Growing evidence has pointed to the benefits of social and mental stimulation in preventing dementia, but until now no one has looked at the role of physical environment.
A study involving 1294 healthy older adults found that those whose life-space narrowed to their immediate home were almost twice as likely to develop the condition as those with the largest life-space (out-of-town). The homebound also had an increased risk of MCI and a faster rate of global cognitive decline.
By the end of the eight-year study (average follow-up of 4.4 years), 180 people (13.9%) had developed Alzheimer’s. The association remained after physical function, disability, depressive symptoms, social network size, vascular disease burden, and vascular risk factors, were taken into account.
It may be that life-space is an indicator of how engaged we are with the world, with the associated cognitive stimulation that offers.
 . Life Space and Risk of Alzheimer Disease, Mild Cognitive Impairment, and Cognitive Decline in Old Age. American Journal of Geriatric Psychiatry [Internet]. 2011 :1 - 1. Available from: http://journals.lww.com/ajgponline/Abstract/publishahead/Life_Space_and_Risk_of_Alzheimer_Disease,_Mild.99653.aspx