This is quite interesting...it's not "scientific" Charles, but give it a read:
http://users.westnet.gr/~cgian/upi.htm
"The NutraSweet Co. also has paid up to $3 million a year for a 100- person public relations effort by the Chicago offices of Burson, Marsteller, a former employee of the New York PR firm said. The employee said Burson Marsteller has hired numerous scientists and physicians, often at $1,000 a day, to defend the sweetener in media interviews and other public forums. Burson Marsteller declines to discuss such matters."
You do NOT have a team that large and a budget that big for an INGREDIANT unless you know you have to defend it. Remember, it's not like these PR people are out there promothing the actual products using it.
The bottom line for me is that there are some things that mankind really screws up when they try to emulate nature - I think aspartame is one of them.
I turned this article series into an MS Reader file -
download it and give it a read.