For centuries, people around the world have brewed a strange concoction of yeasts and bacteria with sweetened tea to make an effervescent drink thought to have medicinal benefits. In China, it was called "Manchurian Mushroom tea," in Russia, it was known as "Tea Kvass," the French called it "Champignon de Longue Vie." In Japan it was known as Kombucha. While many people still prepare their own Kombucha, these days you can find this fermented drink in health food stores and cafes under names like Kombucha Wonder Drink, Kombucha Power and G.T. Kombucha.

Makers of these products claim Kombucha detoxifies and energizes the body and some say it even has curative powers. Does the tea live up to its reputation? Lime investigates.

Curative Elixir

Kombucha has been used as a folk remedy across the world since at least 200 B.C. Loyalists believe drinking Kombucha stimulates liver detoxification, relieving everything from intestinal discomfort to chronic fatigue syndrome to cancer. While there has been little scientific research on the substance, the handful of studies that have been conducted have not backed up the ardent testimonials, though a few have suggested the fermented drink has high levels of B vitamins.

While Kombucha itself has not been proven to have beneficial properties, green and black tea, which are used to make the fermented drink, do. Both are rich in antioxidants, and researchers have found tea may inhibit the growth of cancer cells and protect the heart.

Dangerous Brew

The most distressing news about kombucha came in April 1995, when a 59-year-old woman died and a second became violently ill in a rural town in Iowa. Both had been drinking Kombucha tea daily for approximately 2 months, according to a report by the Centers for Disease Control. More than 100 other people in the town drank prepared from the same culture without ill effects. The Food and Drug Administration subsequently put out a warning about Kombucha saying, "The unconventional nature of the process used to make Kombucha tea has led to questions as to whether the product could become contaminated with potentially harmful microorganisms, such as the mold Aspergillus. Such contamination could produce serious adverse effects in immune-compromised individuals." The report went on to say that Kombucha products fermented under sterile conditions were probably safe, but that "home-brewed versions of this tea manufactured under non-sterile conditions may be prone to microbiological contamination." In addition, there have been a few scattered reports of liver problems, including hepatitis and jaundice, possibly associated with Kombucha.

The Verdict

There is little hard evidence that Kombucha products offer any health benefits. However, considering its widespread use in many parts of the world, reports of negative health effects have been rare. Some (most conspicuously, purveyors of brew-your-own kits) say Kombucha is best when freshly brewed and fermented and that commercial products aren't as effective as the homemade stuff. But there may be some danger in home-brewed kombucha. Acid in the tea may cause it to leach harmful materials from its container, so Kombucha tea should not be brewed in a ferrous metal vessels (Iron, copper, lead crystal) or in ceramic containers that contain lead.

If you decide to brew your own Kombucha drink, be sure to follow preparation and storage instructions provided. As for the prepared Kombucha drinks sold in stores, they're most likely safe and may well be tasty. But don't expect any medical miracles.

Further Reading on the Web:
American Cancer Society Fact Sheet on Kombucha Tea

Report on the history and cultivation of Kombucha by mycologist Paul Stamets

Image: Kombucha House