Letter: Keep drinking black tea

Sir: Contrary to your article on green tea ("... and how a cuppa can put the lid on cancer", 5 June) the black tea we drink in the UK also contains substances which have anticarcinogenic activity.

The focus of the article - a substance called EGCG which helps to stop the production and growth of cancer cells and is found abundantly in green tea - is also present in black tea in significant quantities. In addition, research in the Food Safety Group at the University of Surrey has shown that, during the change from green to black tea, new substances are formed which themselves also have antimutagenic activity.

In terms of its potential influence on cancer, the UK's favourite drink has as much going for it as the green tea preferred in some other parts of the world.

Professor R WALKER

Food Safety Group

School of Biological Sciences

University of Surrey

Guildford,

Surrey