Kombucha Tea
What is it? Overview Usage Side Effects and Warnings

What is Kombucha Tea?

Just like friends can pass along sourdough starter, a small, round, flat, gray, gelatinous object has become a popular gift among those interested in natural medicine. You insert this object in sweetened black tea and let it ferment for 7 days. By the end of the week, you have a strong-tasting drink and a big, flat, gray, gelatinous object you can cut up and pass on to your friends.

Described variously as Manchurian mushroom, Kombucha tea, or just Kombucha, this tea is said to have been used for centuries to cure a wide variety of illnesses. The earliest known scientific analysis of Kombucha occurred in Germany in the 1930s, and subsequent studies have provided accurate information about this dubious product. 1 The word kombuchaliterally means "tea made from kombu seaweed."...

Kombucha tea is widely supposed to have miraculous medicinal properties, ranging from curing cancer to restoring gray hair to its original color. Other reputed effects include normalizing weight, improving blood pressure, increasing energy, decreasing arthritis pain, restoring normal bowel movements, removing wrinkles, curing acne, strengthening bones, improving memory, and generally solving every health problem that exists.

However, there is no evidence that Kombucha tea is effective for these or any other uses.

Safety Issues

In a set of animal studies, researchers prepared a batch of Kombucha and found that it was essentially nontoxic when taken at appropriate doses. 2 However, because Kombucha is a complex and variable mixture of microorganisms, it isn't clear that any other batch of the tea would be equally safe. In fact, there are case reports, which suggest that Kombucha preparations can cause such problems as nausea, jaundice, shortness of breath, throat tightness, headache, dizziness, liver inflammation, and even unconsciousness. 3 It isn't clear whether the cause of these symptoms is an unusual reaction to a generally nontoxic substance, or a response to unusual toxins that developed in a particular batch of Kombucha.

In addition, there is one case report of severe lead...