In the Long Run: Physical Activity in Early Life and Cognitive Aging

Cognitive Reserve and Frontotemporal Disorders: Exploring the Relationship Between Education, Physical Activity, and Cognitive Dysfunction in Older Adults

In this study we investigated the relationship between cognitive reserve (CR) proxies, such as education, physical activity (PA), and cognitive dysfunction (CD) in the presence or absence of frontotemporal disorders (FTD). Previous research has suggested that education and PA may delay the onset of CD and reduce the risk of developing dementia. However, it remains unclear whether these CR proxies can protect against CD when FTD is present. We aimed to explore this relationship and determine whether sustained CR may be evident regardless of FTD. We recruited 149 older adults (aged 65-99 years) from community centers where they were voluntarily participating in leisure activities. We used bioelectrical impedance to measure their body composition, and we administered the International PA Questionnaire and the Mini-Mental State Examination to measure their PA and cognitive function, respectively. We used the Frontal Assessment Battery to screen for frontotemporal dementia. Our results showed that people with FTD were older, had lower education, and engaged in less PA, relative to other participants. Regression models revealed that age, education, and PA were significant predictors of FTD. More specifically, FTD was negatively associated with cognitive functioning, and there were significant interaction effects between FTD and education and PA. PA and education were significant predictors of cognitive functioning, and, when values for PA and education were high, they offset the effects of FTD on cognitive function. These findings support impressions that PA and years of education provide an insulating or compensatory effect on cognitive functioning in older adults with executive dysfunction or frontotemporal dementia, highlighting the importance of encouraging both pursuits.

The causality of physical activity status and intelligence: A bidirectional Mendelian randomization study

BACKGROUND

Observational studies suggest physical activity (PA) enhances intelligence, while sedentary behavior (SB) poses a risk. However, causality remains unclear.

METHODS

We extracted genetic instruments from large genome-wide association studies summary data and employed an inverse-variance weighted (IVW) approach within a random-effects model as the primary method of Mendelian randomization (MR) analysis to estimate the overall effect of various physical activity statuses on intelligence. To assess IVW stability and MR sensitivity, we also utilized supplementary methods including weighted median, MR-Egger, and MR-PRESSO. Furthermore, multivariable MR analysis was conducted to examine the independent effects of each physical activity trait on intelligence.

RESULTS

The MR primary results indicated that LST was negatively associated with intelligence (β = -0.133, 95%CI: -0.177 to -0.090, p = 1.34×10-9), while SBW (β = 0.261, 95% CI: 0.059 to 0.463, p = 0.011) may have a positive effect on intelligence; however, MVPA and SC did not show significant effects on intelligence. Inverse causality analyses demonstrated intelligence significantly influenced all physical activity states.

CONCLUSIONS

Our study highlights a bidirectional causal relationship between physical activity states and intelligence.

Association of physical activity with dementia and cognitive decline in UK Biobank

INTRODUCTION

There is a lack of studies on the association between specific physical activity (PA) types and dementia. We examined the association of leisure time physical activity (LTPA), occupational physical activity (OPA), and sedentary lifestyle with dementia risk and cognitive decline using the UK-Biobank study.

METHODS

Baseline PA was collected using questionnaires. A total of 502,481 dementia-free participants were recruited in 2006-2010 and followed for 10 years until the end of 2020 for the ascertainment of dementia. Associations of PA with incident dementia and cognitive decline were examined.

RESULTS

Higher levels of LTPA and OPA and lower levels of sedentary hours were associated with lower dementia risk. The fifth quintiles of LTPA (hazard ratio [HR] = 0.53, 95% confidence interval [CI]: 0.43-0.67) and OPA (HR = 0.68, 95% CI:0.51-0.90) had lower dementia risk, whereas the fifth quintile of sedentary lifestyle had higher dementia risk (HR = 1.23, 95% CI:1.08-1.41).

DISCUSSION

Our findings suggest the promotion of an active lifestyle suggested to be preventive of dementia risk. This research has been conducted using the UK Biobank Resource under Application Number 71022.

Physical activity moderates the association between white matter hyperintensity burden and cognitive change

Objective

Greater physical activity (PA) could delay cognitive decline, yet the underlying mechanisms remain unclear. White matter hyperintensity (WMH) burden is one of the key brain pathologies that have been shown to predict faster cognitive decline at a late age. One possible pathway is that PA may help maintain cognition by mitigating the detrimental effects of brain pathologies, like WMH, on cognitive change. This study aims to examine whether PA moderates the association between WMH burden and cognitive change.

Materials and methods

This population-based longitudinal study included 198 dementia-free adults aged 20-80 years. Leisure-time physical activity (LTPA) was assessed by a self-reported questionnaire. Occupational physical activity (OPA) was a factor score measuring the physical demands of each job. Total physical activity (TPA) was operationalized as the average of z-scores of LTPA and OPA. Outcome variables included 5-year changes in global cognition and in four reference abilities (fluid reasoning, processing speed, memory, and vocabulary). Multivariable linear regression models were used to estimate the moderation effect of PA on the association between white matter hyperintensities and cognitive change, adjusting for age, sex, education, and baseline cognition.

Results

Over approximately 5 years, global cognition (p < 0.001), reasoning (p < 0.001), speed (p < 0.001), and memory (p < 0.05) scores declined, and vocabulary (p < 0.001) increased. Higher WMH burden was correlated with more decline in global cognition (Spearman's rho = -0.229, p = 0.001), reasoning (rho = -0.402, p < 0.001), and speed (rho = -0.319, p < 0.001), and less increase in vocabulary (rho = -0.316, p < 0.001). Greater TPA attenuated the association between WMH burden and changes in reasoning (βTPA^*WMH = 0.029, 95% CI = 0.006-0.052, p = 0.013), speed (βTPA^*WMH = 0.035, 95% CI = -0.004-0.065, p = 0.028), and vocabulary (βTPA^*WMH = 0.034, 95% CI = 0.004-0.065, p = 0.029). OPA seemed to be the factor that exerted a stronger moderation on the relationship between WMH burden and cognitive change.

Conclusion

Physical activity may help maintain reasoning, speed, and vocabulary abilities in face of WMH burden. The cognitive reserve potential of PA warrants further examination.

An Overview of Cognitive Reserve in Aging Based on Keyword Network Analysis

Many studies have reported that Cognitive reserve is a critical mechanism affecting cognitive statuses, such as dementia. The purposes of this study were to identify the knowledge structure and the research trend on cognitive reserve by conducting keyword analysis on research papers ranging from the earliest to the most recent studies done on the topic and to suggest directions for future research. The Web of Science (WOS) database was used to search for articles on cognitive reserve in aging from 2001 to 2020. NetMiner version 4 (cyram, KOREA), a social network analysis program, was used for keyword network analysis. Data analysis showed keywords that could be categorized as cognitive reserve related keywords (cognitive reserve related concepts, cognitive reserve related factor, cognitive reserve diagnosis and measurement, cognitive reserve outcomes) and cognitive reserve research keywords (research subject/disease, research method, intervention, research field). Through trend analysis, we found that various keywords appeared, indicating that the research has gradually developed conceptually and methodically. Based on these findings, future CR studies require the development of multimodal interface-based tools by applying modern digital technology that can be used to more accurately diagnose and monitor CR; remotely, in real time. In addition, to improve CR, it is suggested that the development of cognitive stimulation interventions utilizing VR which fuses AI based interaction technology with the subjects. Finally, CR could develop further through a cooperation of multidisciplinary professionals such as psychology, medicine and nursing.

Environmental Enrichment Effects on the Brain-Derived Neurotrophic Factor Expression in Healthy Condition, Alzheimer's Disease, and Other Neurodegenerative Disorders

Brain-derived neurotrophic factor (BDNF), a protein belonging to the neurotrophin family, is known to be heavily involved in synaptic plasticity processes that support brain development, post-lesion regeneration, and cognitive performances, such as learning and memory. Evidence indicates that BDNF expression can be epigenetically regulated by environmental stimuli and thus can mediate the experience-dependent brain plasticity. Environmental enrichment (EE), an experimental paradigm based on the exposure to complex stimulations, constitutes an efficient means to investigate the effects of high-level experience on behavior, cognitive processes, and neurobiological correlates, as the BDNF expression. In fact, BDNF exerts a key role in mediating and promoting EE-induced plastic changes and functional improvements in healthy and pathological conditions. This review is specifically aimed at providing an updated framework of the available evidence on the EE effects on brain and serum BDNF levels, by taking into account both changes in protein expression and regulation of gene expression. A further purpose of the present review is analyzing the potential of BDNF regulation in coping with neurodegenerative processes characterizing Alzheimer's disease (AD), given BDNF expression alterations are described in AD patients. Moreover, attention is also paid to EE effects on BDNF expression in other neurodegenerative disease. To investigate such a topic, evidence provided by experimental studies is considered. A deeper understanding of environmental ability in modulating BDNF expression in the brain may be fundamental in designing more tuned and effective applications of complex environmental stimulations as managing approaches to AD.

A Primary Care Agenda for Brain Health: A Scientific Statement From the American Heart Association

A healthy brain is critical for living a longer and fuller life. The projected aging of the population, however, raises new challenges in maintaining quality of life. As we age, there is increasing compromise of neuronal activity that affects functions such as cognition, also making the brain vulnerable to disease. Once pathology-induced decline begins, few therapeutic options are available. Prevention is therefore paramount, and primary care can play a critical role. The purpose of this American Heart Association scientific statement is to provide an up-to-date summary for primary care providers in the assessment and modification of risk factors at the individual level that maintain brain health and prevent cognitive impairment. Building on the 2017 American Heart Association/American Stroke Association presidential advisory on defining brain health that included "Life's Simple 7," we describe here modifiable risk factors for cognitive decline, including depression, hypertension, physical inactivity, diabetes, obesity, hyperlipidemia, poor diet, smoking, social isolation, excessive alcohol use, sleep disorders, and hearing loss. These risk factors include behaviors, conditions, and lifestyles that can emerge before adulthood and can be routinely identified and managed by primary care clinicians.

The Contribution of Physical Exercise to Brain Resilience

Increasing attention has been given to understanding resilience to brain diseases, often described as brain or cognitive reserve. Among the protective factors for the development of resilience, physical activity/exercise has been considered to play an important role. Exercise is known to induce many positive effects on the brain. As such, exercise represents an important tool to influence neurodevelopment and shape the adult brain to react to life's challenges. Among many beneficial effects, exercise intervention has been associated with cognitive improvement and stress resilience in humans and animal models. Thus, a growing number of studies have demonstrated that exercise not only recovers or minimizes cognitive deficits by inducing better neuroplasticity and cognitive reserve but also counteracts brain pathology. This is evidenced before disease onset or after it has been established. In this review, we aimed to present encouraging data from current clinical and pre-clinical neuroscience research and discuss the possible biological mechanisms underlying the beneficial effects of physical exercise on resilience. We consider the implication of physical exercise for resilience from brain development to aging and for some neurological diseases. Overall, the literature indicates that brain/cognitive reserve built up by regular exercise in several stages of life, prepares the brain to be more resilient to cognitive impairment and consequently to brain pathology.

Comparison of Traditional Chinese Exercises and Nontraditional Chinese Exercise Modalities on Cognitive and Executive Function in Community Middle-Aged and Older Adults: A Cross-Sectional Study

Background

Current evidence indicates that regular exercise can have a positive impact on cognitive function in older adults, but whether different exercise modalities may induce differential protective effects in different cognitive domains is uncertain.

Objective

To compare the effect of traditional Chinese exercise (TCE) modalities and non-traditional Chinese exercise (non-TCE) modalities on cognitive and executive function in community middle-aged and older adults through a cross-sectional study.

Methods

A total of 350 community middle-aged and older adults aged over 55 years participated in this study. Information on demographic characteristics, lifestyle and behavioural habits, and regular exercise was collected by a self-designed questionnaire. Global cognitive ability and executive function were assessed using the Montreal Cognitive Assessment (MoCA) scale, the clock drawing test (CDT), the animal naming test (ANT), and the trail making test (TMT). Eligible subjects were categorized into the no regular exercise (no-RE), non-TCE, or TCE groups according to their self-reported exercise information. Comparisons of global cognitive and executive function among the three groups were conducted using ANOVA or the general linear model with adjustment for potential confounding factors.

Results

The results showed that for the non-TCE or TCE groups, the MoCA and CDT scores were significantly higher, and the TMT-A test time was significantly shorter than those in the no-RE group (all P < 0.05), but no significant difference was observed for the TMT-B and ANT tests. After adjustment for potential confounding factors, the MoCA, the CDT, and TMT-A scores in the TCE group were significant compared to those in the no-RE group. In addition, subgroup analysis showed that in the TCE group, the MoCA scores were significantly higher than those in the non-TCE group. Furthermore, in the TCE group, the CDT scores for those with an exercise duration of <5 years were higher and the TMT-A test time for those with an exercise duration of ≥5 years was shorter than those in the non-TCE group.

Conclusions

Both TCE and non-TCE have potential protective effects on global cognitive and executive function in community middle-aged and older adults. Compared to the non-TCE modality, the TCE modality may have a more positive association with these protective effects. Furthermore, prospective studies are needed to confirm these findings.

PET Imaging of Perceptual Learning-Induced Changes in the Aged Rodent Cholinergic System

The cholinergic system enhances attention and gates plasticity, making it a major regulator of adult learning. With aging, however, progressive degeneration of the cholinergic system impairs both the acquisition of new skills and functional recovery following neurological injury. Although cognitive training and perceptual learning have been shown to enhance auditory cortical processing, their specific impact on the cholinergic system remains unknown. Here we used [¹⁸F]FEOBV, a positron emission tomography (PET) radioligand that selectively binds to the vesicular acetylcholine transporter (VAChT), as a proxy to assess whether training on a perceptual task results in increased cholinergic neurotransmission. We show for the first time that perceptual learning is associated with region-specific changes in cholinergic neurotransmission, as detected by [¹⁸F]FEOBV PET imaging and corroborated with immunohistochemistry.