Why is tea good for you?

“Tea consumption, especially green tea, may not be the magic bullet, but it can be incorporated in an overall healthy diet with whole grains, fish, fruits and vegetables, and less red and processed meat,” says Qi Sun, assistant professor in the Department of Nutrition, Harvard School of Public Health.

Some of the best circumstantial evidence on tea and health has come from large, long-term studies of doctors and nurses based at the Harvard School of Public Health: the female Nurses’ Health Study and the male Health Professionals Follow-up Study.

By following these groups for long periods, researchers determined that tea drinkers are less likely over time to develop diabetes, compared with people who drink less tea. That makes sense, in light of research showing that polyphenols help regulate blood sugar (glucose).

As glucose rises in the blood, insulin shoots in from the pancreas to signal the cells to start metabolizing the glucose. Polyphenols seem to assist this process. “It makes cells more sensitive to insulin’s effects,” Sun says.

Some research suggests that tea drinking might be associated with lower risk of cardiovascular disease. That’s consistent with the lower risk of diabetes, which contributes to heart disease and stroke. Also, substances in tea may help to lower blood pressure or improve cholesterol.

Excerpt from Harvard Health Publishing