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Other common
name(s): Manchurian tea, Kargasok tea, tea fungus
Scientific/medical
name(s): none
Description
Kombucha tea is made by fermenting sweetened black tea with a
flat, pancake-like culture of yeasts and bacteria known as the Kombucha
mushroom. It is not actually a mushroom but is called one because of
the shape and color of the sac that forms on top of the tea after it
ferments.
Overview
Available scientific evidence does not support claims that
Kombucha tea promotes good health, prevents any ailments, or is
effective in treating cancer or any other disease. Serious side effects
and occasional deaths have been associated with drinking Kombucha tea.
How is it promoted for use?
Kombucha tea is promoted as a cure-all for a wide variety of
conditions including baldness, insomnia, intestinal disorders,
arthritis, chronic fatigue syndrome, multiple sclerosis, AIDS, and
cancer. Supporters assert that Kombucha tea can boost the immune system
and reverse the aging process. Kombucha tea is said to contain
antioxidants, compounds that block the action of free radicals,
activated oxygen molecules that can damage cells. For people who have
cancer, proponents claim the tea can improve the body's defenses
(especially in the early stages of cancer) by detoxifying the body and
enhancing the immune system. After the body has been detoxified, the
tea is said to help repair and balance the body and fight off disease.
What does it involve?
The culture used in Kombucha tea varies, but consists of
several species of yeast and bacteria. It may include Saccharomycodes ludwigii,
Schizosaccharomyces pombe,
Brettanomyces
bruxellensis, Bacterium
xylinum, Bacterium
gluconicum, Bacterium
xylinoides, Bacterium
katogenum, Pichia
fermentans, Candida
stellata, and Torula
species, among others.
Kombucha tea is made by steeping the "mushroom" culture in tea
and sugar for about a week. During this process, the original mushroom
floats in the tea and produces a "baby mushroom" on its surface. These
new mushrooms can be passed along to other people for starting their
own cultures or can be kept to make new batches of the tea when the
original mushroom "goes bad" (indicated when it turns dark brown).
Proponents often recommend drinking very small daily doses of the tea
(1 to 2 ounces), to start and slowly increasing it over a few days or
weeks.
Some proponents also encourage people to remove all chemicals
from their diets and eat only fresh fruits and vegetables in order to
help the "detoxification" Process. They may also be told to avoid to
quit smoking and avoid caffeine, soft drinks, alcohol, hormone-fed
meat, fertilized or sprayed foods, preservatives, and artificial
coloring and flavoring.
Kombucha mushroom cultures can be obtained from commercial
manufacturers in the United States; however, most people obtain
Kombucha mushrooms from friends. Because of increased demand, some
companies now sell bottles of brewed Kombucha tea. Other products
include capsules made from the dried tea and Kombucha liquid extract,
drops of which are put under the tongue.
What is the history behind it?
Kombucha tea originated in East Asia and was introduced into
Germany at the turn of the century. Since the early 19th century,
Kombucha tea has been promoted as an immunity-boosting tea, that can
strengthen the body against many ailments. It has become prevalent in
the United States because it can be grown and harvested at home. It is
especially popular among people with HIV and the elderly because of
claims of its immunity-boosting and anti-aging powers.
What is the evidence?
No human studies have been published in the available
scientific literature that support any of the health claims made for
Kombucha tea. There have, however, been reports of serious
complications associated with the tea. In April 1995, two women who had
been drinking the tea daily for 2 months were hospitalized with severe
acidosis—an abnormal increase of acid levels in body fluids.
Both had high levels of lactic acid upon hospitalization. One woman
died of cardiac arrest 2 days after admission. The second woman's heart
also stopped, but she stabilized and was able to recover. The mushrooms
used by both women came from the same "parent" mushroom. While no
direct link to Kombucha tea was proven in this case, the U.S. Food and
Drug Administration (FDA) has warned consumers to use caution when
making and drinking the tea.
Are there any possible problems or
complications?
This product is sold as a
dietary supplement in the United States. Unlike drugs (which must be
tested before being allowed to be sold), the companies that make
supplements are not required to prove to the Food and Drug
Administration that their supplements are safe or effective, as long as
they don't claim the supplements can prevent, treat, or cure any
specific disease.
Some such products may not
contain the amount of the herb or substance that is written on the
label, and some may include other substances (contaminants). Actual
amounts per dose may vary between brands or even between different
batches of the same brand.
Most such
supplements have not been tested to find out if they interact with
medicines, foods, or other herbs and supplements. Even though some
reports of interactions and harmful effects may be published, full
studies of interactions and effects are not often available. Because of
these limitations, any information on ill effects and interactions
below should be considered incomplete.
Because several types of yeast and bacteria can grow under
Kombucha tea's brewing conditions, different Kombucha teas may contain
different varieties. Since cultures and preparation methods vary,
Kombucha tea may contain contaminants such as molds and fungi, some of
which can cause illness. After the tea is fermented, it is usually
highly acidic and contains alcohol, ethyl acetate, acetic acid, and
lactate.
Deaths have been linked with the tea. Drinking excessive
amounts of the tea is not recommended. Several experts warn that since
home-brewing facilities vary significantly, the tea could become
contaminated with harmful germs, which could be especially dangerous to
people with HIV, cancer, or other immune problems. Allergic reactions,
possibly to molds in the tea, have been reported, as have anthrax of
the skin and jaundice, a yellowing of the skin and eyes that is usually
caused by liver damage
Kombucha tea should not be brewed in ceramic, lead crystal, or
painted containers, as the acidity of the tea can cause it to absorb
harmful elements from its container. Lead poisoning has been reported
in at least two people who brewed Kombucha tea in a ceramic pot.
Since the potential health risks of Kombucha tea are unknown,
anyone with an immune deficiency or any other medical condition should
consult a physician before drinking the tea. Women who are pregnant or
breast-feeding should not use this tea. Relying on this type of
treatment alone and avoiding or delaying conventional medical care for
cancer may have serious health consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
Boik J. Cancer
& Natural Medicine: A Textbook of Basic Science and Clinical
Research. Princeton, Minn: Oregon Medical Press; 1996.
Cassileth B. The
Alternative Medicine Handbook. New York: W. W. Norton
& Co;1998.
Centers for Disease Control and Prevention. Unexplained severe
illness possibly associated with consumption of Kombucha tea-Iowa,
1995. JAMA.
1996;275:96-98.
Derk CT, Sandorfi N, Curtis MT. A case of anti-Jo1 myositis
with pleural effusions and pericardial tamponade developing after
exposure to a fermented Kombucha beverage. Clin Rheumatol.
2004;23:355-357.
Mayser P, Promme S, Leitzmann C, Grunder K. The yeast spectrum
of the 'tea fungus Kombucha.' Mycoses.
1995;38:289-295.
Phan TG, Estell J, Duggan G, Beer I, Smith D, Ferson MJ. Lead
poisoning from drinking Kombucha tea brewed in a ceramic pot. Med J Aust. 1999;
170:454.
Sloan-Kettering. Kombucha, Clinical Summary. Accessed at:
http://www.mskcc.org/mskcc/html/69274.cfm on June 10, 2008.
Spaulding-Albright N. A review of some herbal and related
products commonly used in cancer patients. J Am Diet Assoc.
1997;97:S208-215.
Teo AL, Heard G, Cox J. Yeast ecology of Kombucha
fermentation. Int J
Food Microbiol. 2004;95:119-126.
US Food and Drug Administration. FDA Talk Paper: FDA cautions
consumers on "Kombucha mushroom tea." Rockville, Md: National Press
Office; March 23,1995. Talk Paper T95-15.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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