The free radicals occur naturally in the body but excess amount increases the risk of coronary attacks and cancer.
Tea is rich in polyphenolic compounds with antioxidant properties, mainly quercetin and catechin, and these compounds may inhibit oxidative damage to DNA, lipid, carbohydrate and protein.
Oxidative damage is associated with various chronic diseases, including cancer, coronary heart disease, cataract and dementia, and it has been suggested that consumption of tea may lower the risk of chronic disease by improving oxidative/antioxidant balance.
Black tea contains a significant amount of theaflavin compounds that make an important contribution to antioxidant activity, but their effectiveness varies with the individual theaflavin.
The domination of theaflavins are simple theaflavin, theaflavin-3-gallate, theaflavin-3’-gallate, theaflavin-3,3’-gallate which comprises 0.3% - 2% of the dry matter of black tea.
Green tea polyphenols are composed of numerous teas of catechin. Studies show that habitual green tea consumption causes in increase in plasma antioxidant status and a quantitative reduction of free radical-induced markers of lipid peroxidation.
Active antioxidants in tea
