The Tea on Kombucha
By Elaine Zhu
Illustrated by Lizka Vaintrob
Kombucha has been one of the trendiest drink items in the past few years, becoming a staple in cafes and supermarkets all around the country. For those who have not tried the drink, kombucha is a fermented drink that is usually flavored with different fruity or floral additive ingredients and has a slightly sweet, tart, and fizzy taste. With its steady rise in fame, claims about kombucha’s numerous health benefits have also started to spread to the mainstream. For example, claims have been made that kombucha detoxifies the blood, improves the immune system, aids gut health, and improves intestinal activity. As kombucha becomes a new essential in people’s lives, researchers are continually exploring the health benefits of this effervescent drink.
Before we dive into the scientific claims on kombucha, let’s visit the actual procedure used to make kombucha. Kombucha is typically made of either green or black tea, sugar, and a SCOBY, which stands for “symbiotic culture of bacteria and yeast.” A SCOBY’s components can vary but usually consist of the yeast species Saccharomyces cerevisiae and bacteria species Gluconacetobacter xylinus. These species interact with sugar and tea to create the fermentation in the drink. During the fermentation process, glycolysis occurs, metabolizing sugar to generate energy and ethanol, which contributes to the slightly sour taste of kombucha. The fermentation in kombucha also changes the polyphenols, which are micronutrients found in the tea leaves, and can actually increase their benefits to the body, like improved brain function.
Claims about kombucha’s effect on human health range along a spectrum: some say it can reduce the risk of cancer and others claim it can be toxic to the body. There are actually no studies showing kombucha’s direct effects on humans, but many studies have been conducted with rats or mice. Based on these studies, kombucha does seem to bring about a number of healthy effects on the body. Due to the fermentation process, kombucha contains a plethora of probiotics that are very similar to the healthy bacteria living in our gut microbiomes. Gut microbiomes play an important role in human bodies, and a 2014 study demonstrated that the gut microbiome can even affect the body’s internal immune response. The American Gastroenterological Association lists many benefits of probiotics, including preventing infection, promoting the growth of other healthy bacteria, and stopping harmful bacteria from growing in the gut lining. However, the association also warns that patients with certain chronic health conditions should be careful and consult a healthcare professional before taking probiotics, as it can interfere with their conditions. Other research studying kombucha’s effects on mice suggests that the drink can help heal stomach ulcers or lower cholesterol levels. A study published in The Royal Society of Chemistry examined kombucha using mouse models and found that it “could effectively heal the gastric ulceration…with relative efficacy.” Another study, published in the Journal of the Science of Food and Agriculture, found that kombucha tea had both hypocholesterolemic, cholesterol-lowering, and antioxidant effects. Though this research still needs to be confirmed with human trials, it suggests that drinking kombucha in moderation can be a beneficial addition to one’s diet.
Overall, kombucha has many properties that can lead to a variety of health benefits. With kombucha’s popularity booming, more research with human subjects is needed to fully address the health effects of kombucha on health and wellbeing.