A meta-analysis of several studies has concluded that green and oolong tea can help prevent diabetes and aid in managing type 1 and 2 diabetes.
People who drank more than four cups of green tea per day had a 20-percent lower risk of developing diabetes than people who did not drink four cups of tea.
For individuals with type 2 diabetes, tea creates a tolerance of glucose (which diabetics do not have) and simultaneously blocks glucose from being absorbed into the blood stream; this keeps blood glucose levels under control. Diabetics who drank 6 cups of oolong tea per day saw a reduction in blood glucose levels from 229 to 162 milligrams/deciliter.
Type 1 diabetes is incurable, yet, taken with insulin shots, drinking green tea at a recommended dose of four to six cups daily does aid the body in insulin use. Tea also slows the progression of type 1 diabetes once it has been diagnosed.