Same this side of the ocean: http://news.independent.co.uk/health/article2586652.ece
Caution: Some soft drinks may seriously harm your health - Independent Online Edition > Health

You don't wanna know what is in your food all additives must be spelled out fortunately so a consumer can decide for him/herself. In the artificial sweetener department, aspartame has a 'warning' notice on the sugar sashells. Certain diet drinks have loads of it.... was rejected many years ago by the US FDA, not even considered by the Europeans and then heavy handedly lobbied into our foodstuffs.

Thought warning was just for phenylketonurics. The 2 amino acids (aspartic acid and phenylalanine) used to make it are naturally occurring. L-phenylalanine is an essential amino acid.

Research has been done on aspartame for over 20 years. There's no definitive proof that it's in any way toxic. There's much more evidence for things people eat on a daily basis and don't think twice about - such as hydrogenated oils and trans-fatty acids (more or less synonymous).