Kombucha mushroom tea, a popular alternative medicine remedy claimed to cure everything from hair loss and wrinkles to high blood pressure and cancer, is coming under increased scrutiny for dangerous side effects in some patients.
Writing in the Journal of General Internal Medicine, doctors at Texas Tech Health Sciences Center report the cases of four patients who developed symptoms ranging from nausea to jaundice after drinking homemade Kombucha tea.The drink, also called Manchurian or Kargasok tea, is made by steeping Kombucha mushrooms - actually a cultured cluster of yeast and bacteria covered by a permeable membrane - in some blend of tea and sugar to create a tonic.
Proponents of the tea point to its use in Russia's Kargasok region, populated by an unusual number of centenarians, and its ancient use across much of Asia.
It has been widely promoted in natural health circles and on a number of alternative medicine sites on the Internet. Among the therapeutic powers claimed, besides anti-aging properties, are lowering cholesterol, cleansing the gall bladder and bolstering the immune system.
But Dr. Radhika Srinivasan and colleagues identify four patients in whom the effect of the tea was less than healthy.
They include a 55-year-old woman with a history of heavy drinking who developed jaundice two months after she started drinking two glasses of Kombucha tea a day. She stopped taking the tea, and the symptoms disappeared after six weeks.
Another woman complained of dizziness, nausea, vomiting and headaches.
Although the tea has been studied and promoted as an alternative therapy for much of this century and consumed by millions of people, the researchers noted that neither the tea's claimed benefits nor any adverse side effects have been widely reported in scientific literature.
Proponents of the tea have, however, had the mixture analyzed in labs and found no dangerous levels of bacteria or other toxins harmful to humans.
Likewise, a 1995 advisory from the Food and Drug Administration reported its studies "have found no evidence of contamination in Kombucha products fermented under sterile conditions."
But as with many herbal remedies, there are few, if any standards for the products, and consumers have considerable leeway in how they prepare them in their homes, how long the tea is steeped, what it's mixed with and so forth.
The FDA warned that it "still has concerns that home-brewed versions of this tea manufactured under non-sterile conditions may be prone to microbiological contamination." The consumer advisory also noted that FDA has not approved Kombucha for treatment of any medical condition.