Sugar free drinks? health risk?

This is not connected to the lager/vodka question previously asked but also to the drinks i supply my child s with. i have heard that the artificial sweeteners can contain chemicals linked with cancer such as aspartame and phenylalanine? someone got any info on this? should i go for full fat, full sugar "fruit shoot" type drinks for them or the sugar free version with sweeteners?
Answer
There`s only one drink that`s` safe.water ! and where i live even thats` questionable !