The effects of tea on diabetes have been studied extensively around the world. Some evidence suggests that tea consumption may reduce the risks of developing diabetes and help control diabetes in patients who already have this condition. People with diabetes interested in the effects of tea on the disease can ask their doctors about the latest research and whether tea would be an appropriate addition to their treatment plan.
It is important to be aware of two issues when looking at studies involving tea and health. The first is that they focus on Camellia sinensis, not herbal tisanes sometimes known as “teas.” Secondly, there are many different kinds of tea, including white, green, oolong, and black tea. Although they originate from the same plant, the various types of teas have different chemical profiles because of different processing methods.
It appears that the effects of green, oolong, and black tea on diabetes are all beneficial. People with diabetes cannot rely on tea alone for management, but drinking tea can keep blood sugar levels lower, limiting damage caused by high blood sugar. Green tea seems to preserve tissue in the body that can produce insulin, and may reduce the size of insulin dosages. In addition, drinking tea lowers blood pressure and can contribute to a reduction in diabetes complications like eye damage and injuries to the blood vessels.
People who do not have diabetes may experience a reduction in risk if they drink tea regularly. Many different factors are involved in the development of diabetes, and drinking tea on its own will not eliminate the chances of contracting this disease. People also need to control their weight, exercise, and eat a balanced and healthy diet. Many studies on the effects of tea on diabetes have focused on populations in China, Taiwan, and Japan, where many people are thin and the diet can vary considerably from that consumed in other areas of the world. The reduction of diabetes risk in these populations thus cannot be entirely attributed to tea.
The effects of tea on diabetes involve complex interactions between the chemical compounds in tea. Depending on how tea is handled and brewed, individual cups may be more or less effective as part of a plan for managing or preventing diabetes. Additives like sugar and cream will also have an impact on how the tea behaves in the body; someone drinking heavily sweetened tea, for example, will respond differently than a person who takes tea without sugar.