We use Coconut Palm Sugar in place of both brown and white sugar. It has a low glycemic index and is an excellent cup for cup replacement for sugar. (Those who must avoid corn, be sure that your sugar is corn free. Coconut palm sugar is corn free.)
If you prefer to use cane sugar and are following a corn-free diet please check the Corn-Free Foods Blogspot for an up-to-date listing of safe sugars.