Has stimulating, alerting and diuretic properties.
"Black tea" is the name given to tea leaves subjected to a particular processing and from the infusion of which a dark red drink, also called black tea, is obtained. Black tea is more oxidized than oolong, green and white varieties.
While green tea loses its flavour in one year of storage, black tea retains its properties for several years. For this reason that since the 19th century, when it even took on the role of currency, it has been sold in the form of compressed bricks, in Mongolia, Tibet and Siberia.
Typically native to India and Sri Lanka, from where it is exported a bit all over the world, black tea generally has a stronger and more decisive flavour and aroma than less oxidized teas.
Black tea is also rich in theophylline, a substance similar to the one just described which is used - in much higher concentrations - in the treatment of asthma and bronchitis.
Theophylline, in fact, promotes bronchial dilation, improving - among other things - the contractility of the diaphragm and other respiratory muscles.
Black tea, like other varieties, is also rich in polyphenols.
Polyphenols are nutritional factors with antioxidant action, which prevent cardiovascular diseases and tumours.
Black tea also contains tannins, which have many of the metabolic characteristics of generic polyphenols.
In addition, tannins boast astringent properties because they reduce glandular secretion in the intestine by fighting diarrhea.