Black Tea and Diabetes: Protecting the Body

Learn more about World Tea Expo’s new Tea Up for Health education track.


A new study from Framingham State University finds potentially positive effects of black tea on the risk of developing type 2 diabetes, according to Frontiers in Nutrition.

Framingham-photo_15988.Under the direction of Lisa Striegel, a team of scientists from Framingham State University in Framingham, Mass. and Technische Universitaet Muenchen in Freising, Germany, examined the impact of black tea and black tea pomace in inhibiting the absorption of glucose in the body.

Diabetes is a serious health condition that is growing at a massive scale globally. In 2013, the International Diabetes Federation estimated that 387 million people suffered from the condition and they projected that it could increase by 205 million more by 2035. Type 2 diabetes, the subject of this study, makes up 90% of these cases and is caused when glucose levels in the blood become too high because the insulin in the body cannot modulate those levels. Phenols have been examined by nutrition scientists as offering a protective effect by preventing some carbohydrates from hydrolizing to glucose. Tea’s high levels of polyphenols make it an interesting subject for researchers.

For use in this study, tea was steeped for 30 minutes at 90°C. The tea was then filtered. Phenolic compounds were extracted from the steeped beverage, as well as the filtered contents and the dried leaves. The compounds were then examined for their ability to stop the work of the enzymes, primarily α-glucosidase, that hydrolize carbohydrates. They found that the compounds did have this effect, particularly the high molecular weight phenolics. The study also revealed that the effect is improved with fermentation.

“We identified that both black tea water extract and black tea pomace have potential for type 2 diabetes prevention,” the paper concludes.

Green tea has been studied related to diabetes previously and this study confirms that black tea may have similar effects.

Source: Independent UK and Frontiers in Nutrition