The role of lifestyle behaviors on 20-year cognitive decline

Associations of childhood, adolescence, and midlife cognitive function with DNA methylation age acceleration in midlife

Prior studies showed increased age acceleration (AgeAccel) is associated with worse cognitive function among old adults. We examine the associations of childhood, adolescence and midlife cognition with AgeAccel based on DNA methylation (DNAm) in midlife. Data are from 359 participants who had cognition measured in childhood and adolescence in the Child Health and Development study, and had cognition, blood based DNAm measured during midlife in the Disparities study. Childhood cognition was measured by Raven's Progressive Matrices and Peabody Picture Vocabulary Test (PPVT). Adolescent cognition was measured only by PPVT. Midlife cognition included Wechsler Test of Adult Reading (WTAR), Verbal Fluency (VF), Digit Symbol (DS). AgeAccel measures including Horvath, Hannum, PhenoAge, GrimAge and DunedinPACE were calculated from DNAm. Linear regressions adjusted for potential confounders were utilized to examine the association between each cognitive measure in relation to each AgeAccel. There are no significant associations between childhood cognition and midlife AgeAccel. A 1-unit increase in adolescent PPVT, which measures crystalized intelligence, is associated with 0.048-year decrease of aging measured by GrimAge and this association is attenuated after adjustment for adult socioeconomic status. Midlife crystalized intelligence measure WTAR is negatively associated with PhenoAge and DunedinPACE, and midlife fluid intelligence measure (DS) is negatively associated with GrimAge, PhenoAge and DunedinPACE. AgeAccel is not associated with VF in midlife. In conclusion, our study showed the potential role of cognitive functions at younger ages in the process of biological aging. We also showed a potential relationship of both crystalized and fluid intelligence with aging acceleration.

The influence of healthy lifestyle behaviors on cognitive function among older Chinese adults across age and gender: Evidence from panel data

Cognitive decline has become one of the major issues affecting the health and quality of life of older people. We aimed to examine the combined effect of healthy lifestyle behaviors on cognition among older adults. We utilized data from the Chinese Longitudinal Healthy Longevity Survey dataset and constructed four waves (2008-2018) of panel data of 8423 individuals over 60 years of age. Fixed-effects regression models were used to analyze the relationship between healthy lifestyle behaviors and cognition. Controlling for social and health-related factors, we found that older adults with higher healthy lifestyle scores were associated with better cognition (β=0·308, SE=0·061). Combined healthy lifestyle behaviors have a positive association with cognition among older Chinese adults. Older age (β=0·020, SE=0·007) and women gender (β=0·257, SE=0·129) could increase the effect of healthy lifestyle behaviors on cognitive function. Meanwhile, older age could also promote the impact of diet (β=0·041, SE=0·014) and exercise (β=0·074, SE=0·012) on cognitive performance. Our findings indicated that healthy lifestyle behaviors could prevent cognitive decline among the older Chinese adult population. Older age and women gender may enhance the protective effect of lifestyle behaviors on cognition. Our study suggests that the government needs to launch campaigns and health policies on healthy lifestyle promotion interventions to reduce health inequality and health burden for older adults.

Clinical, neuroimaging, and behavioural risk factors for neurocognitive impairment in Chinese patients with haemophilia: A multicentre study

BACKGROUND

Few studies have evaluated the impact of subclinical microstructural changes and psychosocial factors on cognitive function in patients with haemophilia.

OBJECTIVES

To determine the prevalence and characteristics of cognitive impairment in patients with haemophilia, and identify associated risk factors.

METHODS

We recruited haemophilia A or B patients who were aged ≥10 years old from three public hospitals in Hong Kong. A neurocognitive battery was administered to evaluate their attention, memory, processing speed and cognitive flexibility performances. They also underwent magnetic resonance imaging to identify cerebral microbleeds. Validated self-reported questionnaires were administered to assess their mental health status and adherence to prophylactic treatment. General linear modelling was used to investigate the association of neurocognitive outcomes with risks factors, adjusting for age and education attainment.

RESULTS

Forty-two patients were recruited (median age 32.0 years; 78.6% haemophilia A; 80.9% moderate-to-severe disease). Six patients (14.3%) had developed cerebral microbleeds. A subgroup of patients demonstrated impairments in cognitive flexibility (30.9%) and motor processing speed (26.2%). Hemarthrosis in the previous year was associated with worse attention (Estimate = 7.62, 95% CI: 1.92-15.33; p = .049) and cognitive flexibility (Estimate = 8.64, 95% CI: 2.52-13.29; p = .043). Depressive (Estimate = 0.22, 95% CI: 0.10-0.55; p = .023) and anxiety (Estimate = 0.26, 95% CI: 0.19-0.41; p = .0069) symptoms were associated with inattentiveness. Among patients receiving prophylactic treatment (71.4%), medication adherence was positively correlated with cognitive flexibility (p = .037).

CONCLUSION

A substantial proportion of patients with haemophilia demonstrated cognitive impairment, particularly higher-order thinking skills. Screening for cognitive deficits should be incorporated into routine care. Future studies should evaluate the association of neurocognitive outcomes with occupational/vocational outcomes.

Timing of physical activity across adulthood on later-life cognition: 30 years follow-up in the 1946 British birth cohort

BACKGROUND

To assess how timing, frequency and maintenance of being physically active, spanning over 30 years in adulthood, is associated with later-life cognitive function.

METHODS

Participants (n=1417, 53% female) were from the prospective longitudinal cohort study, 1946 British birth cohort. Participation in leisure time physical activity was reported five times between ages 36 and 69, categorised into: not active (no participation in physical activity/month); moderately active (participated 1-4 times/month); most active (participated 5 or more times/month). Cognition at age 69 was assessed by tests of cognitive state (Addenbrooke's Cognitive Examination-III), verbal memory (word learning test) and processing speed (visual search speed).

RESULTS

Being physically active, at all assessments in adulthood, was associated with higher cognition at age 69. For cognitive state and verbal memory, the effect sizes were similar across all adult ages, and between those who were moderately and most physically active. The strongest association was between sustained cumulative physical activity and later-life cognitive state, in a dose-response manner. Adjusting for childhood cognition, childhood socioeconomic position and education largely attenuated these associations but results mainly remained significant at the 5% level.

CONCLUSIONS

Being physically active at any time in adulthood, and to any extent, is linked with higher later-life cognitive state, but lifelong maintenance of physical activity was most optimal. These relationships were partly explained by childhood cognition and education, but independent of cardiovascular and mental health and APOE-E4, suggestive of the importance of education on the lifelong impacts of physical activity.

Trajectories of self-reported hearing and their associations with cognition: evidence from the United Kingdom and United States of America

OBJECTIVE

This study aimed to investigate the relationships between trajectories of change in self-reported hearing over eight years with subsequent effects on cognition, measured using episodic memory.

METHODS

Data were drawn from 5 waves (2008-2016) of the English Longitudinal Study of England (ELSA) and the Health and Retirement Study (HRS), involving 4,875 individuals aged 50+ at the baseline in ELSA and 6,365 in HRS. The latent growth curve modelling was used to identify trajectories of hearing over eight years, and linear regression models were performed to investigate the relationship between hearing trajectory memberships and episodic memory scores, controlling for confounding factors.

RESULTS

Five trajectories of hearing (stable very good, stable fair, poor to fair/good, good to fair, and very good to good) were retained in each study. Individuals whose hearing remains suboptimal and those whose hearing deteriorates within suboptimal levels throughout eight years have significantly poorer episodic memory scores at follow-up than those with stable very good hearing. Conversely, individuals whose hearing declines but is within an optimal category at baseline do not see significantly poorer episodic memory scores than those with consistently optimal hearing. There was no significant relationship between individuals whose hearing improved from suboptimal baseline levels to optimal by follow-up and memory in ELSA. However, analysis using HRS data shows a significant improvement for this trajectory group (-1.260, P < 0.001).

CONCLUSIONS

Either stable fair or deterioration in hearing is associated with worse cognitive function, both stable good or improving hearing is associated with better cognitive function specifically episodic memory.

Associations between Lifestyle Factors and Neurocognitive Impairment among Chinese Adolescent and Young Adult (AYA) Survivors of Sarcoma

BACKGROUND

The effect of lifestyle on neurocognitive impairment among cancer survivors remain an understudied area. This study explored the association between lifestyle factors and neurocognitive outcomes (specifically, attention, memory, processing speed and cognitive flexibility) in AYA survivors (aged 15-39 years) of sarcoma.

METHODS

This study recruited 116 AYA survivors (age 28.2 (SD = 8.2) years), who were diagnosed with osteosarcoma (49%) or soft-tissue sarcoma (51%) at age 13.3 (SD = 7.2) years. The neurocognitive battery included measures of attention, memory, motor-processing speed, and cognitive flexibility. Survivors reported health-damaging practices, which included: physical inactivity, smoking, alcohol intake, inadequate sleep (<7 h of actual sleep/day), sleep-related fatigue (Multidimensional Fatigue Scale) and long working hours (>9 h/day). General linear modeling was conducted to examine the association between lifestyle factors and neurocognitive outcomes, adjusting for age at diagnosis, sex, education attainment and clinical/treatment variables.

RESULTS

At 14.9 (SD = 7.6) years post-diagnosis, survivors demonstrated impairment in attentiveness (4.3-13.0%), processing speed (34.5%) and cognitive flexibility (18.1%). Nearly half (45.7%) had developed a chronic health condition (CHC). Low physical activity (estimate = -0.97, p = 0.003) and sleep-related fatigue (estimate = -0.08, p = 0.005) were associated with inattention. Survivors who worked >9 h/day (n = 15) demonstrated worse attention (estimate = 5.42, p = 0.023) and cognitive flexibility (estimate = 5.22, p = 0.005) than survivors who worked ≤9 h/day (n = 66). Interaction analysis (CHCs*physical activity) showed that survivors who developed CHCs and reported low physical activity had worse attention (p = 0.032) and cognitive-flexibility (p = 0.019) scores than other subgroups.

CONCLUSION

Treatment-related CHCs, coupled with continued physical inactivity, may exacerbate inattention and executive dysfunction among survivors. Long working hours and sleep-related fatigue are associated with worse functioning; this finding should be validated with prospective assessment of work-related stressors and objective sleep measures.

Whole Dietary Patterns, Cognitive Decline and Cognitive Disorders: A Systematic Review of Prospective and Intervention Studies

Dementia prevalence is a global public health concern. Adherence towards a healthy dietary pattern (DP) may reduce the risk of cognitive decline and dementia. This narrative systematic review aimed to synthesise prospective and intervention study data to evaluate the impact of a-posteriori and a-priori derived DPs on cognitive ageing, from cognitive decline to incident dementia. Ninety-three studies were included: 83 prospective studies and 10 randomised controlled trials (RCT). Most prospective studies (77%) examined a-priori DPs, with the Mediterranean diet examined most frequently. A total of 52% of prospective and 50% of RCTs reported a protective relationship between 'healthy' DPs and global cognitive decline. Overall, 59% of prospective studies reported positive associations between healthy DPs and risk of cognitive disorder. Incident cognitive disorder was examined by only one intervention study (subgroup analysis) which reported a beneficial effect of a low-fat diet on risk of probable dementia in women. Unhealthy DPs were examined less frequently (n = 17; 21%), with 41% of these studies reporting associations between adherence and poorer cognitive outcomes. Overall, there were mixed results for healthy and unhealthy DPs on cognition, likely due to between-study heterogeneity. Standardisation of diet exposure and cognitive outcome measurement would help to reduce this. Future research would benefit from investigating effects of culturally appropriate DPs on individual cognitive domains and incident cognitive disorders in diverse and high-risk populations.

The Effects of Multi-Domain Interventions on Cognition: A Systematic Review

This review aimed to evaluate the effects of multi-domain interventions on cognition among individuals without dementia. Multi-domain interventions refer to those combining any single preventive measure such as physical activity, cognitive training, and/or nutrition to prevent dementia. Seventeen studies were included (n = 10,056 total participants; mean age = 73 years), eight of which were rated as strong in quality while the other nine showed moderate quality. The standardized mean difference (SMD; d) was used to calculate the effect size for each included study. Multi-domain interventions consisting of physical activity, cognitive training, cardioprotective nutrition, and/or cardiovascular health education exerted beneficial effects on global cognition, episodic memory, and/or executive function with very small to moderate effect sizes (0.16-0.77). Nurses may consider combining these components to potentially stave off dementia. Future research is warranted to identify the optimal multi-domain intervention components that can induce clinically significant beneficial effects on cognition.

My Healthy Brain: a multimodal lifestyle program to promote brain health

BACKGROUND

Promoting brain health depends on sustaining healthy behaviors across the lifespan. Yet, public adoption of lifestyle behaviors and knowledge of cognitive decline (CD) prevention remains poor. Our multidisciplinary team developed My Healthy Brain (MHB) to promote a healthy lifestyle (e.g. diet, exercise, alcohol, sleep) and build cognitive reserve (e.g. memory compensatory strategies). Our objective was to demonstrate early proof-of-concept for MHB by exploring the feasibility, acceptability, and improvement in primary lifestyle outcomes as well as secondary outcomes of self-determination and subjective wellbeing.

MATERIALS AND METHODS

Older adults with subjective (self-report only) or objective (confirmed by cognitive testing) CD, referred by neurologists to modify lifestyle risk factors (e.g. sedentary), participated in a non-randomized open pilot of MHB (N = 24). Participants completed the 8-week MHB group (90 min each) and pre-post outcome measures.

RESULTS

MHB met all a-priori set benchmarks, including good feasibility of recruitment (71% of patients screened) and enrollment (75% completed baseline), and good acceptability of treatment (75% completed 6 of 8 sessions and post-testing). Program satisfaction was excellent (100% of participants) and no adverse events were reported. We also observed improvements in primary lifestyle outcomes as well as secondary outcomes of self-determination and subjective well-being.

DISCUSSION

While MHB demonstrated preliminary feasibility and the potential to modify lifestyle risk factors for CD, the program can be improved. Future work will explore the integration of mindfulness skills with behavioral principles to bolster multidomain lifestyle change, and the live video delivery format to bypass barriers to participation.

Polyphenol-rich tart cherries (Prunus Cerasus, cv Montmorency) improve sustained attention, feelings of alertness and mental fatigue and influence the plasma metabolome in middle-aged adults: a randomised, placebo-controlled trial

Tart Montmorency cherries (MC) are a particularly rich source of anthocyanins and other polyphenols that have been shown to elicit antioxidant, anti-inflammatory and vasomodulatory actions. The current study aimed to determine the influence of chronic MC supplementation on cognitive function and mood. In a 3-month double-blinded, placebo-controlled parallel study, middle-aged adults (mean ± sd: 48 ± 6 years) were randomly assigned to either 30 ml twice daily of MC (n 25) or the same amount of an isoenergetic placebo (n 25). Cognitive function and mood were assessed before and after supplementation using a computerised cognitive task battery and visual analogue scales. Cerebral blood flow was also monitored by near-infrared spectroscopy during the task battery, and questionnaires were administered to determine subjective sleep and health status and plasma metabolomics were analysed before and after supplementation. After 3 months, the MC resulted in higher accuracy in digit vigilance (mean difference: 3·3, 95 % CI: 0·2, 6·4 %) with lower number of false alarms (mean difference: -1·2, 95 % CI: -2·0, -0·4) compared with the placebo. There was also a treatment effect for higher alertness (mean difference: 5·9, 95 % CI: 1·3, 10·5 %) and lower mental fatigue ratings (mean difference -9·5, 95 % CI: -16·5, -2·5 %) with MC. Plasma metabolomics revealed an increase in a number of amino acids in response to MC intake, but not placebo. These data suggest an anti-fatiguing effect of MC supplementation as well as the ability to improve sustained attention during times of high cognitive demand, this could be related to changes in amino acid metabolism.

My Healthy Brain: Rationale and Case Report of a Virtual Group Lifestyle Program Targeting Modifiable Risk Factors for Dementia

Nearly half of dementia cases may be explained by modifiable lifestyle risk factors. Multidomain interventions are needed to bypass cognitive decline (CD) and aging-related barriers to sustained healthy lifestyles in at-risk older adults. We iteratively developed  My Healthy Brain, a group-based lifestyle program (8 weeks, 90 min sessions) delivered via live video that applies behavioral principles to target multiple risk factors for dementia. We describe the program structure, virtual delivery, and outcomes for a group of older adults with subjective CD or mild cognitive impairment and lifestyle risk factors (e.g., sedentary, poor sleep or diet). We also conducted a group exit interview to qualitatively assess participant experiences and elicit feedback to improve My Healthy Brain. This case report demonstrates that delivering evidence-based brain health education and behavior change skills in a group setting via live video is feasible, acceptable, and has the potential to improve lifestyle, cognitive, and psychosocial outcomes in older adults with CD.

Adult children's education and trajectories of episodic memory among older parents in the United States of America

The purpose of this study is to assess the relationship between adult children's education and older parents’ cognitive health, and the extent to which this relationship is moderated by parents’ own socio-economic and marital statuses. Data using Waves 5 (2000) to 13 (2016) are drawn from the Health and Retirement Study (HRS), a nationally representative panel survey of individuals age 50 and above in the United States of America (USA). Older parents’ cognitive functioning is measured using episodic memory from Waves 5–13. Adult children's education is measured using years of schooling, on average, for all adult children of a respondent. Analyses based on multilevel linear growth curve modelling reveal that parents with well-educated adult children report higher memory score over time compared to their counterparts whose children are not as well-educated. We also find that the positive effect of children's education on parents’ cognitive health is moderated by parents’ own education, though not by their income, occupation or marital status. Our work contributes to the growing body of research on the ‘upward’ flow of resources model that assesses the ways in which personal and social assets of the younger generation shape the health and wellbeing of the older generation. Our findings are particularly relevant to the USA given the enduring linkage between socio-economic status and health, and the limited social and economic protection for those of lower social status.

Prediction of brain age and cognitive age: Quantifying brain and cognitive maintenance in aging

The concept of brain maintenance refers to the preservation of brain integrity in older age, while cognitive reserve refers to the capacity to maintain cognition in the presence of neurodegeneration or aging-related brain changes. While both mechanisms are thought to contribute to individual differences in cognitive function among older adults, there is currently no "gold standard" for measuring these constructs. Using machine-learning methods, we estimated brain and cognitive age based on deviations from normative aging patterns in the Whitehall II MRI substudy cohort (N = 537, age range = 60.34-82.76), and tested the degree of correspondence between these constructs, as well as their associations with premorbid IQ, education, and lifestyle trajectories. In line with established literature highlighting IQ as a proxy for cognitive reserve, higher premorbid IQ was linked to lower cognitive age independent of brain age. No strong evidence was found for associations between brain or cognitive age and lifestyle trajectories from midlife to late life based on latent class growth analyses. However, post hoc analyses revealed a relationship between cumulative lifestyle measures and brain age independent of cognitive age. In conclusion, we present a novel approach to characterizing brain and cognitive maintenance in aging, which may be useful for future studies seeking to identify factors that contribute to brain preservation and cognitive reserve mechanisms in older age.

Improving Age-Related Cognitive Decline through Dietary Interventions Targeting Mitochondrial Dysfunction

Aging is inevitable and it is one of the major contributors to cognitive decline. However, the mechanisms underlying age-related cognitive decline are still the object of extensive research. At the biological level, it is unknown how the aging brain is subjected to progressive oxidative stress and neuroinflammation which determine, among others, mitochondrial dysfunction. The link between mitochondrial dysfunction and cognitive impairment is becoming ever more clear by the presence of significant neurological disturbances in human mitochondrial diseases. Possibly, the most important lifestyle factor determining mitochondrial functioning is nutrition. Therefore, with the present work, we review the latest findings disclosing a link between nutrition, mitochondrial functioning and cognition, and pave new ways to counteract cognitive decline in late adulthood through diet.

Taurine supplementation reduces myeloperoxidase and matrix-metalloproteinase-9 levels and improves the effects of exercise in cognition and physical fitness in older women

Immunosenescence contributes to cognitive impairment and neurodegeneration, and those conditions could be attenuated by non-pharmacological anti-inflammatory strategies, such as exercise and supplementation with the amino acid taurine. Since taurine body content decreases with aging, we investigated the effects of supplementation (alone and combined with exercise) on oxidative stress, extracellular matrix degradation, white blood cells, neurotrophins, cognition and physical fitness of elderly women. Forty-eight women (83.58 ± 6.98 years) were enrolled into exercise training only (EO: n = 13), taurine supplementation (TS: n = 12), exercise training + taurine supplementation (ETTS: n = 11), and control group (CG: n = 12). All interventions lasted 14 weeks. Exercise was applied twice a week, and taurine was given once a day (1.5 g). Data collection occurred before and after interventions with the determination of myeloperoxidase (MPO), matrix metalloproteinase-9 (MMP-9), brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) levels, and white blood cell counts (WBC). Montreal cognitive assessment (MoCA) and physical fitness tests were also evaluated. Concentration of MPO and MMP-9 decreased after intervention in TS (p < 0.05). No effect of time or time × group was observed for WBC parameters; however, univariate analysis showed a significant decrease in lymphocytes for TS, while an increase in monocytes occurred in the CG (p < 0.05). MoCA scores decreased over time in the CG (p < 0.05). Improvements in physical fitness occurred in ETTS (better agility and aerobic capacity), mostly likely due to exercise and boosted by taurine supplementation. No changes in BDNF levels were observed (p > 0.05), while NGF concentration were undetectable in almost subjects. Exercise together with taurine supplementation appears to be a valuable strategy to enhance health-related outcomes in older persons.

Cognitive reserve and brain maintenance in aging and dementia: An integrative review

This research is an integrative review of scientific evidence differentiating between cognitive reserve (CR) and brain maintenance concepts. Thus, we have examined how CR socio-behavioral proxies (i.e. education, occupational attainment, and leisure activities) may help to cope with age-related cognitive decline and negative consequences of brain pathology. We also analyze lifestyle factors associated with brain maintenance or the relative absence of change in neural resources over time. Medline and Web of Science databases were used for the bibliographic search in the last 20 years. Observational cohort studies were selected to analyze the effect of different CR proxies on cognitive decline, including dementia incidence, whereas studies employing functional neuroimaging (fMRI) were used to display the existence of compensation mechanisms. Besides, structural MRI studies were used to test the association between lifestyle factors and neural changes. Our findings suggest that education, leisure activities, and occupational activity are protective factors against cognitive decline and dementia. Moreover, functional neuroimaging studies have verified the existence of brain networks that may underlie CR. Therefore, CR may be expressed either through a more efficient utilization (neural reserve) of brain networks or the recruitment of additional brain regions (compensation). Finally, lifestyle factors such as abstaining from smoking, lower alcohol consumption, and physical activity contributed to brain maintenance and were associated with the preservation of cognitive function. Advances in multimodal neuroimaging studies, preferably longitudinal design, will allow a better understanding of the neural mechanisms associated with the prevention of cognitive decline and preservation of neural resources in aging.

Systemic inflammation and modifiable risk factors for cognitive impairment in older persons: Findings from a British birth cohort

Serum pro‐inflammatory markers may contribute to dementia pathophysiology and cognitive impairment. In a population‐representative birth cohort, serum C‐reactive protein (CRP), interleukin‐6 (IL‐6), and white cell count (WCC) were measured at age 60‐64 years and cognition was assessed using the Addenbrooke's Cognitive Examination (ACE‐III) at age 69 years. Higher baseline CRP and IL‐6 were associated with lower ACE‐III scores, but associations were attenuated on adjustment for educational attainment, sex, and other modifiable life course factors. No associations were found for CRP, IL‐6, and WCC with visual search speed or verbal memory. In conclusion, the relationship between increased baseline systemic inflammation and poorer cognition in later life may be explained by, or share pathways with, education and other modifiable life course factors.

Advantaged socioeconomic conditions in childhood are associated with higher cognitive functioning but stronger cognitive decline in older age

There is increasing evidence that socioeconomic conditions early in life have an impact on cognitive functioning in later life. Based on the large longitudinal sample from SHARE we find a clear pattern in cognitive functioning in old age, related to childhood socioeconomic conditions: Those from more affluent households show higher levels of fluid intelligence in old age and experience stronger decline over time in executive functions. The latter phenomenon is not often documented. Although modifications in cognitive functioning with aging are inevitable, life course socioeconomic circumstances impact the timing of this process. We conclude that the etiology of cognitive aging is the result of multiple social processes, defined by the socioeconomic conditions in childhood and all along the life course.

Cognitive aging is characterized by large heterogeneity, which may be due to variations in childhood socioeconomic conditions (CSC). Although there is substantial evidence for an effect of CSC on levels of cognitive functioning at older age, results on associations with cognitive decline are mixed. We examined by means of an accelerated longitudinal design the association between CSC and cognitive trajectories from 50 to 96 years. Cognition included two functions generally found to decline with aging: delayed recall and verbal fluency. Data are from six waves of the Survey of Health, Aging, and Retirement in Europe (SHARE), conducted between 2004 and 2015 (n = 24,066 at baseline; 56% female, age 50+). We found a consistent CSC pattern in levels of cognitive functioning in later life. Older people with disadvantaged CSC had lower levels of cognitive functioning than those with more advantaged CSC. We also find that decline is almost 1.6 times faster in the most advantaged group compared with the most disadvantaged group. The faster decline for people with more advantaged CSC becomes less pronounced when we additionally control for adulthood socioeconomic conditions and current levels of physical activity, depressive symptoms, and partner status. Our findings are in line with the latency, pathway, and cumulative model and lend support to theories of cognitive reserve, stating that neuronal loss can no longer be repaired in people with more cognitive reserve once the underlying pathology is substantial and speed of decline is accelerated.

Dietary glycaemic index and cognitive function: prospective associations in adults of the 1946 British birth cohort

Objective

Evidence suggests that the rate of glucose release following consumption of carbohydrate-containing foods, defined as the glycaemic index (GI), is inversely associated with cognitive function. To date, most of the evidence stems from either single-meal studies or highly heterogeneous cohort studies. We aimed to study the prospective associations of diet GI at age 53 years with outcomes of verbal memory and letter search tests at age 69 years and rate of decline between 53 and 69 years.

Design

Longitudinal population-based birth cohort study.

Setting

MRC National Survey for Health and Development.

Participants

Cohort members (n 1252).

Results

Using multivariable linear and logistic regression, adjusted for potential confounders, associations of higher-GI diet with lower verbal memory, lower letter search speed and lower number of hits in a letter search test were attenuated after adjustments for cognitive ability at age 15 years, educational attainment, further training and occupational social class. No association was observed between diet GI at 53 years and letter search accuracy or speed–accuracy trade-off at 69 years, or between diet GI at 53 years and rate of decline between 53 and 69 years in any cognitive measure.

Conclusions

Diet GI does not appear to predict cognitive function or decline, which was mainly explained by childhood cognitive ability, education and occupational social class. Our findings confirm the need for further research on the association between diet and cognition from a life-course perspective.

Physical Activity Throughout the Adult Life Span and Domain-Specific Cognitive Function in Old Age: A Systematic Review of Cross-Sectional and Longitudinal Data

BACKGROUND

A growing body of literature suggests that physical activity might alleviate the age-related neurodegeneration and decline of cognitive function. However, most of this evidence is based on data investigating the association of exercise interventions or current physical activity behavior with cognitive function in elderly subjects.

OBJECTIVE

We performed a systematic review and hypothesize that physical activity during the adult life span is connected with maintained domain-specific cognitive functions during late adulthood defined as age 60+ years.

METHODS

We performed a systematic literature search up to November 2017 in PubMed, Web of Science, and Google Scholar without language limitations for studies analyzing the association of leisure physical activity during the adult life span (age 18+ years) and domain-specific cognitive functions in older adults (age 60+ years).

RESULTS

The literature review yielded 14,294 articles and after applying inclusion and exclusion criteria, nine cross-sectional and 14 longitudinal studies were included. Moderate- and vigorous-intensity leisure physical activity was associated with global cognitive function and specific cognitive domains including executive functions and memory but not attention or working memory. Most studies assessed mid- to late-adulthood physical activity, thus information concerning the influence of young adult life-span physical activity is currently lacking.

CONCLUSIONS

Observational evidence that moderate- and vigorous-intensity leisure physical activity is beneficially associated with maintained cognitive functions during old age is accumulating. Further studies are necessary to confirm a causal link by assessing objective physical activity data and the decline of cognitive functions at multiple time points during old age.

Motor performance in early life and participation in leisure-time physical activity up to age 68 years

BACKGROUND

This study examined associations between motor performance in early life and leisure-time physical activity (LTPA) participation across adulthood, and whether these changed with age.

METHODS

Data were from 2526 participants from the Medical Research Council National Survey of Health and Development. Motor indicators were mother-reported ages at first standing and walking, teacher-rated games ability at age 13, and finger- and foot-tapping speed at age 15. LTPA was reported at ages 36, 43, 53, 60-64, and 68 years and classed at each age as none, moderate (1-4/mo), or regular (≥5/mo). Associations were examined using mixed-effects Poisson regression models with robust error variance.

RESULTS

Better ability at games and faster tapping speed were associated with more frequent participation in LTPA across adulthood, for example, fully adjusted relative risk of regular LTPA across adulthood (vs none) for above-average ability (vs below average or average) = 1.46 (95% CI 1.32, 1.61); and per 10-unit higher number of finger-taps/15 seconds = 1.04 (95% CI 1.02, 1.07). These associations did not vary by age (P ≥ .33 for interactions with age at LTPA). Ages at reaching motor milestones were not associated with LTPA (eg, fully adjusted relative risk of regular LTPA across adulthood for walking ≤10 and ≥18 months (vs 11-17 months) were 1.01 (95% CI 0.86, 1.20) and 0.89 (95% CI 0.75, 1.06) respectively.

CONCLUSIONS

Better ability at games and faster tapping speed in adolescence were associated with greater participation in LTPA throughout adult life; from age 36 up to age 68. Childhood motor skill interventions may therefore have the potential to promote lifelong LTPA.

Practical applications of physical activity for successful cognitive aging

As patients lose cognitive function, they lose autonomy and increasingly use fiscal, social, and medical resources. Healthcare costs for Americans older than age 65 years are three to five times higher than for the remaining population, and dementia is the third most costly disease in the United States. Interventions that promote successful aging can help patients and reduce the financial, workforce, and treatment resource burdens on the population. Because a relationship between physical activity, particularly aerobic exercise, and cognitive decline has been established, physical activity interventions may prove practical, affordable, and effective. Attention to empiric research and knowledge of evidence-based strategies for prescribing physical activity are critical for PAs to embrace.

Delirium symptoms are associated with decline in cognitive function between ages 53 and 69 years: Findings from a British birth cohort study

INTRODUCTION

Few population studies have investigated whether longitudinal decline after delirium in mid-to-late life might affect specific cognitive domains.

METHODS

Participants from a birth cohort completing assessments of search speed, verbal memory, and the Addenbrooke's Cognitive Examination at age 69 were asked about delirium symptoms between ages 60 and 69 years. Linear regression models estimated associations between delirium symptoms and cognitive outcomes.

RESULTS

Period prevalence of delirium between 60 and 69 years was 4% (95% confidence interval 3.2%-4.9%). Self-reported symptoms of delirium over the seventh decade were associated with worse scores in the Addenbrooke's Cognitive Examination (-1.7 points; 95% confidence interval -3.2, -0.1; P = .04). In association with delirium symptoms, verbal memory scores were initially lower, with subsequent decline in search speed by the age of 69 years. These effects were independent of other Alzheimer's risk factors.

DISCUSSION

Delirium symptoms may be common even at relatively younger ages, and their presence may herald cognitive decline, particularly in search speed, over this time period.

Demographic factors and retrieval of object and proper names after age 70

Purpose

This research aimed to investigate whether demographic factors are similarly related to retrieval of object and proper names.

Methods

The sample included 5,907 individuals above age 70 who participated in the Health and Retirement Study between 2004 and 2012. Participants were asked to name two objects as well as the US President and Vice President. Latent growth curve models examined the associations of age, education, and self-rated health with baseline levels and change trajectories in retrieval.

Results

Age and education were more strongly related to retrieval of proper names than to retrieval of object names, both for baseline scores and for change trajectory. Similar effects of self-rated health emerged for both types of stimuli.

Conclusions

The results show that examining object names and proper names together as indication of cognitive status in the HRS might overlook important differences between the two types of stimuli, in both baseline performance and longitudinal change.

Decreased Central Nervous System Grey Matter Volume (GMV) in Smokers Affects Cognitive Abilities: A Systematic Review

Although cigarette smoking is a leading cause of preventable mortality, tobacco is consumed by approximately 22% of the adult population worldwide. Smoking is also a risk factor for cardiovascular disease, affects brain processing, and is a recognized risk factor for Alzheimer disease (AD). Tobacco toxins (e.g., nicotine at high levels) inhaled in smoke may cause disorders resulting in preclinical brain changes. Researchers suggest that there are differences in brain volume between smokers and non-smokers. This review examines these differences in brain grey matter volume (GMV). In March/April 2015, MedLine, Embase, and PsycINFO were searched using the terms: "grey matter" AND "voxel-based" AND "smoking" AND "cigarette". The 4 studies analyzed found brain GMV decreases in smokers compared to non-smokers. Furthermore, sex-specific differences were found; while the thalamus and cerebellum were affected in both sexes, decreased GMV in the olfactory gyrus was found only in male smokers. Age-group differences were also found, and these may suggest pre-existing abnormalities that lead to nicotine dependence in younger individuals. Only 1 study found a positive correlation between number of pack-years smoked and GMV. Smoking decreases GMV in most brain areas. This decrease may be responsible for the cognitive impairment and difficulties with emotional regulation found in smokers compared with non-smokers.

An International Evaluation of Cognitive Reserve and Memory Changes in Early Old Age in 10 European Countries

BACKGROUND

Cognitive reserve was postulated to explain individual differences in susceptibility to ageing, offering apparent protection to those with higher education. We investigated the association between education and change in memory in early old age.

METHODS

Immediate and delayed memory scores from over 10,000 individuals aged 65 years and older, from 10 countries of the Survey of Health, Ageing and Retirement in Europe, were modeled as a function of time in the study over an 8-year period, fitting independent latent growth models. Education was used as a marker of cognitive reserve and evaluated in association with memory performance and rate of change, while accounting for income, general health, smoking, body mass index, gender, and baseline age.

RESULTS

In most countries, more educated individuals performed better on both memory tests at baseline, compared to those less educated. However, education was not protective against faster decline, except for in Spain for both immediate and delayed recall (0.007 [SE = 0.003] and 0.006 [SE = 0.002]), and Switzerland for immediate recall (0.006 [SE = 0.003]). Interestingly, highly educated Italian respondents had slightly faster declines in immediate recall (-0.006 [SE = 0.003]).

CONCLUSIONS

We found weak evidence of a protective effect of education on memory change in most European samples, although there was a positive association with memory performance at individuals' baseline assessment.

HDL-cholesterol and apolipoproteins in relation to dementia

PURPOSE OF REVIEW

Dementia is a major cause of disability and institutionalization. Apart from age and apolipoprotein E (APOE) genotype, there are currently no established, clinically relevant, noninvasive markers of dementia. We conducted a literature search of recent observational epidemiological studies evaluating the relevance of HDL cholesterol (HDL-C) and apolipoproteins as biomarkers of future and prevalent risk of dementia.

RECENT FINDINGS

HDL-C and apolipoproteins, such as apoE have been suggested to play important roles in brain function and have been associated with dementia and Alzheimer's disease in observational studies. However, findings have been inconsistent, especially across study designs. In recent years, modern proteomic approaches have enabled the investigation of further apolipoproteins involved in the deposition and clearance of β-amyloid, a determining factor for subsequent neurodegeneration.

SUMMARY

Associations in cross-sectional studies are not always indicative of a prospective relationship. Large studies find that plasma HDL-C and apoE are inversely associated with dementia. Higher apoJ levels might be a marker of prevalent dementia, but were not associated with risk of future dementia. The investigation of HDL-C and apolipoproteins in relation to dementia represents an area of opportunity. Additional prospective studies that account for potential confounding factors and that explore potential effect modifiers such as APOE genotype and sex are needed to fully investigate the potential of these noninvasive measures in disease prediction.

Effect of smoking on physical and cognitive capability in later life: a multicohort study using observational and genetic approaches

OBJECTIVES

The observed associations between smoking and functional measures at older ages are vulnerable to bias and confounding. Mendelian randomisation (MR) uses genotype as an instrumental variable to estimate unconfounded causal associations. We conducted a meta-analysis of the observational associations and implemented an MR approach using the smoking-related single nucleotide polymorphism rs16969968 to explore their causal nature.

SETTING

9 British cohorts belonging to the HALCyon collaboration.

PARTICIPANTS

Individual participant data on N=26,692 individuals of European ancestry (N from earliest phase analysed per study) of mean ages 50-79 years were available for inclusion in observational meta-analyses of the primary outcomes.

PRIMARY OUTCOMES

Physical capability, cognitive capability and cognitive decline. The smoking exposures were cigarettes per day, current versus ex-smoker, current versus never smoker and ever versus never smoker.

RESULTS

In observational analyses current and ever smoking were generally associated with poorer physical and cognitive capability. For example, current smokers had a general fluid cognition score which was 0.17 z-score units (95% CI -0.221 to -0.124) lower than ex-smokers in cross-sectional analyses. Current smokers had a walk speed which was 0.25 z-score units lower than never smokers (95% CI -0.338 to -0.170). An MR instrumental variable approach for current versus ex-smoker and number of cigarettes smoked per day produced CIs which neither confirmed nor refuted the observational estimates. The number of genetic associations stratified by smoking status were consistent with type I error.

CONCLUSIONS

Our observational analysis supports the hypothesis that smoking is detrimental to physical and cognitive capability. Further studies are needed for a suitably powered MR approach.

Alzheimer's disease and vascular dementia: one potentially preventable and modifiable disease? Part II: Management, prevention and future perspective

The management of dementia and mild cognitive impairment (MCI) includes pharmacological, nonpharmacological and caregiver interventions. Acetyl-cholinesterase inhibitors and memantine have a small beneficial effect in mild-to-moderate dementia. Attention is increasingly focused on long-term measures that may prevent, delay or minimize MCI and dementia, including Mediterranean diet, exercise, early active treatment of hypercholesterolaemia hypertension, and diabetes starting in midlife and earlier. High cognitive activity and a high cognitive reserve may prevent or delay the onset of aging-related MCI and dementia. Although the numbers of the elderly with dementia are rapidly increasing worldwide, the incidence of dementia in some countries is decreasing attributable to higher educational levels, decreased vascular risk factors and healthier lifestyles. Prevention of dementia is feasible and reasonable.

Alcohol consumption and cognitive performance: a Mendelian randomization study

AIMS

To use Mendelian randomization to assess whether alcohol intake was causally associated with cognitive function.

DESIGN

Mendelian randomization using a genetic variant related to alcohol intake (ADH1B rs1229984) was used to obtain unbiased estimates of the association between alcohol intake and cognitive performance.

SETTING

Europe.

PARTICIPANTS

More than 34 000 adults.

MEASUREMENTS

Any versus no alcohol intake and units of intake in the previous week was measured by questionnaire. Cognitive function was assessed in terms of immediate and delayed word recall, verbal fluency and processing speed.

FINDINGS

Having consumed any versus no alcohol was associated with higher scores by 0.17 standard deviations (SD) [95% confidence interval (CI) = 0.15, 0.20] for immediate recall, 0.17 SD (95% CI = 0.14, 0.19) for delayed recall, 0.17 SD (95% CI = 0.14, 0.19) for verbal fluency and 0.12 SD (95% CI = 0.09, 0.15) for processing speed. The minor allele of rs1229984 was associated with reduced odds of consuming any alcohol (odds ratio = 0.87; 95% CI = 0.80, 0.95; P = 0.001; R(2)  = 0.1%; F-statistic = 47). In Mendelian randomization analysis, the minor allele was not associated with any cognitive test score, and instrumental variable analysis suggested no causal association between alcohol consumption and cognition: -0.74 SD (95% CI = -1.88, 0.41) for immediate recall, -1.09 SD (95% CI = -2.38, 0.21) for delayed recall, -0.63 SD (95% CI = -1.78, 0.53) for verbal fluency and -0.16 SD (95% CI = -1.29, 0.97) for processing speed.

CONCLUSIONS

The Mendelian randomization analysis did not provide strong evidence of a causal association between alcohol consumption and cognitive ability.

Subjective cognitive complaints across the adult life span: a 14-year analysis of trends and associations using the 1993, 2000 and 2007 English Psychiatric Morbidity Surveys

BACKGROUND

Cognitive complaints are common in all age groups but most often researched in old age. We aimed to investigate prevalences and time trends over 14 years of subjective memory complaints (SMC) and subjective concentration complaints (SCC) in adults and investigate associations with mood disorders and cognitive function.

METHOD

Data from three English national mental health surveys carried out in 1993, 2000 and 2007 were analysed. SMC and SCC were measured using the Clinical Interview Schedule-Revised and cognitive function using the modified Telephone Interview for Cognitive Status.

RESULTS

Both SMC and SCC increased up to middle age and then declined, followed by a second rise in the very oldest age groups. Age-specific prevalence of both increased across survey years but relationships with mental health and cognitive outcomes were relatively stable.

CONCLUSIONS

Cognitive complaints are most common in middle age and have become more prevalent over time.

[Factors Associated with Cognitive Decline in a Population Less than 65 Years Old. A Systematic Review]

INTRODUCTION

Cognitive decline could begin 20 years before the diagnosis of dementia. Besides age, several factors related to medical, socioeconomic, and behavioral and genetic condition may be associated with cognitive decline. The aim of this systematic review was to summarize evidence on the risk and protective factors for cognitive decline in people under 65 years old.

METHODS

A systematic review was conducted using a search strategy in MEDLINE and Embase, including longitudinal studies to analyze the effect of protective or risk factors on cognitive decline in a population under 65 years old.

RESULTS

A total of 22 studies were included in this review. Factors such as diabetes, hyperinsulinemia, overweight or obesity, metabolic syndrome, education, physical activity, cognitive stimulation, marital status and diet, could be related to cognitive decline before 65 years of age.

CONCLUSIONS

Cardiovascular risk factors and lifestyle conditions may be associated with cognitive decline before 65 years of age. However, the quality of the evidence was low.

Relationship between diet quality and cognition depends on socioeconomic position in healthy older adults

Both diet quality and socioeconomic position (SEP) have been linked to age-related cognitive changes, but there is little understanding of how the socioeconomic context of dietary intake may shape its cognitive impact. We examined whether equal adherence to "prudent" and "Western" dietary patterns, identified by principal components analysis, was associated with global cognitive function [Modified Mini-Mental State Examination (3MS)] in independently living older adults with different SEPs (aged 68-84 y; n = 1099). The interaction of dietary pattern adherence with household income, educational attainment, occupational prestige, and a composite indicator of SEP combining all 3 was examined in multiple-adjusted mixed models over 3 y of follow-up in participants of the NuAge study (Quebec Longitudinal Study on Nutrition and Successful Aging). Adherence to the prudent pattern (vegetables, fruits, fish, poultry, and lower-fat dairy products) was related to higher 3MS scores at recruitment only in the upper categories of income [parameter estimate (B): 0.56; 95% CI: 0.11, 1.01], education (B: 0.44; 95% CI: 0.080, 0.80), or composite SEP (B: 0.37; 95% CI: 0.045, 0.70). High prudent pattern adherence was associated with less cognitive decline only in those with low composite SEP (B: 0.25; 95% CI: 0.0094, 0.50). Conversely, adherence to the Western pattern (meats, potatoes, processed foods, and higher-fat dairy products) was associated with more cognitive decline (B: -0.23; 95% CI: -0.43, -0.032) only in those with low educational attainment. In summary, among individuals with equivalent diet quality, the magnitude and characteristics of the diet-cognition relationship depended on their socioeconomic circumstances. These results suggest that interventions promoting retention of cognitive function through improved diet quality would provide maximum benefit to those with relatively low SEP.

Prevention of common mental disorders: what can we learn from those who have gone before and where do we go next?

OBJECTIVE

Prevention strategies have made a major contribution to the considerable successes in reductions in cardiovascular disease and cancer mortality seen in recent decades. However, in the field of psychiatry, similar population-level initiatives in the prevention of common mental disorders, depression and anxiety, are noticeably lacking. This paper aims to provide a brief overview of the existing literature on the topic of the prevention of common mental disorders and a commentary regarding the way forward for prevention research and implementation.

METHODS

This commentary considers what we currently know, what we might learn from the successes and failures of those working in prevention of other high prevalence health conditions, and where we might go from here. Taking cognisance of previous preventive models, this commentary additionally explores new opportunities for preventive approaches to the common mental disorders.

RESULTS

The consensus from a large body of evidence supports the contention that interventions to prevent mental disorders across the lifespan can be both effective and cost-effective. However, funding for research in the area of prevention of common mental disorders is considerably lower than that for research in the areas of treatment, epidemiology and neurobiology. Thus, there is a clear imperative to direct funding towards prevention research to redress this imbalance. Future prevention interventions need to be methodologically rigorous, scalable to the population level and include economic evaluation. Evidence-based knowledge translation strategies should be developed to ensure that all stakeholders recognise preventing mental disorders as an imperative, with appropriate resources directed to this objective.

CONCLUSION

There has been a recent expansion of research into potentially modifiable risk factors for depression, and it is now timely to make a concerted effort to advance the field of prevention of common mental disorders.