Could drinking tea every day reduce type 2 diabetes risk?

ISLAMABAD, Oct 05 (Online): Type 2 diabetes occurs when the body is unable to regulate blood sugar levels, usually because the body stops responding correctly to insulin, the hormone that controls blood glucose. If uncontrolled, type 2 diabetes can lead to high blood pressure, cardiovascular disease, nerve damage, vision loss, and kidney damage.
The condition currently affects around 462 million peopleTrusted Source worldwide and numbers are rising. In the United States alone, more than 37 million people have diabetes, and 96 million have prediabetes, a condition where blood glucose levels are higher than they should be, which often leads to type 2 diabetes.

Lifestyle changes are the best way to reduce the risk of developing type 2 diabetes and alongside medication, to control symptoms of the condition. Doctors recommend a healthful diet, including plenty of fresh vegetables, whole grains, protein, and heart-healthy fats, together with regular exercise and maintaining a healthy body mass indexTrusted Source (BMI).
Now, an observational study from China suggests that people who drink tea regularly, particularly dark tea, may improve their blood glucose levels and decrease insulin resistanceTrusted Source, reducing the risk of type 2 diabetes.

The study, by the University of Adelaide, Australia, and SouthEast University, China, was presented at this year’s Annual Meeting of The European Association for the Study of Diabetes (EASD), Hamburg (Oct. 2–6 Oct).

“Given that this is a cross-sectional study with only a small-ish amount of participants (1,923) in China, it is hard to apply the results to a broader population, and we cannot establish a cause-effect relationship between dark tea and its role in glucose regulation in our bodies.”
— Dr. Sue Inonog, internal medicine, primary care doctor at Harbor Health in Austin, Texas, who was not involved in the study.

Regular tea drinkers have better blood glucose control
A total of 562 men and 1,361 women ages 20–80 years from eight provinces in China took part in the study. Of them, 436 had diabetes, 352 had prediabetes, and 1,135 had healthy blood glucose levels.
Of the 1,923 people, 1,000 were habitual tea drinkers. They drank different types of tea — 300 reported drinking green tea, 125 black tea, 521 dark tea, and 54 people drank other types of tea. All drank their tea without milk or sugar.

The researchers looked for any association between the frequency and type of tea consumption and the excretion of glucose in the urine, which they assessed using the morning spot urine glucose-to-creatine ratio (UGCR) Trusted Source. They also measured insulin resistance and recorded glycaemic status (a history of type 2 diabetes, current use of antidiabetic medications, or an abnormal 75g oral glucose tolerance test).
They found that people who drank tea every day excreted more glucose in their urine and had reduced insulin resistance. They also had a 15% lower risk for prediabetes, and a 28% reduced risk for type 2 diabetes compared with those who never drank tea.