"Ralph" wrote in message
om...
From the June 19, 2003 New England Journal of Medicine:

Use It or Lose It - Do Effortful Mental Activities Protect against
Dementia?
Joseph T. Coyle, M.D.


Of course, Alzheimers-resistant brains may be more likely
to pursue intellectual activities (like chess, bridge), thus
accounting for the findings of the study. In other words,
chess doesn't prevent anything by itself. It may be that brains
that are less likely than other brains to develop Alzheimer's
"find" chess along the way.