Healthy Cognitive Aging Research Articles

Internet use and cognitin among American middle-aged and older adults: The gendered moderating effect of age

The popularity of Internet use brings more potential for healthy cognitive aging among older adults. Emerging studies have examined the age and gender differences in the link between older adults’ Internet use and cognition. However, few studies have investigated the gendered age difference regarding this association. The purpose of this study was to examine whether age would moderate the effect of Internet use on cognition among middle-aged and older adults and whether this relationship would be different between men and women. A total of 6,338 adults aged 50 or older were drawn on from the 2016 Wave of the Health and Retirement Study. Sequential linear regressions were conducted to examine the interactions between Internet use, age, and gender on cognition. The three-way interaction of Internet use, age, and gender was a significant predictor of cognition (β = 0.01, p < 0.05). Specifically, the positive effect of Internet use on cognition was higher among older women of older age than those of younger age, while the positive effect remained the same for older men of different ages. The Internet offers a valuable resource for engaging middle-aged and older adults in activities that not only provide social interaction but also stimulate cognitive processes. The study suggests that the aging process does not necessarily inhibit the cognitive benefits that middle-aged and older adults can gain from using the Internet. Findings from this study indicated that future Internet/technology training to increase cognition among middle-aged and older adults should be age- and gender-tailored.

Effect of a cash transfer intervention on memory decline and dementia probability in older adults in rural South Africa

Evidence on cash transfers as a population-level intervention to support healthy cognitive aging in low-income settings is sparse. We assessed the effect of a cash transfer intervention on cognitive aging outcomes in older South African adults. We leveraged the overlap in the sampling frames of a Phase 3 randomized cash transfer trial [HIV Prevention Trial Network (HPTN) 068, 2011-2015] and an aging cohort [Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community (HAALSI), 2014-2022] in rural Mpumalanga Province, South Africa. In 2011/12, young women and their primary caregivers were randomly assigned 1:1 to receive a monthly cash transfer or control. In 2014/2015, 862 adults aged 40+ y living in trial households were enrolled in the HAALSI cohort, with cognitive data collected in three waves over 7 y. We estimated the impact of the intervention on rate of memory decline and dementia probability scores. Memory decline in the cash transfer arm was 0.03 SD units (95% CI: 0.002, 0.05) slower per year than in the control arm. Dementia probability scores were three percentage points lower in the cash transfer arm than the control arm (β = -0.03; 95% CI: -0.05, -0.001). Effects were consistent across subgroups. A modestly sized household cash transfer delivered over a short period in mid- to later-life led to a meaningful slowing of memory decline and reduction in dementia probability 7 y later. Cash transfer programs could help stem the tide of new dementia cases in economically vulnerable populations in the coming decades.

Resting-state EEG data before and after cognitive activity across the adult lifespan and a 5-year follow-up

This dataset consists of 64-channels resting-state EEG recordings of 608 participants aged between 20 and 70 years, 61.8% female, as well as follow-up measurements after approximately 5 years of 208 participants, starting 2021. The EEG was measured for three minutes with eyes open and eyes closed before and after a 2-hour block of cognitive experimental tasks. The data set is part of the Dortmund Vital Study, a prospective study on the determinants of healthy cognitive aging. The dataset can be used for (1) analyzing cross-sectional resting-state EEG of healthy individuals across the adult life span; (2) generating normalization data sets for comparison of resting-state EEG data of patients with clinically relevant disorders; (3) studying effects of performing cognitive tasks on resting-state EEG and age; (4) exploring intra-individual changes in resting-state EEG and effects of task performance over a time period of about 5 years. The data are provided in Brain Imaging Data Structure (BIDS) format and are available on OpenNeuro.

Age differences in BOLD modulation to task difficulty as a function of amyloid burden.

Effective cognitive performance often requires the allocation of additional neural resources (i.e. blood-oxygen-level-dependent [BOLD] activation) as task demands increase, and this demand-related modulation is affected by amyloid-beta deposition and normal aging. The present study investigated these complex relationships between amyloid, modulation, and cognitive function (i.e. fluid ability). Participants from the Dallas Lifespan Brain Study (DLBS, n = 252, ages 50-89) completed a semantic judgment task during functional magnetic resonance imaging (fMRI) where the judgments differed in classification difficulty. Amyloid burden was assessed via positron emission tomography (PET) using 18F-florbetapir. A quadratic relationship between amyloid standardized value uptake ratios (SUVRs) and BOLD modulation was observed such that modulation was weaker in those with moderately elevated SUVRs (e.g. just reaching amyloid-positivity), whereas those with very high SUVRs (e.g. SUVR > 1.5) showed strong modulation. Greater modulation was related to better fluid ability, and this relationship was strongest in younger participants and those with lower amyloid burden. These results support the theory that effective demand-related modulation contributes to healthy cognitive aging, especially in the transition from middle age to older adulthood, whereas high modulation may be dysfunctional in those with substantial amyloid deposition.

Impact of the South African Child Support Grant on memory decline and dementia probability in rural and low-income mothers, 2014–2021

IntroductionAging populations across sub-Saharan Africa are rapidly expanding, leading to an increase in the burden of Alzheimer's disease and related dementias (ADRD). Cash transfer interventions are one plausible mechanism to combat ADRD at a population-level in low-income settings. We exploited exogenous variation in eligibility for South Africa's Child Support Grant (CSG) to estimate the longitudinal association between potential CSG benefit and cognitive trajectories in rural mothers with <10 children (n = 1090). MethodsSouth Africa's CSG delivers monthly cash payments to primary caregivers, predominantly mothers, to offset the costs associated with child rearing. This study implemented a quasi-experimental design using data (2014–2022) from a rural, low-income cohort in the Agincourt research area, South Africa. We fit linear mixed effects models and generalized linear models to estimate the association of potential CSG benefit per eligible child with memory decline and dementia probability, respectively. We stratified all models by the mother's total number of children (1–4 and 5–9) and examined effect modification by household wealth and the mother's education level. ResultsHaving above median CSG per eligible child was associated with higher baseline memory scores (β = 0.12 SD units, 95% CI = 0.02, 0.22) but steeper memory decline (β = −0.02 SD units, 95% CI = −0.04, -0.00) compared to below median CSG. Within stratified analyses, this effect was primarily observed among mothers with 5–9 children. No associations were observed between potential CSG per eligible child and dementia probability. ConclusionsOur findings support the use of large-scale cash transfers as a promising intervention to promote healthy cognitive aging in mid-life women within rural, low-income settings. However, we found evidence that the CSG in its current structure may not be sufficient support for women to sustain measurable cognitive benefits over the long-term.

The Best of Two Worlds to Promote Healthy Cognitive Aging: Definition and Classification Approach of Hybrid Physical Training Interventions.

A healthy lifestyle can be an important prerequisite to prevent or at least delay the onset of dementia. However, the large number of physically inactive adults underscores the need for developing and evaluating intervention approaches aimed at improving adherence to a physically active lifestyle. In this regard, hybrid physical training, which usually combines center- and home-based physical exercise sessions and has proven successful in rehabilitative settings, could offer a promising approach to preserving cognitive health in the aging population. Despite its potential, research in this area is limited as hybrid physical training interventions have been underused in promoting healthy cognitive aging. Furthermore, the absence of a universally accepted definition or a classification framework for hybrid physical training interventions poses a challenge to future progress in this direction. To address this gap, this article informs the reader about hybrid physical training by providing a definition and classification approach of different types, discussing their specific advantages and disadvantages, and offering recommendations for future research. Specifically, we focus on applying digital technologies to deliver home-based exercises, as their use holds significant potential for reaching underserved and marginalized groups, such as older adults with mobility impairments living in rural areas.

Implementation and evaluation of a community-based mindful walking randomized controlled trial to sustain cognitive health in older African Americans at risk for dementia

BackgroundWith an increasing proportion of older adults and the associated risk of Alzheimer’s Disease and Related Dementias (ADRD) around the globe, there is an urgent need to engage in ADRD risk reduction efforts. African American (AA) older adults in the U.S. are disproportionally impacted by ADRD compared to other races and ethnicities. Mindful walking integrates two potentially protective factors of ADRD by elevating mindfulness and physical activity (i.e., walking), resulting in a synergistic behavioral strategy that is feasible and safe for older adults. However, the efficacy of applying this intervention for cognitive health outcomes has not been evaluated using experimental designs.MethodsThis paper documents the goal and protocol of a community-based, mindful walking randomized controlled trial to examine the short- and longer-term efficacy on cognitive and other health-related outcomes in ADRD at-risk AA older adults. The study outcomes include various brain health determinants, including cognitive function, quality of life, psychological well-being, physical activity, mindfulness, sleep, and overall health status. In addition, the estimated costs of program implementation are also collected throughout the study period. This study will recruit 114 older adults (ages 60+ years) with elevated ADRD risk from the Midlands region of South Carolina. Older adults are randomly assigned to participate in 24 sessions of outdoor mindful walking over three months or a delayed mindful walking group (n=57 in each group). Participants in both groups follow identical measurement protocols at baseline, after 12 weeks, after 18 weeks, and after 24 weeks from baseline. The outcome measures are administered in the lab and in everyday settings. Costs per participant are calculated using micro-costing methods. The eliciting participant costs for mindful walking engagement with expected results are reported using the payer and the societal perspectives.DiscussionThis study will generate evidence regarding the efficacy of mindful walking on sustaining cognitive health in vulnerable older adults. The results can inform future large-scale effectiveness trials to support our study findings. If successful, this mindful walking program can be scaled up as a low-cost and viable lifestyle strategy to promote healthy cognitive aging in diverse older adult populations, including those at greatest risk.Trial registrationClinicalTrials.gov number NCT06085196 (retrospectively registered on 10/08/2023).

Lifestyle medicine for healthy cognitive aging: A narrative review

Many countries across the globe are experiencing aging populations, which brings into question the fitness and capacity of these populations. Rates of neurodegenerative diseases worldwide are increasing, even after adjusting for increasing lifespans. This worrying trend motivates taking steps in the population to prevent dementia. This review summarizes the work on lifestyle medicine based prevention of dementia and cognitive decline using multiple modalities and interventions. Our results bring hope to those seeking to stay cognitively healthy in advanced age through combinations of diet, exercise, and mindfulness based interventions. Leveraging cheap and scalable interventions is an important strategy for alleviating the expected tide of neurodegenerative illnesses. This review covers the potential lifestyle and dietary interventions which can alleviate Alzheimer’s disease burden, paving the way for population level preventative approaches for neurodegenerative disease.

Effects of sleep deprivation on brain atrophy in individuals with mild cognitive impairment and Alzheimer's disease

Dementia, a prevalent condition in the United States, affecting millions of individuals and their families, underscores the importance of healthy cognitive ageing, which involves maintaining cognitive function and mental wellness as individuals grow older, promoting overall well-being and quality of life. Our original research study investigates the correlation between lifestyle factors and brain atrophy in individuals with mild cognitive impairment (MCI) or Alzheimer's disease (AD), as well as healthy older adults. Conducted over six months in West Texas, the research involved 20 participants aged 62–87. Findings reveal that sleep deprivation in MCI subjects and AD patients correlate with posterior cingulate cortex, hippocampal atrophy and total brain volume, while both groups exhibit age-related hippocampal volume reduction. Notably, fruit/vegetable intake negatively correlates with certain brain regions' volume, emphasizing the importance of diet. Lack of exercise is associated with reduced brain volume and hippocampal atrophy, underlining the cognitive benefits of physical activity. The study underscores lifestyle's significant impact on cognitive health, advocating interventions to promote brain health and disease prevention, particularly in MCI/AD cases. While blood profile data showed no significant results regarding cognitive decline, the study underscores the importance of lifestyle modifications in preserving cognitive function.

Force Fluctuations During Role-Differentiated Bimanual Movements Reflect Cognitive Impairments in Older Adults: A Cohort Sequential Study.

During role-differentiated bimanual movements (RDBM), an object is typically stabilized with 1 hand and manipulated with the other. RDBM require coupling both hands for coordinated action (achieved through interhemispheric connections), but also inhibition of crosstalk to avoid involuntary movements in the stabilizing hand. We investigated how healthy cognitive aging and mild cognitive impairments (MCI) affect force stabilization during an RDBM in a cohort sequential study design with up to 4 measurement points over 32 months. In total, 132 older adults (>80 years) participated in this study, 77 were cognitively healthy individuals (CHI) and 55 presented with MCI. Participants performed a visuomotor bimanual force-tracking task. They either produced a constant force with both hands (bimanual constant) or a constant force with 1 and an alternating force with the other hand (role-differentiated). We investigated force fluctuations of constant force production using the coefficient of variation (CV), detrended fluctuation analysis (DFA), and sample entropy (SEn). Results showed higher CV and less complex variability structure (higher DFA and lower SEn) during the role-differentiated compared to the bimanual constant task. Furthermore, CHI displayed a more complex variability structure during the bimanual constant, but a less complex structure during the role-differentiated task than MCI. Interestingly, this complexity reduction was more pronounced in CHI than MCI individuals, suggesting different changes in the control mechanisms. Although understanding these changes requires further research, potential causes might be structural deteriorations leading to less efficient (intra- and interhemispheric) networks because of MCI, or an inability to appropriately divert the focus of attention.

Outcomes of home design to support healthy cognitive ageing: modified e-Delphi exercise with older people and housing-related professionals

BackgroundThere is emerging agreement that living in a home designed to support healthy cognitive ageing can enable people to live better with dementia and cognitive change. However, existing literature has used a variety of outcome measures that have infrequently been informed by the perspectives of older people or of professional in design and supply of housing. The DesHCA (Designing Homes for Healthy Cognitive Ageing) study aimed to identify outcomes that were meaningful for these groups and to understand their content and meanings.MethodsA presurvey of older people and housing professionals (n = 62) identified potential outcomes. These were then used in three rounds of a modified e-Delphi exercise with a panel of older people and housing professionals (n = 74) to test meanings and identify areas of agreement and disagreement. Descriptive statistics were used to present findings from previous rounds.ResultsThe survey confirmed a wide range of possible outcomes considered important. Through the e-Delphi rounds, panellists prioritised outcomes relating to living at home that could be influenced by design, and clarified their understanding of the meanings of outcomes. In subsequent rounds, they commented on earlier results. The exercise enabled five key outcome areas to be identified – staying independent, feeling safe, living in an adaptable home, enabling physical activity and enabling enjoyed activities- which were then tested for their content and applicability in panellists’ views.ConclusionThe five key outcome areas appeared meaningful to panellists, whilst also demonstrating nuanced meanings. They indicate useful outcomes for future research, though will require careful definition in each case to become measures. Importantly, they are informed by the views of those most immediately affected by better or poorer home design.

Effectiveness of dairy products to protect against cognitive decline in later life: a narrative review.

As the world's population ages the prevalence of age-related health concerns is increasing, including neurodegeneration disorders such as mild cognitive impairment, vascular dementia and Alzheimer's disease. Diet is a key modifiable risk factor for the development of neurodegeneration, likely due to gut-brain axis interactions related to neuroinflammation. Analyses of dietary patterns identified dairy as being part of a cognitively healthy diet; however, its contribution to cognitive outcomes is difficult to discern. This narrative review evaluates the literature to determine whether there is sufficient evidence that the consumption of dairy products helps to maintain cognitive function in later life. A search using the terms (dairy OR milk OR cheese OR yogurt OR yogurt) AND ("mild cognitive impairment" OR dementia OR "Alzheimer's disease") identified 796 articles. After screening and sorting, 23 observational studies and 6 intervention studies were identified. The results of the observational studies implied that the relationship between total dairy consumption and cognitive outcomes is inverse U-shaped, with moderate consumption (1-2 servings per day) being the most beneficial. The analysis of the intake of different types of dairy products indicated that fermented products, particularly cheese, were most likely responsible for the observed benefits. The experimental studies all used dairy-derived peptides produced during fermentation as the dietary intervention, and the results indicated that these could be an effective treatment for early-stage cognitive impairment. Further experimental studies with whole dairy products, particularly fermented dairy, are needed to determine whether the regular consumption of these foods should be recommended to maximize the likelihood of healthy cognitive aging.

Gardening and cognitive ageing: Longitudinal findings from the Lothian Birth Cohort of 1921

Identifying modifiable lifestyle behaviours that facilitate healthy cognitive ageing is of major public interest for the prevention of cognitive decline and dementia. Gardening is associated with numerous health benefits, yet few studies have explored the significance of gardening activity in relation to cognitive ageing. Here, longitudinal cognitive data from 467 older adults (aged 79 ± 0.6) of the LBC1921 study were used to examine associations of self-reported gardening at age 79 with lifetime cognitive change (age 11 to 79), and cognitive level (age 79) and slope across later life (age 79 to 90). Cognitive function was assessed at age 11 and 79 using the Moray House Test (MHT), and a battery of psychometric tests assessed cognitive function at ages 79, 83, 87 and 90 (MHT, Raven's Matrices, Verbal Fluency, Logical Memory). Models controlled for individual-level socio-demographic, lifestyle and health covariates including overall physical activity. Higher frequency of gardening was significantly associated with greater lifetime cognitive gain from age 11 to 79 on the MHT (std β = 0.112 P = 0.024), higher general cognitive ability (g) level at age 79 (std β = 0.145, P = 0.001), and higher test-specific scores on the MHT (std β = 0.153, P = 0.001) and Raven's Matrices (std β = 0.102, P = 0.040). Gardening was not associated with subsequent cognitive slopes from age 79 to 90. Overall, these findings suggest that engaging in gardening activities may contribute modestly to healthy cognitive functioning up to the eighth decade of life. Although physical activity was higher in gardeners, it did not explain the gardening and cognitive function relationship.

Subjective Cognitive Impairment Can Be Detected from the Decline of Complex Cognition: Findings from the Examination of Remedes 4 Alzheimer's (R4Alz) Structural Validity.

To reveal the cognitive-control dimensions that can differentiate between adults and older adults with healthy cognition, people with subjective cognitive impairment, and people diagnosed with mild cognitive impairment by examining the factorial structure of the R4Alz tool. The study comprised 404 participants: (a) healthy adults (n = 192), (b) healthy older adults (n = 29), (c) people with SCI (n = 74), and (d) people diagnosed with MCI (n = 109). The R4Alz battery was administered to all participants, including tests that assess short-term memory storage, information processing, information updating in working memory, and selective, sustained and divided attention), task/rule-switching, inhibitory control, and cognitive flexibility. A two-factorial structural model was confirmed for R4Alz, with the first factor representing "fluid intelligence (FI)" and the second factor reflecting "executive functions (EF)". Both FI and EFs discriminate among all groups. The R4Alz battery presents sound construct validity, evaluating abilities in FI and EF. Both abilities can differentiate very early cognitive impairment (SCI) from healthy cognitive aging and MCI.

Nutrition for dementia prevention: a state of the art update for clinicians.

Dementia prevalence continues to rise. It is therefore essential to provide feasible and effective recommendations to encourage healthy brain ageing and reduce dementia risk across the population. Appropriate nutrition represents a potential strategy to mitigate dementia risk and could be recommended by clinicians as part of mid-life health checks and other health initiatives to reduce dementia prevalence. The purpose of this review is to provide a clinician-focused update on the current state of the knowledge on nutrition and dementia prevention. Narrative review. Strong evidence exists to support the consumption of healthy, plant-based dietary patterns (e.g. Mediterranean, MIND or Nordic diet) for maintaining cognitive function and reducing dementia risk in later life and is supported by dementia prevention guideline from leading public health bodies (e.g. World Health Organization). Emerging evidence suggests potential cognitive benefits of consuming specific nutrients/foods (e.g. n-3 fatty acids or fish, flavonols and B-vitamins) and multi-nutrient compounds (e.g. Fortasyn Connect). Challenges and opportunities for integrating nutritional/dietary interventions for dementia prevention into clinical practice are explored in this review. Appropriate nutrition represents an important factor to help facilitate healthy cognitive ageing and allay dementia risk. The information provided in this article can help clinicians provide informed opinions on appropriate nutritional strategies as part of mid-life Health Checks and other risk reduction initiatives.

Interplay of age, gender, education, and heart rate in dementia among older adults in Wakiso, Uganda: a cross sectional study

Background In this cross-sectional study conducted in Wakiso, Uganda, from May to July 2023, we investigated the interactions among age, sex, education, and heart rate in relation to dementia and Mild Cognitive Impairment (MCI) among individuals aged 65 years and older. Methods We purposively sampled 106 participants, focusing on those with Alzheimer’s disease and related dementias, leveraging collaborations with local health teams. Data collection involved comprehensive questionnaires covering sociodemographic details and health parameters, and employed the Montreal Cognitive Assessment Tool for dementia screening. Results Our findings highlight a nuanced landscape of risk factors; each additional year of age was associated with a 1.19- and 1.22-times increased risk of MCI and dementia, respectively. Gender analysis revealed a protective effect against MCI in males, but no significant impact on dementia risk. Education emerged as a protective factor, with each additional year associated with a 28% reduction in MCI risk, although its effect on dementia risk remains ambiguous. Significantly, an elevated heart rate was strongly linked to an increased risk of both MCI and dementia, underscoring the potential cardiovascular dimension in cognitive health. Conclusions This study contributes to the understanding of the complex interplay of risk factors for dementia, emphasizing the need for further research to elucidate the underlying mechanisms and interventions for healthy cognitive aging in the older adult population.

A Two-Phased Pilot Study Evaluating the Feasibility and Acceptability of the Cognitively Enriched Walking Program "Take a Walk with Your Brain" for Older Adults.

Given the aging population, finding solutions to retain optimal cognitive capacity is a research priority. The potential of physical activity to reduce the risk of cognitive decline and to enhance cognitive functioning is established. Combining physical with cognitive activity has been put forward as a potentially even more effective way to promote healthy cognitive aging. Most studies on combined interventions have however been conducted in laboratory settings. This paper reports on a two-phased pilot study evaluating the acceptability and feasibility of a newly developed real-life cognitively enriched walking program for adults aged 65+ years. In Phase I, the feasibility and enjoyability of the cognitive tasks was evaluated by conducting walk-along interviews with older adults (n = 163). In Phase II, the cognitively enriched walking program was piloted in two groups of older adults (n = 19), and the feasibility and acceptability of the program and cognitive tasks was evaluated by means of questionnaires and focus groups. The cognitive tasks (i.e., median scores of ≥3 on a total of 4 (Phase I) and ≥6 on a total of 10 (Phase II) for most of the tasks) and the cognitively enriched walking program (i.e., median scores of ≥7 on a total of 10) were considered feasible and acceptable. Based on the input of the participants, key considerations for a feasible and acceptable program were defined: participants should be sufficiently challenged cognitively and physically, social interaction is an important motivator, cognitive tasks should make use of stimuli reflecting daily life and be conducted in group, the rationale for the tasks should be explained to participants, the frequency of the group sessions should be maximum 2 times a week, and the program should be supervised by a trained coach. These results warrant future research to establish the effectiveness of this program.

Event-related theta and gamma band oscillatory dynamics during visuo-spatial sequence memory in younger and older adults.

Visuo-spatial working memory (VSWM) for sequences is thought to be crucial for daily behaviors. Decades of research indicate that oscillations in the gamma and theta bands play important functional roles in the support of visuo-spatial working memory, but the vast majority of that research emphasizes measures of neural activity during memory retention. The primary aims of the present study were (1) to determine whether oscillatory dynamics in the Theta and Gamma ranges would reflect item-level sequence encoding during a computerized spatial span task, (2) to determine whether item-level sequence recall is also related to these neural oscillations, and (3) to determine the nature of potential changes to these processes in healthy cognitive aging. Results indicate that VSWM sequence encoding is related to later (∼700 ms) gamma band oscillatory dynamics and may be preserved in healthy older adults; high gamma power over midline frontal and posterior sites increased monotonically as items were added to the spatial sequence in both age groups. Item-level oscillatory dynamics during the recall of VSWM sequences were related only to theta-gamma phase amplitude coupling (PAC), which increased monotonically with serial position in both age groups. Results suggest that, despite a general decrease in frontal theta power during VSWM sequence recall in older adults, gamma band dynamics during encoding and theta-gamma PAC during retrieval play unique roles in VSWM and that the processes they reflect may be spared in healthy aging.

Association between Marital Status and Cognitive Impairment in a Multi-Ethnic Asian Population

Objective: This study aimed to examine the potential factors associated with marital status and determine the association between marital status and cognitive impairment in a multi-ethnic Asian population. Method: This study included 2,321 participants from Singapore Multi-Ethnic Cohort revisit study (aged 40–89). Participants were classified into married and unmarried group at baseline and follow-up according to self-reported marital status. Mini-Mental Status Examination (MMSE) was administered, and cognitive impairment was defined as a MMSE <26. We conducted both cross-sectional and longitudinal analyses to examine the association of marital status at 1 timepoint as well as marital transition with cognitive impairment. Results: Of the 2,321 participants, a total of 1,914 (82.5%) were married. The factors associated with marital status included younger age, male sex, higher household income, higher education, and higher physical activity levels. Additionally, married participants also had higher alternative healthy eating index (AHEI-2010) scores and a lower burden of hypertension and diabetes. Among those who were married, the median (Q1, Q3) MMSE score was 29 (28, 30) while among those who were unmarried it was 29 (27, 30) (p < 0.01). Participants who had never been married had the highest odds of cognitive impairment compared to their married counterparts (model III: OR = 1.48, 95% CI: 1.03, 2.14). Older age (p interaction value = 0.003) and Indian ethnicity (p interaction value = 0.028) further strengthened these associations. Conclusion: Marriage was associated with lower odds of cognitive impairment. Marriage provides social support, companionship, and engagement in mentally stimulating activities contributing to better cognitive health. By identifying risk factors such as marital status, interventions and support systems can be developed to promote healthy cognitive aging.

Child support grant expansion and cognitive function among women in rural South Africa: Findings from a natural experiment in the HAALSI cohort.

Cash transfers are a promising but understudied intervention that may protect cognitive function in adults. Although South Africa has a rapidly ageing population, little is known about the nature of association between cash transfers and cognitive function in this setting. We leveraged age-eligibility expansions to South Africa's Child Support Grant (CSG) to investigate the association between duration of CSG eligibility and cognitive function of biological mothers of child beneficiaries in South Africa. We analysed 2014/2015 baseline data from 944 women, aged 40-59 years with at least one CSG-eligible child, enrolled in the population-representative HAALSI cohort in Agincourt, South Africa. Duration of CSG eligibility for each mother was calculated based on the birth dates of all their children and the CSG age-eligibility expansion years (2003-2012). Cognitive function was measured using a cognitive battery administered at the HAALSI baseline interview. Linear regression was used to estimate the association between duration of CSG eligibility, dichotomized as low (≤10 years) and high (>10 years) eligibility, and cognitive function z-scores of the mothers. High vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores in the full sample [β: 0.15 SD units; 95% CI: 0.04, 0.26; p-value = 0.01]. In mothers with one to four lifetime children, but not five or more, high vs. low duration of CSG eligibility, was associated with higher cognitive function z-scores [β: 0.19 SD units; 95% CI: 0.05, 0.34, p-value = 0.02]. Government cash transfers given to support raising children may confer substantial protective effects on the subsequent cognitive function of mothers. Further studies are needed to understand how parity may influence this relationship. Our findings bring evidence to policymakers for designing income supplementation programmes to promote healthy cognitive ageing in low-income settings.