We are stardust, we are golden, we are caught in the devil's bargain,
Most of the atoms in your body have been through at least one supernova and are probably more than 6 billion years old. The lighter atoms, and in particular the Hydrogen were probably formed shortly after the Big Bang so are more like 13.5 billion years old.
http://www.pbs.org/wgbh/nova/space/star-in-you.html