Ralph Carabetta wrote:
> but speculate that
> because whole grains have more insoluble fiber they spend less time in
> the digestive tract.

Whole grains contain much of this fiber, mostly celulose.  That
increasing the amount of this inert substance lowers the risk is not
surprising.  Refined grains can be thought of as concentrated grain
extracts.  If you took 1/3 of your bread away and replaced it with pure
cellulose you would have the same result.  About 20 years ago a large
bread manufacturer was caught doing exactly this.  It's "High Fiber"
bread was found to have been merely plain bread to which sawdust had been
added.  Replacing all grain consumption with sawdust probally would
produced even better results in the tests you mention.

Ray Audette
Author "NeanderThin:A Caveman's Guide to Nutrition"
http://www.sofdesign.com/neander