Kombucha tea, a fermented beverage commonly sold in stores, reduced fasting blood glucose levels better in those who drank it compared with those who didn’t, according to a new study.
Results from the 12-person trial were published in Frontiers in Nutrition. The study was conducted by a team from Georgetown University, the University of Nebraska–Lincoln and MedStar Health. Based on the findings, the team wants to conduct a larger study.
Kombucha tea has been around for centuries, but it only got popular in the United States during the 1990s. Some people say it does wonders for energy levels and immunity, but research is lacking on confirmed health benefits.
“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,” Dan Merenstein, MD, a professor at Georgetown, said in a statement. “A lot more research needs to be done, but this is very promising.”
For the study, people drank approximately 8 ounces of kombucha tea each day for four weeks. Another group didn’t have the tea, but didn’t know it.
Then the researchers waited two months and made changes. The group that formerly had the tea got a placebo drink, and the people formerly on the placebo drink got actual kombucha tea. They drank the same amount daily for four weeks. No one knew when they were drinking real kombucha.
People who got it were drinking Craft Kombucha, a popular brand that also goes by the name Brindle Boxer Kombucha.
The tea seemed to lower average fasting blood glucose levels after four weeks, from 164 to 116 milligrams per deciliter, but there wasn’t a big difference seen in those on the placebo.
Not only were there some results in terms of what the tea did, but the researchers wanted to know what ingredients made the tea seemingly so effective at lowering blood sugar. The drink is made up mostly of lactic acid bacteria, acetic acid bacteria and Dekkera yeast.
“Different studies of different brands of kombucha by different manufacturers reveal slightly different microbial mixtures and abundances,” Robert Hutkins, PhD, a researcher from University of Nebraska–Lincoln and senior author, said. “However, the major bacteria and yeasts are highly reproducible and likely to be functionally similar between brands and batches, which was reassuring for our trial.”
“We were able to provide preliminary evidence that a common drink could have an effect on diabetes,” Chagai Mendelson, MD, lead author who was working in Merenstein’s lab at Georgetown while completing his residency at MedStar Health, also said. “We hope that a much larger trial, using the lessons we learned in this trial, could be undertaken to give a more definitive answer to the effectiveness of kombucha in reducing blood glucose levels, and hence prevent or help treat type 2 diabetes.”
