Tea

Positive aspects

Stimulates the nervous system, clears congestion, prevents certain cancers and wards off heart disease.

What makes a 'Tea'?

Technically, any concoction of plants steeped in water is a tea. However, when most people say "tea," they mean the bracing brew beloved by everyone from Asian peasants to the English aristocracy: the fragrant leaves of an Asian evergreen shrub called Camellia sinensis.

Medicinal properties

Research suggests that tea, especially the green tea popular in the Orient, may have beneficial actions against heart disease and cancer.

Tea contains several stimulant compounds, including caffeine and theophylline. An average cup of tea contains between 10 and 50 milligrams of caffeine, depending on the type of tea and the preparation method. Both caffeine and theophylline act as bronchodilators, agents that help open clogged respiratory passages.

Benefits

Recently, scientists have been finding that tea may offer broader health benefits. Mostly, their research has been on green tea, a type more popular in the Orient than elsewhere, where black tea is the leading seller. Green tea supplies generous amounts of substances called polyphenols, including one called catechin. Black tea leaves, which undergo an added process of fermentation, contain less catechin. There is a small but growing body of evidence that the catechin and some related substances in green tea may have cancer-fighting properties.

It is well established that moderate tea drinking does no harm to the heart, and it may do some good.

Japanese researchers found that green tea polyphenols seemed to lower blood cholesterol and blood pressure in laboratory animals. Researchers have also found that tea is a mild diuretic, helping to rid the body of excess fluid.