Kombucha is the not so new, new health fad that seems to be popping up everywhere. This yeast and bacteria fermented green, black and even white tea beverage is considered to be an elixir of health that has been used for centuries in Asia. Acetic acid bacteria such as Acetobacter spp is combined with different yeast species, such as Saccharomyces sp., forming a SCOBY which then ferments a sugar and black or green tea mixture. Resulting in a fizzy, somewhat sweet/sour concoction with by products that have some impressive health benefits.
Kombucha preparations vary in their chemical composition but commercially prepared beverages contain various organic acids, B vitamins (1, 2, 6, and 12), vitamin C, and 14 amino acids in varying amounts. Most notably the acetic, lactic, usinic, and gluconic acid formed during fermentation have clear health benefits. These compounds have been associated with antimicrobial activity and liver detoxification support. Another study published this September attributed this activity to polyphenols found in kombucha. The study looked at the zone cleaning ability of different types of kombucha on a number of enterotoxigenic bacteria such as E.coli, V.cholerae, S. flexneri and S.typhimurium. What they found was that kombucha fermented for 14 days was best at killing off these bacterial strains due to the increased concentration of catechin (from the tea) and isorhamnetin (produced as a metabolite in fermentation).
Gluconic acid produced during fermentation has been shown to increase conjugation (or tagging) of toxic compounds, improving their excretion from the body.
While black and green tea are considered strong antioxidants in their own right, able to quench free radicals that are associated with many inflammatory disorders (retinal degeneration, allergies, rheumatoid arthritis etc.) The antioxidant potential of the fermented kombucha is considered to be significantly higher, likely due to the polyphenol metabolites formed as well as the fact that it increased production of one of the body’s most potent antioxidants glutathione (GSH). Kombucha tea was shown to have 100X more antioxidant activity when compared with vitamin C and 25X more than vitamin E.
While research in this area is still developing, the antioxidant capabilities of kombucha tea are being applied to immune related conditions. Preliminary cell studies have shown that there is some protection against cellular damage, particularly with liver cells. Therapeutic effects in a number of other conditions are also underway from metabolic conditions, obesity, gastric diseases, heavy metal poisoning and more.
Often times people assume that because yeast is used in the fermentation that they are increased susceptibility to candida infections. While this is true the full composition of fungal species has recently been evaluated. However, since the yeast is combined with acetic bacterial species the fermentation produces metabolites that seem to regulate overgrowth of harmful fungi in the GI tract. Healthy individuals should not be susceptible to infections, while immunosuppressed individuals should consume commercially controlled preparations to avoid the risk of contamination.
Kombucha provides a healthy alternative to sugary pop drinks, and more and more companies are taking notice.