Puzzles and crosswords may help keep dementia at bay for a longer period of time, but research in the journal Neurology suggests once the disease sets in, the decline is more rapid.
It has long been thought that exercising their brain helps protect against Alzheimer's.
Researchers at Rush University Medical Center say their study with more than 1,000 people suggests mental activity does delay the disease.
Doctors speculate the cognitive activity enhances the brain's ability to maintain normal function, even as the disease develops. So, the active brain is better able to keep functioning as if all is well, but when Alzheimer's is finally diagnosed the disease appears to be at a more advanced stage.
More research is now needed to establish why this happens and what role mental stimulation may play.