Is this drink really a magic health elixir?

Kombucha—a fermented tea—is having a moment. Yet, despite its fairly recent ascent to popularity in America, particularly among hipsters, kombucha has been consumed for thousands of years. It is so old that its origins are even hazy—it may be from China, it may be from Japan. No one is really sure.

Kombucha is a slightly sour drink that is made by adding specific strains of bacteria, yeast, and sugar to black or green tea. It is then allowed to sit for a week or more to ferment. During fermentation, the added bacteria and yeast produce acetic acid and other acidic compounds, large amounts of probiotic bacteria, and trace levels of alcohol and gases that carbonate the liquid.

During the making of kombucha, the bacteria and yeast form into a mushroom-like film on the liquid’s surface, a sort of blob that contains the now-symbiotic colony of bacteria and yeast—affectionately known as the SCOBY. The SCOBY is removed from the liquid, and the kombucha is consumed. This gelatinous, slimy blob, in turn, can be used to ferment new kombucha.

Perhaps kombucha’s greatest claim to fame is that—although it is similar to and carries the same benefits as tea—it is rich in probiotics and antioxidants. It can also kill harmful bacteria and has been purported to help fight several diseases.

Let’s take a look at some of the possible health benefits of kombucha:

1. Contains antioxidants: In preclinical studies, researchers have shown that kombucha, especially that made with green tea, can have antioxidant effects on the liver. In a murine model, researchers found that kombucha tea modulated apoptosis in hepatocytes that was caused by induced oxidative stress. They concluded that this was “probably due to its antioxidant activity and functioning via mitochondria dependent pathways and could be beneficial against liver diseases, where oxidative stress is known to play a crucial role.”
2. Contains the goodness of green tea: Green tea contains polyphenols, which are powerful antioxidants. It stands to reason that kombucha made from green tea will contain the same ingredients and benefits, which include lower cholesterol and blood sugar, as well as reduced risks of prostate, colon, and breast cancers. Green tea has also been studied for its effects on increasing caloric expenditure by increasing metabolism.
3. Is a rich source of probiotics: Similar to kimchi and sauerkraut, kombucha contains probiotics, which are produced during the fermentation of bacteria and yeast. Probiotics are wonderful for balancing the gut microbiome. A balanced gut not only improves immunity and digestion, it can also improve glucose control.
4. Has antibacterial and antifungal properties: What does kombucha have in common with apple cider vinegar? Acetic acid—which is produced in abundance during the fermentation process and has well-known antimicrobial properties and effects. Both black and green kombucha teas also contain antibacterial and antifungal properties.
5. May reduce the risk of heart disease and help manage type 2 diabetes: In preclinical studies, researchers have shown that kombucha may have both hypoglycemic and antilipidemic properties. In 2 studies, kombucha both reduced LDL and increased HDL levels in as little as 30 days. Teas, especially green teas, have been shown to be protective against LDL oxidation.
   
   According to some studies, those who drink green tea can have up to a 31% lowered risk of heart disease. Kombucha made from green tea may offer the same benefit.
   
   Kombucha may also improve liver and kidney function, as well as slow the digestion of carbohydrates, thereby reducing serum glucose levels. Types made from green tea may be particularly beneficial. In a systematic review and meta-analysis of 7 studies that included nearly 300,000 subjects, researchers found that green tea consumption (more than 3-4 cups daily) reduced the risk of diabetes by 18%.

1. May reduce the risk of cancer: In in vitro studies, kombucha’s high concentrations of tea polyphenols—including flavonoids—and antioxidants were effective in preventing the growth and proliferation of cancerous cells. Although the exact mechanism of action is not known, kombucha’s ability to deter cancer cells from spreading is thought to be due to the ability of polyphenols to block mutation of genes and cancer cell growth, as well as promote cancer cell apoptosis.

Of note is that no clinical studies have yet been performed in humans. The CDC has also marked the recent surge in the popularity of kombucha with a recommendation to drink less than 12 oz/day. This may be because kombucha can cause stomach upset, infection, and even allergic reactions.

Kombucha can be purchased online or in stores, or prepared at home. An important caveat, however, is that in order to be healthful, kombucha must be prepared properly. Overfermentation or contamination during preparation can cause serious health problems, and even death. Kombucha consumers might be wise to stick with a well-known and well-established brand, at least when they first try kombucha.

Three more kombucha ingredients are worthy of a final mention: sugar, alcohol, and caffeine.

Loyal kombucha fans and newbies alike should be aware that “booch” contains sugar, with about 6-7 g/serving in many popular brands. Another thing to note is that most bottles contain 2 servings—which basically results in a 12-14 g/bottle. One way to reduce your sugar intake with kombucha is to mix it with seltzer water. Kombucha also contains trace amounts of alcohol because it has been fermented, as well as caffeine.

So, whether you enjoy kombucha regularly, or are thinking of trying it, remember that it may have some very beneficial health effects. Bacteria, yeast, and sugar—what’s not to like?

But also take heed: Even this potential elixir of health is best drunk in moderation. Enjoy your “booch!”