Green-tea drinkers have been a little blue this past month in the wake of bad news from a group of Tohoku University researchers: Green tea, according to the Japanese scientists' recent report in the New England Journal of Medicine, may not be such a panacea after all. But consumers should not feel either surprised or gloomy. We may find ourselves in hot water for saying so, but this is the way things go in the world of health fads. The only real surprise is that it took so long for someone to point out that, as with red wine, there is nothing black-and-white about green tea.

Asians have been drinking the comforting beverage for centuries without needing scientific studies to encourage them to consume what they already enjoyed. No doubt they will continue to drink it. A few years ago, however, green tea also burst onto the Western market, following a wave of promotional hype about its supposed preventive properties. Japanese researchers naturally jumped on the tea wagon, too, adding to the growing stack of claims regarding the ancient brew's health benefits. Green tea, it was said, prevented everything from cancer to cavities, reduced cholesterol and blood sugar levels, controlled high blood pressure, suppressed aging, deterred food poisoning and, for all we know, cleaned the house while we were at work. People started drinking 10 or 20 cups a day of the magic elixir.

The facts were always murkier. Human, as distinct from animal, studies of green tea have never been either consistent or conclusive. Now it is Japanese researchers, perhaps appropriately, who are dampening the hype. The eight-year-long study of over 26,000 Miyagi Prefecture residents showed no link at all between green-tea consumption and lower stomach-cancer rates. Drinkers and nondrinkers alike were equally vulnerable. At the very least, this study finally returns green tea to a more rational perspective.