Dark tea consumption on a regular basis might substantially mitigate the risk and advancement of type 2 diabetes by boosting glucose management, a joint research by the University of Adelaide and Southeast University reveals.
This positive effect is thought to arise from the distinct microbial fermentation that occurs in the production of dark tea, resulting in bioactive substances beneficial for blood sugar regulation. Studies suggest potential mechanisms by which drinking tea could decrease the chances of acquiring prediabetes and type 2 diabetes.
The risk and progression of type 2 diabetes in adults may be reduced through daily dark tea intake, as shown in findings presented at the recent Annual Conference of The European Association for the Study of Diabetes (EASD) in Hamburg (from 2nd to 6th October).
This research, conducted by experts from the University of Adelaide in Australia and Southeast University in China, showed that, in comparison to those who don’t drink tea, daily dark tea drinkers experienced a 53% decreased risk of prediabetes and a 47% lower risk of type 2 diabetes.
This was observed even after considering known diabetes risk factors such as age, gender, race, BMI, arterial blood pressure, fasting glucose levels, cholesterol levels, alcohol consumption, smoking habits, family diabetes history, and consistent exercise.
The advantageous metabolic impacts might be attributed to the distinct method of producing dark tea. It undergoes microbial fermentation, producing unique bioactive elements like alkaloids, free amino acids, polyphenols, polysaccharides, and derivatives.
These compounds possess strong antioxidant and anti-inflammatory properties, enhance insulin responsiveness and pancreatic beta cell function, and alter gut bacterial composition.
This contemporary cross-sectional research encompassed 1,923 adults (comprising 562 males and 1,361 females aged between 20 and 80) residing across eight Chinese provinces.
Among them, 436 had diabetes, 352 were prediabetic, and 1,135 maintained regular blood sugar. The cohort included sporadic tea drinkers as well as those committed to a single tea type.
Their tea drinking habits, both in terms of frequency and variety (e.g., green, black, dark, or another kind), were assessed. The team evaluated the correlation between the frequency and variety of tea intake, urinary glucose discharge (determined by the morning spot urine glucose-to-creatinine ratio [UGCR]), insulin opposition (ascertained through the triglyceride and glucose index [TyG] sourced from fasting glucose and triglyceride counts), and glycaemic condition (defined by a history of type 2 diabetes, ongoing antidiabetic drug use, or an irregular 75g oral glucose tolerance test).
For diabetic individuals, their kidneys often reclaim more glucose, preventing its urinary release, and leading to elevated blood glucose levels.
After adjusting for variations in age, gender, clinical and lifestyle elements, the data revealed that daily tea consumption correlated with increased glucose expulsion in urine (UGCR by 0.11 mmol/mmol) and diminished insulin resistance (TyG by -0.23), as well as a 15% reduced prediabetes risk and 28% lesser risk for type 2 diabetes, in contrast to non-tea drinkers.
These beneficial outcomes were particularly pronounced among dark tea enthusiasts, with daily dark tea drinking correlating with UGCR increasing by 0.16 mmol/mmol and TyG decreasing by 0.31.
Nevertheless, the researchers emphasize the interpretive limitations of their observational data, indicating that while the results are encouraging, they cannot conclusively claim that daily tea drinking directly enhances glucose control through increased glucose release in urine and diminished insulin resistance.
To affirm their conclusions, they are initiating a double-blind, randomized study focused on dark tea’s impact on glucose management in type 2 diabetes patients. Moreover, potential influences from other unaccounted lifestyle and physiological variables on the findings cannot be discounted.