Frequent dancing, for example, which demands musical concentration and knowing where to put your feet while engaging in polite conversation, showed a robust 75 percent reduction in risk. Activities like knitting, gardening, and traveling afford similar benefits.
Having a healthy mind and body is important. Find interesting and challenging things to do as a couple. Things that don't require sitting on the couch.
So here's a prescription: a few chapters of Harry Potter, the New York Times Sunday crossword puzzle, and some ballroom dancing to relaxing music with a partner you really like. That just may be the real secret to happy retirement.