A systematic review and meta-analysis of structural magnetic resonance imaging studies investigating cognitive and social activity levels in older adults

Abstract

Population aging has prompted considerable interest in identifying modifiable factors that may help protect the brain and its functions. Collectively, epidemiological studies show that leisure activities with high mental and social demands are linked with better cognition in old age. The extent to which socio-intellectual activities relate to the brain's structure is, however, not yet fully understood. This systematic review and meta-analysis summarizes magnetic resonance imaging studies that have investigated whether cognitive and social activities correlate with measures of gray and white matter volume, white matter microstructure and white matter lesions. Across eighteen included studies (total n = 8429), activity levels were associated with whole-brain white matter volume, white matter lesions and regional gray matter volume, although effect sizes were small. No associations were found for global gray matter volume and the evidence concerning white matter microstructure was inconclusive. While the causality of the reviewed associations needs to be established, our findings implicate socio-intellectual activity levels as promising targets for interventions aimed at promoting healthy brain aging.

Mid-life and late life activities and their relationship with MRI measures of brain structure and functional connectivity in the UK Biobank cohort

“…visiting friends and family, going to the pub or social clubs, undertaking religious activities), measured in either mid-life or late life, were associated with markers of GM, WM microstructure, functional connectivity or cognitive function, after applying FDR corrections. While prior meta-analytic investigations have identified associations with brain structure [10] and cognition [39] when such activities are combined into composite scores, our results suggest that comparatively speaking, they do not uniquely contribute to brain health in early late life. Considering that the present findings imply dissociable effects between activities in brain-cognition associations, our results are in favour of an approach sensitive to these inter-activity differences, rather than the use of composite leisure activity scores, although the possibility has to be considered that cumulative activity over separate activities is required to improve brain function.…”

“…Leisure activities have been systematically linked to better cognitive performance and structural brain integrity in older adults [5][6][7][8][9][10][11][12][13]. However, one of the major drawbacks of published studies is the longstanding use of composite measures of leisure activities, which provides limited insight into the specific activities that should be targeted by interventions to promote brain health in older individuals.…”

“…We further expected that more frequent leisure activity participation correlates with greater structural integrity, including greater regional GM and higher white matter integrity (i.e. higher fractional anisotropy (FA), lower mean diffusivity (MD) [10]). Given the limited evidence investigating activity-specific effects on resting-state functional connectivity, no predictions were made regarding this modality.…”

Associations of lifestyle activities and a heathy diet with frailty in old age: a community-based study in Singapore

“…The mechanisms underlying these associations have not been fully elucidated, but involvement in social/intellectual activities may provide a sense of value, belonging, attachment, self-esteem and selfworth [34], thus enhancing psychological health and potentially improving late-life outcomes [11]. Social and intellectual activities may also exert physiological benefits such as enhancing the humoral immune response [35], reducing systemic chronic inflammation (a major biological factor underlying aging) [36] and altering the brain structure [37][38][39].…”

White Matter Plasticity Keeps the Brain in Tune: Axons Conduct While Glia Wrap

“…To date, WM changes have been observed to occur during development, adulthood, and aging. Aging in particular has been linked to changes in WM volume (reduction), WM lesions as seen by hyperintensities, and WM microstructure as measured by FA decreases, with social and cognitive activities acting in a neuroprotective fashion to decrease the magnitude of these changes (meta-analysis by Anatürk et al, 2018 ), hinting that WM neuroanatomy may be altered by experience over the lifetime of an organism.…”