Mental activity and dementia risk – the evidence
There is consistent evidence that higher participation in mentally stimulating activities may protect against cognitive decline and dementia in old age.
A reduced risk of dementia is associated with:
- Higher levels of education
- Mentally demanding occupations
- More cognitively stimulating leisure activities
- Higher intelligence
Meta-analysis suggests around half the risk of dementia for those with high educational attainment compared to low, those with high occupational status compared to low, and those participating in more cognitively stimulating leisure activities compared to those participating in few such activities [1].
Importantly for older or retired people, increased complex mental activity in late life is associated with lower dementia risk independent of other predictors such as education [1]. A dose–response relationship is also evident, so the more activity that can be done, the better.
Complex mental activity across the lifespan may reduce the risk or delay the onset of dementia by improving brain reserve [1,2].
Mental activity, challenge and learning stimulate neurogenesis and new synapses [2]. Complex cognitive activity contributes to neurological brain reserve (increased synapses, neural numbers and brain volume) and behavioural brain reserve (flexible cognitive strategies). This reserve may allow normal cognitive function to continue for longer in the face of underlying neural dysfunction or degeneration [3].
Commercial brain training games and programs have as yet not been shown to reduce the risk of dementia [4].
Activities that combine mental, social and physical components may provide even greater protection against dementia [2].
References
- Valenzuela MJ & Sachdev P (2006) Brain reserve and dementia: a systematic review. Psychological Medicine, 36:441-454
- Valenzuela MJ (2009) It’s never to late to change your mind. ABC Books, Sydney
- Welsh-Bohmer KA & White CL (2009) Alzheimer disease: What changes in the brain cause dementia? Neurology, 72:e21-e23
- Valenzuela MJ & Sachdev P (2009) Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up. Am J Geriatr Psychiatry, 17:179-187
