Q & A Library

Also called the Manchurian or Kargasok mushroom, kombucha is not a mushroom at all but a mixed culture of several species of bacteria and yeasts that are added to black or green tea and sugar to produce a fermented "tea," a drink that tastes something like fizzy cider. Kombucha tea sipped daily has been recommended as a treatment for everything from AIDS and arthritis to baldness. I've also heard claims that kombucha boosts energy and improves eyesight. A few years ago, kombucha was credited with the recovery of a patient suffering from advanced AIDS. Accounts of this seemingly miraculous turnaround left out the fact that the patient had begun treatment with an FDA-approved experimental therapy at the same time.

I don't recommend kombucha tea at all. I know of no scientific studies backing up the health claims made for it. Beyond that, there's evidence that kombucha tea may have some antibiotic activity. If so, by drinking the tea you could be unnecessarily taking antibiotics, which could encourage development of resistant strains of bacteria.

I am also concerned about the culture becoming contaminated, as it could in the home-brewing process. Some batches have contained aspergillus, a toxin-producing fungus. This would actually pose significant risks to people with compromised immune systems such as those with AIDS or undergoing chemotherapy for cancer. There have also been reports in the medical literature of adverse reactions including nausea, vomiting and headaches among those who drink more than four ounces of kombucha tea daily. Allergic reactions, jaundice and head and neck pain have also been reported. I would particularly caution pregnant women, nursing mothers, the elderly, children and anyone with a compromised immune system against drinking kombucha tea.

Andrew Weil, M.D.