My own experience took place long before I ever _heard_ of Betty or the s.m.n Aspartame wrangle.
I’m an aerobics instructor. During classes, I chew gum to keep my mouth and throat moist for cueing. When I started out, I was using an Aspartame-sweetened chewing gum, and I chewed quite a lot of it. Over a period of about three months, I began experiencing joint pain in my elbows mostly, but also wrists and fingers. There didn’t seem to be any source for the pain – I don’t do heavy weights, nor am I a proponent of the use of hand weights during my classes, so overuse injury seemed out of the picture. To make a long story short, I started examining my routines, both physical and nutritional, to determine what was causing the problem.
The only thing which I could identify as being a major change from the time prior to teaching aerobics was the gum, so I changed over to a sugar-sweetened gum just to see. Now, this is the part which makes little sense to me – the pain stopped within a couple of days. Mind you, it wasn’t ever severe or debilitating, just a nagging, annoying little ache, but it really did exist, and now it was gone!
I wasn’t entirely out of the Aspartame-sweetened gum, and I didn’t see any way it could really be the problem, so I took up chewing it again, and the aches came back within days. It is well to note that I was not using a single brand-name of the gum – just grabbed whatever was near the checkout. So, I stopped chewing the stuff again, and the pain went away again.
Now I don’t use Aspartame _anything_ anymore, and the only time I get joint pain is when there is some identifiable cause.
As I said, it’s anecdotal. Your mileage may vary, and you may not believe it at all. I don’t really care whether or not you do – I merely present it as my own experience – not as any sort of scientific evidence for or against Aspartame use.