Aspartame

Wow.

So, a concerned and intelligent friend of mine send me an article on the side effects of Aspartame, which include a host of fuzzy neurological symptoms, many of which I sometimes seem to display. I read the article, decided I didn't really know much about the chemical other than the fact that it pops up from time to time as having caused "health problems"

Turns out, the note she sent me was already listed as an Urban Legend.
Okay, not a promising start, but also not really evidence either way.
Turns out it's surprisingly hard to get a decent review of Aspartame that isn't sponsored by someone with a clear interest in it being safe/unsafe. Even the wiki entry is surprisingly unscientific claiming:

"Some point to the rapid breakdown of aspartame causing spikes of phenylalanine and aspartic acid which can upset chemical balances and cross the blood-brain barrier, as well as unnatural spikes in levels of methanol in places the body does not normally encounter it (like within metabolic processes), raising concerns as to its safe containment and elimination."

There are victim groups, lawsuit groups, consipracy groups etc. etc. Jesus Christ folks! It's not like the want to put floride in your water!

After digging through a couple of dozen sites, I finally found a decent one with some science in it.

Bottom line: You're at more risk from fruit juice than aspartame.