Aug. 1, 2023 – People with type 2 diabetes who drank the fermented tea beverage kombucha for a month lowered their blood sugar from dangerous to safe levels, a small new pilot study from Georgetown University shows.
Kombucha is made from tea fermented with bacteria and yeasts. The drink’s history dates back to 200 B.C. in China, and it has become so popular in recent years that it is stocked in major grocery stores and quick marts. This latest study, published Monday in Frontiers in Nutrition, logged the blood sugar levels of 12 people who drank 8 ounces of ginger-flavored kombucha daily for 4 weeks. It compared that data with their blood sugar levels during another 4-week period of drinking a similar-tasting placebo drink.
The average age of people in the study was 57 years old. Nine were women, six of the people were Black, and the other six were White. Nine were on insulin therapy.
On average, their fasting blood glucose levels decreased from 164 milligrams to 116 milligrams per deciliter after drinking kombucha. The American Diabetes Association recommends blood sugar levels before meals between 70 and 130 milligrams per deciliter, according to a summary of the research published by the university.
“Some laboratory and rodent studies of kombucha have shown promise, and one small study in people without diabetes showed kombucha lowered blood sugar, but to our knowledge, this is the first clinical trial examining effects of kombucha in people with diabetes,” researcher Dan Merenstein, MD, a Georgetown professor of human science and family medicine, said in a statement. “A lot more research needs to be done, but this is very promising.”
A strength of the research was that people were not told to change their diets during the study, Merenstein said.
The kombucha used in the study was made by Washington, DC-based maker Craft Kombucha, which is being rebranded as Brindle Boxer Kombucha. The researchers said the major bacteria and yeasts in kombucha are likely to be similar between varying brands and batches.
More than 33 million people in the U.S. have type 2 diabetes, according to the CDC. If it's not managed, the condition results in high blood sugar levels that can lead to heart disease, vision loss, and kidney disease.
