A physiological perspective

Exercise may prevent age-related deterioration of cognitive and brain function and reduce age-related brain atrophy as in both prospective and retrospective observational studies, it has been shown a lower incidence of cognitive impairment, depression and dementia develops in people who maintained regular physical activity.
Data from many studies have overwhelmingly suggested that regular cognitive activity may convey benefits similar to those achieved by regular physical activity. Specifically, they have suggested that people who engage in more cognitively stimulating leisure, social and job activities are at a reduced risk for cognitive decline
A healthy diet is a third modifiable lifestyle factor that has been linked to overall brain health and attenuated cognitive decline. One diet in particular, the Mediterranean Diet which is characterised by high intake of fruits, vegetables, cereals, fish, nuts and olive oil, has received particular attention in the literature.