COMMENT: If you Google "what causes cancer" you'll probably scare yourself silly.
You may read, for example, that canned food is "full of preservatives and other substances" that may increase your chance of developing cancer.
Refined sugar is described as a "main culprit" in cancer-causing diets, and white bread is also on the scary list. So are random things such as farmed fish, microwave popcorn and vegetable oils.
It's possible that if you ate nothing but white bread sprinkled with white sugar you'd be at higher risk for cancer. But the evidence seems scant that any of the other things is going to significantly shorten your life. For the record, there's little evidence that antiperspirant, cellphones, power lines or hair dye cause cancer either.
We do know, though, that according to the World Health Organization up to half of cancers are preventable.