Participating in mentally challenging leisure activities such as reading and playing board games may help elderly people stay mentally sharp.

Researchers found that people aged 75 years or more who engaged in leisure activities had a lower risk of dementia than other elderly people. It is unclear whether increased participation in leisure activities lowers the risk of dementia or whether participation in such activities declines during the preclinical phase of dementia (New England Journal of Medicine 2003;348:2508-16).

But not all activities seem to be equally effective in reducing the risk of dementia. People who reported often playing board games, reading, playing a musical instrument or doing crossword puzzles were less likely to develop dementia than people who said they engaged …