Facts About Kombucha, the Fermented Tea Drink
Kombucha is a slightly acidic, fermented drink made from a base of tea, sugar, bacteria and yeast. Kombucha originated in China about 2,000 years ago. It has been growing in popularity at health food stores and among holistic health consumers, who drink it for its many alleged health benefits.
To make kombucha, a symbiotic colony of bacteria and yeast, or a "SCOBY," is added to the tea and sugar, and the mixture is allowed to ferment. The result is a beverage that some say smells like beer and tastes like fizzy apple cider. Others say it tastes like wine; other say it tastes like vinegar. Though this fizzy drink is sometimes called kombucha mushroom tea, there are no mushrooms in the tea. Other names this tea goes by are Manchurian tea, Russian tea and Kargasok tea.
Fans of kombucha have attributed several unproven health effects to the tea, including the restoration of hair color and thickening of hair, dissolution of gallstones, reversal of the signs of aging, lowering of cholesterol and blood pressure, increase in blood circulation, relief of menopausal symptoms, strengthening of the immune system, and improvement of digestion and liver functions. People have claimed that it detoxifies the body and can even prevent cancer. [Related: Detox Diets & Cleansing: Facts & Fallacies]
"While it is replete with B vitamins, probiotics and antioxidants, there is no official medical research on the health benefits of the drink, so be mindful of health claims," said Rebecca Shenkman, director at the Villanova College of Nursing's MacDonald Center for Obesity Prevention and Education (COPE). "Drink because you like the taste, not because you want to improve your liver function or enhance your immune system."
While there have been no direct studies of kombucha, there have been studies on probiotics, which are found in this tea. Probiotics have been found to aid in digestion and may help with irritable bowel syndrome, according to the National Institutes of Health.
While there is little evidence that this tea is good for the body, it may make the body feel worse. Some people experience stomach upset, infections and allergic reactions, according to the Mayo Clinic. This may be due to unsterile conditions where the tea is made or because of the tea itself.
The Peninsula Medical School did a systematic review of the clinical evidence that kombucha has any health benefits. The paper concluded that, "No clinical studies were found relating to the efficacy of this remedy. Several case reports and case series raise doubts about the safety of kombucha. They include suspected liver damage, metabolic acidosis and cutaneous anthrax infections. One fatality is on record."
According to the Centers for Disease Control and Prevention (CDC), healthy adults should limit their consumption of kombucha to about 4 ounces a day to avoid potential risks associated with overconsumption. Those who do have pre-existing health conditions, as well as women who are pregnant or breastfeeding, should consult with their doctors before drinking kombucha.
Live Science newsletter
Stay up to date on the latest science news by signing up for our Essentials newsletter.