I found an article on Diabetes Health about Stevia. Stevia is a plant native to South America that has been used by the natives of Paraguay as a sweetner and medicinal herb. Being 200 to 300 times sweeter than sugar without any of the calories it is gaining popularity as an alternative to artificial chemical sweetners.
The FDA lists Stevia as an unsafe additive because there are insufficient studies to determine its safety as an additive or recommended daily intake values. However Brazil and Japan have approved Stevia as a food additive. I find the FDA's "unsafe" label to be misleading. They don't know if it's safe but they also don't know if it's harmful.
With studies having been performed that seem to show using stevia lowers blood sugar levels and hypertension I'm going to look at it some more. I would love to find a natural sweetener so that I can cut out all of the aspartame and other artificial sweeteners.