Evidence on Protective Factors for Dementia and Cognitive Impairment in Older Adults: An Umbrella Review.
Level 1 - systematic review of randomized trials
Umbrella review synthesizing systematic reviews and meta-analyses
PubMed 40179847 · doi:10.1159/000545503
What was done
An umbrella review searched four databases for systematic reviews and meta-analyses published between 2018 and January 2025. Eligible studies evaluated associations between interventions or exposures to protective factors and the incidence of dementia or cognitive decline in non-demented older adults.
What was found
From 6,324 screened articles, 17 systematic reviews and meta-analyses met inclusion criteria. Psychosocial factors (social engagement, purpose in life, life satisfaction, cognitive reserve) and influenza vaccination were found to protect against dementia. Evidence was promising for antihypertensives, and promising yet inconclusive for low-dose aspirin. No clear results emerged for single- or multi-domain lifestyle interventions. The abstract reports no numerical effect sizes or confidence intervals.
Why it matters
This review aggregates secondary evidence to highlight psychosocial factors and influenza vaccination as potentially valuable and underemphasized targets in dementia prevention initiatives.
Limits
The abstract does not provide quantitative effect estimates or formal GRADE certainty ratings. As an umbrella review, conclusions depend entirely on the quality, risk of bias, and potential primary-study overlap among the included systematic reviews.