Cosmeceutical Critique: Mushrooms, Part III: KombuchaDr. Leslie Baumann
Kombucha is a somewhat sweet or sour and acidic tea that is prepared through the fermentation of sweetened black tea with a symbiotic culture of yeasts and acetic acid bacteria. It is popular worldwide, particularly in China, Russia, and Germany (Int. J. Food Microbiol. 2004;95:119-26; Rev. Latinoam. Microbiol. 2003;45:5-11; J. Food Prot. 2000;63:976-81; Biomed. Environ. Sci. 2001;14:207-13).
The resulting culture often resembles a large bulbous pancake or mushroom, thus the erroneous appellation.
A thin membrane surrounds the yeast and bacterial culture and binds it together (JAMA 1998;280:1567-8).
The bacteria used in the fermentation of kombucha include Acetobacter xylinum as a characteristic species. Some of the yeasts isolated from commercially available kombucha products include Brettanomyces bruxellensis, Candida stellata, Schizosaccharomyces pombe, Torulaspora delbrueckii, and Zygosaccharomyces bailii (Mycoses 1995;38:289-95; Int. J. Food Microbiol. 2004;95:119).
The beverage, which is believed by many to confer health benefits, contains trace amounts of alcohol, antibiotic compounds, and acids, including gluconic, lactic, and acetic acids (Mycoses 1995;38:289-95; Rev. Latinoam. Microbiol. 2003;45:5-11).
Kombucha tea has been used as a folk remedy, especially to aid in weight loss, improve cognition, and prolong life (Nutrition 2000;16:755-61).
In fact, kombucha is known as the “long-life fungus” in Russia and other countries.
Kombucha tea also is used as an antimicrobial agent; as a laxative and digestive aid; as an alternative therapy for relieving arthritis; and as an immunomodulatory agent to ameliorate the effects of stress, aging, and cancer (J. Ethnopharmacol. 2000;71:235-40); Biomed. Environ. Sci. 2000;13:293-9).
In a computerized literature review of medical investigations of kombucha, without regard to study design, a researcher found no clinical studies establishing the efficacy of kombucha as a remedy. Safety also is unclear, as suspected liver damage, metabolic acidosis, and cutaneous anthrax infections—as well as one fatality—have emerged from case reports and case series.
The author concluded that the uncertain benefits of kombucha do not outweigh the documented risks and, therefore, its use for therapeutic purposes is not warranted (Forsch. Komplementarmed Klass Naturheilkd. 2003;10:85-7). Nevertheless, antioxidant and other healthful properties have been attributed to kombucha.
A few months after this literature review appeared, a study of the effects of oral administration of kombucha tea on lead-induced oxidative stress was published.
The investigators administered 1 mL of 3.8% lead acetate solution alone or in combination with oral kombucha daily for 45 days to Sprague Dawley rats.
The researchers found less DNA damage and lipid peroxidation in the rats fed kombucha tea, and noted increases in reduced glutathione level and glutathione peroxidase activity.
On the basis of these findings, the authors concluded that the controversial tea exhibits strong antioxidant and immunomodulating activity (Biomed. Environ. Sci. 2003;16:276-82).
Previously, most of the same researchers showed that kombucha protects against stress and liver damage. In that study, the investigators assessed the effects of oral administration of kombucha tea on albino rats, and could find no evidence of toxicity as evaluated by various biochemical and histologic tests.
Antistress activity was revealed, as kombucha fed to rats exposed to cold and hypoxia prevented lipid peroxidation and a decline in reduced glutathione level; in addition, kombucha-fed rats subjected to restraint stress had reduced wrap-restraint fecal output.
Furthermore, the hepatotoxicity that was induced by orally administered paracetamol was significantly diminished by kombucha tea (Biomed. Environ. Sci. 2001;14:207-13).
One year earlier, in a study of the effect of kombucha tea on oxidative stress-induced changes in rats treated with chromate, the tea significantly reduced the delayed hypersensitivity response, enhanced the activities of catalase and glutathione peroxidase, and reversed the effects of chromate, which had caused a rise in malondialdehyde levels. The investigators concluded that kombucha tea strongly exhibited antioxidant and immunopotentiating properties (J. Ethnopharmacol. 2000;71:235-40).
In a study of the antimicrobial activity of kombucha, investigators found that a large number of bacteria displayed some sensitivity to the popular tea, including Staphylococcus aureus, Shigella sonnei, Escherichia coli, Aeromonas hydrophila, Yersinia enterocolitica, Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus epidermis, Campylobacter jejuni, Salmonella enteritidis, Salmonella typhimurium, Bacillus cereus, Helicobacter pylori, and Listeria monocytogenes (J. Agric. Food Chem. 2000;48:2589-94).
In the same study, the researchers also found that, while they could attribute some of the inhibitory effect of kombucha to acetic acid, as supported in the literature, the antimicrobial activity against E. coli, S. sonnei, S. typhimurium, S. enteritidis, and C. jejuni, even at neutral pH and after thermal denaturation, implied the presence of additional antimicrobial substances.
In a 90-day study of subacute oral toxicity in five groups of rats, the control group was given tap water and the test groups received kombucha 2 mL/kg daily, plain tea 2 mL/kg daily, kombucha in drinking water 1% (v/v) daily, and plain tea in drinking water 1% (v/v) daily.
The investigators observed no significant differences in any growth measures, or any toxic or adverse events in the rats fed kombucha (Biomed. Environ. Sci. 2000;13:293-9).
A 3-year longitudinal pilot study of 64 male and female C57BL/6 mice assessed longevity, general health, and behavioral outcomes. Half the mice were consistently fed kombucha. All the animals experienced natural mortality during the study period.
The researchers found that kombucha-fed mice displayed greater longevity and overall health than controls, with the greatest difference observed among the male mice. The authors also noted that uncertainty remains about such effects in humans, particularly because of some of the adverse events associated with kombucha consumption (Nutrition 2000;16:755-61).
At the Store
Kombuchka is the trademark of a cosmetic active version of kombucha that is intended to produce a lipofilling effect upon topical application.
According to Dr. Zoe Draelos, this substance is high in organic acids and B vitamins, and includes glycerin and hydroxyethylcellulose. It is said to exert a cosmetic effect by hindering glycation and augmenting cultured fibroblast factors to further adipocyte maturation, thereby expanding subcutaneous fat on the face and hands.
Dr. Draelos notes that skin smoothness is the clinical test used to evaluate the level of lipofilling and, importantly, moisturization and exfoliation can confound such a determination (“What is the difference between spa line and cosmetic counter skin care products?” Cosmetic Conundrums, Dermatology Times, Nov. 1, 2004).
Revercel PM combines palmitoyl oligopeptide (Dermaxyl) and diacetyl boldine (Lumiskin), the latter is a potent antioxidant derived from the bark of a tree that grows in the Chilean and Peruvian Andes.
The product also contains Kombuchka, along with botanicals such as jojoba esters, apricot kernel oil, sunflower seed oil, and shea butter. Revercel PM is designed to restore tone, volume, and healthy color to the skin, and reduce the appearance of lines and wrinkles.
Kombuchka is also used in Global Beauty Anti-Ageing Radiance Cream, which was created by Dr. Laurent Miralles. He claims that his 3% concentration results in an increase in collagen cells and adipocytes that expand skin volume.
Teda Facial Tonic Toner & Moisturizer combines kombucha with a botanical antioxidant brew of sea algae, green tea, grape seed extract, calendula, echinacea, and mallow. The product is designed to spur cell renewal, moisturize and protect facial skin, relieve sunburn, and prevent peeling.
TriAction Age Defense Complex combines three peptides (acetyl hexapeptide-3, palmitoyl oligopeptide, and palmitoyl tetrapeptide-3), intended to regenerate skin and reverse aging, with kombucha. According to the manufacturer, the kombucha enhances skin tone, color, texture, and elasticity.
The HydroPeptide Anti-Aging system contains a wide array of antioxidants, including Kombuchka, to prevent and combat the effects of cutaneous aging.
The longtime use of herbs in folk or traditional medicine is often a worthy starting point for the scientific assessment of such compounds for medical efficacy. It is important to remember, though, that it is only a starting point—and that significant research is required to establish the efficacy, safety, and effectiveness of products. In particular, research is needed to ascertain whether the potential of particular ingredients is actually being harnessed as claimed.
Kombucha shows promise, but much more work is necessary to determine whether this popular compound can confer dermatologic benefits.