Thanks for the excellent information Steve. 

I've got pdf copies of 7 or 8 large studies since 2000 that all report that
grain fiber has no impact on colorectal cancer risk if anyone is interested
in reading them. 

The only reason I can see for the continuing study of this issue is that
there are many peer reviewed publications that report a protective impact of
insoluble grain-derived fiber. Some are repeating this whole-grain mantra
without citing a source for their "misinformation" although there are many
sources out there. 

Best Wishes, 
Ron Hoggan