Unhealthy lifestyles and brain condition: Examining the relations of BMI, living alone, alcohol intake, short sleep, smoking, and lack of exercise with gray matter volume

Whole-brain gray matter volume mediates the relationship between psychological distress and job satisfaction

Individual differences in brain structure are not only seen between healthy and diseased individuals, or between young and elderly people, but also in middle-aged men and women. Previous studies have shown that the cause is related to psychological distress and stress, and that it is accompanied by a decline in performance. This suggests that among middle-aged male and female workers who consider themselves healthy, the brain may atrophy depending on the level of psychological distress, which may reduce job satisfaction. Therefore, in this study, we analyzed the relationship between brain structure and psychological variables from the analysis of brain images obtained by magnetic resonance imaging (MRI) and the results of a questionnaire survey of 80 middle-aged male and female workers who consider themselves healthy. The results showed that the gray matter of the whole brain, frontal lobe, temporal lobe, and parietal lobe mediated the relationship between psychological distress and job satisfaction. This suggests that more workers than previously believed may have symptoms like frontotemporal dementia (FTD) due to psychological distress, reducing their job performance and job satisfaction.

Expatriates' Cultural Intelligence Mediates the Relationship Between Lifestyle and Performance: A Cross-Sectional Analysis and a Longitudinal Pilot Study

INTRODUCTION

Cultural intelligence (CQ) has been attracting increasing attention in recent years as a necessary caability for adapting to a different culture and improving expatriate performance (EP). However, the methods for improving this intelligence have not been fully elucidated, and in particular, the relationship with lifestyle (LS) has hardly been clarified.

METHODS

In this paper, we therefore conducted a cross-sectional analysis using questionnaire response data obtained from 184 Japanese expatriates working for Japanese subsidiaries overseas in Study 1, and in Study 2, we measured changes in 15 of them as an exploratory pilot study after using a smartphone app with health promotion functions for two weeks.

RESULTS

The results showed that CQ mediated the relationship between LS and EP in both Study 1 and Study 2.

CONCLUSION

The results of this study suggest that a health science approach that improves LS can be effective in improving the EP of businesspeople working in different cultural environments through improving their CQ.

Multimodal Neuroimaging of Obesity: From Structural-Functional Mechanisms to Precision Interventions

PURPOSE

Obesity's metabolic consequences are well documented; however, its neurobiological underpinnings remain elusive. This systematic review addresses a critical gap by synthesizing evidence on obesity-induced neuroplasticity across structural, functional, and molecular domains through advanced neuroimaging.

METHODS

According to PRISMA guidelines, we systematically searched (2015-2024) across PubMed/Web of Science, employing MeSH terms: ("Obesity" [Majr]) AND ("Neuroimaging" [Mesh] OR "Magnetic Resonance Imaging" [Mesh]). A total of 104 studies met the inclusion criteria. The inclusion criteria required the following: (1) multimodal imaging protocols (structural MRI/diffusion tensor imaging/resting-state functional magnetic resonance imaging (fMRI)/positron emission tomography (PET)); (2) pre-/post-intervention longitudinal design. Risk of bias was assessed via the Newcastle-Ottawa Scale.

KEY FINDINGS

1. Structural alterations: 7.2% mean gray matter reduction in prefrontal cortex (Cohen's d = 0.81). White matter integrity decline (FA reduction β = -0.33, p < 0.001) across 12 major tracts. 2. Functional connectivity: Resting-state hyperactivity in mesolimbic pathways (fALFF + 23%, p-FDR < 0.05). Impaired fronto-striatal connectivity (r = -0.58 with BMI, 95% CI [-0.67, -0.49]). 3. Interventional reversibility: Bariatric surgery restored prefrontal activation (Δ = +18% vs. controls, p = 0.002). Neurostimulation (transcranial direct current stimulation (tDCS) enhanced cognitive control (post-treatment β = 0.42, p = 0.009).

CONCLUSION

1. Obesity induces multidomain neural reorganization beyond traditional reward circuits. 2. Neuroimaging biomarkers (e.g., striatal PET-dopamine binding potential) predict intervention outcomes (AUC = 0.79). 3. Precision neuromodulation requires tripartite integration of structural guidance, functional monitoring, and molecular profiling. Findings highlight neuroimaging's pivotal role in developing stage-specific therapeutic strategies.

Examination of the impact of curiosity and fatigue on brain condition

With a growing emphasis on cognitive well-being, this study investigates factors influencing brain health, measured by Fractional Anisotropy Brain Healthcare Quotient (FA-BHQ). We find a positive correlation between curiosity, assessed by the Curiosity and Exploration Inventory-II (CEI-II), and brain health as indicated by FA-BHQ. Conversely, fatigue, evaluated using the Chalder Fatigue Scale (CFS), demonstrates a negative correlation with brain health. Furthermore, curiosity and fatigue serve as significant mediators in the relationship between these factors and FA-BHQ, respectively. Specific brain regions, including the corpus callosum, internal capsule, fornix, and posterior thalamic radiation, show significant negative correlations with fatigue, while the corpus callosum, fornix, internal capsule, corona radiata, external capsule, cingulum, and posterior thalamic radiation exhibit significant positive correlations with curiosity. Notably, this study highlights that more brain regions exhibit significant correlations with curiosity compared to fatigue, shedding light on the growing recognition of curiosity's role in influencing brain health and emphasizing the importance of considering curiosity in the research on cognitive well-being.

Uncovering mediational pathways behind racial and socioeconomic disparities in brain volumes: insights from the UK Biobank study

Mediation pathways explaining racial/ethnic and socioeconomic (SES) disparities in structural MRI markers of brain health remain underexplored. We examined racial/ethnic and SES disparities in sMRI markers and tested total, direct, and indirect effects through lifestyle, health-related, and cognition factors using a structural equations modeling approach among 36,184 UK Biobank participants aged 40-70 years at baseline assessment (47% men). Race (non-White vs. White) and lower SES-predicted poorer brain sMRI volumetric outcomes at follow-up, with racial/ethnic disparities in sMRI outcomes involving multiple pathways and SES playing a central role in those pathways. Mediational patterns differed across outcomes, with the SES-sMRI total effect being partially mediated for all outcomes. Over 20% of the total effect (TE) of race/ethnicity on WMH was explained by the indirect effect (IE), by a combination of different pathways going through SES, lifestyle, health-related, and cognition factors. This is in contrast to < 10% for total brain, gray matter (GM), white matter (WM), and frontal GM left/right. Another significant finding is that around 57% of the total effect for SES and the normalized white matter hyperintensity (WMH) was attributed to an indirect effect. This effect encompasses many pathways that involve lifestyle, health-related, and cognitive aspects. Aside from WMH, the percent of TE of SES mediated through various pathways ranged from ~ 5% for WM to > 15% up to 36% for most of the remaining sMRI outcomes, which are composed mainly of GM phenotypes. Race and SES were important determinants of brain volumetric outcomes, with partial mediation of racial/ethnic disparities through SES, lifestyle, health-related, and cognition factors.

Kawaii-Ness Mediates Between Demographic Variables, Happiness, and Brain Conditions

Background/Objectives: In many societies, especially in highly masculine societies like Japan, being a man, getting older, engaging in knowledge work, and earning a high annual salary are seen as conditions for success. On the other hand, an increasing number of studies have shown that incorporating kawaii-ness into our lives can help maintain and improve happiness and well-being. Methods: Therefore, in this study, we employed a variable expressing the response to kawaii-ness together with four demographic variables (sex, age, income, and knowledge work), happiness, and fractional anisotropy brain healthcare quotient (FA-BHQ) which is derived from magnetic resonance imaging (MRI) images calculations to analyze the relationship between them. Results: The results of a path analysis using data obtained from 182 healthy men and women showed that kawaii-ness mediates the association between demographic variables and happiness, which is in turn associated with FA-BHQ. Furthermore, with the correlation analysis between happiness and individual FA regions, we were able to confirm that FA regions, including the limbic-thalamo-cortical pathway, which is responsible for emotional regulation, are related to happiness. Conclusions: These results indicate the following: Men, older people, people engaged in knowledge work, and people with high annual incomes avoid kawaii-ness; As a result, they are unable to obtain the sense of happiness that they should have; as a result, they are unable to keep their brains healthy, and their brain functions, including emotional regulation, are not functioning properly; This may prevent them from maintaining or improving their performance. This study is the first attempt to clarify the relationship between demographic scales, kawaii-ness, happiness, and brain conditions.

The Brain That Understands Diversity: A Pilot Study Focusing on the Triple Network

Background/Objectives: Interest in diversity is growing worldwide. Today, an understanding and social acceptance of diverse people is becoming increasingly important. Therefore, in this study, we aimed to clarify the relationship between an individual's gray matter volume (GMV), which is thought to reflect brain health, and their understanding of diversity (gender, sexuality (LGBTQ), and origin). Methods: GMV was determined as the value of the Gray Matter Brain Healthcare Quotient (GM-BHQ) based on MRI image analysis. Meanwhile, participants' understanding and acceptance of diversity was calculated based on their answers to the psychological questions included in the World Values Survey Wave 7 (WVS7). Results: Our analysis indicated that, in the group of participants with the highest understanding of diversity (PHUD. n = 11), not only the GMV at the whole brain level (t = 2.587, p = 0.027, Cohen's d = 0.780) but also the GMV of the central executive network (CEN: t = 2.700, p= 0.022, Cohen's d = 0.814) and saliency network (SN: t = 3.100, p = 0.011, Cohen's d = 0.935) were shown to be significantly higher than the theoretical value estimated from sex, age, and BMI at the 5% level. In addition, the GMV of the default mode network (DMN: t = 2.063, p = 0.066, Cohen's d = 0.622) was also higher than the theoretical value at the 10% level. Meanwhile, in the group of others (n = 10), there was no significant difference from the theoretical value. These differences between PHUD and others were also observed when comparing the two with and without controlling for educational and occupational covariates at the 5% or 10% levels. Conclusions: These results suggest that understanding diversity requires a healthy brain, centered on three networks that govern rational judgment, emotion regulation, other-awareness, self-awareness, and the valuing of actions. This is the first study to show that brain structure is related to an understanding and acceptance of the diversity of people.

Incorporating "kawaii-ness" into your life may increase gray matter volume in the putamen and frontal gyrus

Interest in kawaii-ness is growing day by day around the world. However, the relationship between the brain and kawaii-ness remains unclear. Previous studies have revealed how adults' brains respond to infants, but there is little research into the relationship between non-infant objects that have kawaii-ness and the brain, particularly its structure. Therefore, in this study, using data from 182 healthy men and women, including 90 participants from a toy manufacturer's fan community (TMFC), we analyzed the relationship between the adoption of kawaii-ness and the gray matter volume (GMV) of region of interest (ROI). The results showed that the adoption of kawaii-ness was significantly and positively related to the GMV of the putamen, insula, frontal gyrus (FG), and rectus in the TMFC sample in an analysis that controlled for demographic data. Of these, the significant relationships between putamen and FG and adoption survived multiple comparisons. This is the first study to clarify the relationship between adoption of kawaii-ness and brain structure.

The Interactions between Smoking and Sleep

Smoking a cigarette before bed or first thing in the morning is a common habit. In this review, the relationship between smoking and sleep is investigated based on the existing literature. Out of 6504 unique items that were identified via a PubMed search related to smoking and sleep, 151 were included in this review. Tobacco smoking disrupts sleep architecture by reducing slow wave and rapid eye movement (REM) sleep and undermining sleep quality. Furthermore, smoking affects sleep-related co-morbidities, such as obstructive sleep apnea-hypopnea syndrome (OSAHS), insomnia, parasomnias, arousals, bruxism, and restless legs, as well as non-sleep-related conditions such as cardiovascular, metabolic, respiratory, neurologic, psychiatric, inflammatory, gynecologic and pediatric issues, while poor sleep quality also seems to worsen the chances of successful smoking cessation. In conclusion, the existing literature suggests that there is a wicked relation between smoking and sleep.

Blood brain barrier dysfunction in healthy aging and dementia: Why, how, what for?

The blood brain barrier (BBB) is an indispensable structure that maintains the central nervous system (CNS) microenvironment for a correct neuronal function. It is composed by highly specialized microvessels, surrounded by astrocytes, pericytes, neurons and microglia cells, which tightly control the influx and efflux of substances to the brain parenchyma. During aging, the BBB becomes impaired, and it may contribute to the development of neurodegenerative and neurological disorders including Alzheimer's disease and other dementias. Restoring the BBB can be a strategy to prevent disease onset and development, reducing the symptoms of these conditions. This work critically reviews the major mechanisms underlying BBB breakdown in healthy and unhealthy aging, as well as biomarkers and methodologies that accurately assess its impairment. Complementarily, potential therapeutic targets are discussed as new strategies to restore the normal function of the BBB in aging.

Clinical Characteristics and Outcomes of Aneurysmal Subarachnoid Hemorrhage Patients Who Live Alone

It has been shown that living alone is one of the risk factors for unfavorable outcomes in ischemic stroke patients, mostly due to delay in receiving appropriate treatment. A single-center retrospective observational study was conducted to evaluate whether living alone was associated with unfavorable outcomes in aneurysmal subarachnoid hemorrhage (SAH) patients. Among 451 SAH patients admitted to our institution between January 2013 and December 2022, 43 patients who lived alone had sustained SAH at home (group A) and 329 patients who lived with family had sustained SAH at home (group F). The mortality rate (46.5% vs. 29.8%, p = 0.04) and a tendency for having unfavorable outcomes were higher in group A than in group F. The incidence of concomitant hydrocephalus was significantly higher in the former (37.2% vs. 21.3%, p = 0.03). Group A was further classified to the Able to Call (n = 15, group AC) and Unable to Call (n = 28, group UC) subgroups based on their ability to call for help by themselves. Group AC tended to have favorable outcomes (27% vs. 4%, p = 0.04). Treatment to obliterate a ruptured aneurysm had particularly been challenging in group UC, in which the accurate time of onset often remained unidentifiable: Their overall mortality was as high as 57% and their capability to undergo surgical/interventional treatment was only 67%. Perioperative complications resulting from delayed presentation had been common. Considering the present finding that most of those who lived alone could not call for help, further effort is warranted to facilitate early detection of those patients.

Brain functional training: a perspective article

Introduction: Physical exercise (PE) positively affects the nervous system, impacting morphology and physiology. It increases brain gray and white matter, improves cerebral blood flow, and stimulates neurogenesis, synaptogenesis, and angiogenesis, promoting brain function. Although exercise already affects cognition, some training modalities place greater demands on the cognitive aspects of physical exercise, such as perceptual-motor and visual-motor training. This type of approach aims to emphasize the cognitive adaptations that occur chronically. Specifically for older people, functional training, a multi-component approach, is a promising exercise modality that stimulates functionality using multi-joint, multi-planar exercises mirroring daily activities. However, applying a greater focus on cognitive adaptations in line with the functional training proposal for maximal benefits remains underexplored. Aim: Thus, this perspective article initially explores different exercise approaches emphasizing cognitive adaptations and proposes Brain Functional Training to improve older adult's functionality. Methods: Furthermore, we explain how brain functional training can be explored to emphasize cognitive aspects based on increasing complexity to stimulate the executive function and its subdomains. Conclusion: This proposal is one alternative to combining motor and cognitive stimuli to promote autonomy and health in older people.

Association between household size and risk of incident dementia in the UK Biobank study

Currently, the relationship between household size and incident dementia, along with the underlying neurobiological mechanisms, remains unclear. This prospective cohort study was based on UK Biobank participants aged ≥ 50 years without a history of dementia. The linear and non-linear longitudinal association was assessed using Cox proportional hazards regression and restricted cubic spline models. Additionally, the potential mechanisms driven by brain structures were investigated by linear regression models. We included 275,629 participants (mean age at baseline 60.45 years [SD 5.39]). Over a mean follow-up of 9.5 years, 6031 individuals developed all-cause dementia. Multivariable analyses revealed that smaller household size was associated with an increased risk of all-cause dementia (HR, 1.06; 95% CI 1.02-1.09), vascular dementia (HR, 1.08; 95% CI 1.01-1.15), and non-Alzheimer's disease non-vascular dementia (HR, 1.09; 95% CI 1.03-1.14). No significant association was observed for Alzheimer's disease. Restricted cubic splines demonstrated a reversed J-shaped relationship between household size and all-cause and cause-specific dementia. Additionally, substantial associations existed between household size and brain structures. Our findings suggest that small household size is a risk factor for dementia. Additionally, brain structural differences related to household size support these associations. Household size may thus be a potential modifiable risk factor for dementia.

Smartphone app for lifestyle improvement improves brain health and boosts the vitality and cognitive function of healthy middle-aged adults

INTRODUCTION

The number of smartphone apps for brain training is increasing, and the number of people who are working on brain training is also increasing. However, researchers disagree about the effectiveness of brain training.

METHODS

Therefore, in this study, we conducted an intervention test with the participation of 70 healthy middle-aged men and women and measured the effect of smartphone apps on lifestyle improvement using brain healthcare quotient calculated from brain imaging data.

RESULTS

As a result, in the intervention group, significant improvements were seen in fractional anisotropy (FA) of the whole brain, corpus callosum, internal capsule, corona radiata, posterior thalamic radiation, external capsule, and superior longitudinal fasciculus. Additionally, in the intervention group, these FA increments correlated with improvements in cognitive function as measured by the trail-making test and vigor as measured by the Profile of Mood States 2nd Edition.

CONCLUSION

The results of this study suggest that improving lifestyle habits through smartphone apps can improve brain health and cognitive and emotional performance of healthy middle-aged adults. This is consistent with previous research that suggests that FA integrity in the limbic-thalamo-cortical pathway influences cognitive function and emotion regulation.

The Association between Lifestyles (Walking/Diet) and Cultural Intelligence: A New Attempt to Apply Health Science to Cross-Cultural Research

A growing amount of research is being conducted on cultural intelligence (CQ), which is the ability to adjust and adapt successfully to a variety of surroundings. CQ is a vital quality for people in diversified societies, as are seen today. However, it is still unclear how an individual can develop or strengthen CQ because previous studies have shown that variables such as foreign experience and personality are not exclusively sufficient as CQ antecedents. If CQ can be treated health-scientifically, as the CQ developers argue, diet and exercise that are effective in keeping the body and brain healthy may also correlate with CQ. It is of great significance to clarify the relationship between lifestyle and CQ by applying recent previous research showing the relationship between CQ and both the brain and intelligence, as well as between lifestyle and both the brain and intelligence. Using data derived from 142 Japanese businesspersons, the results of structural equation modeling indicate that lifestyles (dietary balance and walking frequency) are significantly associated with CQ after controlling for personalities (curiosity and grit) and international experiences (length of studying and working abroad), which have been used as predictors of CQ in previous studies. Furthermore, the moderation test showed that the effect of dietary balance on increasing CQ is greater for people with less overseas experience, indicating that dietary balance compensates for lack of overseas experience in the effect of maintaining the level of CQ. These suggest the effectiveness of a health-scientific approach to the influencing factors of CQ. This study is the first to show that CQ is influenced by lifestyle such as walking and dieting, in addition to personality and overseas experience, and will contribute to the future development of health science and cross-cultural research.

Meta-analytic evidence for a sex-diverging association between alcohol use and body mass index

Alcohol use is an important health issue and has been suggested to contribute to the burden produced by obesity. Both alcohol use and obesity are subject to sex differences. The available studies on the relationship between alcohol use and body mass index (BMI) report inconsistent results with positive, negative, and null findings which requests a meta-analytic approach. Therefore, we conducted a meta-analysis of case-control, cohort, and cross-sectional studies. The systematic literature search and data extraction was performed by 3 independent raters. We conducted sex-separated meta-analyses and -regressions to investigate how alcohol consumption associates with BMI. Our systematic literature search resulted in 36 studies with 48 data sets (Nmen = 172,254; kmen = 30; Nwomen = 24,164; kwomen = 18; Nunknown sex = 672,344; kunknown sex = 24). Alcohol use was associated with higher BMI in men (g = 0.08 [0.07; 0.09]) and lower BMI in women (g = - 0.26 [- 0.29; - 0.22]). Moreover, we found the amount of daily alcohol intake in men (β = 0.001 [0.0008; 0.0014]) and ethnicity in women (g[Caucasians] = - 0.45 versus g[Asians] = - 0.05; z = 11.5, p < 0.0001) to moderate these effects. We here identified sex-diverging relationships between alcohol use and BMI, found daily alcohol intake and ethnicity to sex-specifically moderate these effects, and argue that sex-specific choice of beverage type and higher amount of daily alcohol use in men than in women account for these observations. Future research is needed to provide empirical evidence for the underlying mechanisms.

Brain conditions mediate the association between aging and happiness

As the population ages, the realization of a long and happy life is becoming an increasingly important issue in many societies. Therefore, it is important to clarify how happiness and the brain change with aging. In this study, which was conducted with 417 healthy adults in Japan, the analysis showed that fractional anisotropy (FA) correlated with happiness, especially in the internal capsule, corona radiata, posterior thalamic radiation, cingulum, and superior longitudinal fasciculus. According to previous neuroscience studies, these regions are involved in emotional regulation. In psychological studies, emotional regulation has been associated with improvement in happiness. Therefore, this study is the first to show that FA mediates the relationship between age and subjective happiness in a way that bridges these different fields.

The link between the brain volume derived index and the determinants of social performance

Motivation, defined as the energizing of behavior in pursuit of a goal, is a fundamental element of our interaction with the world and with each other. Furthermore, as it is known that cooperation leads to higher levels of performance than do individual conditions, empathic concern is also crucial to all forms of helping relationships. A growing number of studies indicate that motivation and empathy are associated not only with organizational performance and study achievements, but also with the human brain. However, to date, no definite neuroimaging-derived measures are available to measure motivation and empathy objectively. The current research evaluated the association of motivation and empathy with the whole brain using the gray-matter brain healthcare quotient (GM-BHQ), an MRI-based quotient. Participants were 47 healthy adults. All subjects underwent structural T1-weighted imaging. Motivation levels were evaluated using four motivation scales: Behavioral Activation System (BAS), Self-Monitoring Scale (SMS), Self-Control Scale (SCS), and Behavioral Inhibition System (BIS). Interaction levels, including empathic concern, were evaluated using four subscales of the Interpersonal Reactivity Index (IRI). It was found that the GM-BHQ was most significantly sensitive to the BAS scale (p = 0.002). Furthermore, the GM-BHQ was moderately sensitive to the SMS (p = 0.028) and subscales of the IRI (p = 0.044 for Fantasy and p = 0.036 for Empathic Concern). However, no significant association was found between the GM-BHQ and other variables (BIS and SCS). These results suggest that the GM-BHQ might reflect motivation and empathic concern.