People have enjoyed caffeinated drinks for many years – with tea being no exception to this fact. The earliest record of caffeine consumption dates back to at least 2700 B.C., when Chinese Emperor Shen Nung drank hot brewed tea.

Caffeine is a naturally occurring substance found in the leaves, seeds or fruits of at least 100 different species worldwide and is part of a group of compounds known as methylxanthines. The most commonly known sources of caffeine are coffee, cocoa beans, cola nuts and tea leaves.

Tea also contains other dimethylxanthines; theophylline which has similar properties to caffeine and theobromine whose pharmacological actions is far less potent than caffeine and theophylline.

However, the amount of caffeine present in your cup of tea depends on the serving size and the preparation method.

Caffeine levels of tea as consumed in the UK have been determined in a recent survey conducted for the FSA Food Surveillance Unit.i In this survey caffeine in a serving of tea, as brewed by adults in the UK, was found to be typically 33mg in a 190ml cup. This compares to an earlier estimate of 50mg per cup, which was based on laboratory-prepared beverages.

Despite recent publicity about caffeine, the fact remains that the consumption of caffeine at intakes of 300mg/ day has no adverse effects in the vast majority of the adult population. For this reason an average intake of three cups of teai a day is well within the level considered safe.

[tags]tea, caffeine[/tags]