Black tea reduces risk of type 2 diabetes, heart disease

Regular black tea consumption each day may reduce the risk of type 2 diabetes and coronary heart disease, according to new research published in Nutrition Bulletin in the UK.

Two independent UK nutritionists, Carrie Ruxton and Pamela Mason, reviewed 40 research papers for this study. Ten papers focused on the links between black tea and diabetes. The other 30 studies examined the association between black tea and coronary heart disease, coronary artery disease, and stroke.

The studies showed that people could reduce their risk of developing type 2 diabetes by drinking one to five cups of black tea every day.

In addition, most of the studies showed significant reduction in heart disease risk with regular black tea consumption. People who drank the most tea had a 30 to 57 percent lower risk of heart disease compared with groups who drank little or no tea.

Drinking black tea regularly also reduced the risk of stroke, arterial stiffness and inflammation, according to the study.

“Mechanistically, these beneficial findings are thought to be due to positive factors in black tea such as flavonoids and theanine, which may help control blood pressure by regulat[ing] nitric oxide production and inhibiting platelet aggregation,” said Ruxton in a statement.

Link between diabetes and heart disease
There's a strong association among diabetes, heart disease and stroke. High blood glucose levels can eventually cause increased deposits of fat on the insides of the blood vessel walls, according to National Diabetes Information Clearinghouse (NDIC). These deposits increase the chance of clogging and hardening of blood vessels.

People with diabetes are twice as likely to have a heart attack or stroke than people without diabetes, according to the American Diabetes Association. Two out of three people with diabetes die from cardiovascular disease.

People with diabetes tend to develop heart disease or have strokes at an earlier age than people without diabetes, according to NDIC. In addition, heart attacks in people with diabetes are more serious and more likely to result in death.

Risk factors for heart disease and stroke include family history, obesity around the waist (central obesity), abnormal cholesterol levels, high blood pressure, smoking, and diabetes itself.

Sources: nutrition-communications.com, American Diabetes Association, National Diabetes Information Clearinghouse