When it comes to staving off dementia, new evidence suggests that the "use it or lose it" dictum holds true — at least for a while. But it also appears that mentally stimulating lifestyles may speed up dementia once it hits in old age.
"We do think that a cognitively active lifestyle is protective up to some point," says Robert Wilson, a professor of neurological sciences at Rush University Medical Center in Chicago.
But the protection doesn't hold up indefinitely.



