Cognitive reserve (CR) or brain reserve capacity is a hypothesis about why people with a higher IQ, education or level of occupational attainment appear to have a lower risk of developing dementia, Alzheimer’s disease (AD) or vascular dementia (VaD).
Persons with higher initial cognitive reserve are presumed to be able to withstand greater brain pathology before manifesting the clinical symptoms of dementia. Clinical disease onset among people with initially greater cognitive reserve subsequently triggers an apparently faster decline in cognition and function, and increased mortality.
This study took education as a proxy measure of CR to review the evidence for the CR hypothesis. The studies analysed covered 437,477 subjects. Low educational attainment increased the risk of dementia. Higher education was associated with apparent “protective effects” against developing recognisable dementia, but clinical disease onset later on resulted in faster declines in cognition, function and brain pathology.
The authors conclude that a wide range of observational studies from diverse settings provide robust support for the CR hypothesis, and go on to suggest that the CR hypothesis might offer approaches to dementia prevention (in the short-term / medium-term).
Meng, X. D’Arcy, C. (2012). Education and dementia in the context of the cognitive reserve hypothesis: a systematic review with meta-analyses and qualitative analyses. PloS One, 2012, Vol.7(6), e38268. (Click here to view the PubMed abstract).