The new research effort will enable physicians to determine whether green tea actually inhibits the formation and growth of cancerous cells in human patients. Both seem to be active against human cancer cells. In a study presented at the International Symposium on Physiological and Pharmacological Effects of tea in 1991, researchers from the National Defense Medical College in Saitama, Japan revealed that total serum cholesterol levels were reduced in Japanese men who were heavy green tea drinkers. The study involved 1,306 men aged 49 and 56 years old. Lowering blood cholesterol is associated with preventing heart disease.
Green tea is consumed to a much greater extent in China and other parts of Asia.
Subjects who drank green tea and avoided burning hot fluids had significantly lower cancer risk. Most researchers believe that it is the polyphenols in green tea that are responsible for the health benefits. More specifically, certain catechins found in tea are believed to be the most powerful. The catechins in green tea make up a large percentage of the total amount of polyphenols. While the level of polyphenols and catechins in green tea can vary, depending on growing conditions, quality of the leaf, and brewing methods, the following approximates the amount in a cup of green tea.