Association of dietary and nutritional factors with cognitive decline, dementia, and depressive symptomatology in older individuals according to a neurogenesis-centred biological susceptibility to brain ageing

Hippocampal neurogenesis (HN) occurs throughout the life course and is important for memory and mood. Declining with age, HN plays a pivotal role in cognitive decline (CD), dementia, and late-life depression, such that altered HN could represent a neurobiological susceptibility to these conditions. Pertinently, dietary patterns (e.g., Mediterranean diet) and/or individual nutrients (e.g., vitamin D, omega 3) can modify HN, but also modify risk for CD, dementia, and depression. Therefore, the interaction between diet/nutrition and HN may alter risk trajectories for these ageing-related brain conditions. Using a subsample (n = 371) of the Three-City cohort-where older adults provided information on diet and blood biobanking at baseline and were assessed for CD, dementia, and depressive symptomatology across 12 years-we tested for interactions between food consumption, nutrient intake, and nutritional biomarker concentrations and neurogenesis-centred susceptibility status (defined by baseline readouts of hippocampal progenitor cell integrity, cell death, and differentiation) on CD, Alzheimer's disease (AD), vascular and other dementias (VoD), and depressive symptomatology, using multivariable-adjusted logistic regression models. Increased plasma lycopene concentrations (OR [95% CI]  =  1.07 [1.01, 1.14]), higher red meat (OR [95% CI]  =  1.10 [1.03, 1.19]), and lower poultry consumption (OR [95% CI]  =  0.93 [0.87, 0.99]) were associated with an increased risk for AD in individuals with a neurogenesis-centred susceptibility. Increased vitamin D consumption (OR [95% CI]  =  1.05 [1.01, 1.11]) and plasma γ-tocopherol concentrations (OR [95% CI]  =  1.08 [1.01, 1.18]) were associated with increased risk for VoD and depressive symptomatology, respectively, but only in susceptible individuals. This research highlights an important role for diet/nutrition in modifying dementia and depression risk in individuals with a neurogenesis-centred susceptibility.

The association between adherence to the EAT-Lancet diet and cognitive ageing

BACKGROUND

The EAT-Lancet commission has proposed a dietary pattern that is both sustainable and healthy. However, the impact of this diet on cognition in older adults remains unexplored. Therefore, we examined the association between adherence to the EAT-Lancet diet and cognitive ageing.

METHODS

We used data from a previous intervention study involving cognitively healthy community-dwelling adults aged ≥65 years. Adherence to the EAT-Lancet diet was calculated using a recently published index and a 190-item food frequency questionnaire. Global and domain-specific cognitive functioning were assessed at baseline and after 2 years using a neuropsychological test battery. Multivariate-adjusted linear regression was conducted to examine associations between EAT-Lancet diet adherence and cognitive functioning (n = 630) and 2-year change (n = 302).

RESULTS

Greater adherence to the EAT-Lancet diet was associated with better global cognitive functioning (β per SD = 3.7 points [95% CI]: 0.04 [0.00, 0.08]) and slower rate of decline (β per SD [95% CI]: 0.05 [0.02, 0.08]). With respect to domain-specific functioning, beneficial associations were observed cross-sectionally for executive functioning (P < 0.01), and longitudinally for change in executive functioning (P < 0.01) and attention and working memory (P < 0.01). The degree of adherence to the EAT-Lancet was not associated with (changes in) information processing speed or episodic memory.

CONCLUSION

We demonstrated that greater adherence to the EAT-Lancet diet is associated with better global cognitive functioning and slower cognitive decline among cognitively healthy older adults. Further research is needed to confirm these findings and assess the potential benefits of the EAT-Lancet diet for the ageing population in a broader context.

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

BACKGROUND AND OBJECTIVES

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.

METHODS

Narrative review.

RESULTS

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.

CONCLUSIONS

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.

Cardiovascular Health, Race, and Decline in Cognitive Function in Midlife Women: The Study of Women's Health Across the Nation

BACKGROUND

Cognitive decline may progress for decades before dementia onset. Better cardiovascular health (CVH) has been related to less cognitive decline, but it is unclear whether this begins early, for all racial subgroups, and all domains of cognitive function. The purpose of this study was to determine the impact of CVH on decline in the 2 domains of cognition that decline first in White and Black women at midlife.

METHODS AND RESULTS

Subjects were 363 Black and 402 White women, similar in baseline age (mean±SD, 46.6±3.0 years) and education (15.7±2.0 years), from the Chicago site of the Study of Women's Health Across the Nation. Cognition, measured as processing speed and working memory, was assessed annually or biennially over a maximum of 20 years (mean±SD, 9.8±6.7 years). CVH was measured as Life's Essential 8 (blood pressure, body mass index, glucose, non-high-density lipoprotein cholesterol, smoking, physical activity, diet, sleep). Hierarchical linear mixed models identified predictors of cognitive decline with progressive levels of adjustment. There was a decline in processing speed that was explained by race, age, and the 3-way interaction of race, CVH, and time (F1,4308=8.8, P=0.003). CVH was unrelated to decline in White women but in Black women poorer CVH was associated with greater decline. Working memory did not decline in the total cohort, by race, or by CVH.

CONCLUSIONS

In midlife Black women, CVH promotion may be a target for preventing the beginnings of cognitive decline, thereby enhancing independent living with aging.

My Parent, Myself, or My Child: Whose Education Matters Most for Trajectories of Cognitive Aging in Middle Age?

The growing body of evidence linking intergenerational education and late-life cognitive decline is almost exclusively from high-income countries, despite rapid intergenerational changes in education in low- and middle-income countries (LMICs). We used data from the Mexican Health and Aging Study (n = 8,822), a cohort study of Mexican adults aged ≥50 years (2001-2018), to evaluate whether parental education (none vs. any formal schooling), one's own education (less than primary school vs. completion of primary school), or an adult child's education (less than high school vs. completion of high school) was associated with verbal memory z scores. We used linear mixed models with inverse probability of attrition weights. Educational attainment in all 3 generations was associated with baseline verbal memory scores, independent of the prior generation's education. Lower parental (β = -0.005, 95% confidence interval: -0.009, -0.002) and respondent (β = -0.013, 95% confidence interval: -0.017, -0.010) educational level were associated with faster decline in delayed (but not immediate) verbal memory z scores. Associations between adult child's education and respondent's verbal memory decline varied by exposure specification. The educational attainment of parents and adult children may influence the cognitive aging of middle-aged and older adults in LMICs. These results have important implications given recent structural shifts in educational attainment in many LMICs.

Longitudinal associations of volunteering, grandparenting, and family care with processing speed: A gender perspective on prosocial activity and cognitive aging in the second half of life

An active lifestyle has been associated with better cognitive performance in many studies. However, most studies have focused on leisure activities or paid work, with less consideration of the kind of prosocial activities, many people engage in, including volunteering, grandparenting, and family care. In the present study, based on four waves of the German Ageing Survey (N = 6,915, aged 40-85 at baseline), we used parallel growth curves to investigate the longitudinal association of level and change in volunteering, grandparenting, and family care with level and change in processing speed. Given the gendered nature of engagement in these activities over the life span, we tested for gender differences in the associations. Only volunteering was reliably associated with higher speed of processing at baseline, no consistent longitudinal associations were found. Our results show that although prosocial activities are of great societal importance, expectations of large rewards in terms of cognitive health may be exaggerated. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Signatures of Neuropsychological Test Results in the Long Life Family Study: A Cluster Analysis

BACKGROUND

Discovering patterns of cognitive domains and characterizing how these patterns associate with other risk factors and biomarkers can improve our understanding of the determinants of cognitive aging.

OBJECTIVE

To discover patterns of cognitive domains using neuropsychological test results in Long Life Family Study (LLFS) and characterize how these patterns associate with aging markers.

METHODS

5,086 LLFS participants were administered neuropsychological tests at enrollment. We performed a cluster analysis of six baseline neuropsychological test scores and tested the association between the identified clusters and various clinical variables, biomarkers, and polygenic risk scores using generalized estimating equations and the Chi-square test. We used Cox regression to correlate the clusters with the hazard of various medical events. We investigated whether the cluster information could enhance the prediction of cognitive decline using Bayesian beta regression.

RESULTS

We identified 12 clusters with different cognitive signatures that represent profiles of performance across multiple neuropsychological tests. These signatures significantly correlated with 26 variables including polygenic risk scores, physical and pulmonary functions, and blood biomarkers and were associated with the hazard of mortality (p < 0.01), cardiovascular disease (p = 0.03), dementia (p = 0.01), and skin cancer (p = 0.03).

CONCLUSION

The identified cognitive signatures capture multiple domains simultaneously and provide a holistic vision of cognitive function, showing that different patterns of cognitive function can coexist in aging individuals. Such patterns can be used for clinical intervention and primary care.

Effects of Mindfulness Training and Exercise on Cognitive Function in Older Adults: A Randomized Clinical Trial

IMPORTANCE

Episodic memory and executive function are essential aspects of cognitive functioning that decline with aging. This decline may be ameliorable with lifestyle interventions.

OBJECTIVE

To determine whether mindfulness-based stress reduction (MBSR), exercise, or a combination of both improve cognitive function in older adults.

DESIGN, SETTING, AND PARTICIPANTS

This 2 × 2 factorial randomized clinical trial was conducted at 2 US sites (Washington University in St Louis and University of California, San Diego). A total of 585 older adults (aged 65-84 y) with subjective cognitive concerns, but not dementia, were randomized (enrollment from November 19, 2015, to January 23, 2019; final follow-up on March 16, 2020).

INTERVENTIONS

Participants were randomized to undergo the following interventions: MBSR with a target of 60 minutes daily of meditation (n = 150); exercise with aerobic, strength, and functional components with a target of at least 300 minutes weekly (n = 138); combined MBSR and exercise (n = 144); or a health education control group (n = 153). Interventions lasted 18 months and consisted of group-based classes and home practice.

MAIN OUTCOMES AND MEASURES

The 2 primary outcomes were composites of episodic memory and executive function (standardized to a mean [SD] of 0 [1]; higher composite scores indicate better cognitive performance) from neuropsychological testing; the primary end point was 6 months and the secondary end point was 18 months. There were 5 reported secondary outcomes: hippocampal volume and dorsolateral prefrontal cortex thickness and surface area from structural magnetic resonance imaging and functional cognitive capacity and self-reported cognitive concerns.

RESULTS

Among 585 randomized participants (mean age, 71.5 years; 424 [72.5%] women), 568 (97.1%) completed 6 months in the trial and 475 (81.2%) completed 18 months. At 6 months, there was no significant effect of mindfulness training or exercise on episodic memory (MBSR vs no MBSR: 0.44 vs 0.48; mean difference, -0.04 points [95% CI, -0.15 to 0.07]; P = .50; exercise vs no exercise: 0.49 vs 0.42; difference, 0.07 [95% CI, -0.04 to 0.17]; P = .23) or executive function (MBSR vs no MBSR: 0.39 vs 0.31; mean difference, 0.08 points [95% CI, -0.02 to 0.19]; P = .12; exercise vs no exercise: 0.39 vs 0.32; difference, 0.07 [95% CI, -0.03 to 0.18]; P = .17) and there were no intervention effects at the secondary end point of 18 months. There was no significant interaction between mindfulness training and exercise (P = .93 for memory and P = .29 for executive function) at 6 months. Of the 5 prespecified secondary outcomes, none showed a significant improvement with either intervention compared with those not receiving the intervention.

CONCLUSIONS AND RELEVANCE

Among older adults with subjective cognitive concerns, mindfulness training, exercise, or both did not result in significant differences in improvement in episodic memory or executive function at 6 months. The findings do not support the use of these interventions for improving cognition in older adults with subjective cognitive concerns.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02665481.

Age-related impairments on the touchscreen paired associates learning (PAL) task in male rats

Discovery research in rodent models of cognitive aging is instrumental for identifying mechanisms of behavioral decline in old age that can be therapeutically targeted. Clinically relevant behavioral paradigms, however, have not been widely employed in aged rats. The current study aimed to bridge this translational gap by testing cognition in a cross-species touchscreen-based platform known as paired-associates learning (PAL) and then utilizing a trial-by-trial behavioral analysis approach. This study found age-related deficits in PAL task acquisition in male rats. Furthermore, trial-by-trial analyses and testing rats on a novel interference version of PAL suggested that age-related impairments were not due to differences in vulnerability to an irrelevant distractor, motivation, or to forgetting. Rather, impairment appeared to arise from vulnerability to accumulating, proactive interference, with aged animals performing worse than younger rats in later trial blocks within a single testing session. The detailed behavioral analysis employed in this study provides new insights into the etiology of age-associated cognitive deficits.

Longitudinal Within-Person Associations Between Quality of Social Relations, Structure of Social Relations, and Cognitive Functioning in Older Age

OBJECTIVES

Individuals' social connections and interpersonal experiences can both shape and be shaped by cognitive functioning. This study examines longitudinal within-person associations between quality of social relations, structure of social relations, and cognitive functioning in older age.

METHODS

We examined 16-year longitudinal data (3 waves) from 497 older adults (M = 66.07 years, SD = 0.83, range = 64-68 years) from the Interdisciplinary Longitudinal Study of Adult Development and Aging. Quality of social relations was measured by scales on perceived emotional support, instrumental support, and social integration. Structure of social relations was measured by self-reported number of leisure time partner types, indicating social network diversity. Cognitive functioning was assessed as a latent construct consisting of five cognitive tests (i.e., Information, Similarities, Letter Fluency, Picture Completion, Block Design). We used a random intercept cross-lagged panel model in the analysis.

RESULTS

At the within-person level, prior quality of social relations, but not structure of social relations, was positively associated with subsequent cognitive functioning. Moreover, prior cognitive functioning was positively associated with subsequent structure of social relations, but not with quality of social relations.

DISCUSSION

Quality of social relations is a protective factor of cognitive aging. Additionally, responding to prior lower cognitive functioning, social network diversity reduced, but quality of social relations did not seem to change. Overall, this study suggested that social relations and cognitive functioning mutually influence each other, but different aspects of social relations (i.e., quality, structure) might have different directional associations with cognitive functioning.

Association between alcohol consumption in midlife and cognitive function in old age: Findings from the China health and Nutrition Survey

BACKGROUND AND AIMS

Alcohol consumption has been reported to impair the physical and mental health of the elderly. This study aimed to explore the association between alcohol consumption patterns in midlife and cognition in the elderly among the Chinese population.

METHODS AND RESULTS

Study subjects were individuals aged ≥45 years in the shared database of the China Health and Nutrition Survey in 1997, who were followed up in 2006. A questionnaire was used to collect information about alcohol consumption (frequency, amount and type). Alcohol consumption (grams/week) was classified into none, light (≤84), light-to-moderate (84.01-168), moderate-to-heavy (168.01-336) and heavy (≥336.01) categories in men, and none, light (<42) and moderate (≥42) categories in women. Cognitive function was measured in 2006 using a subset of items from the modified Telephone Interview for Cognitive Status. The lowest quintile was used as the cut-off point for cognitive impairment. A multivariate logistic regression model was applied. The study involved 1926 participants with a mean age of 56.91 years, and men accounted for 51.66% of the total participants. Drinking behaviours and cognitive scores had significant sexual difference (P < 0.001). Cognitive impairment was identified in 135 men and 237 women. Compared with light drinking, heavy drinking and non-drinking were associated with cognitive impairment in men [adjusted odds ratio (aOR) and 95% CI were 2.19 (1.59-3.00), 1.54 (1.21-1.96), respectively; P < 0.001]. Compared with light drinkers, female non-drinkers and moderate drinkers were associated with cognitive impairment [aOR and 95% CI were 1.54 (1.16-2.03) and 1.75 (1.08-2.85), respectively; P < 0.001].

CONCLUSIONS

Scientific evidence on the adverse effects of heavy drinking on elderly cognition and the possibly protective effects of light drinking could influence policy decisions on alcohol consumption in China.

Associations between total MRI-visible small vessel disease burden and domain-specific cognitive abilities in a community-dwelling older-age cohort

Cerebral small vessel disease (SVD) is a leading cause of vascular cognitive impairment, however the precise nature of SVD-related cognitive deficits, and their associations with structural brain changes, remain unclear. We combined computational volumes and visually-rated MRI markers of SVD to quantify total SVD burden, using data from the Lothian Birth Cohort 1936 (n = 540; age: 72.6 ± 0.7 years). We found negative associations between total SVD burden and general cognitive ability (standardized β: -0.363; 95%CI: [-0.49, -0.23]; p(FDR) < 0.001), processing speed (-0.371 [-0.50, -0.24]; p(FDR) < 0.001), verbal memory (-0.265; [-0.42, -0.11]; p(FDR) = 0.002), and visuospatial ability (-0.170; [-0.32, -0.02]; p(FDR) = 0.029). Only the association between SVD burden and processing speed remained after accounting for covariance with general cognitive ability (-0.325; [-0.61, -0.04]; p(FDR) = 0.029). This suggests that SVD's association with poorer processing speed is not driven by, but is independent of its association with poorer general cognitive ability. Tests of processing speed may be particularly sensitive to the cognitive impact of SVD, but all major cognitive domains should be tested to determine the full range of SVD-related cognitive characteristics.

Age-Related Cognitive Decline May Be Moderated by Frequency of Specific Food Products Consumption

Our study aimed to evaluate whether the type of food products and the frequency of their consumption are associated with cognitive functioning in younger and older adults. The impact of diets that are high in added sugars and saturated fat on cognitive functioning, especially on memory, was at the center of our interest. Participants in the study were 204 healthy adults (aged 20-55) who performed a multitasking cognitive test and completed dietary and psychological questionnaires. Stepwise regression analysis with age and food consumption patterns as predictors, and the cognitive task performance as a dependent variable, revealed that cognitive task performance worsened with age. However, we found that the frequency of consuming different types of foods (healthy versus unhealthy dietary patterns) moderates the effects of age on cognitive functioning. Red meat and animal fat consumption were negatively correlated with cognitive performance, and this relation was dependent on the age of our participants. Conversely, white meat and fish consumption were positively related to memory. Different indices of dietary patterns (both positive and negative) were stronger predictors of cognitive performance in the older adult group. We interpret our results as evidence that diet may be a protective (or worsening) factor in age-related cognitive decline.

Unmet needs for assistance related to subjective cognitive decline among community-dwelling middle-aged and older adults in the US: prevalence and impact on health-related quality of life

OBJECTIVES

To estimate the prevalence of unmet needs for assistance among middle-aged and older adults with subjective cognitive decline (SCD) in the US and to evaluate whether unmet needs were associated with health-related quality of life (HRQOL).

DESIGN

Cross-sectional.

SETTING

US - 50 states, District of Columbia, and Puerto Rico.

PARTICIPANTS

Community-dwelling adults aged 45 years and older who completed the Cognitive Decline module on the 2015--2018 Behavioral Risk Factor Surveillance System reported experiencing SCD and always, usually, or sometimes needed assistance with day-to-day activities because of SCD (n = 6,568).

MEASUREMENTS

We defined SCD as confusion or memory loss that was happening more often or getting worse over the past 12 months. Respondents with SCD were considered to have an unmet need for assistance if they sometimes, rarely, or never got the help they needed with day-to-day activities. We measured three domains of HRQOL: (1) mental (frequent mental distress, ≥14 days of poor mental health in the past 30 days), (2) physical (frequent physical distress, ≥14 days of poor physical health in the past 30 days), and (3) social (SCD always, usually, or sometimes interfered with the ability to work, volunteer, or engage in social activities outside the home). We used log-binomial regression models to estimate prevalence ratios (PRs). All estimates were weighted.

RESULTS

In total, 40.2% of people who needed SCD-related assistance reported an unmet need. Among respondents without depression, an unmet need was associated with a higher prevalence of frequent mental distress (PR = 1.55, 95% CI: 1.12-2.13, p = 0.007). Frequent physical distress and social limitations did not differ between people with met and unmet needs.

CONCLUSIONS

Middle-aged and older adults with SCD-related needs for assistance frequently did not have those needs met, which could negatively impact their mental health. Interventions to identify and meet the unmet needs among people with SCD may improve HRQOL.

The roles of study setting, response bias, and personality in subjective memory complaints of cognitively normal older adults

OBJECTIVES

This study investigated subjective memory complaints in older adults and the roles of setting, response bias, and personality.

DESIGN

Cognitively normal older adults from two settings completed questionnaires measuring memory complaints, response bias, and personality.

SETTINGS

(A) Neuroimaging study with community-based recruitment and (B) academic memory clinic.

PARTICIPANTS

Cognitively normal older adults who (A) volunteer for research (N = 92) or (B) self-referred to a memory clinic (N = 20).

MEASUREMENTS

Neuropsychological evaluation and adjudication of normal cognitive status were done by the neuroimaging study or memory clinic. This study administered self-reports of subjective memory complaints, response bias, five-factor personality, and depressive symptoms. Primary group differences were examined with secondary sensitivity analyses to control for sex, age, and education differences.

RESULTS

There was no significant difference in over-reporting response bias between study settings. Under-reporting response bias was higher in volunteers. Cognitive complaints were associated with response bias for two cognitive complaint measures. Neuroticism was positively associated with over-reporting in evaluation-seekers and negatively associated with under-reporting in volunteers. The relationship was reversed for Extraversion. Under-reporting bias was positively correlated with Agreeableness and Conscientiousness in volunteers.

CONCLUSION

Evaluation-seekers do not show bias toward over-reporting symptoms compared to volunteers. Under-reporting response bias may be important to consider when screening for memory impairment in non-help-seeking settings. The Memory Functioning Questionnaire was less sensitive to reporting biases. Over-reporting may be a facet of higher Neuroticism. Findings help elucidate psychological influences on self-perceived cognitive decline and help seeking in aging and may inform different strategies for assessment by setting.

Adverse Childhood Experiences and Rate of Memory Decline From Mid to Later Life: Evidence From the English Longitudinal Study of Ageing

Evidence on the role of early-life adversity in later-life memory decline is conflicting. We investigated the relationships between adverse childhood experiences (ACEs) and memory performance and rate of decline over a 10-year follow-up among middle-aged and older adults in England. Data were from biennial interviews with 5,223 participants aged 54 years or older in the population-representative English Longitudinal Study of Ageing from 2006/2007 to 2016/2017. We examined self-reports of 9 ACEs prior to age 16 years that related to abuse, household dysfunction, and separation from family. Memory was assessed at each time point as immediate and delayed recall of 10 words. Using linear mixed-effects models with person-specific random intercepts and slopes and adjusted for baseline age, participants' baseline age squared, sex, ethnicity, and childhood socioeconomic factors, we observed that most individual and cumulative ACE exposures had null to weakly negative associations with memory function and rate of decline over the 10-year follow-up. Having lived in residential or foster care was associated with lower baseline memory (adjusted β = -0.124 standard deviation units; 95% confidence interval: -0.273, -0.025) but not memory decline. Our findings suggest potential long-term impacts of residential or foster care on memory and highlight the need for accurate and detailed exposure measures when studying ACEs in relation to later-life cognitive outcomes.

Social Engagement and Cognitive Function of Older Adults in Mexico and the United States: How Universal Is the Interdependence in Couples?

OBJECTIVES

Increased social engagement in older adults has been linked to positive cognitive outcomes; however, it is unclear if the social engagement of husbands and wives influences their own cognition as well as each other's cognition. Moreover, it is unknown if any such patterns persist in different country contexts.

METHODS

Data from the 2001 Mexican Health and Aging Study (MHAS) and the 2000 Health and Retirement Study (HRS) were combined, and comparable samples of married couples without cognitive impairment at baseline were drawn. Follow-up cognition data was obtained from the 2012 MHAS and the 2012 HRS. Structural equation models (SEM) were used to test the actor-partner interdependence model with moderating effect of country on the association of social engagement with cognition.

RESULTS

Significant actor effects were observed for wives in both countries. Actor effects for husbands were observed in the United States only. In Mexico, a significant partner effect was observed where wives' social engagement benefited their own cognition as well as their husbands', but not vice versa. Partner effects were not observed in the United States. No moderation effects of country were observed.

DISCUSSION

Our results suggest asymmetric patterns of actor-partner interdependence in Mexico, which may be reflective of the more traditional social role of women, and codependence within the couple. On the other hand, our results for the United States, where each spouse had significant actor effects but no partner effects, may suggest more independence within the couple.

The Effect of Diabetes on the Cognitive Trajectory of Older Adults in Mexico and the United States

OBJECTIVES

To study the impact of diabetes on the long-term cognitive trajectories of older adults in 2 countries with different socioeconomic and health settings, and to determine whether this relationship differs by cognitive domains. This study uses Mexico and the United States to confirm if patterns hold in both populations, as these countries have similar diabetes prevalence but different socioeconomic conditions and diabetes-related mortality.

METHODS

Two nationally representative cohorts of adults aged 50 years or older are used: the Mexican Health and Aging Study for Mexico and the Health and Retirement Study for the United States, with sample sizes of 18,810 and 26,244 individuals, respectively, followed up for a period of 14 years. The outcome is cognition measured as a total composite score and by domain (memory and nonmemory). Mixed-effect linear models are used to test the effect of diabetes on cognition at 65 years old and over time in each country.

RESULTS

Diabetes is associated with lower cognition and nonmemory scores at baseline and over time in both countries. In Mexico, diabetes only predicts lower memory scores over time, whereas in the United States it only predicts lower memory scores at baseline. Women have higher total cognition and memory scores than men in both studies. The magnitude of the effect of diabetes on cognition is similar in both countries.

DISCUSSION

Despite the overall lower cognition in Mexico and different socioeconomic characteristics, the impact of diabetes on cognitive decline and the main risk and protective factors for poor cognition are similar in both countries.

Fertility History and Cognitive Function in Late Life: The Case of Mexico

OBJECTIVES

Mexico is aging rapidly, which makes identification of life-course factors influencing cognition a public health priority. We evaluate how the number of children one has relates to cognition in Mexico, a rapidly aging country that experienced fertility declines across recent cohorts of older people.

METHOD

We analyze older adults (age 50+, n = 11,380) from the 2015 Mexican Health and Aging Study. Respondents were categorized by number of children ever born (0-1, 2-3, 4-5, 6+). Using ordinary least squares regression, we estimate independent associations between fertility history and cognition accounting for demographic, socioeconomic, health, and psychosocial factors.

RESULTS

We observed an inverse U-shaped relationship between number of children (peaking at 2-3 children) and cognitive function, regardless of gender. In regression analyses adjusted for confounding variables, having 0-1 (vs 2-3 children) was associated with poorer cognitive function only for females. Regardless of gender, having 6+ (vs 2-3 children) was associated with poorer cognitive function. These associations remained significant even after accounting for socioeconomic, health, employment, and psychosocial factors.

DISCUSSION

Our results suggest fertility history may play a role in late-life cognitive health and provide evidence that both low and high fertility may relate to poorer cognitive function. We discuss differences by gender.

Central Obesity, Cardiometabolic Risk, and Cognitive Change in the Study of Latinos - Investigation of Neurocognitive Aging

BACKGROUND

The relationships between obesity and cognitive decline in aging are mixed and understudied among Hispanics/Latinos.

OBJECTIVE

To understand associations between central obesity, cognitive aging, and the role of concomitant cardiometabolic abnormalities among Hispanics/Latinos.

METHODS

Participants included 6,377 diverse Hispanics/Latinos enrolled in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) and SOL-Investigation for Neurocognitive Aging (SOL-INCA). Participants were 45 years and older at the first cognitive testing session (Visit 1). Cognitive outcomes (z-score units) included global composite and domain specific (learning, memory, executive functioning, processing speed) measures at a second visit (SOL-INCA, on average, 7 years later), and 7-year change. We used survey linear regression to examine associations between central obesity (waist circumference≥88 cm and≥102 cm for women and men, respectively) and cognition. We also tested whether the relationships between obesity and cognition differed by cardiometabolic status (indication of/treatment for 2 + of the following: high triglycerides, hypertension, hyperglycemia, low high-density lipoprotein cholesterol).

RESULTS

Central obesity was largely unassociated with cognitive outcomes, adjusting for covariates. However, among individuals with central obesity, cardiometabolic abnormality was linked to poorer cognitive function at SOL-INCA (ΔGlobalCognition =-0.165, p < 0.001) and to more pronounced cognitive declines over the average 7 years (ΔGlobalCognition = -0.109, p < 0.05); this was consistent across cognitive domains.

CONCLUSION

Central obesity alone was not associated with cognitive function. However, presence of both central obesity and cardiometabolic abnormalities was robustly predictive of cognition and 7-year cognitive declines, suggesting that in combination these factors may alter the cognitive trajectories of middle-aged and older Hispanics/Latinos.

Role of nutraceuticals in cognition during aging and related disorders

Cognitive abilities are compromised with advancing age posing a great risk for the development of dementia and other related brain disorders. Genetic susceptibility as well as environmental exposures determine the fate of cognitive aging and its transition to pathological states. Emerging epidemiological and observational studies have revealed the importance of lifestyle factors including dietary patterns and nutritional intake in the maintenance of cognitive health and reducing the risk of neurodegenerative disorders. In this context, nutraceutical interventions have gained considerable attention in preventing age-related cognitive deficits and counteracting pathological processes. Nutraceuticals include dietary plants and derivatives, food supplements and processed foods with nutritional and pharmaceutical values. The present review highlights the importance of nutraceuticals in attenuating cognitive aging and its progression to dementia, with specific emphasis on chemical constituents, neurocognitive properties and mechanism of action.

Cognitive-communication difficulties following traumatic brain injury sustained in older adulthood: a scoping review

BACKGROUND

Older adults are a peak incidence group for traumatic brain injury (TBI). However, empirical evidence on TBI in older adults is often limited to extrapolated findings from studies involving younger adults. While cognitive-communication deficits are an established consequence of TBI with substantial impact on social outcome for younger adults, little is known about the nature of cognitive-communication changes experienced by older adults following a new-onset TBI. In order to inform evidence-based service delivery and support older adults who sustain TBI, it is important to understand how these difficulties manifest in older adults.

AIMS

To review the empirical literature to determine the nature and breadth of research that has addressed the influence of older age on cognitive-communication outcomes following TBI sustained in older adulthood.

METHODS & PROCEDURES

A scoping review framework was used. Five electronic databases (Medline, PsycINFO, Embase, CINAHL and Scopus) were searched to locate peer-reviewed studies addressing cognitive-communication following TBI sustained at ≥ 55 years. Given the absence of dedicated investigations within the search yield, studies were included where at least 30% of participants were aged ≥ 55 years at injury, and age was a stated focus of the investigation.

OUTCOMES & RESULTS

A total of 2468 unique records were identified and reduced to 225 after title and abstract screening. Full-text review revealed only three studies that met the criteria. Collectively these studies included adults aged 55-93 years at injury. Two studies focused on age as a predictor for acute cognitive-communication difficulty, and one on the impact of age on facial emotion recognition in the chronic stages of injury. None of the studies had a dedicated focus on cognitive-communication outcomes for older adults who sustained a TBI within the defined period of older adulthood.

CONCLUSIONS & IMPLICATIONS

This scoping review produced limited results and insufficient evidence to inform rehabilitation for older adults. Indeed, very little is known about cognitive-communication outcomes for older adults who sustain a TBI. This review highlights the need, in the context of an ageing population, for research within this area to be prioritized. What this paper adds What is already known on the subject Empirical evidence to support the management of post-TBI cognitive-communication difficulties in adults predominantly stems from studies with young adults. However, the broader TBI literature suggests that outcome for older adults requires specific consideration due to its distinct nature and occurrence during a stage of life when there is the potential for subtle change to the processes of cognition and communication as part of typical ageing. What this paper adds to existing knowledge This scoping review identifies that research related to cognitive-communication outcomes for older adults who have sustained a TBI is very much in its infancy. Overarching statements about post-TBI cognitive-communication outcomes for older adults cannot be drawn, nor can it be determined if outcomes for older adults differ from younger adults. What are the potential or actual clinical implications of this work? The lack of research in this area means that tangible guidance cannot be provided to clinicians working with older adults following TBI to support evidence-based practice for cognitive-communication. This scoping review strongly supports the need for further research in this area.

MicroRNA predicts cognitive performance in healthy older adults

The expression of microRNA (miRNA) is influenced by ongoing biological processes, including aging, and has begun to play a role in the measurement of neurodegenerative processes in central nervous system. The purpose of this study is to utilize machine learning approaches to determine whether miRNA can be utilized as a blood-based biomarker of cognitive aging. A random forest regression combining miRNA with biological (brain volume), clinical (comorbid conditions), and demographic variables in 115 typically aging older adults explained the greatest level of variance in cognitive performance compared to the other machine learning models explored. Three miRNA (miR-140-5p, miR-197-3p, and miR-501-3p) were top-ranked predictors of multiple cognitive outcomes (Fluid, Crystallized, and Overall Cognition) and past studies of these miRNA link them to cellular senescence, inflammatory signals for atherosclerotic formation, and potential development of neurodegenerative disorders (e.g., Alzheimer's disease). Several novel miRNAs were also linked to age and multiple cognitive functions, findings which together warrant further exploration linking these miRNAs to brain-derived metrics of neurodegeneration in typically aging older adults.

Looking on the Bright Side: Aging and the Impact of Emotional Future Simulation on Subsequent Memory

OBJECTIVES

When younger adults simulated positive future events, subsequent memory is positively biased. In the current studies, we explore age-related changes in the impact of emotional future simulation on subsequent memory.

METHODS

In Experiment 1, younger and older adults simulated emotional future events before learning the hypothetical outcome of each event via narratives. Memory was assessed for emotional details contained in those narratives. In Experiment 2, a shorter temporal delay between simulation and narrative encoding was used to reduce decay of simulation memory over time.

RESULTS

Future simulation did not bias subsequent memory for older adults in Experiment 1. However, older adults performed similar to younger adults in Experiment 2, with more liberal responses to positive information after positive simulation.

DISCUSSION

The impact of an optimistic outlook on subsequent memory is reduced with age, which may be at least partly attributable to declining memory for future simulations over time. This work broadens our understanding of the functional consequences of age-related declines in episodic future simulation and adds to previous work showing reduced benefits of simulation with age on tasks tapping adaptive functions.

Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed

OBJECTIVES

To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether (a) these domains show different associations with age and education, (b) these domains show similar patterns of age-related change over time, and (c) education moderates the rate of decline in these domains.

METHOD

We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education.

RESULTS

We identified 2 language domains, that is, semantic control and semantic memory efficiency, and 2 cognitive domains, that is, working memory and cognitive speed. Older age negatively affected all domains except semantic memory efficiency, and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain.

DISCUSSION

Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.

Modeling human age-associated increase in Gadd45γ expression leads to spatial recognition memory impairments in young adult mice

Aging is associated with the progressive decay of cognitive function. Hippocampus-dependent processes, such as the formation of spatial memory, are particularly vulnerable to aging. Currently, the molecular mechanisms responsible for age-dependent cognitive decline are largely unknown. Here, we investigated the expression and function of the growth arrest DNA damage gamma (Gadd45γ) during aging and cognition. We report that Gadd45γ expression is increased in the hippocampus of aged humans and that Gadd45γ overexpression in the young adult mouse hippocampus compromises cognition. Moreover, Gadd45γ overexpression in hippocampal neurons disrupted cAMP response element-binding protein signaling and the expression of well-established activity-regulated genes. This work shows that Gadd45γ expression is tightly controlled in the hippocampus and its disruption may be a mechanism contributing to age-related cognitive impairments observed in humans.

Spousal Education and Cognitive Functioning in Later Life

OBJECTIVES

Numerous studies have documented the relationship between education and cognitive functioning at the individual level. Yet few studies have examined whether a spouse's education spills over to influence the other spouse's cognitive functioning. This study, therefore, investigates the association between spousal education and cognitive functioning, the pathways that may account for this association, and gender differences in this association.

METHOD

Growth curve models were analyzed by using longitudinal couple data from the Health and Retirement Study (N = 5,846 individuals).

RESULTS

More years of spousal education are associated with higher level of cognitive functioning at age 65 (γ000 = 0.0532, 95% confidence interval [CI] = 0.0163-0.0901) and slower decline in cognitive functioning in later adulthood (γ100 = 0.0054, 95% CI = 0.0026-0.0082). The positive association between spousal education and the level of cognitive functioning at age 65 is fully explained by economic resources. The association of spousal education with the rate of change in cognitive functioning decreases but remains significant after controlling for economic resources and health behaviors (γ100 = 0.0043, 95% CI = 0.0014-0.0072). The association between spousal education and cognitive functioning is similar for men and women.

DISCUSSION

Findings suggest that more years of spousal education may slow decline in cognitive functioning for men and women in later life.

Education and Cognitive Decline: An Integrative Analysis of Global Longitudinal Studies of Cognitive Aging

BACKGROUND

The objective of this study was to examine the association between education and incidence of accelerated cognitive decline.

METHODS

Secondary analyses of data from the Health and Retirement Study (HRS), a nationally representative prospective cohort study of U.S. residents were conducted (N = 28,417). Cox proportional hazards survival models were layered on longitudinal mixed-effects modeling to jointly examine healthy cognitive aging and incidence of accelerated cognitive decline consistent with patterns seen in preclinical Alzheimer's disease and related dementias (ADRD). Replication analyses were completed on a database including 62,485 additional respondents from HRS sister studies. Life expectancy ratios (LER) and 95% confidence intervals (CIs) were reported.

RESULTS

This study replicated research showing that education was positively associated with cognition at baseline. Model fit improved using the survival method compared to random-slopes models alone. Analyses of HRS data revealed that higher education was associated with delayed onset of accelerated cognitive decline (LER = 1.031 95% CI = [1.013-1.015], p < 1E-06). Replication analyses using data from 14 countries identified similar results.

CONCLUSIONS

These results are consistent with cognitive reserve theory, suggesting that education reduces risk of ADRD-pattern cognitive decline. Follow-up work should seek to differentiate specific dementia types involved and consider potential mechanisms.

Education and Cognitive Functioning Across the Life Span

Cognitive abilities are important predictors of educational and occupational performance, socioeconomic attainment, health, and longevity. Declines in cognitive abilities are linked to impairments in older adults' everyday functions, but people differ from one another in their rates of cognitive decline over the course of adulthood and old age. Hence, identifying factors that protect against compromised late-life cognition is of great societal interest. The number of years of formal education completed by individuals is positively correlated with their cognitive function throughout adulthood and predicts lower risk of dementia late in life. These observations have led to the propositions that prolonging education might (a) affect cognitive ability and (b) attenuate aging-associated declines in cognition. We evaluate these propositions by reviewing the literature on educational attainment and cognitive aging, including recent analyses of data harmonized across multiple longitudinal cohort studies and related meta-analyses. In line with the first proposition, the evidence indicates that educational attainment has positive effects on cognitive function. We also find evidence that cognitive abilities are associated with selection into longer durations of education and that there are common factors (e.g., parental socioeconomic resources) that affect both educational attainment and cognitive development. There is likely reciprocal interplay among these factors, and among cognitive abilities, during development. Education-cognitive ability associations are apparent across the entire adult life span and across the full range of education levels, including (to some degree) tertiary education. However, contrary to the second proposition, we find that associations between education and aging-associated cognitive declines are negligible and that a threshold model of dementia can account for the association between educational attainment and late-life dementia risk. We conclude that educational attainment exerts its influences on late-life cognitive function primarily by contributing to individual differences in cognitive skills that emerge in early adulthood but persist into older age. We also note that the widespread absence of educational influences on rates of cognitive decline puts constraints on theoretical notions of cognitive aging, such as the concepts of cognitive reserve and brain maintenance. Improving the conditions that shape development during the first decades of life carries great potential for improving cognitive ability in early adulthood and for reducing public-health burdens related to cognitive aging and dementia.

Aging impairs perceptual decision-making in mice: integrating computational and neurobiological approaches

Decision-making is one of the cognitive domains which has been under-investigated in animal models of cognitive aging along with its neurobiological correlates. This study investigated the latent variables of the decision process using the hierarchical drift-diffusion model (HDDM). Neurobiological correlates of these processes were examined via immunohistochemistry. Young (n = 11, 4 months old), adult (n = 10, 10 months old), and old (n = 10, 18 months old) mice were tested in a perceptual decision-making task (i.e. two-alternative forced-choice; 2AFC). Observed data showed that there was an age-dependent decrease in the accuracy rate of old mice while response times were comparable between age groups. HDDM results revealed that age-dependent accuracy difference was a result of a decrease in the quality of evidence integration during decision-making. Significant positive correlations observed between evidence integration rate and the number of tyrosine hydroxylase positive (TH+) neurons in the ventral tegmental area (VTA) and axon terminals in dorsomedial striatum (DMS) suggest that decrease in the quality of evidence integration in aging is related to decreased function of mesocortical and nigrostriatal dopamine.

Investigating the Effects of Spacing on Working Memory Training Outcome: A Randomized, Controlled, Multisite Trial in Older Adults

OBJECTIVE

The majority of the population will experience some cognitive decline with age. Therefore, the development of effective interventions to mitigate age-related decline is critical for older adults' cognitive functioning and their quality of life.

METHODS

In our randomized controlled multisite trial, we target participants' working memory (WM) skills, and in addition, we focus on the intervention's optimal scheduling in order to test whether and how the distribution of training sessions might affect task learning, and ultimately, transfer. Healthy older adults completed an intervention targeting either WM or general knowledge twice per day, once per day, or once every-other-day. Before and after the intervention and 3 months after training completion, participants were tested in a variety of cognitive domains, including those representing functioning in everyday life.

RESULTS

In contrast to our hypotheses, spacing seems to affect learning only minimally. We did observe some transfer effects, especially within the targeted cognitive domain (WM and inhibition/interference), which remained stable at the 3-month follow-up.

DISCUSSION

Our findings have practical implications by showing that the variation in training schedule, at least within the range used here, does not seem to be a crucial element for training benefits.

Pathological Continuum From the Rise in Pulse Pressure to Impaired Neurovascular Coupling and Cognitive Decline

The "biomechanical hypothesis" stipulates that with aging, the cumulative mechanical damages to the cerebral microvasculature, magnified by risk factors for vascular diseases, contribute to a breach in cerebral homeostasis producing neuronal losses. In other words, vascular dysfunction affects brain structure and function, and leads to cognitive failure. This is gathered under the term Vascular Cognitive Impairment and Dementia (VCID). One of the main culprits in the occurrence of cognitive decline could be the inevitable rise in arterial pulse pressure due to the age-dependent stiffening of large conductance arteries like the carotids, which in turn, could accentuate the penetration of the pulse pressure wave deeper into the fragile microvasculature of the brain and damage it. In this review, we will discuss how and why the vascular and brain cells communicate and are interdependent, describe the deleterious impact of a vascular dysfunction on brain function in various neurodegenerative diseases and even of psychiatric disorders, and the potential chronic deleterious effects of the pulsatile blood pressure on the cerebral microcirculation. We will also briefly review data from antihypertensive clinical trial aiming at improving or delaying dementia. Finally, we will debate how the aging process, starting early in life, could determine our sensitivity to risk factors for vascular diseases, including cerebral diseases, and the trajectory to VCID.

Age-related memory deficits are associated with changes in protein degradation in brain regions critical for trace fear conditioning

Brain aging is accompanied by an accumulation of damaged proteins, which results from deterioration of cellular quality control mechanisms and decreased protein degradation. The ubiquitin-proteasome system (UPS) is the primary proteolytic mechanism responsible for targeted degradation. Recent work has established a critical role of the UPS in memory and synaptic plasticity, but the role of the UPS in age-related cognitive decline remains poorly understood. Here, we measured markers of UPS function and related them to fear memory in rats. Our results show that age-related memory deficits are associated with reductions in phosphorylation of the Rpt6 proteasome regulatory subunit and corresponding increases in lysine-48 (K48)-linked ubiquitin tagging within the basolateral amygdala. Increases in K48 polyubiquitination were also observed in the medial prefrontal cortex and dorsal hippocampus. These data suggest that protein degradation is a critical component of age-related memory deficits. This extends our understanding of the relationship between the UPS, aging, and memory, which is an important step toward the prevention and treatment of deficits associated with normal cognitive aging and memory-related neurodegenerative diseases.

The Ups and Downs of Cognitive Function: Neuroticism and Negative Affect Drive Performance Inconsistency

OBJECTIVES

Response time inconsistency (RTI)-or trial-to-trial variability in speeded performance-is increasingly recognized as an indicator of transient lapses of attention, cognitive health status, and central nervous system integrity, as well as a potential early indicator of normal and pathological cognitive aging. Comparatively, little research has examined personality predictors of RTI across adulthood.

METHODS

We evaluated the association between the personality trait neuroticism and RTI in a community-dwelling sample of 317 adults between the ages of 19-83 and tested for two indirect pathways through negative affect (NA) and cognitive interference (CI).

RESULTS

The personality trait neuroticism predicted greater RTI independent of mean response time performance and demographic covariates; the results were age-invariant. Furthermore, NA (but not CI) accounted for this association and moderated mediation model results indicated that older adults were more vulnerable to the adverse effects of NA.

DISCUSSION

Neuroticism predicts greater RTI irrespective of mean performance and this effect is driven largely by heightened negative emotionality that may be particularly detrimental for older adults.

The Impact of Working Memory Training on Cognitive Abilities in Older Adults: The Role of Cognitive Reserve

OBJECTIVES

The aims of this study were to determine whether Working Memory (WM) training improves the cognitive functioning of older adults and to determine the role of cognitive reserve in WM training.

METHODS

Twenty-one older adults, aged between 65 and 91 years were included in the study. Ten of them were in the experimental group and 11 in the passive control group. The experimental group underwent 15 training sessions of n-back training over a period of five weeks, whereas the control group remained passive. All participants (from the experimental and control group) were tested before the training, one week after the training, and three months after the training with Rey- Osterrieth/Taylor Complex Figure test (ROCF), Digit span, and TMT (part A and part B).

RESULTS AND CONCLUSION

Results of our study suggest that although the experimental group slightly improved their performance on the trained task, the progress was not statistically significant. There was also no statistically significant transfer of training effects onto tasks of visual-spatial and verbal memory, as well as those related to executive functioning. However, the study did identify a statistically significant correlation between cognitive reserve and certain tests performed at the final testing: tasks measuring executive functioning and spatial ability. Results also revealed that the group that showed improvement in the training task was significantly better in the ROCF test in comparison with the group that had not improved their performance on the N-back task. Thus, visual-spatial abilities (visual perception, construction, and memory) were more connected with success in WM training, than other measured cognitive abilities (e.g. verbal and numerical memory).

Community engagement and dementia risk: time-to-event analyses from a national cohort study

BACKGROUND

There is increasing interest in the potential health benefits of referring older adults to engage in community leisure activities ('social prescribing') to help promote healthy cognitive ageing. However, it remains unclear whether beneficial effects of community engagement are independent of the well-known protective effects of broader structural, functional and subjective social factors.

METHODS

We analysed data from 9550 adults aged 50+ from the English Longitudinal Study of Ageing, with baseline from 2004 to 2005. We assessed associations between different types of community engagement and dementia incidence over a 12-year period. Specifically, we used Cox proportional hazards models, competing risk regressions models, and modified Fine and Gray subdistribution hazards models while controlling for all identified demographic, health-related, and social covariates.

RESULTS

Community cultural engagement (eg, visiting museums, galleries, the theatre) was associated with a lower hazard of developing dementia in older age independent of demographic, health-related and a broad range of social factors, using all three statistical approaches (fully adjusted Cox models: HR 0.58, 95% CI 0.41 to 0.80). Community group engagement (eg, attending clubs or societies) was only associated with dementia prior to adjustment for social factors. Results were robust to sensitivity analyses considering reverse causality, over-adjustment and baseline cognitive function.

CONCLUSION

It is not just social factors that are associated with reduced risk of dementia onset, but community engagement may also be protective, particularly when relating to cultural activities. These findings are of relevance when considering the current interest in social prescribing to support healthy ageing.

Integrating assessment of cognitive status in elderly cardiovascular care

Cardiovascular clinicians tend to pay little attention to issues related to cognition, and yet those caring for older adults will encounter a variety of conditions that may lead to cognitive impairment. Most commonly, these include cardiovascular disease-specific conditions such as cerebrovascular disease or heart failure, but may also include neurodegenerative conditions, mood disorders, medication side effects and polypharmacy, and nutritional deficiencies and metabolic derangements among others. This review presents evidence supporting the importance of assessing cognitive status in older adults with cardiovascular disease, and suggests a practical approach to assessment and management of cognitive impairment in this population when it is found. Special attention is paid to the importance of collaboration between cardiovascular and geriatric specialists, and the value it may bring to patients.

c-Fos revealed lower hippocampal participation in older homing pigeons when challenged with a spatial memory task

Homing pigeons experience age-related spatial-cognitive decline similar to that seen in mammals. In contrast to mammals, however, previous studies have shown the hippocampal formation (HF) of old, cognitively impaired pigeons to be greater in volume and neuron number compared with young pigeons. As a partial explanation of the cognitive decline in older birds, it was hypothesized that older pigeons have reduced HF activation during spatial learning. The present study compared HF activation (via the activity-dependent expression of the immediate early gene c-Fos) between younger and older pigeons during learning of a spatial, delayed nonmatch-to-sample task. On the last day of training, c-Fos activation significantly correlated with behavioral performance in the young, but not old, pigeons suggesting more HF engagement by the young pigeons in solving the task. The behavioral correlation was additionally associated with consistently higher, but insignificant c-Fos activation across practically every HF subdivision in the young compared with the old pigeons. In sum, the results of the present study are consistent with the hypothesis that age-related decline in the spatial cognitive ability of homing pigeons is in part a result of an older HF being less responsive to the processing of spatial information. However, alternative interpretations of the data are discussed.

Effects of affective symptoms in adolescence and adulthood on trajectories of cognitive function from middle to late adulthood

BACKGROUND

Little is known about the link between affective symptoms and cognitive function across the life course. This study aims to investigate whether affective symptoms in adolescence and adulthood predict trajectories of cognitive function from middle to late-adulthood.

METHODS

Data from the MRC National Survey of Health and Development (NSHD), a cohort of 5362 individuals born in mainland UK in 1946, were utilised. Linear mixed models were used to model cognitive trajectories (memory and processing speed) over a three-decade period (from 43 to 69) and to test effects of affective symptoms in adolescence (ages 13-15) and adulthood (ages 36 and 43) on cognitive function at first testing (age 43) and decline in cognitive function (from 43 to 69). Models were adjusted for sex, childhood cognition, childhood socioeconomic position, and education.

RESULTS

A quadratic model best fitted memory and processing speed data. Models revealed that adolescent affective symptoms were associated with lower memory (b = -1.11, SE = 0.53, p = .04) and processing speed (b = -18.17, SE = 7.53, p = .02) at first cognitive testing, but not with rates of decline from 43 to 69. There were no significant associations between adult affective symptoms and cognitive trajectories.

LIMITATIONS

Missing data is a potential limitation of this study. This was dealt with using maximum likelihood estimation and multiple imputation.

CONCLUSIONS

Findings suggest that adolescent, but not adult, affective symptoms are important predictors of cognitive function in midlife, but not rate of cognitive decline. This highlights the importance of early intervention to manage mental health in adolescence to protect later cognitive function.

Amyloid, Vascular, and Resilience Pathways Associated with Cognitive Aging

OBJECTIVE

To investigate the multifactorial processes underlying cognitive aging based on the hypothesis that multiple causal pathways and mechanisms (amyloid, vascular, and resilience) influence longitudinal cognitive decline in each individual through worsening brain health.

METHODS

We identified 1,230 elderly subjects (aged ≥50 years) with an average of 4.9 years of clinical follow-up and with amyloid positron emission tomography, diffusion tensor imaging, and structural magnetic resonance imaging scans from the population-based Mayo Clinic Study of Aging. We examined imaging markers of amyloid and brain health (white matter microstructural integrity and cortical thinning), systemic vascular health preceding the imaging markers, and early to midlife intellectual enrichment to predict longitudinal cognitive trajectories. We used latent growth curve models for modeling longitudinal cognitive decline.

RESULTS

All the pathways (amyloid, vascular, resilience) converged through their effects on cortical thinning and worsening cognition and together explained patterns in cognitive decline. Resilience and vascular pathways (aging process, sex differences, education/occupation, and systemic vascular health) had significant impact on white matter microstructural integrity. Education/occupation levels contributed to white matter integrity through systemic vascular health. Worsening white matter integrity contributed to significant cortical thinning and subsequently longitudinal cognitive decline. Baseline amyloidosis contributed to a significant proportion of cognitive decline that accelerated with longer follow-up times, and its primary impact was through cortical thinning.

INTERPRETATION

We developed an integrated framework to help explain the dynamic and complex process of cognitive aging by considering key causal pathways. Such an approach is important for both better comprehension of cognitive aging processes and will aid in the development of successful intervention strategies. ANN NEUROL 2019;86:866-877.

Education Differentially Buffers Cognitive Performance in Black and White Older Adults

OBJECTIVES

Given that black American older adults are more likely to have lower educational attainment and perform worse on cognitive tests than white Americans, we examined whether increased education would confer greater cognitive advantage to black Americans on measures of global and specific domains of cognitive function.

METHODS

The sample included 522 community-dwelling older adults from a larger study. An analysis of covariance was conducted with race and education as between-participant factors and global cognition as the dependent variable. A multivariate analysis of covariance was conducted with five cognitive domains (immediate memory, visuospatial/constructional ability, language, attention, and delayed memory) as the dependent variables.

RESULTS

Significant main effects indicated that black Americans, F(1,516) = 29.18, p < .001, and individuals with less education, F(1,516) = 44.93, p < .001, evidenced lower cognitive functioning, controlling for age and overall health status, and the interaction term reached statistical significance, F(1,516) = 7.95, p = .005. The impact of education on global cognitive function for black participants was more than twice as large (Cohen's d = 1.30) than for white participants (Cohen's d = .52). There was a significant race × education interaction for the cognitive domain of attention (p < .001) and a composite measure of non-memory domains (i.e., language, visuospatial/constructional, and attention; p < .001).

DISCUSSION

Our findings suggest that educational attainment is particularly important for black Americans with respect to global cognitive function, attention, and non-memory domains.

Genetic and environmental architecture of processing speed across midlife

OBJECTIVE

Processing Speed (PS) is an important domain in cognitive aging that is characterized by multiple related but nonidentical abilities. Few studies have directly investigated the relationships among PS measures, and none have used genetically informed methods. In this study, we examined the relationship between measures of PS at up to two time points during middle age.

METHOD

We examined data from 1,262 middle-aged men when the sample was at a mean age of 56 and a mean age 62 years. Participants completed 6 measures of PS from three different cognitive tests. We used a genetically informative, confirmatory factor analytic approach to evaluate the phenotypic and genetic relationships cross-sectionally at both single time points and across time.

RESULTS

A higher-order common PS factor accounted for the covariance among three test-specific factors, and each test-specific factor accounted for the covariance between two observed measures. The general PS factor was explained primarily by genetic influences at both time points (a²age56 = .75, a²age62 = .64), and all test-specific factors were heritable (a² range: .45 to .65). Factor loadings from the test-specific factors to the general PS factor varied from λ = .46 to .82. The model was stable over time, although there were differing rates of phenotypic change among latent factors (.20 SD to .44 SD). Cross-time genetic correlations were near unity for all latent factors.

CONCLUSION

These results suggest that PS is highly heritable when considered at a latent variable level, and that there are different rates of change in tests of PS within this sample. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Longitudinal associations between hearing loss and general cognitive ability: The Lothian Birth Cohort 1936

Hearing impairment is associated with poorer cognitive function in later life. We tested for the potential contribution of childhood cognitive ability to this relationship. Childhood cognitive ability is strongly related to cognitive function in older age, and may be related to auditory function through its association with hearing impairment risk factors. Using data from the Lothian Birth Cohort, 1936, we tested whether childhood cognitive ability predicted later-life hearing ability then whether this association was mediated by demographic or health differences. We found that childhood cognitive ability was negatively associated with hearing impairment risk at age 76 (odds ratio = .834, p = .042). However, this association was nonsignificant after subsequent adjustment for potentially mediating demographic and health factors. Next, we tested whether associations observed in older age between hearing impairment and general cognitive ability level or change were accounted for by childhood cognitive ability. At age 76, in the minimally adjusted model, hearing impairment was associated with poorer general cognitive ability level (β = -.119, p = .030) but was not related to decline in general cognitive ability. The former association became nonsignificant after additional adjustment for childhood cognitive ability (β = -.068, p = .426) suggesting that childhood cognitive ability contributes (potentially via demographic and health differences) to the association between levels of hearing and cognitive function in older age. Further work is needed to test whether early life cognitive ability also contributes to the association (documented in previous studies) between older-age hearing impairment and cognitive decline. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Association of Lifelong Intake of Barley Diet with Healthy Aging: Changes in Physical and Cognitive Functions and Intestinal Microbiome in Senescence-Accelerated Mouse-Prone 8 (SAMP8)

Barley intake reportedly reduces the risk of cardiovascular disease, but effects on the systemic phenotypes during healthy aging have not yet been examined. Therefore, we examined the effects of barley on the lifespan; behavioral phenotypes, such as locomotor activity, and cognitive functions, and intestinal microbiome in the senescence-accelerated mouse-prone 8 (SAMP8) mouse. We prepared two mild high-fat diets by adding lard, in which the starch components of AIN-93G were replaced by rice or barley "Motchiriboshi." SAMP8 (four weeks old, male) mice were fed AIN-93G until eight weeks old, and then rice (rice group) or barley diet (rice: barley = 1:4, barley group) until death. Changes in aging-related phenotypes, object and spatial recognition, locomotor and balancing activities, and the intestinal microbiome were recorded. Moreover, plasma cholesterol levels were analyzed at 16 weeks old. Barley intake prolonged the lifespan by approximately four weeks, delayed locomotor atrophy, and reduced balancing ability and spatial recognition. Barley intake significantly increased the medium and small particle sizes of high-density lipoprotein (HDL) cholesterol, which is associated with a reduced risk of total stroke. The Bacteroidetes to Firmicutes ratio in the barley group was significantly higher than that in the rice group during aging. Thus, lifelong barley intake may have positive effects on healthy aging.

Posttraumatic Stress Disorder in Older Adults: A Conceptual Review

Objectives: We provide a review of the literature on posttraumatic stress disorder (PTSD) in older adults, focusing largely on older U.S. military veterans in two primary areas: 1) assessment and diagnosis and 2) non-pharmacological treatment of PTSD in late life. Methods: We performed a search using PubMed and Academic Search Premier (EBSCO) databases and reviewed reference sections of selected papers. We also drew on our own clinical perspectives and reflections of seven expert mental health practitioners. Results: Rates of PTSD are lower in older compared with younger adults. The presence of sub-syndromal/partial PTSD is important and may impact patient functioning. Assessment requires awareness and adaptation for potential differences in PTSD experience and expression in older adults. Psychotherapies for late-life PTSD appear safe, acceptable and efficacious with cognitively intact older adults, although there are relatively few controlled studies. Treatment adaptations are likely warranted for older adults with PTSD and co-morbidities (e.g., chronic illness, pain, sensory, or cognitive changes). Conclusions: PTSD is an important clinical consideration in older adults, although the empirical database, particularly regarding psychotherapy, is limited. Clinical Implications: Assessment for trauma history and PTSD symptoms in older adults is essential, and may lead to increased recognition and treatment.

Observational cohort study investigating cognitive outcomes, social networks and well-being in older adults: a study protocol

INTRODUCTION

Social networks play a role in slowing the development of dementia. However, there is a need for further investigation of the effects of improving social networks on health-related quality of life and cognitive performance. Targeted community aged care services are a central strategy for supporting older adults to initiate and maintain their social engagement with other individuals at all stages of later life. This protocol describes a prospective observational cohort study aimed at (1) characterising interpersonal relationships in older adults receiving community care services, (2) assessing the relationship social networks and health-related quality of life and cognition and (3) identifying the association between community care use, social networks and cognition. The findings will contribute to our understanding of how specific social network structures and social support services can maintain cognitive function in community-dwelling older adults.

METHODS AND ANALYSIS

This is a prospective, observational cohort study of 201 older Australians residing in the community and receiving care services from one of three aged care organisations. Clients with a history of neurological injury will be excluded. Participants will undergo baseline measures of social networks, health-related quality of life and cognitive function, and a follow-up at 6 months. Service use and sociodemographic variables will also be collected. The primary outcome is cognitive function, and secondary outcomes include social networks and health-related quality of life. Multivariable linear regression will test the hypothesis that increased social networks are associated with an increase in cognitive function.

ETHICS AND DISSEMINATION

Approval of the study by Macquarie University Research Ethics Committee (reference number 5201831394062) has been obtained. This work will be disseminated by publication of peer-reviewed manuscripts, presentations in abstract form at scientific meetings and results will be made available to home and community-based care older adults and care staff of the involved organisations.

TRIAL REGISTRATION NUMBER

ACTRN12618001723279; Pre-results.

Green Tea Intake and Risks for Dementia, Alzheimer's Disease, Mild Cognitive Impairment, and Cognitive Impairment: A Systematic Review

Dementia has become a major issue that requires urgent measures. The prevention of dementia may be influenced by dietary factors. We focused on green tea and performed a systematic review of observational studies that examined the association between green tea intake and dementia, Alzheimer’s disease, mild cognitive impairment, or cognitive impairment. We searched for articles registered up to 23 August 2018, in the PubMed database and then for references of original articles or reviews that examined tea and cognition. Subsequently, the extracted articles were examined regarding whether they included original data assessing an association of green tea intake and dementia, Alzheimer’s disease, mild cognitive impairment, or cognitive impairment. Finally, we included three cohort studies and five cross-sectional studies. One cohort study and three cross-sectional studies supported the positive effects of green tea intake. One cohort study and one cross-sectional study reported partial positive effects. The remaining one cohort study and one cross-sectional study showed no significant association of green tea intake. These results seem to support the hypothesis that green tea intake might reduce the risk for dementia, Alzheimer’s disease, mild cognitive impairment, or cognitive impairment. Further results from well-designed and well-conducted cohort studies are required to derive robust evidence.

Cognitive aging is not created equally: differentiating unique cognitive phenotypes in "normal" adults

Age-related cognitive decline is a public health problem but highly diverse and difficult to predict. We captured nonoverlapping cognitive phenotypes in high-functioning adults and identified baseline factors differentiating trajectories. Three hundred fourteen functionally normal adults (M = 69 y) completed 2+ visits. Participants with sample-based longitudinal slopes in memory or processing speed less than -1 SD were classified as "declining" on that measure; 29 and 50 individuals had slopes less than -1 SD on processing speed or memory, respectively; 2.5% met criteria for both, who were excluded. At baseline, speed decliners demonstrated greater age, inflammation, and cognitive complaints compared with speed-stable adults; memory decliners were more likely to be male and had lower depressive symptoms, gray matter volumes, and white matter hyperintensities compared with memory-stable adults. Baseline speed, TNFα, and cognitive complaints accurately classified 96.3% of future speed decliners; baseline memory, sex, precuneal volume, and white matter hyperintensities accurately classified 88.5% of future memory decliners. There are discrete cognitive aging phenotypes reflecting nonoverlapping vulnerabilities in high-functioning adults. Early markers can predict cognition even within the "normal" spectrum and underscore therapeutic targets.