Kombucha: Health elixir or risky experiment?

Kombucha tea is a popular complementary remedy, which after many decades of small-scale home brewing made a commercial debut in the marketplace and got off to a flying start. Kombucha drinks are a multimillion business, and these beverages are marketed as the elixir of health in both specialty and mainstream stores. Many people—including celebrities—swear by them.

But commercially brewed raw kombucha will be harder to find this summer. Last week Whole Foods Market pulled all raw (live) kombucha bottles off the shelf due to a concern that their alcohol levels may exceed the 0.5 percent ceiling allowed by law in non-alcoholic beverages. Other retailers are following suit. Products with alcohol levels exceeding 0.5 percents are subject to special regulations regarding permits, labeling, advertizing and taxation. Most importantly, alcoholic beverages must bear a health warning statement, as alcohol poses special risks for kids, pregnant women and people on certain medications. The Alcohol and Tobacco Tax Trade Bureau received several complaints about kombucha teas’ alcohol content, and is now looking into the matter.

What is kombucha? Where’s the alcohol from?

Kombucha tea is prepared by fermenting sweetened black or green tea with a symbiotic culture of yeast and bacteria. The resulting liquid contains acids, B vitamins and a number of other chemical compounds. Alcohol is another natural product of the fermentation process. In live kombucha drinks fermentation can continue in the bottle, and therefore the alcohol levels may rise with time, providing an extra kick.

Is kombucha truly magical?

Kombucha tea is promoted in some alternative therapy circles as a cure-all for a wide range of conditions, from memory loss, baldness, insomnia and intestinal disorders, all the way to cancer and AIDS.

Unfortunately, there is no scientific evidence that kombucha is an effective treatment for any condition. In fact, a systematic review of scientific literature found no clinical trials of kombucha in humans. The limited studies on rodents yielded conflicting results: kombucha had antioxidant activity in some studies, but caused liver and spleen enlargement in others.

Although there are no proven health claims that can be made regarding this drink, the well established commercial kombucha brands tell an artful story that suggests eternal health and freedom from disease without actually saying anything that can get them in trouble with current labeling laws—rules which leave plenty of room for confusing consumers into believing a product is a healing elixir.

Is alcohol the only concern? Should we be concerned?

Despite the dearth of scientific support for kombucha’s health benefits in humans, there are several case reports in the medical literature of adverse reactions associated with the consumption of home-grown kombucha tea, including abdominal complaints, allergic reactions, jaundice, toxic reactions, metabolic acidosis, and occasionally even death.

The fact that there are only a few case reports of bad outcomes after kombucha consumption is perhaps somewhat reassuring—it means that the described outcomes are an unusual occurrence. On the other hand these case reports suggest kombucha’s safety profile needs further study.

The Food and Drug Administration cautions that because of the method of preparation, home brewed Kombucha can easily become contaminated if brewed in unsanitary conditions. Medical experts warn that Kombucha may reduce the absorption of certain pH sensitive drugs and caution people with a compromised immune system against drinking it. Evidence-based practitioners advise prudence with this unproven drink, and even open-minded, holistic and alternative therapy embracing Andrew Weil M.D. counsels: “I don't recommend kombucha tea at all”.

What’s next?

Kombucha has a dedicated following—people say it gives them energy (perhaps easily explained by kombucha’s caffeine and sugar content) and makes them feel good, which is hard to argue with. It’s going to be interesting to see whether attention to kombucha’s alcohol levels will also raise interest in its other controversial features—there are no scientific studies to back the health claims made for it, there are concerns about its safety, and the health claims touted on these products are baseless and misleading.

Taste is a personal matter, but in a quick survey among my kombucha consuming friends and acquaintances I couldn’t find even one who drinks it because it’s a culinary delight. In the mind of most of its consumers kombucha is a healing elixir, and as such should be judged on its healing merits—proof of which is seriously lacking.

Will raw kumbucha makers shift to pasteurizing their brew? Pasteurization—a process that wipes out most bacteria and mold—stops fermentation, ensuring stable alcohol levels, and also prevents microbial contamination. On the other hand pasteurization takes away kombuchas biggest claim to fame—its live cultures.

Dr. Ayala

Full disclosure: I’m vice president of product development for Herbal Water, where we make organic culinary herb infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.
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