I sound like a broken record, but just lowering blood sugar numbers may not stop the underlying damage done by having all that insulin released into the body after eating carbs. Yes, low glycemic carbs will do the damage more slowly, but a carb is still a carb.
As for the medicines for diabetes...
http://abcnews.go.com/Health/story?id=3232247&page=1
Are you aware that your brain only gets its energy from glucose? Thanks for the link.