Recent scientific studies of a traditional chinese medicine, tea, on prevention of chronic diseases

Abstract

Green tea ( Lǜ Chá), made from the leaves of the plant Camellia sinensis, has traditionally been used as a medicine in China for thousands of years. According to the classical work of Li Shizhen ( Lǐ Shí Zhēn) of the Ming Dynasty, "tea is cold and lowers the fire." Since fire (inflammation) causes many diseases, could tea be effective in the prevention of many diseases? The possible prevention of chronic diseases such as cancer, metabolic syndrome, obesity, diabetes, and cardiovascular diseases has been studied with contemporary scientific methods, and the results are promising. The molecular mechanisms underlining these observations will be discussed in this presentation. One of the reasons for the failure to demonstrate a disease-preventive effect of tea in some epidemiological studies is the lower quantities of tea consumption in humans. Can we increase the quantity of tea consumption to harness its health benefits without causing gastrointestinal irritation? This is a topic for further research.

Keywords: Cancer; Cardiovascular diseases; Diabetes; Green tea; Metabolic syndrome; Obesity.

Figure 1

The structures of tea catechins and l-theanine (from [1])

Figure 2

The proposed mechanisms by which tea constituents (polyphenols, caffeine, and theanine) prevent chronic diseases. ROS: Reactive oxygen species; MetS: Metabolic syndrome; CVDs: Cardiovascular disease; NDDs: Neurodegenerative diseases (from [1])