April 21, 2003 -- Add germ fighting to the health benefits of tea. Sorry, java lovers: The crucial ingredient's in tea leaves, not coffee beans
Tea is extremely rich in chemicals called alkylamines. Lots of germs also carry these chemicals. Could there be a link? A research team led by Jack F. Bukowski, MD, PhD, of Boston's Brigham and Women's Hospital, took a look
Sure enough, test-tube studies showed that alkylamines gave a big boost to some of the most important immune cells in the human body. Once these gamma-delta T cells saw them, they were primed to go after germs.
Next, a real test. Eleven healthy, non-tea-drinking volunteers drank five or six cups -- about 21 ounces -- of Lipton tea every day for two or four weeks. Another 10 non-tea, non-coffee drinking volunteers drank five or six cups a day of Nescafe instant coffee.
Both groups of volunteers donated immune cells before and after drinking tea or coffee. When the gamma delta cells from coffee drinkers saw pieces of germs, nothing much happened. In contrast, immune cells from tea drinkers went wild. Just two weeks after starting tea drinking, cells from seven of the 11 volunteers jumped into action soon after sensing germs.
This health benefit of tea may go farther than fighting germs. The same kinds of immune responses are important in fighting cancer.
Alkylamines aren't just found in tea. There are smaller concentrations in foods such as mushrooms, apples, and wine.
"These data provide evidence that dietary intake of tea and perhaps other vegetables and fruits containing alkylamine ... may prime human gamma delta T cells that they can provide natural resistance to microbial infections and perhaps tumors," the researchers write.
The study appears in the April 21 early online edition of the Proceedings of the National Academy of Sciences.