You should ignore any study that claims less than a 100% increase in risk, as it is subject to selection bias, publication bias and statistical insignificance. It's only when the increase in risk is over 100% that you can start to think there is a link. Lots of these studies are done by looking at loads of variables and loads of diseases. Unfortunately, it is a statistical truism that if you look at enough variables and enough outcomes, you will see correlation purely by chance. Unfortunately, the media tend to run with the sillier ones. Also, correlation doesn't imply causation. The cause could be something completely different. So to sum up, worry about breast cancer, but you're probably okay with colon cancer. Rgds