Discover the sweet solution: How kombucha can lower blood sugar in type-2 diabetes

A small pilot study shows that fermented tea may benefit health in more extensive trials.

Type 2 diabetes diagnosis

There are several ways to diagnose diabetes. Each course usually must be repeated on a second day to diagnose diabetes. Healthcare providers should conduct testing (such as in a doctor’s office or lab) [1]. 

You may not need a second test for diabetes if your doctor determines your blood glucose (blood sugar) level is very high or if you have classic symptoms of high blood glucose along with one positive test.

Learn more about tests like the AIC, FPG, OGT and Plasma Glucose Test from the American Diabetes Association.

What is kombucha

A zesty and effervescent fermented tea rich in probiotics, antioxidants and enzymes, kombucha supports detoxification and may contribute to the well-being of the liver and digestive system.

It is thought that kombucha originated in China or Japan. Black or green tea is fermented for a week or more after bacteria, yeast and sugar strains are added [2].

Kombucha for T2D?

According to a clinical trial conducted by Georgetown University, Nebraska-Lincoln and MedStar Health, people with T2D diabetes who drank fermented tea drink kombucha for four weeks had lower fasting blood glucose levels than those who consumed a similar-tasting placebo drink [3].

Recently reported in Frontiers in Nutrition, this finding from a pilot 12-person feasibility trial points to the potential for a dietary intervention that could help lower blood sugar levels in people with diabetes and also establishes the basis for a larger trial to confirm and expand upon these results.

The effects of kombucha on people with diabetes have been studied in laboratory and rodent models. Still, to their knowledge, this is the first clinical trial to examine the effects of kombucha on people with diabetes, says study author Dan Merenstein, MD, professor of Human Sciences at Georgetown University School of Medicine and family medicine.

The crossover design involved one group of people drinking about eight ounces of kombucha or a placebo beverage daily for four weeks. Following two months to ‘wash out’ the biological effects, the kombucha and placebo were swapped between groups for another four weeks. Neither group was told which drink they were receiving at the time.

Promising results

After four weeks, kombucha appeared to lower average fasting blood glucose levels from 164 to 116 milligrams per deciliter, while the difference with placebo was not statistically significant [4]. The American Diabetes Association recommends blood sugar levels between 70 and 130 milligrams per deciliter before meals.

Researchers also examined the composition of fermenting microorganisms in kombucha to determine which ingredients might be the most active. An RNA gene sequencing analysis confirmed that the beverage contained about equal amounts of lactic acid bacteria, acetic acid bacteria, and a yeast called Dekkera.

Craft Kombucha, a commercial manufacturer in Washington, DC, provided the kombucha used in this study. The product has been rebranded as Brindle Boxer Kombucha.

According to Robert Hutkins, PhD, University of Nebraska-Lincoln and the study’s senior author, microbial mixtures and abundances in different kombucha brands differ slightly between manufacturers [3].

Many Americans have pre-diabetes, and diabetes is the eighth leading cause of death in the United States. It also increases the risk of heart disease, stroke, and kidney failure, according to Chagai Mendelson, MD, who completed his residency at MedStar Health while working in Merenstein’s lab at Georgetown [3]. 

The study provided preliminary evidence that a typical drink could affect diabetes. As a result of the lessons learned from this trial, a more extensive test may be conducted to determine whether kombucha effectively reduces blood glucose levels, which can help prevent or treat T2D.

Learn further information on the use of kombucha tea as an anti-hyperglycemic agent in diabetics by reading this clinical trial article. 

[1] https://diabetes.org/diabetes/type-2[2] https://www.ncbi.nlm.nih.gov/pubmed/26796581[3] https://health.georgetown.edu/news-release/drinking-kombucha-may-reduce-blood-sugar-levels-in-people-with-type-2-diabetes/[4] https://www.frontiersin.org/articles/10.3389/fnut.2023.1190248/full

Photograph: iloli/Envato