It appears that that the Cuna (kuna) tribe in Panama are long time users 
of Cocoa.  The benefits of cocoa consumption is significant with respect 
to cancer and heart disease.  I don't think one can say rationally that 
hunter gatherers never touched the stuff and had no use for it.

http://en.wikipedia.org/wiki/Cocoa

Personally, I'm a pragmatist when it comes to diet and nutrition which 
for me means generally to go with what's best DNA wise and in that 
regard I think the paleo diet has a lot going for it  ... BUT ... I'm 
not about to make a religion out of that given that advances in 
knowledge bring benefits above and beyond your basic evolutionary diet 
which doesn't have maximum health and longevity as it's objective, but 
genetic reproduction.

My interests are in healthy life extension and for that I find benefits 
in paleo, CRON, supplements, science, and modern health/science.  I 
personally don't think it wise to pick one and ignore the rest.  Heck, 
people with a good set of friends and a bad diet may live longer than a 
lonely paleo purest.

Steve