Brain Reserve and the Prevention of Dementia
Brain Reserve and the Prevention of Dementia
Purpose of Review: To evaluate and synthesize recent evidence linking mental activity and dementia risk, which commonly invokes ‘brain reserve’ as the mediating construct.
Recent Findings: Brain reserve has acquired several interpretations; however, the most reliable and practical definition focuses at the behavioural level by assessing frequency and range of participation in complex mental activities. Epidemiological research suggests a clear and consistent link of high brain reserve with reduced dementia risk. Furthermore, emerging clinical trials of cognitive exercise suggest that it may be effective for the prevention of longitudinal cognitive and functional decline. Recent animal studies implicate several mechanisms, including disease-dependent and disease-independent compensatory pathways.
Summary: Given the precipitous forecasts for dementia over the coming decades, effective preventive strategies are of utmost importance. Findings from brain reserve studies now meet many of the formal criteria for causal agency between complex mental activity and reduced dementia risk. Key clinical trials are therefore under way to test these claims and results are keenly awaited.
‘Use it or lose it!’ is a maxim which captures public imagination when applied to almost any physiological system and particularly in relation to the brain and dementia. ‘Brain reserve’ has been invoked to explain this phenomenon; however, as a scientific concept it has suffered from overuse and lack of rigorous definition. Competing terms such as cognitive reserve and neural reserve only serve to further confuse the area. In this review, we first draw distinctions between different notions of brain reserve before settling on a straightforward behavioural account based on participation in complex mental activities. This allows us to then evaluate its aetiological status within a large body of epidemiological research. Significantly, there are now a series of clinical trials demonstrating that mental exercise can slow the rate of cognitive decline in late life. When coupled with a rich neurobiological literature implicating multiple potential mechanistic pathways, the possibility of delaying dementia onset via community-based mental activity programmes is emerging as a practical and empowering preventive strategy.
Abstract and Introduction
Abstract
Purpose of Review: To evaluate and synthesize recent evidence linking mental activity and dementia risk, which commonly invokes ‘brain reserve’ as the mediating construct.
Recent Findings: Brain reserve has acquired several interpretations; however, the most reliable and practical definition focuses at the behavioural level by assessing frequency and range of participation in complex mental activities. Epidemiological research suggests a clear and consistent link of high brain reserve with reduced dementia risk. Furthermore, emerging clinical trials of cognitive exercise suggest that it may be effective for the prevention of longitudinal cognitive and functional decline. Recent animal studies implicate several mechanisms, including disease-dependent and disease-independent compensatory pathways.
Summary: Given the precipitous forecasts for dementia over the coming decades, effective preventive strategies are of utmost importance. Findings from brain reserve studies now meet many of the formal criteria for causal agency between complex mental activity and reduced dementia risk. Key clinical trials are therefore under way to test these claims and results are keenly awaited.
Introduction
‘Use it or lose it!’ is a maxim which captures public imagination when applied to almost any physiological system and particularly in relation to the brain and dementia. ‘Brain reserve’ has been invoked to explain this phenomenon; however, as a scientific concept it has suffered from overuse and lack of rigorous definition. Competing terms such as cognitive reserve and neural reserve only serve to further confuse the area. In this review, we first draw distinctions between different notions of brain reserve before settling on a straightforward behavioural account based on participation in complex mental activities. This allows us to then evaluate its aetiological status within a large body of epidemiological research. Significantly, there are now a series of clinical trials demonstrating that mental exercise can slow the rate of cognitive decline in late life. When coupled with a rich neurobiological literature implicating multiple potential mechanistic pathways, the possibility of delaying dementia onset via community-based mental activity programmes is emerging as a practical and empowering preventive strategy.
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