I agree with Joe.
One important thing to remember about the media: it preys on the public with scare tactics. The propaganda and lies are similar in nature as to what we see on the internet all the time. Just think of how many spam/chain mails we get with the most interesting and provocative information so cleverly put-together only to to find that it wasn't true after referring to snopes.com. after we foolishly took the time to pass them on to everyone in our address books.
If you're worried about something like Diet Coke, then it's probably the phosphoric acid, caffine and corn syrup that you should be more concerned with.
You could take this a step further and say it is perhaps the corporations that purvey the products in question that issue phony, sham-like press releases based on bogus test results that use the media to implant information such as this in an effort to dissuade people from buying some competitor's product and to look more favorably at their own.
I got my whopping AN growth after never having touched Aspartame or ever even having owned a cell phone.
Paul