Most of us drink coffee to be mentally fit, it is a plant alkaloid and it is also a psychoactive stimulant in human beings. It is found in more than 60 plants where it acts as a natural pesticide and paralyses and kills certain insects which are feeding the plants.

The main sources of caffeine are coffee beans of the coffee plant, tea plants, cacao and kola nut and guarana berries, a famous source in South America.

Caffeine from tea is called theine, mateine from mate, guaranine from guarana, but the chemical compound is only caffeine.

Caffeine is a central nervous system stimulant in human beings and it removes our tiredness and makes us alert or fit. This is the reason why the beverages containing caffeine like coffee, tea, soft drinks and energy drinks have much popularity.

To get the effects the amount of caffeine needed per person is different and it depends on weight and tolerance. Caffeine takes approximately 45 minutes to begin the effects and it wears off in three to four hours from a normal cup of coffee. It cannot stop sleep and it is only a temporary relief from the tiredness.

In normal or moderate consumption it has no such effect. Many studies using a concentration of 5.5 mg per kg bodyweight to 9 mg per kg bodyweight are reporting more endurance.

Caffeine can make one addict. If you take 400 mg caffeine three times a day, you can develop tolerance in a week. But my personal experience is very different and there are several people who drink two litres of coffee have no problems and others with moderate consumption have problems. Two to four cups but not extremely strong is enough if you like coffee.

Tea has less caffeine compared to coffee and it is very good.

Here are the values of caffeine in different beverages:

Coffee, brewed, one cup (about 100 ml)…………………around 50 mg
Decaffeinated coffee, one cup (about 100 ml)……………around 3 mg
Black tea, leaf or bag, one cup (about 100 ml)…………..around 30 mg
Green tea, one cup (around 100 ml)……………………...around 15 mg

Coffee espresso, around 50 ml……………………………around 100 mg

Moderate consumption of coffee is not bad to our health.

Coca cola has 96 mg caffeine per litre.

Red bull, an energy drink, has 320 mg caffeine per litre.

If you think of the other sources like chocolates and cacao milk drinks, the amounts may add up to a heavy dose.

The health authorities must be careful so that soft drinks with much caffeine do not come to the market. The dose makes the poison.

Today decaffeinated coffee also tastes so good that many are not in a position to distinguish between the two. Everybody can drink because sacrificing something like coffee is really a punishment.

Children should not drink coffee because the caffeine stays in their blood much longer than the adults.