Background:
Social isolation is rapidly increasing in many societies, having strong negative effects
on general health as well as mortality. Cognitive decline and dementia are two outcomes
associated with social isolation. We aimed to investigate whether cognitive reserve
could buffer the adverse effect that social isolation has on cognitive function.
Methods:
Data from dementia-free participants between age 40 and 79 years of the population-based
„Adult Study“ of the Leipzig Research Centre for Civilization Diseases (LIFE, n =
10,000) were investigated. Cognitive reserve was operationalized as educational attainment
and indices of occupational mental demands derived from the O*NET database. Adjusted
multiple mediation analysis was used to assess the mediating effect of cognitive reserve
between social isolation and cognitive function.
Results:
Analyses included 8,168 (81.6%) individuals with a mean age of 58.5 (SD= 10.9) years and 55% being female. Social isolation was present in 1,448 (17.7%)
participants. Cognitive reserve accounted for 20.0% of the effect of social isolation
on executive function, and 22.8% on verbal/semantic abilities. Educational attainment
had a greater effect than occupational mental demands. The effect of educational attainment
persisted into older age (≥65 years).
Conclusion:
Cognitive reserve is an important mediator on the pathway between social isolation
and cognitive function, attenuating the negative association of social isolation and
cognitive function. Older individuals, particularly socially isolated ones, may benefit
from maintaining a cognitively active life style.
