Tea is widely considered as a health-promoting beverage, and the beneficial effects generally associated with green tea have been attributed to its polyphenol content, particularly to catechins and their antioxidant activity.
Flavonoids exhibit anti-inflammatory properties; it was confirmed that they can also reduce blood pressure, strengthen the cell walls of blood vessels, and improve the immune system.
Its polyphenolic compounds appear to lower cholesterol levels, improve cardiovascular health and help guard against some cancers. In some studies, tea has been associated with antiallergic action and antimicrobial properties.
Moreover some epidemiological studies have associated consumption of tea with a lower risk of several types of cancer including those of the stomach, oral cavity, oesophagus and lungs.
Antioxidants are important in living organisms as well as in food because they may delay or stop formation of free radical by giving hydrogen atoms or scavenging them.
The ability to scavenge for free radicals by tea polyphenols due to possession of a phenolic hydroxyl group attached to the flavan-3-ol structure has been associated with teas’ therapeutic action against free radical mediated diseases. The mechanism of oxidation reactions is strictly dependent on the chemical structure of the compound.
Free radicals are known to contribute to numerous disorders in humans including cancer, artheroscerolosis, arthritis, ischemia, Central Nervous System (CNS) injury, gastritis, dementia, renal disorders and Acquired Immune Deficiency Syndrome (AIDS)
Biological activity of antioxidants in tea
