Caffeine is the most popular legal drug in the world. One hundred and twenty thousand tonnes is consumed every year. Coffee and tea are the most popular sources of caffeine. Cola soft drinks, energy drinks and chocolate are other popular sources.

Caffeine can increase the body’s metabolic rate by ten percent. It is quickly absorbed, reaching maximum concentration within an hour. Caffeine can increase the heart rate and the rate of blood flow through the lungs.

Caffeine has been shown to make a person more mentally alert, including an improvement in mental speed-related tasks, but it can cause insomnia.

Drinking three cups of coffee per day can improve memory. It is possible it can help in Alzheimer’s disease.

Decaffeinated coffee contains about 2mg of caffeine, brewed coffee has about 95mg. Black tea contains 47mg of caffeine but tea contains an enzyme which counteracts the jitters, which you get from drinking too much coffee.

Tea contains antioxidants and is the latest healthy drink. Green tea is especially in favour, although like anything else, moderation is the key.

Energy drinks like Red Bull have 76mg of caffeine, while coke has 34mg per can. Children should not be drinking Red Bull or other energy drinks with caffeine, as caffeine is not a suitable stimulant for children.

Caffeine is a stimulant and is sometimes used in weight loss. Sadly, it is not a good choice as it temporarily increases the metabolism but over time your body resists its effect and it can slow the metabolism. It is also addictive. Products like diet coke are great for their producers because customers drink it to control their weight, become addicted and need more to get the effect. For weight loss, it is recommended you follow a healthy eating and exercise program and do not go for the quick fix.

Too much caffeine can cause the jitters, heart palpitations, blood pressure increase, insomnia and eventually fatigue. Caffeine is addictive and your body becomes adjusted to the dose so you crave more. Withdrawal symptoms are usually a headache and feeling of unease, nervousness and sleep difficulties.

It is a good idea to have some caffeine free days. If you have withdrawal symptoms, you should consider cutting down on the quantity you drink daily.

Caffeine can be useful, especially if you have to think clearly and quickly in an emergency, but it is not a good idea to become dependent. Like any other drug, it has its good points and its bad.