I have some questions I'm looking for answers on, and confirmation on...

I am wondering if anyone has information concerning grains and blood flow, or
constriction of blood flow.  I imagine it may decrease blood flow to the
extremeties as grain eating can lead to MS, I am wondering if this has been
documented, and also how grains effect blood flow to the brain?  Increase or
decrease to brain?

Caffeine effects constriction of blood flow in a particular way, I think it
constricts flow to the brain.  Any confirmation, or do I have it backwards?

Any info on hunter/gatherers having larger veins and arteries, I seem to
recall reading that.  Is this true in athletes regardless of diet?  Or is it
grain-linked?

I am working on it experientially, but any research would be appreciated as it
helps me to speculate about other things, and back up my own experiences with
interesting scientifics.

Thanks,
Aaron