The flexibility of the brain and its ability to cope with the loss of neurons or other injuries is called cognitive reserve and is key to brain health, as confirmed by new research that includes a follow-up of participants for 15 years. The study was carried out by researchers at the Karolinska Institutet Aging Research Center (ARC) and their findings suggest that a lifelong cognitive reserve helps maintain cognitive health in old age by delaying the cognitive transition in the preclinical stages of dementia.
“We found evidence that greater cognitive reserve throughout life is associated with a lower risk of moving from normal cognition to mild cognitive impairment and death in old age, but not with the transition from mild cognitive impairment to dementia,” said Chengxuan Qiu, senior professor and lead author of the study, whose results have been published in the journal Alzheimers & Dementia and could help develop preventive interventions to promote cognitive health and healthy aging.
Impact of cognitive reserve throughout life
Most previous studies have examined the association of individual indicators of cognitive reserve (such as education and leisure activities) with static cognitive conditions such as mild cognitive impairment and dementia. “Our study suggests that a large cognitive reserve could help maintain cognitive health, especially in the preclinical phase of dementia, and that cognitive reserve could also benefit survival in older people with cognitive impairment,” says Chengxuan Qiu.
The study included 2,631 older residents who did not have dementia and lived in central Stockholm. At the beginning of the study, the researchers collected data on several indicators of cognitive reserve (for example, education in childhood, job complexity in middle age, and leisure activities in old age).
Participants were examined regularly for 15 years to determine their cognitive states (e.g., normal function, mild cognitive impairment, and dementia) and survival. “We used multi-state models to investigate the composite measure of cognitive reserve in relation to the risk of transitions between different cognitive states and death, considering the impact of other factors,” explains Serhiy Dekhtyar, associate professor and co-author.
“Our study suggests that a large cognitive reserve could help maintain cognitive health, especially in the preclinical phase of dementia.”
The researchers’ goal is to evaluate the impact of measures that increase cognitive reserve on the maintenance of cognitive function through randomized controlled trials, explained Chengxuan Qiu, adding: “We can carry out this study using data from our trials of ongoing randomized controlled intervention within the FINGERS Global Network (e.g., the FINGER and MIND-China trials), a global network for dementia risk reduction and prevention.”
In these intervention studies, social activity, physical activity and cognitive training, which could increase cognitive reserve, are part of the intervention measures and cognitive function and dementia are the main outcomes. Additionally, researchers want to further explore the mechanisms linking cognitive reserve to cognitive transitions using blood biomarkers and brain injury imaging in their projects.
