April 21, 2003 — Certain types of tea have long been known to protect against cancer, but now US researchers have reason to believe they may also boost the immune system. The findings are very preliminary, but Brigham and Women's researchers reported that volunteers who were asked to drink 20 ounces of black tea a day demonstrated stronger immune responses to infection than they had previously, or than a control group of coffee drinkers. "The health benefits of tea have been touted for centuries but no human research has demonstrated an association between tea drinking and immunology," said lead author...