Sugar-free

I just had a drink of this famous softdrink brand which boast of being a sugar-free soda and ahhh! And then a minute later I received an SMS from my sister warning me not to drink the "I just bottomed-up soda coz it contains a sort of cancer-causing chemical".
Was I scared? Not at all...why? Well, I think everything now that we eat, smell, touch, hear or what contains cancer-causing chemicals or whatever.. as what the chain SMS or spam emails told us so far. I was amazed reading these emails and SMS that I suddenly felt that the only THING that doesn't contain cancer-causing substance is...NOTHING!
One thing is for sure though, we are all gonna perish, but how and when is never for sure.