The health benefits of drinking tea made Discover magazine's list of the top 100 science stories of 2003. This article was not about the well-known antioxidant benefits of tea, but rather the fact that tea bolsters the immune system with a substance called L-theanine. This helps the body to produce ethylamine, which in turn makes T cells produce far more infection-killing chemicals, including interferon.
Another poster posted the complete AP story on this forum in April - you can go back and read it on Google if you are interested. A search on "interferon" works.
-- Randy (if replying by e-mail, remove SPAMFREE from my address)