A study coming out in March 2006 not funded by the manufacturer shows that there is a strong link between aspartame (Nutrasweet^®) and cancer.  Rsearchers at the nonprofit European Ramazzini Foundation of Oncology and Environmental Sciences in Bologna, Italy examined 1,800 lab rats consuming this artificial sweetner. They found more lymphomas and leukemias in the rats exposed to aspartame proportionate to the amount they ate.

Dose-response reactions are good indicators of causation of cancer so the link is quite strong.  Opponents of this study cite previous work which did not show a link.  Those studies were either funded by the makers of this poison (wow, surprise surprise they found nothing bad), were poorly done or were too small. Come on FDA, do your job and ban this poison!!!