An active mind is a healthy mind. That is the conclusion of a recent US study covering 21 years. Researchers found that regularly reading books, playing cards and board games, and doing crossword puzzles reduced the risk of developing Alzheimer's and other forms of dementia (N Engl J Med, 2003; 348: 2508-16). This finding supports earlier research suggesting that higher levels of education (Neuroloogy, 1994; 44: 2073-80) and lifelong learning can have a protective effect on the brain (West Ind Med J, 2002; 51: 143-7; J Alzheimer's Dis, 2003; 5: 91-104).
Likewise, your social-support system may also play an important role in maintaining a healthy mind. Evidence suggests that those who have the least social interactions have the highest incidence of dementia (Lancet, 2000; 355: 1315-9).