Original sentence: In 2006, the US National Cancer Institute concluded in a study of over 470,000 men and women aged 50 to 69 that there was no statistically significant link between aspartame consumption and leukemias, lymphomas or brain tumors.In a series of studies, the European Ramazzini Foundation of Oncology and Environmental Sciences (ERF) reported what they claimed was a dose-independent, statistically significant increase in several malignancies of rats, concluding that aspartame is a potential carcinogen at normal dietary doses
Edited sentence: In 2006, the  US National Cancer Institute concluded in a study of over 470,000 men and women aged 50 to 69 that there was no statistically significant link between aspartame consumption and leukemias, lymphomas or brain tumors.In two widely criticised and later discounted studies, the European Ramazzini Foundation of Oncology and Environmental Sciences (ERF) reported what they claimed was a dose-independent, statistically significant increase in several malignancies of rats, concluding that aspartame is a potential carcinogen at normal dietary doses