Number of children and mid- to later-life cognitive function and cognitive impairment in rural South Africa: Evidence from "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI)

BackgroundCognitive impairment is projected to rise substantially by 2050, particularly in low- and middle-income countries with aging populations. Reproductive life history may be associated with later-life cognitive function. We aim to estimate the association between number of children and mid- to later-life cognitive performance. MethodData were from 5059 older adults (46% men) aged [≥]40 years in the population-representative rural cohort of the "Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa" (HAALSI). We fit linear regression and modified Poisson models to estimate the associations between number of children and cognitive function. Analyses were stratified by sex/gender, controlling for age, education, literacy, self-reported childhood health, country of birth, and fathers occupation. ResultsAfter adjustment, men with any number of children and women with 5+ children had higher cognitive function compared to those without children ({beta}[95% CI]: Men: 1-2: 0.29[0.13 - 0.45], 3-4: 0.50[0.34 - 0.65], 5+: 0.48[0.33 - 0.63]; Women: 5+: 0.17[0.01 - 0.34]). Results from the adjusted modified Poisson regression models found that for men and women, groups with any number of children showed a lower prevalence of cognitive impairment than the group with 0 children (PR[95% CI] Men: 1-2: 0.48[0.31 - 0.75], 3-4: 0.21[0.12 - 0.37], 5+: 0.28[0.19 - 0.41], Women: 1-2: 0.52[0.31 - 0.88], 3-4: 0.55[0.33 - 0.91], 5+: 0.41[0.25 - 0.69]). ConclusionAmong older rural South African adults, having children was associated with greater cognitive performance and lower prevalence of cognitive impairment. Men tended to have larger protective associations than women, which may be due to sex/gender differences in biological and social roles of childbearing and rearing. Understanding the complex relationship between having children and later-life cognitive function may help identify interventions to reduce the impact of cognitive decline.