Chinese Green Tea

Green tea's ability to fight cancer is even more potent and varied than scientists suspected, research suggests.

Scientists already know that green tea contains anti-oxidants which may have a protective effect against cancer. But now they have discovered that chemicals in the tea also shut down a key molecule which can play a significant role in the development of cancer.

The molecule, known as the aryl hydrocarbon (AH) receptor, has the ability to activate genes - but not always in a positive way. The researchers, from Rochester University, found that two chemicals in green tea inhibit AH activity.

Both chemicals are similar to compounds called flavonoids, which are found in broccoli, cabbage, grapes and red wine, and which are also known to help prevent cancer.

The Rochester team showed that the chemicals shut down the AH receptor in cancerous mouse cells. Early results indicate the same is true in human cells.

However, the scientists say that the results in the laboratory do not necessarily translate to everyday life as the crucial factor is how green tea is broken down inside the body. In addition, there are a lot of differences between various types of green tea.

Dr Julie Sharp, a science information office at Cancer Research UK, said: "This research describes additional properties of green tea that may be beneficial but which have yet to be tested properly.

Research has also suggested that green tea may help to reduce the risk of rheumatoid arthritis and to lower cholesterol levels. The research is published in the journal Chemical Research in Toxicology.

Adapted from BBC Online, August 2003

chinese translation | japanese translation | korean translation