In one study, green tea was given to diabetic rats for three months. The results showed that blood sugar levels were lowered, and that the tea inhibited the development of diabetic cataracts. The researchers recommended that the the effects of tea should be studied in humans as a simple, natural, and affordable way to prevent diabetes, or delay the disease or its complications.
Another study was done in Japan that examined the link between drinking green tea (as well as black and oolong teas) and the development of type 2 diabetes. Researchers found that people who drank 6 or more cups of green tea per day were less likely to develop diabetes than those who drank 1 cup or less per week.
It's important to note that the results of these studies are not conclusive. However, green tea is considered a healthy drink and is also inexpensive and simple to prepare. Thus people may decide that it "doesn't hurt and might help."
To benefit from the effects of green tea, it's suggested that a a 143-pound person needs to drink 4 1/4 - 8 ounce cups of tea every day. Some people believe that by drinking green tea, diabetes may be prevented or delayed and its complications minimized. However, engaging in a healthy lifestyle that includes maintaining a healthy weight, enjoying a wide variety of portion-controlled, nutritious foods, plus a regular exercise program, will do more to lower the risk of developing type 2 diabetes or having the disease progress.