According to a study that appeared in the European Journal of Oncology, rats who had aspartame adminstered with their feed showed a statistaically significant increase of 62% in lymphomas and leukemias compared to those in the non-aspartame fed group. The researchers postulate that the increase in risk could be related to methanol, a metabolite of aspartame, which is metabolized to formaldehyde and then to formic acid, in both rats and humans. The carcogenicity of formaldehyde cannot be ignored as evaluated recently by the International Agency for Research on Cancer (IARC) showing strong evidence with leukemias in humans.
Steve - as for those who read this blog daily, you know that we hardly ever mention non-human studies. Although, in the case of aspartame, there are no human studies to show safety. The aforementioned statistics are sobering. If this does not spur on the world to do human trials on aspartame, the least we can do is avoid it like the plague!