The trendy beverage with a "floating mushroom" has been making the American celebrity rounds, according to Michele Berman, M.D., but it's been used in other parts of the world for centuries. Kombucha tea, a fermented mixture of sugar, bacteria and yeast, has many reputed medicinal uses and general health benefits. If you're always on the lookout for tasty ways to get more nutrition into your kids, you might have tried adding kombucha tea to their daily diet.
It's not really made from a mushroom, but kombucha tea starts with cultured colony of bacteria and yeast that resembles a wide, flat, rubbery fungus. In the kombucha brewing arena, this starter colony is known as "the mother." You add sugar and green or black tea to the mother, and about a week later the fermented result is a clear, amber, slightly effervescent liquid with a large number of organic acids -- the American Cancer Society lists ethyl acetate, acetic acid, and lactate -- as well as some B vitamins and alcohol. You can buy kombucha or make it at home. Several ready-made brands mix kombucha tea, which is said to have a flavor akin to vinegar, with fruit juices and other flavoring ingredients.
The story of how a vinegary, even reportedly "funky tasting," tea became popular in the United States is based mostly on its supposed healing properties rather than its flavor. The list of reported health benefits is long. Naturopathic physician Janet McKenzie, N.D., says some of the positive impacts ascribed to kombucha include improved memory, reduced symptoms and signs of premenstrual syndrome, rheumatism, aging, anorexia, AIDS, cancer and hypertension, and improved T-cell counts, immune system and metabolism. Dr. McKenzie adds that some of these purported improvements actually might be attributable to the tea that's used for fermentation of the culture, rather than properties of the "mother" itself.
Dr. McKenzie says scientific evidence for the health claims of kombucha tea is limited. Dr. Michael Wald, director of Nutritional Services at Integrated Medicine & Nutrition, concurs there is "no hard science on the benefits of Kombucha," and as a result would not make a strong recommendation for its use by any patient of any age. MayoClinic.com reports that virtually all of kombucha's benefits are based on personal reports and lab and animal studies and not "a single human trial reported in a major medical journal." The American Cancer Society adds that while no human studies have been published to support any kombucha tea health claims, there have been unfortunate reports of adverse reactions and even death linked to its use.
Deaths believed to be linked to the drinking of kombucha tea have resulted from lactic acidosis, an abnormal increase of acid levels in body fluids. Part of the reason for kombucha's shaky claims might be that, like some other nutritional medicinals, it is technically classified as a nutritional supplement. Since it isn't considered a food or drug, kombucha is not evaluated on a routine basis by either the U.S. Department of Agriculture or the U.S. Food and Drug Administration. New York City pediatrician Dr. Anatoly Belilovsky says kombucha tea hasn't been well studied in either adults or children, and due to its homemade nature, "its composition is quite variable." Dr. Belilovsky adds, "As with any organics, there have been reports of allergic reactions, as well as toxicity to the lungs, liver, and blood clotting factors." Nutrition expert Michael Dr. Wald, a proponent of the holistic use of combined therapies including foods, says "a few studies suggest this complex compound should not be taken by those who simultaneously take hormone replacement therapy." Another concern about kombucha, according to Dr. McKenzie, is its high potential for contamination with pathogenic micro-organisms such as aspergillus and anthrax. Also, since it is highly acidic and homemade, kombucha tea can become contaminated with inorganic substances like lead if made in non food-grade containers.
Kids and Kombucha
The basic safety questions, such as high contamination risks, are what cause health practitioners to stop short of recommending kombucha tea, especially for children. Dr. McKenzie says, for example, "Because of the risk for contamination, its acidic nature, its caffeine and alcohol content, I question the wisdom of giving kombucha to children. If immune support or B vitamin supplementation are the goals, there are safer ways of achieving them." Another integrative medicine specialist agrees: Joan Boccino, MS, L.Ac., says kombucha tea generally is not the best for children, especially those younger than 7. She explains, "A child's digestive system is immature and the acids, sugars, caffeine, alcohols and bacteria found in the various brews may be too much for the young gut to handle. Frequently, too, kombucha is brewed with honey, which should not be given to babies under the age of 1 year due to the botulism risk. "