In a type 2 diabetes study, researchers measured antioxidant levels in the diets of 1,018 men and women, aged 38 to 52. Some did not have diabetes, some were pre-diabetic with elevated fasting blood sugar levels, and some had type 2 diabetes. In all three groups, as antioxidants in the diet increased, average blood sugar levels decreased. Differences in age, sex or amount of physical activity did not change the results, although antioxidants did not change blood sugar levels in those who were obese. Doctors believe that antioxidants can lower the oxidative stress that promotes diabetes and may also help pancreatic cells produce insulin.