Kombucha: Power Drink for Blood Sugar and Diabetes

by Mary Shomon Patient Advocate

Have you noticed that supermarkets and health food stores these days are overrun with a wide choice of a bottled drink called kombucha? Kombucha is called a “functional food” — a food that has specific health benefits. If you’re new to kombucha, learn more about this fermented tea, what it tastes like, and its health benefits, especially for people with diabetes.

Taking a scoby out of a jar of kombucha.

What is kombucha?

Kombucha is a drink that is made by fermenting sugared black or green tea. A special culture of yeast, fungus, and bacteria, known as a “scoby” – a symbiotic culture of bacteria and yeast — is added to the tea. The scoby is usually round and jelly-like, and looks like a mushroom cap.

The scoby starts the tea’s fermentation. Over time, the bacteria grow, and remove much of the sugar in the drink.

Brewing kombucha.

What does kombucha look like?

When the kombucha is ready, the scoby is removed. Even after bottling, however, the active cultures can continue to grow. You may notice thin strands of active culture in store-bought kombucha or your own home brew.

Woman drinking kombucha.

What does kombucha taste like?

Kombucha has a tangy and tart taste, with some degree of fizziness. Some people say that kombucha tastes like a tart sparkling apple cider. Others have described kombucha as tasting like a dry, non-alcoholic champagne. Assorted flavors – including fruits and spices like ginger or cinnamon — are often added during production.

Health benefits of kombucha graphic.

The health benefits of kombucha

Jars of kombucha fermenting.

The benefits of acetic acid in kombucha

When it’s fermenting, kombucha also produces acetic acid, which is also found in vinegar. The acetic acid in kombucha has the ability to kill many harmful and infectious bacteria, including staphylococcus, E. coli, salmonella, and H. pylori (the bacteria that causes ulcers.)

Man measuring his blood sugar levels.

Kombucha for blood sugar and diabetes

A 2018 study found that kombucha could significantly reduce blood sugar and hemoglobin A1C levels, and increase insulin production. It also delayed absorption of LDL (“bad”) cholesterol and triglycerides, and significantly raised HDL (“good”) cholesterol levels. The kombucha also seemed to protect both liver and kidney function.

An earlier 2012 study compared regular black tea and black tea kombucha. It turned out that the kombucha was better than plain tea at lowering blood sugar.

Jar of kombucha fermenting.

Polyphenol power

Components of kombucha known as polyphenols may help prevent the damage or death of beta cells in the pancreas. There is even evidence that the polyphenols may help beta cells regenerate. As a result, experts will be conducting more studies on the use of kombucha to prevent and treat diabetes.

Green tea kombucha.

The benefits of green tea kombucha

Drinking green tea kombucha has even more benefits for people with diabetes.

One study compared the effects of green and black tea kombuchas on blood sugar and total cholesterol levels in people with in diabetes. Compared with black tea kombucha, green tea kombucha resulted in significantly lower blood glucose, cholesterol, and triglyceride levels. The green tea kombucha also increased HDL cholesterol.

Studies have also shown that green tea on its own reduces blood sugar and improves insulin sensitivity.

Women buying drinks at a health food store.

Store-bought kombucha

If you want to try kombucha, you’ll find many brands of kombucha available at your supermarket and favorite health food store. One of the best-known brands is GT's Living Foods. I'm a fan of GT’s "Original" kombucha. It’s delicious! I also love GT's “Synergy” line of kombucha drinks, especially Cosmic Cranberry. They have many other flavors, including watermelon, lemonade, mango, guava, ginger, strawberry, and cherry. Another popular brand of kombucha that is widely available is Kevita.

Woman brewing kombucha at home.

Brewing your own kombucha

If you become a kombucha fan, you may want to learn how to brew your own at home. Amazon sells a popular kombucha brewing kit with everything you need – even the scoby — to make your own kombucha at home. If you’re going to brew your own kombucha, make sure you carefully follow preparation guidelines and avoid contamination. Also, be careful to avoid these common kombucha brewing mistakes.

Scoby for kombucha.

Kombucha concerns

  • Some people are allergic to kombucha ingredients.
  • To avoid contaminated kombucha, buy bottled kombucha — or your scoby cultures — from reputable companies or brewers.
  • Home brewers should avoid contamination by carefully following safety guidelines when handling your scoby and preparing kombucha.
  • Experts recommend that home brewing of kombucha be done in glass bottles. Ceramic and other materials sometimes react with the kombucha and releases toxins.
Mary Shomon
Meet Our Writer
Mary Shomon

Mary Shomon is a patient advocate and New York Times bestselling author who empowers readers with information on thyroid and autoimmune disease, diabetes, weight loss and hormonal health from an integrative perspective. Mary has been a leading force advocating for more effective, patient-centered hormonal healthcare. Mary also co-stars in PBS’ Healthy Hormones TV series. Mary also serves on HealthCentral’s Health Advocates Advisory Board.