Consuming This Dark Drink Every Day Halves Diabetes Risk

The drink will help control blood sugar and lower the risk of diabetes by half.

The drink will help control blood sugar and lower the risk of diabetes by half.

Adults who drink tea habitually are more likely to maintain their blood sugar levels and are at reduced risk of type 2 diabetes.

According to a study, consuming dark tea in particular every day halves the odds for developing prediabetes and type 2 diabetes.

Dark tea such as Pu-erh belongs to the fermented teas category so it shouldn’t be confused with regular black tea, although that is also effective.

Adults who consumed dark tea every day were at a 53 percent lower risk of prediabetes and 47 percent reduced chance for type 2 diabetes than non-tea drinkers.

Dr Tongzhi Wu, the study’s co-author, said:

“The substantial health benefits of tea, including a reduced risk of cardiovascular disease and type 2 diabetes, have been reported in several studies over recent years, but the mechanisms underlying these benefits have been unclear.

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.”

Dark tea benefits

The added health benefits might be related to the fermentation method used in producing dark teas.

The tea leaves undergo a microbial fermentation process to keep their quality and flavour intact for a longer period of time.

More importantly, the microbial fermentation increases bioactive compounds such as free amino acids, polysaccharides, alkaloids, and  polyphenols.

These compounds are known for their antioxidant and anti-inflammatory effects, increase levels of good bacteria in the gut, and enhance function of beta cells in the pancreas responsible for the production of insulin.

Lower diabetes risk

In this study, participants were asked what type of tea they consumed (dark, black, green, or other tea) and how often (every day, often, sometimes, or never).

The team looked at the connection between the type of tea, the frequency, and the levels of glucose in the urine samples, insulin tests, and glycaemic status.

The body of a diabetic person has the capacity to reabsorb glucose from the urine resulting in increased blood sugar levels.

The analysis showed that drinking tea every day increased urinary glucose removal from the body and improved insulin sensitivity, lowered the risk of prediabetes by 15 percent and type 2 diabetes by 28 percent.

However, the beneficial health effects were higher for those drinking dark teas than others.

Dr Wu said:

“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 effects on the heart and kidneys.”

Professor Zilin Sun, the study’s co-author, said:

“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.”


The research was presented at the Annual Meeting of The European Association for the Study of Diabetes (EASD), (Wu et al., 2023).

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