Researchers at Oregon State University (OSU) have found at least one of the reasons behind the health benefits of green tea, which has long been held in high regard for its supposed beneficial properties, including preventing cancer.
The researchers at the Linus Pauling Institute found that one of the compounds found in the tea boosts the human immune system by promoting the growth of 'regulatory T cells'.
Pharmaceutical companies have searched for drugs that can produce the same effect, but run into problems as the medicines they produce are often toxic.
'This appears to be a natural, plant-derived compound that can affect the number of regulatory T cells, and in the process improve immune function,' said Emily Ho, an LPI principal investigator and associate professor in the OSU Department of Nutrition and Exercise Sciences.
'When fully understood, this could provide an easy and safe way to help control autoimmune problems and address various diseases,' Ho said.
Autoimmune disease sees the body turn against itself, as the systems designed to protect us from infection and disease malfunction, usually over-reacting as in allergies such as hay fever. Regulatory T cells are the body's mechanism to stop this happening by turning off unneeded autoimmune reactions.
The magical ingredient in green tea is a polyphenol called EGCG, which is already known to have anti-inflammatory and anti-cancer characteristics.
EGCG, crucially, helps create more regulatory T cells without affecting our DNA, meaning, while it is not as powerful as some drugs, it causes less incidental damage.