Japanese health enthusiasts are pursuing another lead in their quest for healthi er living. Following the green-tea boom, they are now drinking a much darker "tea," prepared not from tea leaves but from black soybeans.

The infusion has a savory aroma of roasted beans and a slightly sweet taste. The left-over beans are soft enough to eat as a snack, thereby making them "a great way to consume all the nutrients in soybeans," as a flier advertising black-soybean tea points out.

The black soybean, a rare legume native to China, has long been used in Chinese medicine to clear toxins from the body and promote urination. According to Japanese folklore, the bean infusion is also a cure for sore throat.