Kombucha: Fact or Fiction?
Kombucha tea is also known under different names throughout the world such as red tea fungus, Champignon de longue vie, Ling zhi, kocha kinoko, Chainii grib, and Chainii kvass .
Traditionally, kombucha is prepared through a fermentation process using sugared black tea along with a symbiotic culture of yeast and bacteria (these two form a “tea fungus” starter culture) . This beverage is thought to have originated in China over 2000 years ago , making a comeback in recent years in Whole Foods nationwide! Green tea, oolong tea, and herbs can also be used in this fermentation process instead of black tea . There are many different health claims related to this drink, and some are founded in research, others not as much. For instance, one beneficial effect found in an animal study was that kombucha reduced buildup of calcium in the kidney . Many advantageous effects of kombucha are attributed to the products released during fermentation into the broth; however, it is suggested that most of the health benefits are related to kombucha’s antioxidant capacity, rather than a large variety of factors . Additionally, the presence of glucuronic acid imparts beneficial properties to this drink ; this acid can be converted into compounds that are linked with healthy joints . Perhaps the most common health association is that kombucha provides probiotics, which help balance gut bacteria and help keep the GI system running [1,3].
If kombucha is so wonderful, why aren’t doctors everywhere prescribing it? Well, some individuals have reported concerning symptoms such as dizziness and nausea after consuming certain kombucha products. Following kombucha consumption, two cases of unexplained severe illness were reported to the CDC in 1995. Furthermore, kombucha tea is contraindicated in pregnant and lactating women. Homemade kombucha presents the largest concern, because mold can grow and one kind has carcinogenic effects . Naturally, kombucha tea contains several acids because of the fermentation process [4, 8]. Some of natural products could potentially lead to damage to the liver and kidney at high concentrations, evidenced by a few case reports . Despite these case reports and occasionally reported symptoms, the FDA and Kappa Laboratories in Miami, Florida, have conducted tests resulting in
the FDA conclusion that kombucha tea is safe for human consumption .
On the flip side, a very exciting area of research is that kombucha may play a role inhibiting starch digestion and glucose absorption . This could be especially relevant for diabetics, but further research is certainly required to draw conclusive evidence.
Overall, there haven’t been systematic human trials done, but the animal trial evidence and personal anecdotes are mounting for kombucha consumption. So you’ve decided you want to drink kombucha? Well… which kind? The answer: it depends. Resistance to antibiotics has become an increasingly significant health problem across the globe. In this case, multiple studies have found that the antibacterial potential of kombucha prepared from green tea is higher than that of the typically prepared kombucha from black tea [3,10]. Nevertheless, most health benefits, including probiotics, are present from the fermentation process, and not the specific kind of tea base used.
What do I think? Don't replace water with kombucha, but rather use it as a replacement for carbonated beverages, as long as you watch out for grams of sugar (<5g per 8oz serving) and consume in moderation.
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10. Jayabalan, R., Malbaša, R. V., Lončar, E. S., Vitas, J. S. and Sathishkumar, M. “A Review on Kombucha Tea—Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus,” Comprehensive Reviews in Food Science and Food Safety, 13: 538–550, 2014.