There is very little information available for how much caffeine is safe for children under 18. Because everybody develops at different rates, it is not easy to give a one size fits all recommendation. Current guidance suggests avoiding caffeine if you begin to feel irritable and find it hard to sleep or develop stomach problems. Whether it is an energy drink, coffee or tea, it is always wise to track how much caffeine is in your drinks.
Caffeinated foods and drinks can be safely consumed by most people without incident. To learn more about the effects of caffeine and how to be safe with it, visit: https://foodinsight.org/caffeine/
