Most scientists recommend eating a Mediterranean-style diet, including fish and nuts containing omega-3 fatty acids, antioxidant-rich fruits and vegetables, olive oil and possibly some red wine. (Blueberries are also recommended.) Some also suggest avoiding playing games like football, because of the risk of head injuries, staying away from pesticides and insecticides that contain neurotoxins and not drinking excessively.

“Another thing that’s important as people get older is to maintain flexible attitudes and be willing to try new things,” said K Warner Schaie, who in 1956 started the Seattle Longitudinal Study, which follows the psychological development of participants through adulthood. “You have to expect things will shift over time and won’t be the same as when you were young. Those who manage to roll with the punches, and enjoy change rather than fighting it, tend to do well.”