Kombucha, a sour drink made by fermenting sweetened tea, has shown some promise as a health-promoting beverage. Now, its powers may extend to helping those suffering from type 2 diabetes keep their blood glucose levels in check, according to a new small study.
Kombucha has been consumed around the world for centuries as a stimulating health tonic. In modern times, scientific studies have hinted at its ability to act as an inflammation-reducing antioxidant, an antibacterial, and a potential probiotic. The drink has also been studied before for its effects on blood sugar, with one study showing that in healthy people, it was able to hold down spikes in plasma glucose and insulin when consumed with a carbohydrate-rich meal.
Now, research from scientists at Georgetown University Medical Center shows it might also have a similar blood-sugar effect in people with type 2 diabetes, also previously known as adult-onset diabetes.
In a small feasibility study of just 12 people, researchers split the group in two and had one set of participants drink about eight ounces (237 ml) of kombucha a day for four weeks, while the other set drank a placebo. The participants were able to eat their normal diets. Then the groups switched for the next four weeks.
At the end of the trial, both groups who had been consuming the kombucha saw their fasting blood glucose levels drop, on average, from 164 to 116 milligrams per deciliter (mg/dl). That put the levels in the recommended healthy zone of between 70-130 mg/dl.
"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," said study co-author Dan Merenstein, who is a professor of human science and family medicine at Georgetown. "A lot more research needs to be done, but this is very promising."
The team also analyzed the yeast and bacteria found in the beverage used in the experiment, which was specially brewed for the study by Craft Kombucha, a commercial kombucha producer in the Washington, DC area. They found that acetic and lactic acid bacteria were the most prevalent in the drink, as was a yeast known as Dekkera.
Of course, the research team agrees with Merenstein that larger studies need to be conducted before any conclusive links between the drink and blood sugar levels are established, although studies in obese mice have also backed up the correlation and the hope is that it kombucha could join other natural substances as potential natural therapeutics for diabetics.
"An estimated 96 million Americans have pre-diabetes – and diabetes itself is the eighth leading cause of death in the US as well as being a major risk factor for heart disease, stroke and kidney failure," said Chagai Mendelson, the study's lead author. "We were able to provide preliminary evidence that a common drink could have an effect on diabetes. 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-II diabetes."
The research has been published in the journal, Frontiers in Nutrition.
Source: Georgetown University
“ He was involved in the design of the study, writing the manuscript and decision to publish the results. He was not involved in the collection, analyses, or interpretation of data. The remaining author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.”