Midlife engagement moderates cognitive difference between childhood, older adulthood

Associations between cognitive ability in childhood and cognitive state in older age are moderated by how active and enriching one’s lifestyle remains through the middle years, according to a study published in Neurology.

“Cognitive reserve theory proposes that the knowledge and experiences individuals accumulate through their lives provide increased resilience against the clinical expression of neuropathology, helping to maintain cognitive function,” Pamela Almeida-Meza, MSc, of the department of behavioral science and health at University College London, and colleagues wrote. With an aging population, differences in cognitive abilities become more apparent, they added.

Almeida-Meza and fellow researchers aimed to investigate key genetic and life course influences on cognitive state in a cohort of U.K. residents aged 69 years, building on previous work using the longitudinal MRC National Survey of Health and Development, a British birth cohort from 1946.

The study examined information from 1,184 participants (48% female) in the cohort, taken from an initial selection of 5,362 individuals born within 1 week of March 1946. Data were continuously collected on sociodemographic factors and medical, cognitive and psychological function from birth through all the relevant developmental stages through the final set in 2014 to 2015.

Multivariable regressions investigated the association between four factors: childhood cognition at age 8 years; a cognitive reserve index (CRI) composed of educational attainment by age 26 years, engagement in leisure activities at age 43 years, and occupation up to age 53 years; reading ability assessed by the National Adult Reading Test (NART) at age 53 years and APOE genotype in relation to cognitive state measured at age 69 years with Addenbrooke’s Cognitive Examination third edition (ACE-III). Researchers subsequently investigated the modifying role of the CRI, NART and APOE in the association between childhood cognition and the ACE-III.

Results showed that higher scores in childhood cognition, CRI and NART were associated with higher scores in the ACE-III. The researchers found that the CRI and NART modified the association between childhood cognition and the ACE-III: for 30 additional points in the CRI or 20 additional points in the NART, the simple slope of childhood cognition decreased by approximately 0.10 points (CRI = 70: Marginal Effects [ME], 0.22 [95% CI, 0.12-0.32] vs. CRI = 100: ME, 0.12 [95% CI, 0.06-0.17]; NART = 15: ME, 0.22 [95% CI, 0.09-0.35], compared with NART = 35: ME, 0.11 [95% CI, 0.05-0.17]).

“Our study suggests that the association between childhood cognitive ability and cognitive state in older age is moderated by an intellectually enriching lifestyle, indicating that cognitive ability is subject to environmental influences throughout the life course and that CR can offset the negative influence of low childhood cognition,” Almeida-Meza and fellow researchers wrote.