First, a definition: When scientists talk about tea, they mean black, green, white, or oolong teasall of which are made from the leaves of the Camellia sinensis plant. Herbal brews, like chamomile and peppermint, are not technically considered tea; they're infusions of other plants with different nutritional characteristics. If you're not sure what kind you're drinking, check the ingredients for the word "tea."
Boiling down the hype
All this sounds pretty compelling. So why aren't major health organizations advising us to drink tea like crazy? It's a matter of needing more hard-core evidence. "There are pearls of real promise here, but they have yet to be strung," Dr. Katz says. "We don'have clinical trials in human patients showing that adding tea to one's routine changes health outcomes for the better." The vast majority of the research conducted has been observational, meaning scientists can't know if the medical boosts seen in tea drinkers are definitely a result of that habit, or some other factor that makes these people healthier. And many of the studies that have looked at specific compounds in tea have been conducted in labs or on animals, not on people. "These chemicals act as antioxidants in a test tube, but they may not do the same in your body," explains Emily Ho, PhD, associate professor in the department of nutrition and exercise science at the School of Biological and Population Health Sciences at Oregon State University. "You have to take the claims with a grain of salt."