Kombucha is a fermented beverage prepared from a mushroom (Fungus japonicus ). Known as kombucha tea, the drink is touted for its health-promoting properties. It is also called Manchurian mushroom tea, Manchurian fungus tea, Kwassan, combucha tea, and champagne of life. During fermentation and preparation, the kombucha membrane becomes a tough gelatinous cover composed of several different yeasts (one-celled fungi) and certain nontoxic bacteria derived from the air, similar to a sourdough bread starter. When the fungus is fermented in a mixture containing water, black or green tea , sugar, and vinegar (or other fermentation source), the microorganisms combine into a complex fermenting culture. This culture produces several compounds that have been considered health tonics over the centuries. Kombucha also contains several B vitamins and vitamin C . The tea is said to have a unique, but pleasant taste. The membrane surface of the kombucha is also edible.
In China, kombucha tea has been utilized as a health beverage for thousands of years, dating back to before 200 b.c. It has been consumed for centuries in Japan, Korea, and Russia. In the early 1900s, use of the tea spread from Russia into other European countries including Germany, where it was touted as a health elixir for many years. In the 1950s and 1960s, German and Italian researchers claimed that kombucha tea exhibited strong anticancer properties, and it was promoted as a miracle cure for cancer . Alexander Solzhenitzyn, the Nobel Prize winning Russian author, reported that kombucha tea, which he began to drink during a prison term, cured his stomach cancer. Proponents of kombucha tea continue to tout its possible anticancer and immunity-enhancing properties. However, controlled studies have failed to display conclusive evidence as to its efficacy in treating various medical conditions.
Kombucha tea is taken as a general health tonic. Claims are made for its use as a remedy for specific health conditions and diseases. It is used to introduce and improve healthy intestinal flora and bacteria, as an energy-enhancing tonic, and as a detoxifier in helping to remove pollutants. It is taken to strengthen the immune system after an illness, stimulate hair growth, improve arthritis and skin conditions, and as a health tonic for cancer and autoimmune deficiency syndrom (AIDS ) patients.
Kombucha tea contains significant amounts of the B complex vitamins, as well as vitamin C and minerals. It contains a small amount of alcohol (higher than 1%), which is produced during fermentation, and small amounts of methylxanthine stimulants. Teas do not contain caffeine , but they do contain methylxanthine alkaloids, a similar stimulant.
There is no large body of scientific evidence that supports the strong claims made by advocates of kombucha tea. Some European studies have pointed to positive results in cancer cases, but further research is needed to confirm these results. Its proposed anticancer and detoxification effects have been attributed to certain chemicals in the tea. However, more recent tests have failed to validate the presence of these chemicals in the beverage. One study did confirm improvements in liver function after a three-week treatment. Research in Russia demonstrated antibiotic effects caused by kombucha tea. There are many testimonial claims that the tea increases vitality and overall well-being. In general, properly fermented foods have been shown to aid in the growth of beneficial intestinal flora, reduce the growth of harmful yeasts and bacteria in the digestive tract, and improve digestion and absorption. Some testimonial claims have also been made by cancer and AIDS patients.
Kombucha tea is available in several forms. Kits include the fungi and all ingredients, as well as directions to make the brew at home. The fungi may also be purchased separately. Dried kombucha is available in capsule form.
Making the tea from scratch is a process similar to preparing yogurt, sauerkraut, and other fermented foods. Instructions should be followed carefully. Particular care should be taken to maintain the cleanliness of the tea-making process, to avoid contamination by mold or unhealthy bacteria (a cause of health problems in those drinking poor-quality kombucha). Smoking in the same room as the mixture may contaminate it. Mold typically appears as green, pink, or black blotches in the culture, and should be thoroughly removed and discarded. The fermentation process is generally successful if the kombucha skin remains firm and rubbery. Care should be taken if the membrane becomes crumbly or discolored. On average, the fermentation of kombucha tea takes 12–14 days. After fermentation, new batches can be easily made from the existing culture.
When using the supplement in pill form, consumers can follow the manufacturer's recommended dosages. Users of the tea can drink up to three cups of the beverage per day with food or between meals.
Historically, kombucha was consumed as a tea. The health benefits of other forms of the supplement have not been compared with the original therapeutic beverage. There are reports of consumer illness from home-prepared kombucha. This may have been due to tea that was too old, infected with molds or other contaminants, or had other problems. Consumers must be alert to the risks of home-prepared fermentation methods.
Several precautions concerning kombucha tea have been issued. Because the beverage is fermented at home, there is the risk that the liquid can become contaminated by such dangerous bacteria as anthrax. People with compromised immune systems must be extremely careful not to consume contaminated fermentations. Due to the high acidity of the drink, the tea should not be placed in metal containers or in pottery that has a lead glaze finish. There have been reported cases of lead poisoning and anthrax due to drinking kombucha tea that has been improperly prepared. The United States Food and Drug Administration (FDA) issued a warning concerning the danger of lead poisoning from improperly made kombucha tea. Kombucha tea is not recommended for pregnant or nursing mothers.
Consumption of kombucha tea has been observed to cause stomach upset, yeast infections , allergic reactions, nausea , and headache . Persons with stomach ulcers may find that kombucha increases their symptoms. Due to harmful bacteria that can survive in the culture, ingesting contaminated tea can be dangerous or fatal.
Kombucha tea is high in acidity and should not be consumed by those taking medications that make them susceptible to increased gastrointestinal acidity. The tea contains a small amount of alcohol and should not be consumed with any medications that interact unfavorably with alcohol. The tea should not be taken by people with stabilized alcoholism , to avoid aggravating the condition.
Some people report general and specific improved health from moderate use of kombucha tea. These reports await final validation by current research. There are risks associated with the use of poor quality or contaminated kombucha. Its use may be contraindicated in those who have medical conditions or require certain medications.
Chang, Shu-Ting. Mushrooms: Cultivation, Nutritional Value, Medicinal Effect, and Environmental Impact. Boca Raton, FL: CRC Press, 2004.
Hobbs, Christopher. Medicinal Mushrooms: An Exploration of Tradition, Healing, and Culture. Loveland, CO: Inter-weave Press, 1995.
Pascal, Alana and Lynne Van Der Kar. Kombucha: How To and What It's All About. Malibu, CA: Van Der Kar Press, 1995.
Pryor, Betsy and Sanford Holst. Kombucha Phenomenon: The Miracle Health Tea. Thriving Press, 1996.
Kombucha Tea. <http://www.kombucha.org>.