Archaeological evidence suggests that tea leaves steeped in boiling water were consumed as many as 500,000 years ago. Botanical evidence indicates that India and China were among the first countries to cultivate tea
Green tea contains polyphenols which protect against certain cancers, and are also potent antioxidants. These antioxidants have been shown to be highly beneficial to the heart by helping prevent the oxidation of LDL cholesterol.
There are four primary polyphenols in green tea, often collectively referred to as catechins. They are powerful antioxidants, and have been shown in recent studies to fight viruses, slow aging, and have a beneficial effect on health.
Much of the initial evidence that green tea is anti-carcinogenic is based on epidemiological studies which show lower rates of many types of cancer among populations such as Japan and China that drink green tea as part of a daily cultural habit.
Clinical tests have demonstrated that the catechins in green tea destroy free radicals which are highly reactive molecules and fragments of molecules that can damage the body at the cellular level leaving it susceptible to cancer, heart disease, and many other degenerative diseases More recently, controlled studies on green tea extract have yielded impressive results, identifying the polyphenol (-)-epigallocatechin gallate (EGCG) as the responsible component. EGCG is able to force certain cancer cells into a situation in which they must die or be killed in a process called ”apoptosis”. Further evidence shows that EGCG has an inhibitory effect on the enzyme, urokinase, which is required for tumor formation, thus preventing the formation of tumors.
It has been shown that (EGCG), an antioxidant found in green tea, is at least 100 more times more effective than vitamin C and 25 times more effective than vitamin E at protecting cells and DNA from damage believed to be linked to cancer, heart disease and other serious illnesses. This antioxidant has twice the benefits of resveratrol, found in red wine.
The only possible negative side effect from green tea is possible insomnia because it contains some caffeine. Its caffeine content is, however, much lower than coffee.