Ask the RD

Question: I’ve been seeing lots of kombucha teas in the beverage section of the market. What is kombucha, and why is there so much hype behind it?

Answer: The bottled kombucha beverages you have noticed are effervescent sweetened tea (usually black tea) that is fermented with kombucha. The kombucha itself is a symbiotic colony of bacteria and yeast. A kombucha beverage is made by steeping the kombucha culture in tea and allowing it to ferment. The result is a beverage that contains a host of vitamins, chemical compounds and vinegar, which is why the beverage tends to be very tart.

Used for centuries in Asia, kombucha has been said to cure, alleviate or prevent a host of conditions, the broad claim being that it detoxes the body and energizes the mind. Specific claims have included its ability to lower cholesterol, blood pressure and inflammation, enhance the immune system and increase cognitive abilities.

Unfortunately, many of these health claims have been based on anecdotal information and are not backed by scientific and experimental studies. This does not mean kombucha is void of any positive health benefits; it simply means there is no scientific evidence to support the claims.

There is evidence supporting the role of fermented products in promoting intestinal health. Considering that kombucha tea is a fermented tea, it has been suggested it may have a probiotic effect. This is just one reason to think kombucha may offer positive health effects for humans; however, more research is needed to separate real claims from those that are unjustified.

In terms of the bottled beverages you have noticed filling the shelves, be sure to look carefully at the nutrient labels. Many flavored varieties (guava, ginger, Asian pear) can pack up to 24 grams of sugar per 14-ounce bottle—that’s the equivalent of 2 tablespoons of sugar! Kombucha is very tart (many feel it tastes like vinegar), but 2 tablespoons of sugar is a bit excessive for any 14-ounce beverage.