I drink stupidly hight amounts of Pepsi Max, we're talking multiple litres per day...once upon a time, a dietician gave me a very solid lecture about my beverage choice and suggested tea and coffee, both things I cannot stand the taste of...she then moved on to flavoured water, advising me how this would be much better for me, in general, and how my continued drinking of pepsi max, with the devilish aspartame in it would cause me to get cancer and all sorts of other ailments. To say we agreed to disagree would be painting a very rosy picture of how that conversation ended.
About 6 months later, I was reading a newspaper in work, which was talking about aspartame and other sweeteners, and their health impacts, which contained a picture of the same bottle of water she'd tried to convince me to drink, with a scientist quote beside it, saying this particular brand should be avoided like the plague as the combination of ingredients in it had been linked to a spate of people in the states developing chronic migraines.
I'm sure there will be things about aspartame that make it bad, same as any chemical additives, but if by itself, it was enough a singular component to make someone sick, I'd be patient 0 based on nothing other than the exposure levels I have to it - I don't just poke the lion with a stick when it comes to this stuff, I roll myself in eau du zebra and put my head right inside the lions mouth. And oddly enough virtually the only health problems I *DON'T* have are the ones linked to consuming aspartame lol =)