Diabetes-Fighting Power of Dark Tea

These beneficial effects on metabolic control may be due to the unique way dark tea is produced, which involves microbial fermentation, a process that may yield unique bioactive compounds (including alkaloids, free amino acids, polyphenols, polysaccharides, and their derivatives) that exhibit potent antioxidant and anti-inflammatory effects, improve insulin sensitivity and beta cell performance in the pancreas, and change the composition of bacteria in the gut.

How Tea Consumption Impacts Blood Sugar

The most recent cross-sectional study comprised 1,923 persons (562 males and 1,361 women aged 20-80 years) from 8 Chinese provinces. In total, 436 people had diabetes, 352 had prediabetes, and 1,135 had normal blood glucose levels.

Participants comprised both non-habitual tea users and those who had previously consumed only one variety of tea. They were asked about their tea drinking frequency (never, occasionally, frequently, and every day) and kind (green, black, dark, or other tea).

The researchers looked at the relationship between tea consumption and glucose excretion in the urine (as measured by the morning spot urine glucose-to-creatine ratio [UGCR]), insulin resistance (as measured by the triglyceride and glucose index [TyG] derived from fasting plasma glucose and fasting triglyceride levels), and glycemic status (defined as a history of type 2 diabetes, current use of diabetes medications, or an abnormal 75g oral glucose tolerance test).

Diabetes patients frequently have increased renal glucose reabsorption capacity, thus their kidneys collect more glucose, keeping it from being discharged in urine and contributing to higher blood sugar levels.

After controlling for differences in age, gender, and clinical and lifestyle factors, the researchers discovered that drinking tea every day was associated with an increase in urinary glucose excretion (UGCR by 0.11 mmol/mmol) and a reduction in insulin resistance (TyG by -0.23), as well as a 15% lower risk of prediabetes and a 28% lower risk of type 2 diabetes, when compared to never tea drinkers.

These beneficial health effects were strongest for dark tea drinkers, with dark tea drinking linked with an increase in UGCR of 0.16 mmol/mmol and a decrease in TyG of 0.31.

Dark Tea: A Game-Changer in Diabetes Management and Overall Health

According to Associate Professor Wu: “These findings suggest that the actions of bioactive compounds in dark tea may directly or indirectly modulate glucose excretion in the kidneys, an effect, to some extent, mimicking that of sodium-glucose co-transporter-2 (SGLT2) inhibitors, a new anti-diabetic drug class that is not only effective at preventing and treating type 2 diabetes but also has a substantial protective effect on the heart and kidneys.”

Co-lead author Professor Zilin Sun from Southeast University adds, “Our findings suggest that drinking dark tea every day has the potential to lessen type 2 diabetes risk and progression through better blood sugar control. When you look at all the different biomarkers associated with habitual drinking of dark tea, it may be one simple step people can easily take to improve their diet and health.”

Despite the encouraging findings, the authors note that, as with any observational study, the findings cannot prove that drinking tea daily improves blood sugar control by increasing urine glucose excretion and decreasing insulin resistance, but they do suggest that it may help. To validate these findings, they are currently conducting a double-blind, randomised trial to explore the benefits of dark tea on blood glucose control in persons with type 2 diabetes. Furthermore, they cannot rule out the potential that residual confounding by other lifestyle and physiological factors influenced the findings.

References:

1. https:www.eurekalert.org/news-releases/1003267

Source: Medindia