High cognitive reserve can reduce the risk of cognitive decline, as a study published in Neurology reports the positive effect of cognitive reserve on global cognitive function, episodic memory, and working memory even after considering brain pathologies.
As there is limited data on the effect of cognitive reserve on cognitive trajectories such as global cognitive function, episodic memory and working memory, the aim of the current study was to investigate the relationship between the indicator of cognitive reserve and global cognitive function, to determine episodic memory and working memory over time, and the role of brain pathologies in such associations.
The study sample comprised 1697 patients (mean age 79.6 years; 75.7% women) without dementia, including 648 patients with brain disorders. The participants were divided into 3 groups according to cognitive reserve, with 560 patients in the lowest cognitive reserve group, 560 in the middle cognitive reserve group and 577 in the highest cognitive reserve group.
Continue reading
Information on reserve cognitive factors, including data on education, physical activity, cognitive activities in middle and late life, social activity in late life, and social networking, was collected through in-person interviews at baseline. A battery of 21 baseline and annual cognitive performance tests were used to assess cognitive function, including episodic memory, working memory, semantic memory, cognitive speed, and visuospatial ability.
The cognitive reserve value ranged from -8,002 to 5,378, with a higher value indicating a higher degree of cognitive reserve: lowest group, -8,002 to -0,826; middle group, -0.827 to 1.062; highest group, 1.063 to 5.738.
During the follow-up period of up to 21 years (median 5.31 years), 795 patients died, including 648 patients who underwent an autopsy to examine brain pathologies.
In multiple-adjusted mixed-effect models, there was a connection between the cognitive reserve indicator and a slower decrease in global cognition, episodic memory, semantic memory, working memory and the speed of perception over time. The highest cognitive reserve was associated with slower declines in global cognition, episodic memory, and working memory over the course of follow-up compared to the lowest cognitive reserve. No significant association between mean cognitive reserve and decline in cognitive function was reported.
In the analysis of pathological brain data, the highest cognitive reserve with a lower burden of global Alzheimer’s pathology (odds ratio 0.66; 95% CI 0.45-0.98), neuritic plaque (odds ratio 0.75; 95% CI 0.57-1.00.) And macro-infarcts (odds ratio 0.47; 95% CI 0.29-0.76).
After additional adjustment to brain pathologies, the association between the highest cognitive reserve and a slower decline in global cognitive function, episodic memory, working memory, or visuospatial ability remained significant.
The study had several limitations, including using retrospective self-reported information to collect data on cognitive reserves, lack of nutritional data, and limited generalizability to younger populations or to adults living in rural areas.
“Our results underscore the importance of educational and mentally stimulating activities throughout the life span in maintaining cognitive function later in life,” the researchers concluded.
reference
Li X, Song R, Qi X, et al. Influence of cognitive reserve on cognitive trajectories: role of brain pathologies. Neurology. Published online 7 September 2021. doi: 10.1212 / WNL.0000000000012728
