Tea and Infection

A study carried out at Brigham and Women’s Hospital and Harvard Medical School has indicated the mechanism by which tea is able to help fight infections. Immune T cells in the body are can recognise antigens such as those found in tumour cells, bacteria, parasites and fungi, and then stimulate the production of antibodies to fight infection. Once exposed to antigens, the T cells remember them when exposed again, thus developing immunity. Now similar antigens have been found in tea, and the researchers discovered that the tea antigens tea were able to prime the T cells to remember how to respond to subsequent antigens, even when the source of the antigens was bacterial, thus helping to provide natural resistance. (Proceedings of the National Academy of Sciences). 

Dr Yoshimasa Yamamoto, of Showa University in Japan, says green tea contains chemicals called catechins that "show strong antibacterial activity" against helicobacter, a bacterium which earlier this decade was discovered to be the cause of the majority of stomach ulcers. "The level required for such activity... is easily reached in the stomach after drinking a cup of green tea," he told the American Society of Microbiology's annual conference. And a Dutch team has found that garlic, even in low concentrations, especially when taken in conjunction with chemicals that reduce stomach acidity, also inhibits the growth of Helicobacter.