A recent study conducted by researchers from the University of Adelaide in Australia and Southeast University in China has highlighted the potential of daily black tea consumption in significantly lowering the risk and progression of type 2 diabetes by enhancing blood sugar control.
The study’s findings showed that individuals who regularly consumed black tea experienced a 53% lower risk of prediabetes and a 47% lower risk of developing type 2 diabetes. Even after accounting for established risk factors such as age, gender, ethnicity, body mass index (BMI), average arterial blood pressure, fasting plasma glucose, and cholesterol levels, these results remained consistent.
Associate Professor Tongzhi Wu, co-lead author of the study, explained, “Our findings hint at the protective effects of habitual tea drinking on blood sugar management via increased glucose excretion in urine, improved insulin resistance, and thus better control of blood sugar. These benefits were most pronounced among daily dark tea drinkers.”
The unique production process of dark tea, involving microbial fermentation, is believed to underlie the observed beneficial effects on metabolic control. This process generates distinct bioactive compounds, including alkaloids, free amino acids, polyphenols, polysaccharides, and their derivatives, which possess powerful antioxidant and anti-inflammatory properties. These compounds enhance insulin sensitivity, improve the functioning of pancreatic beta cells, and influence the composition of gut bacteria.
The study examined 1,923 adults from various Chinese provinces, with different glycemic statuses. The participants were categorized based on the frequency and type of tea consumption, including green, black, dark, or other varieties. The association between tea consumption and various factors related to glucose excretion, insulin resistance, and glycemic status was explored.
The study suggests that the bioactive compounds in dark tea may modulate glucose excretion in the kidneys, mimicking the effects of sodium-glucose co-transporter-2 (SGLT2) inhibitors, a class of anti-diabetic drugs known for their effectiveness in preventing and treating type 2 diabetes.
Professor Zilin Sun, co-lead author, noted, “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.”