Lifestyle Factors and Dementia in the Oldest-old: The 90+ Study

Association of caffeine consumption with cerebrospinal fluid biomarkers in mild cognitive impairment and Alzheimer's disease: A BALTAZAR cohort study

INTRODUCTION

We investigated the link between habitual caffeine intake with memory impairments and cerebrospinal fluid (CSF) biomarkers in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients.

METHODS

MCI (N = 147) and AD (N = 116) patients of the Biomarker of AmyLoid pepTide and AlZheimer's diseAse Risk (BALTAZAR) cohort reported their caffeine intake at inclusion using a dedicated survey. Associations of caffeine consumption with memory impairments and CSF biomarkers (tau, p-tau181, amyloid beta 1-42 [Aβ1-42], Aβ1-40) were analyzed using logistic and analysis of covariance models.

RESULTS

Adjusted on Apolipoprotein E (APOE ε4), age, sex, education level, and tobacco, lower caffeine consumption was associated with higher risk to be amnestic (OR: 2.49 [95% CI: 1.13 to 5.46]; p = 0.023) and lower CSF Aβ1-42 (p = 0.047), Aβ1-42/Aβ1-40 (p = 0.040), and Aβ1-42/p-tau181 (p = 0.020) in the whole cohort.

DISCUSSION

Data support the beneficial effect of caffeine consumption to memory impairments and CSF amyloid markers in MCI and AD patients.

HIGHLIGHTS

We studied the impact of caffeine consumption in the BALTAZAR cohort. Low caffeine intake is associated with higher risk of being amnestic in MCI/AD patients. Caffeine intake is associated with CSF biomarkers in AD patients.

Alcohol consumption in relation to cognitive dysfunction and dementia: A systematic review and dose-response meta-analysis of comparative longitudinal studies

BACKGROUND

Alcohol use is associated with a wide spectrum of neurological disorders, including cognitive dysfunction and dementia. Likewise, the high prevalence of cognitive dysfunction and dementia specifies the urgent need to identify modifiable risk factors. Because findings on alcohol and cognitive dysfunction and dementia have been inconsistent, the present dose-response meta-analysis of cohort and case control studies was conducted to evaluate the available evidence.

METHOD AND MATERIALS

A systematic search was conducted on PubMed/MEDLINE, Scopus, Embase, and PsychInfo databases and Google Scholar up to April, 2023. In the dose-response meta-analysis, a restricted cubic spline regression model was conducted to evaluate a possible non-linear relation between alcohol intake and the outcomes. Random-effects model was used to perform the meta-analysis and evaluate heterogeneity. Egger's test and a funnel plot were used to assess small study effects. Subgroup analyses were carried out to explore possible sources of heterogeneity.

RESULTS

Seventeen eligible studies comprising 80,680 total persons with 4929 cases for dementia and 13,530 total persons with 1579 cases for cognitive dysfunction were included for dose-response analysis. When compared to the reference group of 0 g/day of alcohol intake, the dose-response meta-analysis revealed a significant non-linear (J-shaped) association between alcohol intake and the risk of each of cognitive dysfunction, (lower dose range: 1-30.5 g/day, RR: 0.97; 95 % CI 0.95-0.99; higher dose range: >30.5 g/day, RR: 1.07; 95 % CI 1.01-1.15) and dementia (lower dose range: 1-17.5 g/day, RR: 0.92; 95 % CI 0.88-0.96, higher dose range: >17.5 g/day, RR: 1.23; 95 % CI 1.09-1.35). The lowest risk was achieved at approximately 30 g/day of alcohol for cognitive dysfunction and 15 g/day for dementia. The J-shape association remained with subgroups defined by age (≤65; >65 years) or study duration (<10; ≥10 years) for dementia, and within age >65 and duration <10 years for cognitive dysfunction.

CONCLUSION

We observed a J-shape association between alcohol consumption and both cognitive dysfunction and dementia, with light-to-moderate alcohol intake being associated with a reduced risk in adults. Further studies are needed to clarify more specifically the association between alcohol consumption and six domains of cognitive dysfunction based on diagnostic and statistical manual of mental disorders (DSM) criteria.

The impact of nutrition on psycho-affective status in an older Cretan population: a cross-sectional study

BACKGROUND

Cognitive and mood status influence both personal and social daily activities, with great impact on life quality, particularly among the elderly population.

AIM

This cross-sectional study aimed to investigate the psycho-affective status concerning eating habits within an elderly population of the Chania area in Crete, Greece.

METHODS

Cognitive status was assessed in 101 elderly subjects through the Mini-Mental State Examination (MMSE), and mood was evaluated using the Hospital Anxiety and Depression Scale (HADS). Nutritional status was assessed using a validated food frequency questionnaire.

RESULTS

Multivariable statistical analysis, after adjustment for age, marital status, education, and comorbidity, highlighted among males a positive association of the MMSE score with vegetable consumption (RR 1.18; 95%CI 1.03‒1.34) and a negative association with potato consumption (RR 0.83; 95%CI 0.72‒0.95). Conversely, among females, no statistically significant association was observed for any food. Further, among males, a protective effect on affective status was identified for chicken meat (RR 0.45; 95%CI 0.27‒0.77), fish (RR 0.41; 95%CI 0.21‒0.82), fruit (RR 0.70; 95%CI 0.52‒0.94), cereals (RR 0.67; 95%CI 0.53‒0.87), and cheese (RR 0.78; 95%CI 0.63‒0.97) consumption. Among females, the adjusted model showed a significant detrimental effect of vegetable consumption (RR 1.33; 95%CI 1.02‒1.73).

CONCLUSION

A predominantly vegetable-based diet-with the notable exception of fruits and legumes-was associated with better cognitive status in males, albeit not in females. A higher intake of fruit, as well as fish, chicken meat, and cheese among males was associated with a better affective status, indicating that adequate protein supply may play a role in maintaining emotional balance.

Tea, coffee, and caffeine intake and risk of dementia and Alzheimer's disease: a systematic review and meta-analysis of cohort studies

Background: Limited and conflicting evidence exists for the associations between tea, coffee, and caffeine intake and risk of dementia and Alzheimer's disease (AD). This meta-analysis aimed to elucidate these associations and quantify potential dose-response relationships. Methods: PubMed, EMBASE, and Web of Science were searched up to 11 June 2024 for cohort studies. Random effects models were used to calculate pooled relative risks (RRs) and 95% confidence intervals (CIs), with the dose-response relationship assessed using restricted cubic splines. The Grading of Recommendations Assessment Development and Evaluation (GRADE) tool was used to assess the risk of bias. Results: Our analysis encompassed 38 cohorts, totalling 751 824 participants and 13 017 dementia and 17 341 AD cases. For dementia, compared with the lowest category, the pooled RRs (95% CI) in the highest category of tea, coffee, and caffeine were 0.84 (0.74-0.96, n = 6), 0.95 (0.87-1.02, n = 9), and 0.94 (0.70-1.25, n = 5), with all rated as low certainty in GRADE. For AD, the pooled RRs (95% CI) in the highest category of tea, coffee, and caffeine compared to the lowest category were 0.93 (0.87-1.00, n = 6), 1.01 (0.90-1.12, n = 10), and 1.34 (1.04-1.74, n = 2), with certainty ratings of low, low, and very low, respectively. Dose-response analysis indicated a non-linear relationship between coffee intake (Poverall = 0.04 and Pnonlinear = 0.01) and dementia risk, showing the protective association of risk of dementia with 1 to 3 cups per day of coffee intake. There is a linear association between tea intake and risk of dementia, with a significantly decreased risk of dementia for each 1 cup per day increase in tea consumption (0.96, 95% CI 0.94-0.99, Poverall = 0.01 and Pnonlinear = 0.68). Conclusion: Increased tea consumption was associated with a decreased risk of dementia and AD, and a non-linear relationship was found between coffee and dementia, supporting public health recommendations for dementia prevention.

Coffee and Alzheimer's disease

Coffee, a universally consumed beverage, is known to contain thousands of bioactive constituents that have garnered interest due to their potential neuroprotective effects against various neurodegenerative disorders, including Alzheimer's disease (AD). Extensive research has been conducted on coffee constituents such as Caffeine, Trigonelline, Chlorogenic acid, and Caffeic acid, focusing on their neuroprotective properties. These compounds have potential to impact key mechanisms in AD development, including amyloidopathy, tauopathy, and neuroinflammation. Furthermore, apart from its neuroprotective effects, coffee consumption has been associated with anticancerogenic and anti-inflammatory effects, thereby enhancing its therapeutic potential. Studies suggest that moderate coffee intake, typically around two to three cups daily, could potentially contribute to mitigating AD progression and lowering the risk of related neurological disorders. This literature underscores the potential neuroprotective properties of coffee compounds, which usually perform their neuronal protective effects via modulating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), nuclear factor erythroid-derived 2-like 2 (Nrf2), interleukins, tumor necrosis factor-alpha (TNF-α), and many other molecules.

Moderate coffee or tea consumption decreased the risk of cognitive disorders: an updated dose-response meta-analysis

CONTEXT

Although several epidemiological studies have examined the association between coffee or tea intake and the risk of cognitive disorders, the results to date are inconsistent.

OBJECTIVE

An updated systematic review and dose-response meta-analysis was conducted to confirm the association between coffee, tea, and caffeine consumption and the risk of cognitive disorders.

DATA SOURCES

PubMed, Embase, and Web of Science were searched from inception to January 2022 for relevant studies, including dementia, Alzheimer disease (AD), and cognitive impairment or decline.

DATA EXTRACTION

Two reviewers independently performed data extraction and assessed the study quality.

DATA ANALYSIS

Restricted cubic splines were used to conduct the dose-response meta-analysis for coffee and tea intake.

RESULTS

Twenty-two prospective studies and 11 case-control studies involving 389 505 participants were eligible for this meta-analysis. Coffee and tea consumption was linked to a lower risk of cognitive disorders, with an overall relative risk (RR) of 0.73 (95% CI: 0.60-0.86) and 0.68 (95% CI: 0.56-0.80), respectively. The subgroup analysis revealed that ethnicity, sex, and outcomes had significant effects on this association. Protection was stronger for men than that for women in both coffee and tea consumption. A nonlinear relationship was found between coffee consumption and AD risk, and the strength of protection peaked at approximately 2.5 cups/day (RR: 0.74; 95% CI: 0.59-0.93). A linear relationship was found between tea consumption and cognitive disorders, and the risk decreased by 11% for every 1-cup/day increment.

CONCLUSION

This meta-analysis demonstrated that the consumption of 2.5 cups coffee/day minimizes the risk of AD, and 1 cup/day of tea intake leads to an 11% reduction in cognitive deficits. Effective interventions involving coffee and tea intake might prevent the occurrence of dementia.

Neuropathologic Burden and Dementia in Nonagenarians and Centenarians: Comparison of 2 Community-Based Cohorts

BACKGROUND AND OBJECTIVES

The aim of this study was to compare 2 large clinicopathologic cohorts of participants aged 90+ and to determine whether the association between neuropathologic burden and dementia in these older groups differs substantially from those seen in younger-old adults.

METHODS

Autopsied participants from The 90+ Study and Adult Changes in Thought (ACT) Study community-based cohort studies were evaluated for dementia-associated neuropathologic changes. Associations between neuropathologic variables and dementia were assessed using logistic or linear regression, and the weighted population attributable fraction (PAF) per type of neuropathologic change was estimated.

RESULTS

The 90+ Study participants (n = 414) were older (mean age at death = 97.7 years) and had higher amyloid/tau burden than ACT <90 (n = 418) (mean age at death = 83.5 years) and ACT 90+ (n = 401) (mean age at death = 94.2 years) participants. The ACT 90+ cohort had significantly higher rates of limbic-predominant age-related TDP-43 encephalopathy (LATE-NC), microvascular brain injury (μVBI), and total neuropathologic burden. Independent associations between individual neuropathologic lesions and odds of dementia were similar between all 3 groups, with the exception of μVBI, which was associated with increased dementia risk in the ACT <90 group only (odds ratio 1.5, 95% CI 1.2-1.8, p < 0.001). Weighted PAF scores indicated that eliminating μVBI, although more prevalent in ACT 90+ participants, would have little effect on dementia. Conversely, eliminating μVBI in ACT <90 could theoretically reduce dementia at a similar rate to that of AD neuropathologic change (weighted PAF = 6.1%, 95% CI 3.8-8.4, p = 0.001). Furthermore, reducing LATE-NC in The 90+ Study could potentially reduce dementia to a greater degree (weighted PAF = 5.1%, 95% CI 3.0-7.3, p = 0.001) than either ACT cohort (weighted PAFs = 1.69, 95% CI 0.4-2.7).

DISCUSSION

Our results suggest that specific neuropathologic features may differ in their effect on dementia among nonagenarians and centenarians from cohorts with different selection criteria and study design. Furthermore, microvascular lesions seem to have a more significant effect on dementia in younger compared with older participants. The results from this study demonstrate that different populations may require distinct dementia interventions, underscoring the need for disease-specific biomarkers.

Accelerometer-measured physical activity and posture among older adults in assisted-living residences

Objective

Few studies have detailed the physical activity and postural patterns (e.g. lying or sitting) in older adults with declining activities of daily living (ADL). Therefore, we aimed to address this issue by quantifying physical activity using an accelerometer and measuring time spent in various postures among older adults in assisted-living residences.

Methods

We quantified physical activity using an accelerometer (ActivPAL) and measured time spent in various postures in 35 older adults (mean age: 89.1 years) with chronic conditions residing in two assisted-living residences in Japan. ActivPAL was attached to the thigh and trunk of patients to distinguish between sitting and lying postures.

Results

Participants had a mean count of 6.2 comorbidities, and they were divided into three groups (fully independent, requiring minimal assistance and requiring care) based on their activities of daily living capacity using the Barthel Index. Residents aged ⩾90 years walked a mean of 1109.1 steps and spent 167.3 min upright per day. Fully independent participants walked a mean of 3587.6 steps daily; those requiring minimal assistance walked 1681.0 steps daily; and those requiring care walked 428.9 steps daily.

Conclusions

Our findings indicated that step count, number of sit-to-stand transitions, stepping time, and upright time decreased significantly as activities of daily living capacity decreased. Comorbidity type and number of comorbidities were not related to their lying time except for depression status. Lying time was associated with depression status.

Association of Dietary and Supplement Intake of Antioxidants with Risk of Dementia: A Meta-Analysis of Cohort Studies

Background

Dementia is a neuropsychiatric disorder with cognitive decline due to multiple factors. With the arrival of the aging population, the incidence of dementia has gradually increased. There is still no effective treatment for dementia, and therefore, the prevention of dementia has become crucial. Oxidative stress is considered to be one of the pathogenesis of dementia; therefore, antioxidant therapy and prevention of dementia have been gradually proposed.

Objective

Our meta-analysis aimed to investigate the association of antioxidants with risk of dementia.

Methods

We searched PubMed, Embase, and Web of Science databases for articles on antioxidants associated with dementia risk, and those containing cohort studies with high-dose versus low-dose controls were included in our meta-analysis. The resulting risk ratios (RR) and hazard ratios (HR) and 95% confidence intervals were statistically analyzed using Stata12.0 free software.

Results

A total of 17 articles were included in this meta-analysis. Of 98,264 participants, 7,425 had dementia after 3-23 years of follow-up. The results of the meta-analysis showed a trend towards a lower incidence of dementia with high intake of antioxidants (RR = 0.84, 95% CI 0.77-1.19 I2 = 54.6%), but this was not statistically significant. High antioxidant intake significantly reduced the incidence of Alzheimer 's disease (RR = 0.85, 95% CI 0.79-0.92 I2 = 45.5%), and we additionally carried out subgroup analyses by nutrient type, diet or supplement, region, and study quality score.

Conclusion

Dietary intake of antioxidants or supplements reduces both the risk of dementia and the risk of Alzheimer's disease.

Self-reported sleep in relation to risk of dementia a quarter of a century later at age 90+: The 90+ Study

OBJECTIVE

To examine sex-specific associations of sleep duration and napping self-reported at mean age of 69 years (range: 53-81) with risk of incident dementia 24 years later at age 90 +.

METHOD

Analytic sample included individuals from a population-based study who reported sleep and napping once in the 1980s and 24 years later (range: 16-38) joined The 90+ Study and were evaluated in-person. Those without dementia at baseline of The 90+ Study were prospectively followed. Hazard ratios [HR] and 95% confidence intervals [CI] of dementia risk were estimated by Cox regression.

RESULTS

Of 574 participants 71% were women, mean age at start of dementia follow-up with The 90+ Study was 93 years (range: 90-102). After 3.3 years (range: 0.4-13.8) of follow-up 47% developed dementia. Higher risk of dementia at age 90+ was seen in women with <6 hours of self-reported sleep per night (adjusted HR = 2.00; 95% CI = 1.15-3.50; p = .01) compared with 8 hours. Lower risk of dementia at 90+ was seen in men with short-to-moderate (<60 minutes) self-reported naps compared with no naps (HR = 0.33; 95% CI = 0.18-0.63; p < .01).

CONCLUSIONS

Sleep and nap 24 years earlier are important risk factors for dementia after age 90.

Changes in levels of the antioxidant glutathione in brain and blood across the age span of healthy adults: A systematic review

Aging is characterized by a gradual decline of the body's biological functions, which can lead to increased production of reactive oxygen species (ROS). Antioxidants neutralize ROS and maintain balance between oxidation and reduction. If ROS production exceeds the ability of antioxidant systems to neutralize, a damaging state of oxidative stress (OS) may exist. The reduced form of glutathione (GSH) is the most abundant antioxidant, and decline of GSH is considered a marker of OS. Our review summarizes the literature on GSH variations with age in healthy adults in brain (in vivo, ex vivo) and blood (plasma, serum), and reliability of in vivo magnetic resonance spectroscopy (MRS) measurement of GSH. A systematic PubMed search identified 35 studies. All in vivo MRS studies (N = 13) reported good to excellent reproducibility of GSH measures. In brain, 3 out of 4 MRS studies reported decreased GSH with age, measured in precuneus, cingulate, and occipital regions, while 1 study reported increased GSH with age in frontal and sensorimotor regions. In post-mortem brain, out of 3 studies, 2 reported decreased GSH with age in hippocampal and frontal regions, while 1 study reported increased GSH with age in a frontal region. Oxidized glutathione disulfide (GSSG) was reported to be increased in caudate with age in 1 study, suggesting OS. Although findings in the brain lacked a clear consensus, the majority of studies suggested a decline of GSH with age. The low number of studies (particularly ex vivo) and potential regional differences may have contributed to variability in the findings in brain. In blood, in contrast, GSH levels predominately were reported to decrease with advancing age (except in the oldest-old, who may represent a select group of particularly successful agers), while GSSG findings lacked consensus. The larger number of studies assessing age-specific GSH level changes in blood (N = 16) allowed for more robust consensus across studies than in brain. Overall, the literature suggests that aging is associated with increased OS in brain and body, but the timing and regional distribution of changes in the brain require further study. The contribution of brain OS to brain aging, and the effect of interventions to raise brain GSH levels on decline of brain function, remain understudied. Given that reliable tools to measure brain GSH exist, we hope this paper will serve as a catalyst to stimulate more work in this field.

Potential neuroprotective effects of fermented foods and beverages in old age: a systematic review

Purpose

Numerous articles have recently studied the involvement of the gut microbiota in neurological diseases. Aging is associated with changes in the microbiome, which implies a reduction in microbial biodiversity among other changes. Considering that the consumption of a fermented-food diet improves intestinal permeability and barrier function, it seems of interest to study its participation in the prevention of neurodegenerative diseases. This article reviews existing studies to establish whether the consumption of fermented foods and fermented beverages prevents or ameliorates neurodegenerative decline in old age.

Methods

The protocol used was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Details of the protocol for this systematic review are registered on PROSPERO (CRD42021250921).

Results

Out of 465 articles identified in the Pubmed, Scopus, and Cochrane Library databases, a total of 29 that examined the relationship of the consumption of fermented products with cognitive impairment in old people were selected (22 cohort, 4 case-control, and 3 cross-sectional studies). The results suggest that low-to-moderate alcohol consumption and daily intake of coffee, soy products, and fermented-food diets in general are associated with a lower risk of dementia and Alzheimer's disease.

Conclusion

Daily consumption of fermented foods and beverages, either alone or as part of a diet, has neuroprotective effects and slows cognitive decline in old people.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=250921, identifier: CRD42021250921.

Ultra-Early Screening of Cognitive Decline Due to Alzheimer's Pathology

Alzheimer's pathology can be assessed and defined via Aβ and tau biomarkers. The preclinical period of Alzheimer's disease is long and lasts several decades. Although effective therapies to block pathological processes of Alzheimer's disease are still lacking, downward trends in the incidence and prevalence of dementia have occurred in developed countries. Accumulating findings support that education, cognitive training, physical exercise/activities, and a healthy lifestyle can protect cognitive function and promote healthy aging. Many studies focus on detecting mild cognitive impairment (MCI) and take a variety of interventions in this stage to protect cognitive function. However, when Alzheimer's pathology advances to the stage of MCI, interventions may not be successful in blocking the development of the pathological process. MCI individuals reverting to normal cognitive function exhibited a high probability to progress to dementia. Therefore, it is necessary to take effective measures before the MCI stage. Compared with MCI, an earlier stage, transitional cognitive decline, may be a better time window in which effective interventions are adopted for at-risk individuals. Detecting this stage in large populations relies on rapid screening of cognitive function; given that many cognitive tests focus on MCI detection, new tools need to be developed.

Prospective Study of Diet Quality and the Risk of Dementia in the Oldest Old

This study examined the associations between overall diet quality and the risk of dementia in a rural cohort among the oldest old. Included in this prospective cohort study were 2232 participants aged ≥ 80 years and dementia-free at the baseline according to the Geisinger Rural Aging Study (GRAS), a longitudinal cohort in rural Pennsylvania. In 2009, diet quality was assessed by a validated dietary screening tool (DST). Incident cases of dementia during 2009-2021 were identified using diagnosis codes. This approach was validated by a review of electronic health records. Associations between diet quality scores and the incidence of dementia were estimated using the Cox proportional hazards models, adjusted for potential confounders. Across a mean of 6.90 years of follow-up, we identified 408 incident cases of all-cause dementia. Having a higher diet quality was not significantly associated with a lower risk for incidents of all-cause dementia (adjusted HR for the highest compared with the lowest tertile: 1.01, 95% CI: 0.79, 1.29, P-trend = 0.95). Similarly, we did not observe a significant association between diet quality and altered risks of Alzheimer's disease and other forms of dementia. Overall, having a higher diet quality was not significantly associated with a lower risk of dementia among the oldest old during the full follow-up.

Effect of antioxidant intake patterns on risks of dementia and cognitive decline

BACKGROUND

Previous studies have suggested that increased antioxidant intakes might reduce risk of cognitive disorders including Alzheimer's disease (AD). Which avenue of antioxidant intake (vitamin E/C) is more effective for decreasing risk, however, is largely unknown.

OBJECTIVES

To quantitatively investigate the relationships between the pattern of antioxidant intakes and risks of dementia and cognitive decline.

METHODS

We searched all related prospective cohort studies reporting antioxidant intakes (diet and/or supplement) from patients with cognitive disorders. We conducted dose-response meta-analyses to assess potential linear and non-linear dose-response relationships. Summary RRs and 95% CIs were calculated using a random- or fixed-effects model.

RESULTS

73 eligible cohort studies totaling > 28,257 participants were included in the meta-analysis; the pooled relative risks of AD were 0.75 (95% CI 0.57-0.99; I² = 59.9%) for the dietary only intake of vitamin E, 0.73 (95% CI 0.54-1.00; I² = 0%) for the dietary plus supplemental intake of vitamin E, and 0.70 (95% CI 0.51-0.95; I² = 0%) for the dietary plus supplemental intake of vitamin C. Moreover, pooled RRs of AD and vitamin C intake per 20 mg/day increase were 0.98 (95% CI 0.97-0.99) via dietary plus supplemental intake, 0.98 (95% CI 0.96-1.00) in the dietary only intake and 0.98 (95% CI 0.98-0.99) in the overall intake. There were no significant associations of all-cause dementia or cognitive impairment no dementia with the antioxidant intake.

CONCLUSIONS

The risk of incident AD is significantly reduced by higher consumption of vitamin C by the intake avenue of diet plus supplement.

LATE and potential estrogen-related risk factors collected 30 years earlier: The 90+ Study

Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) is a recently described neuropathological construct associated with dementia. This study aimed to investigate in an autopsy study, LATE-NC and its associations with potential estrogen-related risk factors collected about 30 years before death. Participants were part of The 90+ Study and had, as part of the Leisure World Cohort Study, provided information on menstrual and reproductive variables and details of use of estrogen replacement therapy (ERT). No menstrual and reproductive variable showed an association with LATE-NC. Use of ERT, especially long-term use (15+ years) and more recent use (within 1 year of completing the questionnaire), was associated with reduced risk. The odds were significantly lower for long-term (0.39, 95% confidence interval [CI]: 0.16-0.95) and recent use (0.39, 95% CI: 0.16-0.91) compared with no use. In conclusion, we found that women who reported long-term ERT in their 50s and 60s had a significantly reduced odds of harboring LATE-NC when they died in the 10th and 11th decades of their lives. Our study adds to the existing literature reporting seemingly protective effect of peri- and postmenopausal ERT against neurodegenerative dementia.

Reduced structural connectivity of the medial temporal lobe including the perforant path is associated with aging and verbal memory impairment

The perforant path, the white matter bundle connecting the entorhinal cortex (ERC) with the hippocampal formation deteriorates with age-related cognitive decline. Previous investigations using diffusion-weighted MRI to quantify perforant path integrity in-vivo have been limited due to image resolution or have quantified the perforant path using methods susceptible to partial volume effects such as the tensor model and without consideration of its 3-dimensional morphology. In this investigation, we use quantitative-anisotropy informed tractography derived from ultra-high resolution diffusion imaging (ZOOMit) to investigate structural connectivity of the perforant path and other medial temporal lobe (MTL) pathways in older adults (63 to 98 years old, n = 51). We show that graph density within the MTL declines with age and is associated with lower delayed recall performance. We also show that older age and poorer delayed recall are associated with reduced streamlines connecting the ERC and dentate gyrus of the hippocampus (the putative perforant path). This work suggest that intra-MTL connectivity may new candidate biomarkers for age-related cognitive decline.

Alzheimer's Disease Neuropathologic Change and Vitamin Supplement Use Decades Earlier: The 90+ Study

BACKGROUND

Alzheimer's disease (AD) is the most common cause of dementia. AD neuropathologic change (ADNC) likely begins decades before clinical manifestations. One mechanism implicated in AD is oxidative stress. We explored the potential association of ADNC with antioxidant vitamin supplements taken about 30 years before death.

METHODS

The 264 brain-autopsied participants were part of The 90+ Study, a longitudinal study of aging among people aged 90+ years, and originally members of the Leisure World Cohort Study, a population-based health study established in the 1980s. Intake of supplemental vitamins A, C, and E was collected by the Leisure World Cohort Study about 30 years before ADNC assessment. Odds ratios of ADNC (intermediate/high vs. none/low) for vitamin intake were estimated using logistic regression.

RESULTS

The adjusted odds ratio (95% CI) of ADNC was 0.52 (0.29-0.92) for vitamin E supplements and 0.51 (0.27-0.93) for vitamin C supplements. Supplemental vitamin E intake was the first variable, after education, to enter the stepwise model. Intake of vitamin A or C did not improve the model fit.

CONCLUSIONS

The observed association of ADNC and supplemental vitamin E intake decades earlier suggests a beneficial effect and supports further investigation into a nutritional approach to preventing AD with vitamin supplementation.

Leisure Activities and the Risk of Dementia: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Leisure activities are major components of modifiable and healthy lifestyles and are proposed to help prevent the development of dementia. This study aimed to assess the effects of different types of leisure activities, including cognitive, physical, and social activities, on the incidence of all-cause dementia (ACD), Alzheimer disease (AD), and vascular dementia (VD).

METHODS

We performed a systematic review and meta-analysis of the Cochrane, PubMed, Embase, and Web of Science databases to identify longitudinal studies that examined associations between leisure activities and dementia. Relative risks (RRs) and 95% CIs were pooled using random-effects meta-analysis. Subgroup analyses were used to estimate potential effect modifiers. The study was registered with PROSPERO (CRD42019116857).

RESULTS

A total of 38 longitudinal studies, with 2,154,818 participants at baseline, 74,700 ACD cases, 2,848 AD cases, and 1,423 VD cases during follow-up, were included in the meta-analysis. The subgroup analyses showed that physical (RR 0.83, 95% CI 0.78-0.88), cognitive (RR 0.77; 95% CI 0.68-0.87), and social (RR 0.93; 95% CI 0.87-0.99) activities were associated with a decreased incidence of ACD. In addition, physical (RR 0.87; 95% CI 0.78-0.96) and cognitive (RR 0.66; 95% CI 0.52-0.85) activities were related to a reduced risk of AD. Physical activity (RR 0.67; 95% CI 0.53-0.85) was associated with a lower incidence of VD.

DISCUSSION

Our findings suggest that leisure activities are inversely associated with a risk of ACD, AD, and VD.

Physical performance reference values for Japanese oldest old: a SONIC study

Background

The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80.

Methods

We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences.

Result

The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P <  0.001). Hand grip strength decreased with a similar gradient with age cohort increase of 10 years for both sexes. In contrast, SPPB lower limb score showed a larger drop between the age 80 and 90 cohorts than between the age 70 and 80 cohorts. We also constructed sex-specific appraisal standards according to quintiles.

Conclusions

Our study yielded inclusive sex-specific reference values and appraisal standards for major physical performance measures not certified as requiring long-term care, community-dwelling, oldest old Japanese. The characteristics of age-related decline in physical performance differed between the upper and lower extremity assessments.

Association of vitamin E intake in diet and supplements with risk of dementia: A meta-analysis

Background

Dementia is a chronic progressive neurodegenerative disease that can lead to disability and death in humans, but there is still no effective prevention and treatment. Due to the neuroprotective effects of vitamin E, a large number of researchers have explored whether vitamin E can reduce the risk of dementia. Some researchers believe that vitamin E can reduce the risk of dementia, while others hold the opposite conclusion. We therefore performed a meta-analysis to clarify the relationship between them.

Methods

We searched PubMed, Embase, and Web of Science databases for articles on the connection of dietary and supplementation vitamin E with dementia risk from inception through April 2022 using the main keywords “dementia,” “Alzheimer's disease,” “vitamin E,” and “tocopherol,” and used a random-utility model for pooled effect sizes. Odds ratios (OR) and 95% confidence intervals were derived using lower and higher doses as contrasts. Obtained data were shown and assessed using Stata12.0 free software.

Results

We included 15 articles in sum. Among them, there were nine articles containing AD. By comparing the highest intake with the lowest intake, Combined ORs for high intake were as follows: dementia (OR = 0.79, 95% CI 0.70–0.88 I² = 35.0%), Alzheimer's disease (OR = 0.78, 95% CI 0.64–0.94 I² = 36.9%). Subgroup analyses were also performed by study type, diet and supplementation, and NOS score.

Conclusions

High vitamin E intake from diet and supplements significantly reduces the risk of dementia and Alzheimer's disease.

Neuroprotective Effect of Caffeine in Alzheimer's Disease

Alzheimer’s disease (AD) is the leading cause of dementia, predicted to be the most significant health burden of the 21st century, with an estimated 131.5 million dementia patients by the year 2050. This review aims to provide an overview of the effect of caffeine on AD and cognition by summarizing relevant research conducted on this topic. We searched the Web of Science core collection and PubMed for studies related to the effect of caffeine on AD and cognition using title search terms: caffeine; coffee; Alzheimer’s; cognition. There is suggestive evidence from clinical studies that caffeine is neuroprotective against dementia and possibly AD (20 out of 30 studies support this), but further studies, such as the “ideal” study proposed in this review, are required to prove this link. Clinical studies also indicate that caffeine is a cognitive normalizer and not a cognitive enhancer. Furthermore, clinical studies suggest the neuroprotective effect of caffeine might be confounded by gender. There is robust evidence based on in vivo and in vitro studies that caffeine has neuroprotective properties in AD animal models (21 out of 22 studies support this), but further studies are needed to identify the mechanistic pathways mediating these effects.

Physical activity as a protective factor for dementia and Alzheimer's disease: systematic review, meta-analysis and quality assessment of cohort and case-control studies

Objective

Physical activity (PA) is associated with a decreased incidence of dementia, but much of the evidence comes from short follow-ups prone to reverse causation. This meta-analysis investigates the effect of study length on the association.

Design

A systematic review and meta-analysis. Pooled effect sizes, dose–response analysis and funnel plots were used to synthesise the results.

Data sources

CINAHL (last search 19 October 2021), PsycInfo, Scopus, PubMed, Web of Science (21 October 2021) and SPORTDiscus (26 October 2021).

Eligibility criteria

Studies of adults with a prospective follow-up of at least 1 year, a valid cognitive measure or cohort in mid-life at baseline and an estimate of the association between baseline PA and follow-up all-cause dementia, Alzheimer’s disease or vascular dementia were included (n=58).

Results

PA was associated with a decreased risk of all-cause dementia (pooled relative risk 0.80, 95% CI 0.77 to 0.84, n=257 983), Alzheimer’s disease (0.86, 95% CI 0.80 to 0.93, n=128 261) and vascular dementia (0.79, 95% CI 0.66 to 0.95, n=33 870), even in longer follow-ups (≥20 years) for all-cause dementia and Alzheimer’s disease. Neither baseline age, follow-up length nor study quality significantly moderated the associations. Dose–response meta-analyses revealed significant linear, spline and quadratic trends within estimates for all-cause dementia incidence, but only a significant spline trend for Alzheimer’s disease. Funnel plots showed possible publication bias for all-cause dementia and Alzheimer’s disease.

Conclusion

PA was associated with lower incidence of all-cause dementia and Alzheimer’s disease, even in longer follow-ups, supporting PA as a modifiable protective lifestyle factor, even after reducing the effects of reverse causation.

Differential protein expression in the hippocampi of resilient individuals identified by digital spatial profiling

Clinical symptoms correlate with underlying neurodegenerative changes in the vast majority of people. However, an intriguing group of individuals demonstrate neuropathologic changes consistent with Alzheimer disease (AD) yet remain cognitively normal (termed "resilient"). Previous studies have reported less overall neuronal loss, less gliosis, and fewer comorbidities in these individuals. Herein, NanoString GeoMx™ Digital Spatial Profiler (DSP) technology was utilized to investigate protein expression differences comparing individuals with dementia and AD neuropathologic change to resilient individuals. DSP allows for spatial analysis of protein expression in multiple regions of interest (ROIs) on formalin-fixed paraffin-embedded sections. ROIs in this analysis were hippocampal neurofibrillary tangle (NFT)-bearing neurons, non-NFT-bearing neurons, and their immediate neuronal microenvironments. Analyses of 86 proteins associated with CNS cell-typing or known neurodegenerative changes in 168 ROIs from 14 individuals identified 11 proteins displaying differential expression in NFT-bearing neurons of the resilient when compared to the demented (including APP, IDH1, CD68, GFAP, SYP and Histone H3). In addition, IDH1, CD68, and SYP were differentially expressed in the environment of NFT-bearing neurons when comparing resilient to demented. IDH1 (which is upregulated under energetic and oxidative stress) and PINK1 (which is upregulated in response to mitochondrial dysfunction and oxidative stress) both displayed lower expression in the environment of NFT-bearing neurons in the resilient. Therefore, the resilient display less evidence of energetic and oxidative stress. Synaptophysin (SYP) was increased in the resilient, which likely indicates better maintenance of synapses and synaptic connections. Furthermore, neurofilament light chain (NEFL) and ubiquitin c-terminal hydrolase (Park5) were higher in the resilient in the environment of NFTs. These differences all suggest healthier intact axons, dendrites and synapses in the resilient. In conclusion, resilient individuals display protein expression patterns suggestive of an environment containing less energetic and oxidative stress, which in turn results in maintenance of neurons and their synaptic connections.

Daily Level Association of Physical Activity and Performance on Ecological Momentary Cognitive Tests in Free-living Environments: A Mobile Health Observational Study

BACKGROUND

Research suggests that physical activity (PA) has both acute and chronic beneficial effects on cognitive function in laboratory settings and under supervised conditions. Mobile health technologies make it possible to reliably measure PA and cognition in free-living environments, thus increasing generalizability and reach. Research is needed to determine whether the benefits of PA on cognitive function extend from the laboratory to real-world contexts.

OBJECTIVE

This observational study aims to examine the association between daily fluctuations in PA and cognitive performance using mobile health technologies in free-living environments.

METHODS

A total of 90 adults (mean age 59, SD 6.3 years; 65/90, 72% men) with various comorbidities (eg, cardiovascular risk and HIV) and different levels of baseline cognition (ranging from cognitively normal to impaired) completed ecological momentary cognitive tests (EMCTs) on a smartphone twice daily while wearing an accelerometer to capture PA levels for 14 days. Linear mixed-effects models examined the daily associations of PA with executive function and verbal learning EMCTs. Moderation analyses investigated whether the relationship between daily PA and daily performance on EMCTs changed as a function of baseline cognition, cardiovascular risk, and functional status (independent vs dependent).

RESULTS

Days with greater PA were associated with better (faster) performance on an executive function EMCT after covariate adjustment (estimate -0.013; β=-.16; P=.04). Moderation analyses (estimate 0.048; β=.58; P=.001) indicated that days with greater PA were associated with better (faster) executive function performance in individuals who were functionally dependent (effect size -0.53; P<.001) and not in functionally independent adults (effect size -0.01; P=.91).

CONCLUSIONS

EMCTs may be a sensitive tool for capturing daily-level PA-related fluctuations in cognitive performance in real-world contexts and could be a promising candidate for tracking cognitive performance in digital health interventions aimed at increasing PA. Further research is needed to determine individual characteristics that may moderate the association between daily PA and EMCT performance in free-living environments.

Dendritic Spines: Mediators of Cognitive Resilience in Aging and Alzheimer's Disease

Cognitive resilience is often defined as the ability to remain cognitively normal in the face of insults to the brain. These insults can include disease pathology, such as plaques and tangles associated with Alzheimer's disease, stroke, traumatic brain injury, or other lesions. Factors such as physical or mental activity and genetics may contribute to cognitive resilience, but the neurobiological underpinnings remain ill-defined. Emerging evidence suggests that dendritic spine structural plasticity is one plausible mechanism. In this review, we highlight the basic structure and function of dendritic spines and discuss how spine density and morphology change in aging and Alzheimer's disease. We note evidence that spine plasticity mediates resilience to stress, and we tackle dendritic spines in the context of cognitive resilience to Alzheimer's disease. Finally, we examine how lifestyle and genetic factors may influence dendritic spine plasticity to promote cognitive resilience before discussing evidence for actin regulatory kinases as therapeutic targets for Alzheimer's disease.

Kidney Function Is Not Related to Brain Amyloid Burden on PET Imaging in The 90+ Study Cohort

Cognitive decline is common in chronic kidney disease (CKD). While the evidence of vascular cognitive impairment in this population is robust, the role of Alzheimer's pathology is unknown. We evaluated serum cystatin C-estimated glomerular filtration rate (eGFR), brain amyloid-β positron emission tomography (PET) imaging, and cognitive function in 166 participants from The 90+ Study. Mean age was 93 years (range 90-107) and 101 (61%) were women; 107 participants had normal cognitive status while 59 participants had cognitive impairment no dementia (CIND) or dementia. Mean ± standard deviation cystatin C was 1.59 ± 0.54 mg/L with eGFR 40.7 ± 18.7 ml/min/1.73m2. Higher amyloid-β burden was associated with dementia, but not with age, diabetes, hypertension, or cardiovascular disease. We found no association between brain amyloid-β burden and cystatin C eGFR. We previously reported that kidney function was associated with cognition and cerebral microbleeds in the same cohort of oldest-old adults (90+ years old). Collectively, these findings suggest that microvascular rather than Alzheimer's pathology drives CKD-associated cognitive dysfunction in this population.

The role of diet on the risk of dementia in the oldest old: The Monzino 80-plus population-based study

BACKGROUND & AIMS

Longevity also carries its dark side of age-related chronic diseases, dementia being one of the worst and the most prevalent. Since dementia lacks effective treatments, preventing or delaying it is highly desirable. Dietary habits and nutrition have been found to be important modifiable risk factors for many chronic diseases, but evidence on the role of diet on the risk of dementia is still limited, particularly among the very old. Aim of the present work is to study the association of the Mediterranean diet and its components with prevalent and incident dementia in the oldest-old.

METHODS

We analyzed data from the Monzino 80-plus study, a population-based study in subjects 80 years or older in the Varese province, Italy. A validated food frequency questionnaire was used to collect information on 23 different foods consumed in the previous year. A Mediterranean diet score was calculated and its components were classified into tertiles. Multivariable models for dementia prevalence and incidence were adjusted for demographic and clinical characteristics.

RESULTS

Information on nutrition was available for 1390 subjects in the cross-sectional study and 512 subjects in the longitudinal study, mean respective ages 93 and 92. Greater adherence to Mediterranean diet, greater consumption of eggs, fruits and vegetables, carbohydrates, and greater food intake were associated with a lower prevalence of dementia. Increasing number of portions per week and consumption of legumes significantly decreased the incidence of dementia during the 3.6 year mean follow-up: corresponding hazard ratios of highest vs. lowest tertiles (95% confidence intervals) were 0.66 (0.46-0.95) and 0.68 (0.47-0.97), respectively.

CONCLUSION

Oldest-old eating less and having diets with less variety and nutrient density were more frequent among subjects with dementia. The longitudinal analysis confirmed oldest-old subjects who eat more portions, as well as those who have a higher intake of legumes, are at decreased risk of developing dementia even though reverse causality cannot be completely ruled out.

Cognitive dispersion and ApoEe4 genotype predict dementia diagnosis in 8-year follow-up of the oldest-old

BACKGROUND

Cognitive dispersion, or inconsistencies in performance across cognitive domains, has been posited as a cost-effective tool to predict conversion to dementia in older adults. However, there is a dearth of studies exploring cognitive dispersion in the oldest-old (>80 years) and its relationship to dementia incidence.

OBJECTIVE

The main aim of this study was to examine whether higher cognitive dispersion at baseline was associated with dementia incidence within an 8-year follow-up of very old adults, while controlling for established risk factors and suggested protective factors for dementia.

METHODS

Participants (n = 468) were from the Origins of Variance in the Old-Old: Octogenarian Twins study, based on the Swedish Twin Registry. Cox regression analyses were performed to assess the association between baseline cognitive dispersion scores and dementia incidence, while controlling for sociodemographic variables, ApoEe4 carrier status, co-morbidities, zygosity and lifestyle engagement scores. An additional model included a composite of average cognitive performance.

RESULTS

Cognitive dispersion and ApoEe4 were significantly associated with dementia diagnosis. These variables remained statistically significant when global cognitive performance was entered into the model. Likelihood ratio tests revealed that cognitive dispersion and cognitive composite scores entered together in the same model was superior to either predictor alone in the full model.

CONCLUSIONS

The study underscores the usefulness of cognitive dispersion metrics for dementia prediction in the oldest-old and highlights the influence of ApoEe4 on cognition in very late age. Our findings concur with others suggesting that health and lifestyle factors pose little impact upon cognition in very advanced age.

Diagnosis and Management of Cognitive Concerns in the Oldest-Old

Purpose of review

The fastest-growing group of elderly individuals is the "oldest-old," usually defined as those age 85 years and above. These individuals account for much of the rapid increase in cases of dementing illness throughout the world but remain underrepresented in the body of literature on this topic. The aim of this review is first to outline the unique contributing factors and complications that must be considered by clinicians in evaluating an oldest-old individual with cognitive complaints. Secondly, the evidence for management of these cognitive concerns is reviewed.

Recent findings

In addition to well-established associations between impaired cognition and physical disability, falls, and frailty, there is now evidence that exercise performed decades earlier confers a cognitive benefit in the oldest-old. Moreover, though aggressive blood pressure control is critical earlier in life for prevention of strokes, renal disease, and other comorbidities, hypertension started after age 80 is in fact associated with a decreased risk of clinical dementia, carrying significant implications for the medical management of oldest-old individuals. The oldest-old are more likely to reside in care facilities, where social isolation might be exacerbated by a consistently lower rate of internet-connected device use. The COVID-19 pandemic has not only highlighted the increased mortality rate among the oldest-old but has also brought the increased social isolation in this group to the forte.

Summary

Differing from the "younger-old" in a number of respects, the oldest-old is a unique population not just in their vulnerability to cognitive disorders but also in the diagnostic challenges they can pose. The oldest-old are more likely to be afflicted by sensory deficits, physical disability, poor nutrition, frailty, and depression, which must be accounted for in the assessment of cognitive complaints as they may confound or complicate the presentation. Social isolation and institutionalization are also associated with impaired cognition, perhaps as sequelae, precipitants, or both. Ante-mortem diagnostic tools remain particularly limited among the oldest-old, especially given the likelihood of these individuals to have multiple co-occurring types of neuropathology, and the presence of neuropathology in those who remain cognitively intact. In addition to the symptomatic treatments indicated for patients of all ages with dementia, management of cognitive impairment in the oldest-old may be further optimized by use of assistive devices, augmentation of dietary protein, and liberalization of medication regimens for risk factors such as hypertension.

Alcohol, coffee and tea intake and the risk of cognitive deficits: a dose-response meta-analysis

AIMS

Lifestyle interventions are an important and viable approach for preventing cognitive deficits. However, the results of studies on alcohol, coffee and tea consumption in relation to cognitive decline have been divergent, likely due to confounds from dose-response effects. This meta-analysis aimed to find the dose-response relationship between alcohol, coffee or tea consumption and cognitive deficits.

METHODS

Prospective cohort studies or nested case-control studies in a cohort investigating the risk factors of cognitive deficits were searched in PubMed, Embase, the Cochrane and Web of Science up to 4th June 2020. Two authors searched the databases and extracted the data independently. We also assessed the quality of the studies with the Newcastle-Ottawa scale. Stata 15.0 software was used to perform model estimation and plot the linear or nonlinear dose-response relationship graphs.

RESULTS

The search identified 29 prospective studies from America, Japan, China and some European countries. The dose-response relationships showed that compared to non-drinkers, low consumption (<11 g/day) of alcohol could reduce the risk of cognitive deficits or only dementias, but there was no significant effect of heavier drinking (>11 g/day). Low consumption of coffee reduced the risk of any cognitive deficit (<2.8 cups/day) or dementia (<2.3 cups/day). Green tea consumption was a significant protective factor for cognitive health (relative risk, 0.94; 95% confidence intervals, 0.92-0.97), with one cup of tea per day brings a 6% reduction in risk of cognitive deficits.

CONCLUSIONS

Light consumption of alcohol (<11 g/day) and coffee (<2.8 cups/day) was associated with reduced risk of cognitive deficits. Cognitive benefits of green tea consumption increased with the daily consumption.

Cognitive and social activities and long-term dementia risk: the prospective UK Million Women Study

BACKGROUND

Although dementia is associated with non-participation in cognitive and social activities, this association might merely reflect the consequences of dementia, rather than any direct effect of non-participation on the subsequent incidence of dementia. Because of the slowness with which dementia can develop, unbiased assessment of any such direct effects must relate non-participation in such activities to dementia detection rates many years later. Prospective studies with long-term follow-up can help achieve this by analysing separately the first and second decade of follow-up. We report such analyses of a large, 20-year study.

METHODS

The UK Million Women Study is a population-based prospective study of 1·3 million women invited for National Health Service (NHS) breast cancer screening in median year 1998 (IQR 1997-1999). In median year 2001 (IQR 2001-2003), women were asked about participation in adult education, groups for art, craft, or music, and voluntary work, and in median year 2006 (IQR 2006-2006), they were asked about reading. All participants were followed up through electronic linkage to NHS records of hospital admission with mention of dementia, the first mention of which was the main outcome. Comparing non-participation with participation in a particular activity, we used Cox regression to assess fully adjusted dementia risk ratios (RRs) during 0-4, 5-9, and 10 or more years, after information on that activity was obtained.

FINDINGS

In 2001, 851 307 women with a mean age of 60 years (SD 5) provided information on participation in adult education, groups for art, craft, or music, and voluntary work. After 10 years, only 9591 (1%) had been lost to follow-up and 789 339 (93%) remained alive with no recorded dementia. Follow-up was for a mean of 16 years (SD 3), during which 31 187 (4%) had at least one hospital admission with mention of dementia, including 25 636 (3%) with a hospital admission with dementia mentioned for the first time 10 years or more after follow-up began. Non-participation in cognitive or social activities was associated with higher relative risks of dementia detection only during the first decade after participation was recorded. During the second decade, there was little association. This was true for non-participation in adult education (RR 1·04, 99% CI 0·98-1·09), in groups for art, craft, or music (RR 1·04, 0·99-1·09), in voluntary work (RR 0·96, 0·92-1·00), or in any of these three (RR 0·99, 0·95-1·03). In 2006, 655 118 women provided information on reading. For non-reading versus any reading, there were similar associations with dementia, again with strong attenuation over time since reading was recorded, but longer follow-up is needed to assess this reliably.

INTERPRETATION

Life has to be lived forwards, but can be understood only backwards. Long before dementia is diagnosed, there is a progressive reduction in various mental and physical activities, but this is chiefly because its gradual onset causes inactivity and not because inactivity causes dementia.

FUNDING

UK Medical Research Council, Cancer Research UK.

Cognition and Political Ideology in Aging

OBJECTIVE

The impact of cognitive function and decline on political ideology is unknown. We studied the relationship between cognition and both political orientation and political policy choices in a population of older persons.

DESIGN

Longitudinal investigation.

SETTING

A retirement community and its surroundings in Southern California.

PARTICIPANTS

151 members of a longitudinal investigation of aging and dementia in the oldest-old (the 90+ Study), mean age 95 years.

MEASUREMENTS

Participants self-reported their political ideology (7-point scale from extremely liberal to extremely conservative) and policy preferences for federal spending on public schooling, aid to the poor, and protecting the environment, as well as on preferences on immigration rates, death penalty, and university admission. The same political survey was mailed to participants twice: at time one and 6-months later. Cognitive function based on neurological examination and cognitive testing was classified as normal (55%), cognitive impairment/not dementia (CIND) (33%), or dementia (12%). We calculated rank correlations between ideology and policy choices, stratified by cognitive status, and agreement between Surveys 1 and 2.

RESULTS

Political ideology/orientation was highly consistent over a six-month period (84% agreement) among the 122 who returned the second survey, with no significant relationship to cognitive status. Among cognitively impaired (CIND and dementia), however, there was significant loss of consistency between an individual's political orientation and their policy choices. Level of political engagement was high for participants, with more than 90% voting in the 2016 presidential election.

CONCLUSION

In this population of older persons, political identification on the liberal-conservative spectrum was resilient despite cognitive decline, but its meaning and function were changed. For the cognitively impaired it remained a self-defining label, but no longer operated as a higher order framework for orienting specific policy preferences. There appeared to be loss of coherence between the political orientation and political policy choices of cognitively impaired individuals. Given the high level of political engagement of these individuals, these results have substantial public policy implications.

Effect of Caffeine Consumption on the Risk for Neurological and Psychiatric Disorders: Sex Differences in Human

Caffeine occurs naturally in various foods, such as coffee, tea, and cocoa, and it has been used safely as a mild stimulant for a long time. However, excessive caffeine consumption (1~1.5 g/day) can cause caffeine poisoning (caffeinism), which includes symptoms such as anxiety, agitation, insomnia, and gastrointestinal disorders. Recently, there has been increasing interest in the effect of caffeine consumption as a protective factor or risk factor for neurological and psychiatric disorders. Currently, the importance of personalized medicine is being emphasized, and research on sex/gender differences needs to be conducted. Our review focuses on the effect of caffeine consumption on several neurological and psychiatric disorders with respect to sex differences to provide a better understanding of caffeine use as a risk or protective factor for those disorders. The findings may help establish new strategies for developing sex-specific caffeine therapies.

What determines cognitive functioning in the oldest-old? The EMIF-AD 90+ Study

OBJECTIVES

Determinants of cognitive functioning in individuals aged 90 years and older, the oldest-old, remain poorly understood. We aimed to establish the association of risk factors, white matter hyperintensities (WMH), hippocampal atrophy and amyloid aggregation with cognition in the oldest-old.

METHODS

We included 84 individuals without cognitive impairment and 38 individuals with cognitive impairment from the EMIF-AD 90+ Study (mean age 92.4 years) and tested cross-sectional associations between risk factors (cognitive activity, physical parameters, nutritional status, inflammatory markers and cardiovascular risk factors), brain pathology biomarkers (WMH and hippocampal volume on MRI, and amyloid binding measured with PET) and cognition. Additionally, we tested whether the brain pathology biomarkers were independently associated with cognition. When applicable, we tested whether the effect of risk factors on cognition was mediated by brain pathology.

RESULTS

Lower values for handgrip strength, Short Physical Performance Battery (SPPB), nutritional status, HbA1c and hippocampal volume, and higher values for WMH volume and amyloid binding were associated with worse cognition. Higher past cognitive activity and lower BMI were associated with increased amyloid binding, lower muscle mass with more WMH, and lower SPPB scores with more WMH and hippocampal atrophy. The brain pathology markers were independently associated with cognition. The association of SPPB with cognition was partially mediated by hippocampal volume.

DISCUSSION

In the oldest-old, physical parameters, nutritional status, HbA1c, WMH, hippocampal atrophy and amyloid binding are associated with cognitive impairment. Physical performance may affect cognition through hippocampal atrophy. This study highlights the importance to consider multiple factors when assessing cognition in the oldest-old.

Association of Alcohol-Induced Loss of Consciousness and Overall Alcohol Consumption With Risk for Dementia

IMPORTANCE

Evidence on alcohol consumption as a risk factor for dementia usually relates to overall consumption. The role of alcohol-induced loss of consciousness is uncertain.

OBJECTIVE

To examine the risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers.

DESIGN, SETTING, AND PARTICIPANTS

Seven cohort studies from the UK, France, Sweden, and Finland (IPD-Work consortium) including 131 415 participants were examined. At baseline (1986-2012), participants were aged 18 to 77 years, reported alcohol consumption, and were free of diagnosed dementia. Dementia was examined during a mean follow-up of 14.4 years (range, 12.3-30.1). Data analysis was conducted from November 17, 2019, to May 23, 2020.

EXPOSURES

Self-reported overall consumption and loss of consciousness due to alcohol consumption were assessed at baseline. Two thresholds were used to define heavy overall consumption: greater than 14 units (U) (UK definition) and greater than 21 U (US definition) per week.

MAIN OUTCOMES AND MEASURES

Dementia and alcohol-related disorders to 2016 were ascertained from linked electronic health records.

RESULTS

Of the 131 415 participants (mean [SD] age, 43.0 [10.4] years; 80 344 [61.1%] women), 1081 individuals (0.8%) developed dementia. After adjustment for potential confounders, the hazard ratio (HR) was 1.16 (95% CI, 0.98-1.37) for consuming greater than 14 vs 1 to 14 U of alcohol per week and 1.22 (95% CI, 1.01-1.48) for greater than 21 vs 1 to 21 U/wk. Of the 96 591 participants with data on loss of consciousness, 10 004 individuals (10.4%) reported having lost consciousness due to alcohol consumption in the past 12 months. The association between loss of consciousness and dementia was observed in men (HR, 2.86; 95% CI, 1.77-4.63) and women (HR, 2.09; 95% CI, 1.34-3.25) during the first 10 years of follow-up (HR, 2.72; 95% CI, 1.78-4.15), after excluding the first 10 years of follow-up (HR, 1.86; 95% CI, 1.16-2.99), and for early-onset (<65 y: HR, 2.21; 95% CI, 1.46-3.34) and late-onset (≥65 y: HR, 2.25; 95% CI, 1.38-3.66) dementia, Alzheimer disease (HR, 1.98; 95% CI, 1.28-3.07), and dementia with features of atherosclerotic cardiovascular disease (HR, 4.18; 95% CI, 1.86-9.37). The association with dementia was not explained by 14 other alcohol-related conditions. With moderate drinkers (1-14 U/wk) who had not lost consciousness as the reference group, the HR for dementia was twice as high in participants who reported having lost consciousness, whether their mean weekly consumption was moderate (HR, 2.19; 95% CI, 1.42-3.37) or heavy (HR, 2.36; 95% CI, 1.57-3.54).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that alcohol-induced loss of consciousness, irrespective of overall alcohol consumption, is associated with a subsequent increase in the risk of dementia.

Predictors of Dementia in the Oldest Old: A Novel Machine Learning Approach

BACKGROUND

Incidence of dementia increases exponentially with age; little is known about its risk factors in the ninth and 10th decades of life. We identified predictors of dementia with onset after age 85 years in a longitudinal population-based cohort.

METHODS

On the basis of annual assessments, incident cases of dementia were defined as those newly receiving Clinical Dementia Rating (CDR) ≥1. We used a machine learning method, Markov modeling with hybrid density-based and partition-based clustering, to identify variables associated with subsequent incident dementia.

RESULTS

Of 1439 participants, 641 reached age 85 years during 10 years of follow-up and 45 of these became incident dementia cases. Using hybrid density-based and partition-based, among those aged 85+ years, probability of incident dementia was associated with worse self-rated health, more prescription drugs, subjective memory complaints, heart disease, cardiac arrhythmia, thyroid disease, arthritis, reported hypertension, higher systolic and diastolic blood pressure, and hearing impairment. In the subgroup aged 85 to 89 years, risk of dementia was also associated with depression symptoms, not currently smoking, and lacking confidantes.

CONCLUSIONS

An atheoretical machine learning method revealed several factors associated with increased probability of dementia after age 85 years in a population-based cohort. If independently validated in other cohorts, these findings could help identify the oldest-old at the highest risk of dementia.

Cystatin C, cognition, and brain MRI findings in 90+-year-olds

Chronic kidney disease is emerging as a novel risk factor for cerebrovascular disease, but this association remains largely unexplored in older adults. Cystatin C is a more accurate measure than creatinine of kidney function in the elderly. We evaluated cystatin C, cognitive function, and brain imaging in 193 participants from The 90+ Study neuroimaging component. The mean age was 93.9 years; 61% were women. Mean cystatin C was 1.62 mg/L with estimated glomerular filtration rate 39.2 mL/min/1.73 m². Performance on measures of global cognition, executive function, and visual-spatial ability declined at higher tertiles of cystatin C (lower kidney function). Higher cystatin C was significantly associated with infratentorial microbleeds and lower gray matter volume. Adjusted risk of incident dementia was increased in the middle and high cystatin C tertile groups compared with the low group (hazard ratio in highest tertile 3.81 [95% confidence interval 1.14-12.7]), which appeared to be explained in part by the presence of cerebral microbleeds. Overall, cystatin C was associated with cognitive performance, brain imaging pathology, and decline to dementia in this oldest-old cohort.

Prior endogenous and exogenous estrogen and incident dementia in the 10th decade of life: The 90+ Study

Objective: This study aimed to investigate the association of endogenous and exogenous estrogen exposure with risk of incident dementia in the oldest-old (age 90+ years).Methods: Participants were part of The 90+ Study, a longitudinal study begun in 2003 of aging and dementia among people aged 90+ years. Menstrual, reproductive, and menopausal data were collected in the 1980s as part of the population-based Leisure World Cohort Study. Cognitive status at baseline was determined from an in-person neurological evaluation with biannual follow-up through June 2019. Hazard ratios (HRs) of dementia associated with estrogen-related variables were estimated using Cox regression analysis. No adjustment was made for multiple comparisons.Results: A total of 424 women without dementia at baseline had at least one follow-up evaluation. The mean age was 68.5 years at enrollment in the Leisure World Cohort Study, 93.2 years at enrollment in The 90+ Study, and 96.5 years at last follow-up. During follow-up (mean 3.4 years) dementia was diagnosed in 209 (49%) participants. No individual menstrual, reproductive, menopausal, or estrogen replacement variable was associated with risk of incident dementia after age 90 years. However, women with a high endogenous estrogen exposure index (summarizing exposure from menarche to menopause) had a non-significant 25% lower risk (HR = 0.75, 95% confidence interval 0.53-1.06).Conclusions: Prior exposure to estrogen, endogenous or exogenous, had little effect on risk of dementia in the 10th decade of life.

Alcohol and Dementia - What is the Link? A Systematic Review

BACKGROUND

Dementia is a globally increasing health issue and since no cure is currently available, prevention is crucial. The consumption of alcohol is a controversially discussed risk factor for dementia. While many previously published epidemiological studies reported a risk reduction by light to moderate alcohol consumption, there is no persuasive model of an underlying biochemical mechanism. The purpose of this article is to review current models on alcohol neurotoxicity and dementia and to analyze and compare studies focusing on the epidemiological link between alcohol consumption and the risk of dementia.

METHODS

The electronic database Pubmed was searched for studies published between 1994 and 2019 concerning the topic.

RESULTS

Available epidemiological studies are not sufficient to verify a protective effect of alcohol on dementia development.

Associations Between Caffeine Consumption, Cognitive Decline, and Dementia: A Systematic Review

BACKGROUND

Epidemiologic studies have provided inconclusive evidence for a protective effect of caffeine consumption on risk of dementia and cognitive decline.

OBJECTIVE

To summarize literature on the association between caffeine and 1) the risk of dementia and/or cognitive decline, and 2) cognitive performance in individuals with mild cognitive impairment (MCI) or dementia, and 3) to examine the effect of study characteristics by categorizing studies based on caffeine source, quantity and other possible confounders.

METHODS

We performed a systematic review of caffeine effects by assessing overall study outcomes; positive, negative or no effect. Our literature search identified 61 eligible studies performed between 1990 and 2020.

RESULTS

For studies analyzing the association between caffeine and the risk of dementia and/or cognitive decline, 16/57 (28%) studies including a total of 40,707/153,070 (27%) subjects reported positive study outcomes, and 30/57 (53%) studies including 71,219/153,070 (47%) subjects showed positive results that were dependent on study characteristics. Caffeine effects were more often positive when consumed in moderate quantities (100-400 mg/d), consumed in coffee or green tea, and in women. Furthermore, four studies evaluated the relationship between caffeine consumption and cognitive function in cognitively impaired individuals and the majority (3/4 [75% ]) of studies including 272/289 subjects (94%) reported positive outcomes.

CONCLUSION

This review suggests that caffeine consumption, especially moderate quantities consumed through coffee or green tea and in women, may reduce the risk of dementia and cognitive decline, and may ameliorate cognitive decline in cognitively impaired individuals.

Changes in Social Network Size Are Associated With Cognitive Changes in the Oldest-Old

OBJECTIVES

Social isolation is increasing in aging societies and several studies have shown a relation with worse cognition in old age. However, less is known about the association in the oldest-old (85+); the group that is at highest risk for both social isolation and dementia.

METHODS

Analyses were based on follow-up 5 to 9 of the longitudinal German study on aging, cognition, and dementia in primary care patients (AgeCoDe) and the study on needs, health service use, costs, and health-related quality of life in a large sample of oldest-old primary care patients (AgeQualiDe), a multi-center population-based prospective cohort study. Measurements included the Lubben Social Network Scale (LSNS-6), with a score below 12 indicating social isolation, as well as the Mini-Mental Status Examination (MMSE) as an indicator of cognitive function.

RESULTS

Dementia-free study participants (n = 942) were M = 86.4 (SD = 3.0) years old at observation onset, 68.2% were women. One third (32.3%) of them were socially isolated. Adjusted linear hybrid mixed effects models revealed significantly lower cognitive function in individuals with smaller social networks (β = 0.5, 95% CI = 0.3-0.7, p < .001). Moreover, changes in an individual's social network size were significantly associated with cognitive changes over time (β = 0.2, 95% CI = 0.1-0.4, p = .003), indicating worse cognitive function with shrinking social networks.

CONCLUSION

Social isolation is highly prevalent among oldest-old individuals, being a risk factor for decreases in cognitive function. Consequently, it is important to maintain a socially active lifestyle into very old age. Likewise, this calls for effective ways to prevent social isolation.

Ethanol and its metabolites: update on toxicity, benefits, and focus on immunomodulatory effects

This article summarizes recent experimental and epidemiological data on the toxic and beneficial effects of ethanol and its metabolites (acetaldehyde), and focuses on their immunomodulatory effects. The section dealing with the toxic effects of alcohol focuses on its chronic toxicity (liver disorders, carcinogenic effects, cardiovascular disorders, neuropsychic disorders, addiction and withdrawal syndrome, hematologic disorders, reprotoxicity, osteoporosis) although acute toxicity is considered. The role of oxidative metabolism of ethanol by alcohol dehydrogenase, cytochrome P450 2E1, and aldehyde dehydrogenase, as well as the impact of genetic polymorphism in its physiopathology are also highlighted. The section dealing with the beneficial effects of low to moderate alcohol consumption (on cardiovascular system, diabetes, the nervous system and sensory organs, autoimmune diseases, and rheumatology) highlights the importance of anti-inflammatory and immunomodulatory effects in these observations. This knowledge, enriched by a focus on the immunomodulatory effects of ethanol and its metabolites, in particular on the NLRP3 inflammasome pathway, might facilitate the development of treatments that can reduce ethanol's harmful effects or accentuate its beneficial effects.

Blood Pressure Circadian Variation, Cognition and Brain Imaging in 90+ Year-Olds

Purpose: To analyze the relationship between blood pressure (BP) variables, including circadian pattern, and cognition in 90+ year-olds.

Methods: Twenty-four hour ambulatory BP monitoring was completed on 121 participants drawn from a longitudinal study of aging and dementia in the oldest-old. Various measures of BP and its variability, including nocturnal dipping, were calculated. Each person was given both a neuropsychological test battery covering different cognitive domains and a neurological examination to determine cognitive status. Seventy-one participants had a brain magnetic resonance imaging (MRI) scan.

Results: Participants ranged in age from 90 to 102 years (mean = 93), about two-thirds were female, and nearly 80% had at least some college education. Mean nocturnal dips differed significantly between cognitively normal (n = 97) and impaired individuals (n = 24), with cognitively normal participants having on average greater nocturnal dips [6.6% vs. 1.3%, p = 0.006 for systolic BP (SBP); 11% vs. 4.4%, p = 0.002 for diastolic BP (DBP)]. Nocturnal dips were also related to performance on select cognitive test scores (especially those related to language, recent memory and visual-spatial ability), with individuals who performed below previously established median norms having significantly smaller nocturnal dips (both SBP and DBP) than those above the median. DBP reverse dippers had larger mean white matter hyperintensities (WMH as percent of total brain volume; 1.7% vs. 1.2%, 1.1% and 1.0% in extreme dippers, dippers, non-dippers) and a greater proportion had lobar cerebral microbleeds (CMBs; 44% vs. 0%, 7%, 16%, p < 0.05). Impaired participants had higher mean WMH than those with normal cognition (1.6% vs. 1.0% p = 0.03) and more tended to have CMB (31% vs. 20%, p = n.s.).

Conclusion: These findings suggest that cognitive dysfunction is associated with dysregulation in the normal circadian BP pattern. Further study is warranted of the potential role of WHM and CMB as mediators of this association.

Resilience to cognitive impairment in the oldest-old: design of the EMIF-AD 90+ study

BACKGROUND

The oldest-old (subjects aged 90 years and older) population represents the fastest growing segment of society and shows a high dementia prevalence rate of up to 40%. Only a few studies have investigated protective factors for cognitive impairment in the oldest-old. The EMIF-AD 90+ Study aims to identify factors associated with resilience to cognitive impairment in the oldest-old. In this paper we reviewed previous studies on cognitive resilience in the oldest-old and described the design of the EMIF-AD 90+ Study.

METHODS

The EMIF-AD 90+ Study aimed to enroll 80 cognitively normal subjects and 40 subjects with cognitive impairment aged 90 years or older. Cognitive impairment was operationalized as amnestic mild cognitive impairment (aMCI), or possible or probable Alzheimer's Disease (AD). The study was part of the European Medical Information Framework for AD (EMIF-AD) and was conducted at the Amsterdam University Medical Centers (UMC) and at the University of Manchester. We will test whether cognitive resilience is associated with cognitive reserve, vascular comorbidities, mood, sleep, sensory system capacity, physical performance and capacity, genetic risk factors, hallmarks of ageing, and markers of neurodegeneration. Markers of neurodegeneration included an amyloid positron emission tomography, amyloid β and tau in cerebrospinal fluid/blood and neurophysiological measures.

DISCUSSION

The EMIF-AD 90+ Study will extend our knowledge on resilience to cognitive impairment in the oldest-old by extensive phenotyping of the subjects and the measurement of a wide range of potential protective factors, hallmarks of aging and markers of neurodegeneration.

TRIAL REGISTRATION

Nederlands Trial Register NTR5867 . Registered 20 May 2016.

Lifestyle activities and the risk of dementia in older Japanese adults

AIM

The prevalence of dementia is rising due to increases in the aging population and chronic health conditions. The present study examined whether lifestyle activities, including instrumental activities of daily living and social roles, were associated with dementia incidence in Japanese community-dwelling older adults.

METHODS

This longitudinal study involved 4564 participants (age ≥65 years) who were classified by age and sex. Lifestyle activities, risk factors for dementia and incidence of new dementia were recorded.

RESULTS

After an average of 42.6 months, 219 participants (4.8%) experienced a new onset of dementia. Survival analyses using the Cox proportional hazards regression model showed that the probability of dementia was significantly lower in participants who engaged in daily conversation (hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.35-0.89, P = 0.015), driving a car (HR 0.63, 95% CI 0.45-0.88, P = 0.007), shopping (HR 0.57, 95% CI 0.34-0.96, P = 0.033) and field work or gardening (HR 0.71, 95% CI 0.54-0.94, P = 0.016).

CONCLUSIONS

We concluded that specific lifestyle activities might play an important role in preventing dementia in older adults. The activities that prevent dementia might differ depending on sex and age. Geriatr Gerontol Int 2018; 18: 1491-1496.

Prevalence of transactive response DNA-binding protein 43 (TDP-43) proteinopathy in cognitively normal older adults: systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the prevalence of transactive response DNA-binding protein 43 (TDP-43) proteinopathy in cognitively normal older adults.

METHODS

We systematically reviewed and performed a meta-analysis on the prevalence of TDP-43 proteinopathy in older adults with normal cognition, evaluated by the Mini-Mental State Examination or the Clinical Dementia Rating. We estimated the overall prevalence of TDP-43 using random-effect models, and stratified by age, sex, sample size, study quality, antibody used to assess TDP-43 aggregates, analysed brain regions, Braak stage, Consortium to Establish a Registry for Alzheimer's Disease score, hippocampal sclerosis and geographic location.

RESULTS

A total of 505 articles were identified in the systematic review, and 7 were included in the meta-analysis with 1196 cognitively normal older adults. We found an overall prevalence of TDP-43 proteinopathy of 24%. Prevalence of TDP-43 proteinopathy varied widely across geographic location (North America: 37%, Asia: 29%, Europe: 14%, and Latin America: 11%). Estimated prevalence of TDP-43 proteinopathy also varied according to study quality (quality score >7: 22% vs. quality score <7: 42%), antibody used to assess TDP-43 proteinopathy (native: 18% vs. hyperphosphorylated: 24%) and presence of hippocampal sclerosis (without 24% vs. with hippocampal sclerosis: 48%). Other stratified analyses by age, sex, analysed brain regions, sample size and severity of AD neuropathology showed similar pooled TDP-43 prevalence.

CONCLUSIONS

Different methodology to access TDP-43, and also differences in lifestyle and genetic factors across different populations could explain our results. Standardization of TDP-43 measurement, and future studies about the impact of genetic and lifestyle characteristics on the development of neurodegenerative diseases are needed.