http://www.livepositively.com/en_us/healthy_alternative?WT.srch=1#/healthy_alternative/aspartame
Aspartame, the sweetener in Diet Coke, is one of the world's most thoroughly studied food ingredients, with more than 200 scientific studies confirming its safety. It has been approved for use in carbonated beverages by the US Food and Drug Administration (FDA) for more than 25 years. More than 100 other countries also permit its use in a variety of foods and beverages.