Drinking green tea can prevent cancer because it is rich in a polyphenol called catechin. However, too much of a good thing can be harmful. Japanese researchers have found that excessive intake of catechin can damage DNA, which may subsequently lead to cancer. This illustrates the principle that "excess is just as bad as deficiency."

 

 

Many people enjoy drinking green tea in their daily lives, which is a good habit. Moderate intake of catechin through this method is beneficial to health. As a result, some people take catechin supplements in hopes of preventing cancer. However, Professor Kawanishi from Mie University's Medical Department has experimentally demonstrated that if people consume catechin at a concentration 40 times that found in green tea, it can cause DNA damage, which is closely related to cell carcinogenesis.

According to a recent report by Yomiuri Shimbun, catechin inhibits substances that cause arteriosclerosis and is considered a "driving force for health." While daily tea consumption poses no problem, people should be aware of the adverse effects of excessive catechin intake.

Catechin is most abundant in green tea, but it is also relatively rich in oolong tea and black tea.