Diet, lifestyle and cognitive function in old Chinese adults

Dietary consumption of beef and red meat: a scoping review and evidence map on cognitive outcomes across the lifespan

OBJECTIVE

Mixed evidence exists on the impact of beef consumption on cognition. The goal was to create an evidence map capturing studies assessing beef consumption and cognition to reveal gaps and opportunities in the body of literature.

DESIGN

A scoping review was conducted to locate studies up to March 2022 using PubMed and backwards citation screening. Data were extracted by two independent reviewers with conflict resolution, and a database was created and made publicly available.

SETTING

Intervention and observational studies.

PARTICIPANTS

Humans of any age, sex and/or health status, without moderate to severe cognitive impairment and/or abnormalities.

RESULTS

Twenty-two studies were identified that quantified beef or red meat intake and assessed cognition. Six studies assessed beef intake, with the remaining studies describing intake of red meat that may or may not include beef. Nine articles described randomised controlled trials (RCT), mostly conducted in children. Thirteen described observational studies, primarily conducted on adults and seniors. The most common cognitive domains measured included intelligence and general cognition, and memory. The majority of controlled studies were rated with high risk of bias, with the majority of observational trials rated with serious or greater risk of bias.

CONCLUSIONS

Red meat and beef intake and cognition is largely understudied. There is a significant lack of replication across study designs, populations, exposures and outcomes measured. The quality of the research would be considerably enhanced by focused assessments of beef intake (and not red meat in general) and specific cognitive domains, along with improved adherence to reporting standards.

Identifying self-reported health-related problems in home-based rehabilitation of older patients after hip replacement in China: a machine learning study based on Omaha system theory

BACKGROUND

With the aging of the population, the number of total hip replacement surgeries is increasing globally. Hip replacement has undergone revolutionary advancements in surgical methods and materials. Due to the short length of hospitalization, rehabilitation care is mainly home-based. The needs and concerns about such home-based rehabilitation are constantly changing, requiring continuous attention.

OBJECTIVE

To explore effective methods for comprehensively identifying older patients' self-reported outcomes after home-based rehabilitation for hip replacement, in order to develop appropriate intervention strategies for patient rehabilitation care in the future.

METHODS

This study constructed a corpus of patients' self-reported rehabilitation care problems after hip replacement, based on the Omaha classification system. This study used the Python development language and implemented artificial intelligence to match the corpus data on the cooperation platform, to identify the main health-related problems reported by the patients, and to perform statistical analyses.

RESULTS

Most patients had physical health-related problems. More than 80% of these problems were related to neuromusculoskeletal function, interpersonal relationships, pain, health care supervision, physical activity, vision, nutrition, and residential environment. The most common period in which patients' self-reported problems arose was 6 months post-surgery. The relevant labels that were moderately related to these problems were: Physiology-Speech and Language and Physiology-Mind (r = 0.45), Health-Related Behaviors-Nutrition and Health-Related Behaviors-Compliance with Doctors' Prescription (r = 0.40).

CONCLUSION

Physiological issues remain the main health-related issues for home-based rehabilitation after hip replacement in older patients. Precision care has become an important principle of rehabilitation care. This study used a machine learning method to obtain the largest quantitative network data possible. The artificial intelligence capture was fully automated, which greatly improved efficiency, as compared to manual data entering.

Examining the heterogeneity by employment status in dynamics between BMI and cognition: a longitudinal cohort study of the Korean aging population

PURPOSE

This study investigated the potential heterogeneity by employment status in the relationship between body mass index (BMI) trajectory and cognitive function among an aging population.

METHODS

We analyzed 2010-2018 cohort data from the Korean Longitudinal Study of Aging involving 4889 individuals aged over 45. We used statistical techniques of quadratic terms, interaction terms, time-invariant unobserved fixed effects, and time-lag effects to estimate the dynamic and interactive relationships among study variables.

RESULTS

The effect of BMI on cognitive function was heterogeneous based on employment status. For the nonemployed group, the impact of BMI on cognitive function showed an inverted U-shape with a turning point (BMI 25); a higher BMI (up to 25) was associated with higher cognitive function, but further increases beyond this threshold led to decreased cognitive function. For the employed group, however, the impact of BMI on cognitive function was nonsignificant. The nonlinear effect of BMI on cognitive function for the nonemployed group was robust across various subgroups and specifications.

CONCLUSIONS

The findings highlight the risk of obesity (BMI ≥ 25) on cognitive decline, particularly among nonemployed individuals. This illuminates the critical role of labor activity in regulating the impact of BMI on cognitive function among an aging population.

Evaluation of Dietary Intake in Individuals with Mild Cognitive Impairment

The phase of mild cognitive impairment (MCI) holds significant importance for postponing the onset of dementia. Therefore, MCI has become a central focus in research related to dementia prevention. The purpose of this study was to investigate the dietary intake and dietary patterns of MCI patients in Taiwan. In total, 40 subjects were enrolled in this cross-sectional study that was conducted from July 2019 to September 2021 at the Linkou Chang Gung Memorial Hospital. The results of the clinical dementia rating (CDR) and mini-mental state examination (MMSE) were obtained from medical records. Participants were divided into two groups: a healthy group (MMSE ≥ 26 points, CDR = 0) and an MCI group (MMSE ≥ 26 points, CDR = 0.5). Results indicated that the MCI group had significantly higher copper and lower low-fat meat intake compared to the healthy group. Furthermore, the high MIND (Mediterranean dietary approaches to stop hypertension intervention for neurodegenerative delay) diet score represented a lower risk of MCI. After adjusting for age, gender, diabetes mellitus, hypertension, and calorie intake in the multivariate regression analysis, calcium and fruit intake levels were positively associated with the MMSE, whereas low-fat meat intake was negatively associated with the CDR. In conclusion, the prevalence of MCI demonstrated a close correlation with nutrient intake, including copper and calcium. Furthermore, a MIND diet, particularly one high in n-3 polyunsaturated fatty acids, might be useful for preventing MCI. However, more extensive research with larger populations is needed to confirm this potential.

Correlation among sleep quality, physical frailty and cognitive function of the older adults in China: the mediating role

Objective

To explore the correlation among sleep quality, physical frailty, and cognitive function in the older adults in community, and to explore the mediating role of sleep quality.

Methods

A total of 1,182 community-based older adults were investigated with frailty phenotype (FP), Pittsburgh sleep quality index (PISQI), Montreal cognitive assessment (MoCA) and self-made general information questionnaire.

Results

The incidence of physical frailty among the older adults in the community was 25.8% and the incidence of cognitive decline was 19.5%. Cognitive function was negatively correlated with physical frailty (r = -0.236, p < 0.01) and sleep quality (r = -0.558, p < 0.01). Sleep quality was positively correlated with physical frailty (r = 0.337, p < 0.01).

Conclusion

The physical frailty of the older adults has a direct prediction effect on cognitive function, and is regulated by the mediating role of sleep quality. Sleep quality partially mediates the relationship between cognitive dysfunction and physical frailty, which is a new insight into the study of cognition and physical frailty in the older adults. In the future, we can take measures to improve the sleep quality of the older adults, so as to reduce the occurrence of cognitive dysfunction and physical frailty of the older adults.

The Relationship between Whole-Grain Intake and Measures of Cognitive Decline, Mood, and Anxiety-A Systematic Review

Greater intake of whole grains, compared to refined grains, is consistently associated with a reduced risk of cardiovascular disease and type 2 diabetes, both of which are associated with cognitive decline. To better understand the relationship between whole-grain intake, cognition, mood, and anxiety, a systematic review was conducted to synthesize available evidence linking whole grains to these outcomes. Four electronic databases were searched from inception to August 2021 for potentially relevant observational and interventional studies. Risk of bias (RoB) assessments were performed using the newly developed Nutrition Quality Evaluation Strengthening Tools, and the Grades of Recommendation, Assessment, Development, and Evaluation approach was used to determine the strength of evidence for each outcome. In total, 23 studies [4 randomized controlled trials (RCTs) and 19 observational studies] met the predefined eligibility criteria. Of these,12 studies included analysis of whole-grain intake and cognitive decline, 9 included mood outcomes, and 2 included both cognition and mood outcomes. The overall evidence for an association between whole-grain intake and cognition is inconclusive. With respect to mood outcomes, evidence from RCTs prospective cohort and case-control studies suggest that higher intake is linked to improved outcomes for mood and depression although the evidence is mixed for cross-sectional studies. Reporting of whole-grain intake fell short of suggested standards, and the strength of available evidence was low or very low for all outcomes. A high RoB toward studies reporting results was also noted, complicating both the interpretation of some studies and the combined evidence. Of note, few well-designed RCTs assessing the effect of whole-grain intake on measures of cognition, mood, and anxiety were identified, highlighting the need for more studies in this area. The available, although limited, evidence suggests that greater whole-grain intake is associated with better mood and anxiety-related scores and is inconclusive regarding cognitive outcomes. PROSPERO registration: CRD42021266355.

Impact of Nut Consumption on Cognition across the Lifespan

Cognitive health is a life-long concern affected by modifiable risk factors, including lifestyle choices, such as dietary intake, with serious implications for quality of life, morbidity, and mortality worldwide. In addition, nuts are a nutrient-dense food that contain a number of potentially neuroprotective components, including monounsaturated and polyunsaturated fatty acids, fiber, B-vitamins, non-sodium minerals, and highly bioactive polyphenols. However, increased nut consumption relates to a lower cardiovascular risk and a lower burden of cardiovascular risk factors that are shared with neurodegenerative disorders, which is why nuts have been hypothesized to be beneficial for brain health. The present narrative review discusses up-to-date epidemiological, clinical trial, and mechanistic evidence of the effect of exposure to nuts on cognitive performance. While limited and inconclusive, available evidence suggests a possible role for nuts in the maintenance of cognitive health and prevention of cognitive decline in individuals across the lifespan, particularly in older adults and those at higher risk. Walnuts, as a rich source of the plant-based polyunsaturated omega-3 fatty acid alpha-linolenic acid, are the nut type most promising for cognitive health. Given the limited definitive evidence available to date, especially regarding cognitive health biomarkers and hard outcomes, future studies are needed to better elucidate the impact of nuts on the maintenance of cognitive health, as well as the prevention and management of cognitive decline and dementia, including Alzheimer disease.

Association between Micronutrient-Related Dietary Pattern and Cognitive Function among Persons 55 Years and Older in China: A Longitudinal Study

Appropriate dietary patterns for preserving cognitive function in China remains unknown. This study explored the association between dietary pattern and cognitive function in the Chinese population. A total of 6308 adults aged 55 and above who participated in the China Health and Nutrition Survey at least two waves from 1997 to 2018 were selected. The dietary pattern was determined using the reduced rank regression method with responses regarding vitamin C, vitamin E, zinc, iron, copper, and selenium intakes. We used a three-level random coefficient model to evaluate the association. A "vegetable-pork" dietary pattern characterized by high intakes of Legume products, vegetables, fruits, nuts, pork, fish, and plant oil was identified. Compared to the first quartile (Q1) of dietary scores, the regression coefficients (p value) for the global cognitive score across Q2, Q3, and Q4 were 0.27 (p = 0.030), 0.45 (p < 0.001), and 0.50 (p < 0.001), respectively. The adjusted odds ratios (ORs) and the 95% confidence intervals (CIs) for poor cognition across Q2, Q3, and Q4 were 0.82 (0.73 to 0.93), 0.79 (0.69 to 0.91), and 0.74 (0.63 to 0.86), respectively. The relationship appeared to be stronger among people who were 65 years and older, women, people from the south, and smokers. Higher adherence to the "vegetable-pork" diet is associated with better cognitive function among Chinese elders.

Gender differences in the correlation between body mass index and cognitive impairment among the community-dwelling oldest-old in China: a cross-sectional study

OBJECTIVE

This study investigates gender differences in the correlation between body mass index (BMI) and cognitive impairment among Chinese community-dwelling oldest-old.

SETTING

Twenty-three provinces in China. Participants' mini-mental state examination (MMSE) scores <24 were considered cognitive impairment. Furthermore, the assessment standards of BMI status were classified into four categories: obese (BMI >30), overweight (25≤BMI≤30), normal (18.5≤BMI<25) and underweight (BMI <18.5).

PARTICIPANTS

A total of 9218 older adults (age 80+) were included from the 2018 wave of Chinese Longitudinal Healthy Longevity Study.

METHODS

Cognitive impairment, BMI and other covariates consisted of the sociodemographic variables, health behaviours and health status were collected. Cognitive impairment was assessed by the MMSE. Inverse probability weighting procedure was adopted to deal with bias due to dropout.Logistic regression was conducted to examine the correlation between BMI and cognitive impairment.

RESULTS

Among 9218 respondents, 3837 were males. Overall, the percentage of participants with cognitive impairment was 44.7%, with 32.1% among males and 53.7% among females. After controlling for other variables, males who were either overweight or underweight and females who were underweight were found to have higher risk of cognitive impairment among the oldest-old. Age, education, economic status, physical activity, activities of daily living, hypertension as well as heart disease were the predicting factors of cognitive impairment.

CONCLUSIONS

The relationship between BMI and cognitive impairment differs between male and female oldest-old, suggesting that we should pay attention to different BMI groups and adopt precise prevention strategies based on gender.

Plant-based dietary patterns and cognitive function: A prospective cohort analysis of elderly individuals in China (2008-2018)

INTRODUCTION

Plant-based diets confer health benefits, especially on the prevention of noncommunicable diseases. The relationship between plant-based dietary patterns on cognitive function as a neurological outcome needs more evidence. We aimed to assess the associations between plant-based dietary patterns and cognitive function among Chinese older adults.

METHODS

We used four waves (2008-2018) of the Chinese Longitudinal Healthy Longevity Survey. We included 6136 participants aged 65 years and older with normal cognition at baseline. We constructed an overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI) from questionnaires. We used the Mini-Mental State Examination (MMSE) to assess cognitive function. We used the multivariable-adjusted generalized estimating equation to explore the corresponding associations.

RESULTS

The multivariable-adjusted models showed inverse associations between plant-based dietary patterns and cognitive function. The highest quartiles of PDI and hPDI were associated with a 55% (odds ratio [OR] = 0.45, 95% CI: 0.39, 0.52) decrease and a 39% (OR = 0.61, 95% CI: 0.54, 0.70) decrease in the odds of cognitive impairment (MMSE < 24), compared with the lowest quartile. In contrast, the highest quartile of uPDI was associated with an increased risk (OR = 2.03, 95% CI: 1.79, 2.31) of cognitive impairment. We did not observe pronounced differences by selected socioeconomic status, physical activity, residential greenness, and APOE ε4 status.

CONCLUSIONS

Our findings suggested that adherence to healthy plant-based dietary patterns was associated with lower risks of cognitive impairment among older adults, and unhealthy plant-based dietary patterns were related to higher risks of cognitive impairment.

The evolutionary trends of health inequality among elderly Chinese people and influencing factors of these trends from 2005 to 2017

Reducing health inequality and ensuring national health equity have become issues of great concern to all countries in the world. This paper based on the ordered Probit model and concentrated index decomposition method, analysed the influencing factors and evolution trend of health inequality among the elderly with high age in China from 2005 to 2017. The study found that in 2005-2017, the self-rated health distribution of the elderly with high age in China showed an obvious inverted "U" shape, with the proportion of general and relatively healthy being the largest, while the proportion of unhealthy and very healthy was lower. Lifestyle, family income, and age were the main important factors to expand health inequality. Therefore, encouraging the elderly with high age to develop good living habits and narrowing the income gap of the elderly are conducive to solving the health inequality of the elderly with high age and achieving the goals of active ageing and healthy ageing.

Blood glucose mediated the effects of cognitive function impairment related to aluminum exposure in Chinese aluminum smelting workers

OBJECT

To explore the effects of occupational aluminum exposure on workers' cognitive function and blood glucose concentration, and to analyze whether blood glucose concentration can mediate the cognitive changes caused by aluminum.

METHOD

Our study recruited 375 workers from an aluminum factory in northern China. We collected the fasting elbow venous blood of the workers, measured their fasting blood glucose concentration (FBG), and used ICP-MS to determine plasma aluminum concentration (P-Al) as an indicator of internal exposure. The Montreal Cognitive Assessment (MoCA), was used to assess the cognitive function of workers. Generalized linear model was used to analyze the association of P-Al with cognitive function and blood glucose concentration, and the restricted cubic spline model was used to fit the dose-response relationship. We also conducted a mediation effect analysis.

RESULT

We observed the dose-response relationship, that is, as the P-Al increased, sum of MoCA, visuospatial/executive, naming, language, and abstraction scores decreased, and the blood glucose concentration increased. For every e-fold increase in P-Al, sum of MoCA, visuospatial/executive, naming, language, and abstraction scores decreased by 0.328 points, 0.120 points, 0.059 points, 0.060 points, and 0.083 points, respectively, and FBG rose by 0.109 mmol/L. FBG has a significant mediating effect between P-Al and sum of MoCA (P for mediator=0.042), and it could explain 10.7% of the effect of cognitive level related to P-Al.

CONCLUSION

Occupational aluminum exposure negatively affected the cognitive function of workers and positively affected FBG. FBG may partially explain the impact of occupational aluminum exposure on workers' cognitive function.

Causal Relationships Between Relative Intake from the Macronutrients and Alzheimer's Disease: A Two-Sample Mendelian Randomization Study

BACKGROUND

Some observational studies indicated the associations of relative carbohydrate, sugar, fat, and protein intake and Alzheimer's disease (AD). But it remains unclear whether the associations are causal.

OBJECTIVE

This study aimed to identify the effects of relative carbohydrate, sugar, fat, and protein intake in the diet on AD.

METHODS

A two-sample Mendelian randomization was employed. Finally, 14 independent lead SNPs remained in the Social Science Genetic Association Consortium. These SNPs of relative carbohydrate, sugar, fat, and protein intake at the level of genome-wide significance (p <  5×10-8) were used as instrumental variables. The summary data for AD were acquired from the International Genomics of Alzheimer's Project with a total of 54,162 individuals (17,008 AD patients and 37,154 control participants).

RESULTS

This two-sample Mendelian randomization indicated that increased relative protein intake (per 1 standard deviation) causally decreased the AD risk (OR = 0.48, 95% CI: 0.24-0.95, p = 0.036), and increased relative fat intake may decrease the risk of AD (OR = 0.22, 95% CI: 0.06-0.86, p = 0.029). No statistical significance with AD risk was seen for relative carbohydrate or relative sugar intake.

CONCLUSION

A higher relative intake of protein can causally reduce the risk of AD in the elderly. Additionally, a higher relative intake of fat may be protective against AD. No evidence showed that AD was associated with relative carbohydrate and sugar intake.

Metabolic Syndrome, Cognitive Impairment and the Role of Diet: A Narrative Review

Background: This narrative review presents the association between metabolic syndrome (MetS), along with its components, and cognition-related disorders, as well as the potential reversal role of diet against cognitive impairment by modulating MetS. Methods: An electronic research in Medline (Pubmed) and Scopus was conducted. Results: MetS and cognitive decline share common cardiometabolic pathways as MetS components can trigger cognitive impairment. On the other side, the risk factors for both MetS and cognitive impairment can be reduced by optimizing the nutritional intake. Clinical manifestations such as dyslipidemia, hypertension, diabetes and increased central body adiposity are nutrition-related risk factors present during the prodromal period before cognitive impairment. The Mediterranean dietary pattern stands among the most discussed predominantly plant-based diets in relation to cardiometabolic disorders that may prevent dementia, Alzheimer’s disease and other cognition-related disorders. In addition, accumulating evidence suggests that the consumption of specific dietary food groups as a part of the overall diet can improve cognitive outcomes, maybe due to their involvement in cardiometabolic paths. Conclusions: Early MetS detection may be helpful to prevent or delay cognitive decline. Moreover, this review highlights the importance of healthy nutritional habits to reverse such conditions and the urgency of early lifestyle interventions.

Vegetable and Fruit Intake, Its Patterns, and Cognitive Function: Cross-Sectional Findings among Older Adults in Anhui, China

OBJECTIVES

To examine the associations of vegetable and fruit intake frequency, its patterns, and cognition among older Chinese adults.

DESIGN

Cross-sectional data obtained from the Anhui Province Healthy Longevity Survey.

SETTING

Urban and rural communities.

PARTICIPANTS

A total of 5410 older adults (aged 60 or older) were included from selected communities.

MEASUREMENTS

Data on the number of days in a typical week that vegetables and fruits were consumed were collected, and the four intake patterns were defined (V+/F+: daily intake of both vegetables and fruit; V+/F- or V-/F+: daily intake of vegetables or fruit; and V-/F-: no daily intake of either vegetables or fruit). Cognitive function was measured using the Mini-mental State Examination (MMSE), and mild cognitive impairment (MCI) was defined according to education-specific criteria.

RESULTS

Nondaily vegetable intake was associated with lower MMSE scores (β = -0.763, 95% confidence interval (CI): -1.463, -0.064) among males and a higher likelihood of having MCI (OR: 1.409, 95% CI: 1.037, 1.915) among females. Less frequent intake of fruit was associated with lower MMSE scores and a higher prevalence of MCI among both males and females (p for trends < 0.001 for both sexes). Compared with the V+/F+ group, male participants who were classified into the V+/F- and V-/F- groups had lower MMSE scores (V+/F-: β = -0.612, 95% CI: -1.094, -0.131; V-/F-: β = -1.273, 95% CI: -2.090, -0.455). Females classified in the V+/F- and V-/F- patterns had lower MMSE scores (V+/F-: β = -0.862, 95% CI: -1.320, -0.404; V-/F-: β = -1.293, 95% CI: -2.079, -0.507) and elevated risks of MCI (V+/F-: OR: 1.762, 95% CI: 1.386, 2.242; V-/F-: OR: 2.180, 95% CI: 1.505, 3.156).

CONCLUSION

Lower vegetable or fruit intake was associated with poorer cognitive performance among males and females, and the risk was even higher among those with a low intake of both vegetables and fruits. Healthy eating habits, including daily vegetable and fruit intake, are essential for cognition maintenance in both males and females.

Whole egg consumption and cognitive function among US older adults

BACKGROUND

Eggs are an affordable food providing many shortfall nutrients with the potential to improve cognitive health. We assessed the relationship between whole egg consumption and cognitive functioning among a US nationally representative sample of older adults.

METHODS

Individual-level data (2816 adults, aged ≥ 60 years) were obtained from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 waves. Cognitive assessments included the Consortium to Establish a Registry for Alzheimer's Disease Word List Learning Test (CERAD-WL), Word List Recall Test (CERAD-DR), Animal Fluency Test (AF) and Digit Symbol Substitution Test (DSST). A composite cognitive z-score was constructed based on the individual tests to represent one's overall cognitive functioning. Multiple linear and logistic regressions were performed to examine the effect of whole egg consumption on cognitive functioning, adjusting for individual characteristics and survey design.

RESULTS

Approximately 57% of older adults consumed whole eggs, with an average daily intake of 34 g of whole egg equivalent among consumers. The average z-scores of the CERAD-WL, CERAD-DR, AF and DSST tests were -0.08, 0.23, 0.37 and 0.42, respectively, and the overall composite cognitive z-score was 0.24 among older adults. Regression analyses found that neither whole egg consumption status, nor daily intake quantity was associated with cognitive test scores.

CONCLUSIONS

No association was found between whole egg consumption and cognitive functioning among US older adults. Study limitations included cross-sectional study design and measurement errors. Future studies with longitudinal or experimental design are warranted to examine the possible link between egg consumption and cognition in older adults.

Nutrition, Physical Activity, and Other Lifestyle Factors in the Prevention of Cognitive Decline and Dementia

Multiple factors combined are currently recognized as contributors to cognitive decline. The main independent risk factor for cognitive impairment and dementia is advanced age followed by other determinants such as genetic, socioeconomic, and environmental factors, including nutrition and physical activity. In the next decades, a rise in dementia cases is expected due largely to the aging of the world population. There are no hitherto effective pharmaceutical therapies to treat age-associated cognitive impairment and dementia, which underscores the crucial role of prevention. A relationship among diet, physical activity, and other lifestyle factors with cognitive function has been intensively studied with mounting evidence supporting the role of these determinants in the development of cognitive decline and dementia, which is a chief cause of disability globally. Several dietary patterns, foods, and nutrients have been investigated in this regard, with some encouraging and other disappointing results. This review presents the current evidence for the effects of dietary patterns, dietary components, some supplements, physical activity, sleep patterns, and social engagement on the prevention or delay of the onset of age-related cognitive decline and dementia.

Dietary Patterns and Mild Cognitive Impairment Risk in Korean Adults over 50 Years Old

The prevalence of age-related diseases such as dementia and cognitive disorders is rapidly increasing. This study aimed to identify the dietary patterns associated with mild cognitive impairment (MCI) in adults aged over 50 years. This cross-sectional study investigated dietary patterns associated with cognitive function among older adults hospitalized in Gwangju province. Global cognitive function was assessed using the Mini-Mental State Examination. Diet information was obtained using a food frequency questionnaire with 112 food items and 24-h dietary recall. Using a principal component analysis, we identified three dietary patterns, “legumes and vegetables”, “beverage and nuts”, and “white rice”. The “beverage and nuts” pattern was inversely associated with the prevalence of high MCI after adjusting for covariates (third vs. first tertile, adjusted odds ratio: 0.333; 95% confidence interval: 0.133∼0.831; P<0.05). The white rice pattern was associated with the prevalence of MCI in the crude analysis. However, after adjusting for all confounding factors, no association was found. The “beverage and nuts” pattern was inversely associated with the prevalence of MCI. In the future, longitudinal population-based studies and randomized clinical trials are required to confirm the effect of potential dietary patterns on cognitive impairment and reveal the underlying mechanism of their association.

Consumption of dietary nuts in midlife and risk of cognitive impairment in late-life: the Singapore Chinese Health Study

BACKGROUND

evidence from prospective studies investigating the association between consumption of nuts in midlife and risk of cognitive impairment in late life is limited.

METHODS

this study analysed data from 16,737 participants in a population-based cohort, the Singapore Chinese Health Study. Intake of nuts was assessed using a validated food-frequency questionnaire at baseline (1993-1998), when participants were 45-74 years old (mean age = 53.5 years). Cognitive function was tested using the Singapore modified Mini-Mental State Examination during the third follow-up visit (2014-2016), when participants were 61-96 years old (mean age = 73.2 years). Cognitive impairment was defined using education-specific cut-off points. Logistic regression models were used to estimate the odds ratio (OR) and the 95% confidence interval (CI) for the association between intake and risk of cognitive impairment.

RESULTS

cognitive impairment was identified in 2,397 (14.3%) participants. Compared with those who consumed <1 serving/month of nuts, participants who consumed 1-3 servings/month, 1 serving/week and ≥2 servings/week had 12% (95% CI 2-20%), 19% (95% CI 4-31%) and 21% (2-36%) lower risk of cognitive impairment, respectively (P-trend = 0.01). Further adjustment for intake of unsaturated fatty acids attenuated the association to non-significance. Mediation analysis showed that the 50.8% of the association between nuts and risk of cognitive impairment was mediated by the intake of total unsaturated fatty acids (P < 0.001).

CONCLUSION

higher intake of nuts in midlife was related to a lower risk of cognitive impairment in late life, which was partly mediated by unsaturated fatty acids.

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.

Diet-Cognition Associations Differ in Mild Cognitive Impairment Subtypes

Cognitive function is not generally associated with diet, and there is debate over that association. Moreover, little is known about such associations with the specific cognitive domains and subtypes of mild cognitive impairment (MCI). We analyzed data of 4309 Chinese adults aged 55 and over from the Community-based Cohort Study on Nervous System Diseases from 2018–2019. Dietary habits were assessed at inclusion using a validated semi-quantitative food frequency questionnaire. Cognitive function of the participants was measured by using the Montreal Cognitive Assessment. Analyses were performed using multiple logistic regression and quantile regression with adjustment for socio-demographic, lifestyle, and health-related factors. Compared with normal cognition participants, those with a worse cognition state were characterized as being an older age and lower economic level. After adjustment for potential factors, participants with higher consumption of rice, legumes, fresh vegetables, fresh fruit, pork, poultry, fish, and nuts tended to have higher scores of global cognitive function and domains, and to have lower odds of MCI, while those with higher consumption levels of wheat and eggs had worse cognition, compared with the corresponding bottom consumption level of each food. Participants with a medium consumption level of beef or mutton had 57% (OR: 1.57, 95%CI: 1.07–2.32) higher odds of aMCI-SD, whereas they had 50% (OR: 0.50, 95%CI: 0.34–0.73) lower odds of naMCI-MD. Similarly, the highest consumption level of dairy was positively associated with the odds of aMCI-SD (OR:1.51, 95%CI:1.00–2.29), but inversely linked to the odds of naMCI-SD (OR: 0.60, 95%CI: 0.38–0.93) and naMCI-MD (OR: 0.49, 95%CI: 0.29–0.82). Most diet global cognitive benefits were observed to be associated with the preexisting higher consumption of rice, legumes, fresh vegetables, fresh fruit, meat, and nuts. In addition, the heterogeneity of associations between the consumption of certain foods and MCI subtypes was observed among Chinese adults aged over 55 years. These cross-sectional observations require validation in prospective studies.

Sex differences in the association between latent class of lifestyle and disability among older adults in China

Background

A healthy lifestyle may prevent disability for older adults. But research to date is limited to a single lifestyle behavior and ignore sex difference in the lifestyle-disability association. This study aimed at identifying sex-specific latent classes of lifestyle and their relationship with disability among older Chinese adults.

Methods

Data were obtained from adults aged 65 years or above in the 2018 Chinese Longitudinal Healthy Longevity Survey, a nationally representative sample of older adults in China. We used latent class analysis to categorize participants into subgroups based on three dimensions of lifestyle factors: health behaviors, psychological wellbeing, and social engagement. Disability was assessed by the activities of daily living (ADL). Multivariable logistic regression was used to evaluate the associations between the latent lifestyle classes and disability.

Results

A total of 15,771 older adults were included in this analysis, of whom 56% were women and 66% aged 80 years or above. We identified four latent lifestyle classes among older women: “Health Promoting” (28%), “Isolated and Health Harming” (34%), “Restless and Dismal” (21%), and “Restless” (17%). A different set of four lifestyle classes were identified in older men: “Health Promoting” (21%), “Isolated and Health Harming” (26%), “Restless and Dismal” (20%), and “Discordant” (33%). Compared with the “Health Promoting” class, the “Isolated and Health Harming” class (OR = 1.88, 95% CI: 1.46–2.43) and the “Restless and Dismal” class (OR = 1.67, 95% CI: 1.27–2.20) had higher risk of disability in women. The “Discordant” class had lower risk of disability in men (OR = 0.52, 95% CI: 0.37–0.72).

Conclusions

Our analyses revealed different lifestyle patterns for older women and men in China. Sex differences in the associations between lifestyle and disability need to be considered when formulating interventions to prevent disability.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-021-02087-z.

Nuts and Older Adults' Health: A Narrative Review

Although the beneficial effects of nuts on cardiometabolic diseases have been well established, little is known about the effects of nuts on age-related diseases. Given that age-related diseases share many biological pathways with cardiometabolic diseases, it is plausible that diets rich in nuts might be beneficial in ameliorating age-related conditions. The objective of this review was to summarise the findings from studies that have examined the associations or effects of nut consumption, either alone or as part of the dietary pattern, on three major age-related factors—telomere length, sarcopenia, and cognitive function—in older adults. Overall, the currently available evidence suggests that nut consumption, particularly when consumed as part of a healthy diet or over a prolonged period, is associated with positive outcomes such as longer telomere length, reduced risk of sarcopenia, and better cognition in older adults. Future studies that are interventional, long-term, and adequately powered are required to draw definitive conclusions on the effects of nut consumption on age-related diseases, in order to inform dietary recommendations to incorporate nuts into the habitual diet of older adults.

Nutrition, Gut Microbiota, and Alzheimer's Disease

Nutrition is known to play an important role in the pathogenesis of Alzheimer's disease. Evidence is obtained that the gut microbiota is a key player in these processes. Dietary changes (both adverse and beneficial) may influence the microbiome composition, thereby affecting the gut-brain axis and the subsequent risk for Alzheimer's disease progression. In this review, the research findings that support the role of intestinal microbiota in connection between nutritional factors and the risk for Alzheimer's disease onset and progression are summarized. The mechanisms potentially involved in these processes as well as the potential of probiotics and prebiotics in therapeutic modulation of contributed pathways are discussed.

Nut Consumption for Cognitive Performance: A Systematic Review

Diet is considered an important modifiable lifestyle factor capable of attenuating early cognitive changes in healthy older people. The inclusion of nuts in the diet has been investigated as a dietary strategy for maintenance of brain health across the lifespan. This review aimed to present up-to-date evidence regarding the association between nut intake and cognitive performance. Four databases (Ovid MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature (CINAHL) Plus, and Embase) were systematically searched from inception to April 2020. Eligible articles were interventional or observational studies in humans aged ≥18 y that measured the effects (or association) of nuts (almond, hazelnut, macadamia, pistachio, walnut, pecan, pine nut, Brazil nut, cashew, peanut) on cognitive outcomes. Out of the 2374 articles identified in the searches, 22 involving 43,793 participants met the criteria and were ultimately included in this review. Memory (immediate and delayed), attention, processing speed, executive function, and visual-spatial ability, as well as risk of mild cognitive impairment, were the outcomes investigated. Lack of consistency across the studies regarding study design, types of nut used, and cognitive outcomes measured resulted in inconsistent evidence that the regular consumption of mixed nuts has a protective effect on cognition in adults of different ages. Nonetheless, we observed that studies targeting populations with a higher risk of cognitive decline tended to find a more favorable outcome. Furthermore, homogeneous findings were observed in the studies that specifically addressed the association between walnut consumption and cognitive performance: out of the 6 studies, including 2 randomized controlled trials, only 1 did not find a positive association.

Genetic and non-genetic factors associated with the phenotype of exceptional longevity & normal cognition

In this study, we split 2156 individuals from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) data into two groups, establishing a phenotype of exceptional longevity & normal cognition versus cognitive impairment. We conducted a genome-wide association study (GWAS) to identify significant genetic variants and biological pathways that are associated with cognitive impairment and used these results to construct polygenic risk scores. We elucidated the important and robust factors, both genetic and non-genetic, in predicting the phenotype, using several machine learning models. The GWAS identified 28 significant SNPs at p-value [Formula: see text] significance level and we pinpointed four genes, ESR1, PHB, RYR3, GRIK2, that are associated with the phenotype though immunological systems, brain function, metabolic pathways, inflammation and diet in the CLHLS cohort. Using both genetic and non-genetic factors, four machine learning models have close prediction results for the phenotype measured in Area Under the Curve: random forest (0.782), XGBoost (0.781), support vector machine with linear kernel (0.780), and [Formula: see text] penalized logistic regression (0.780). The top four important and congruent features in predicting the phenotype identified by these four models are: polygenic risk score, sex, age, and education.

Association of Circulating Cholesterol Level with Cognitive Function and Mild Cognitive Impairment in the Elderly: A Community-based Population Study

Background:

The present study was designed to examine the association of circulating cholesterol with cognitive function in non-demented community aging adults.

Methods:

This was a cross-sectional study including 1754 Chinese adults aged 55-80 years. The association between serum cholesterol levels and cognitive function was examined. Participants were categorized into four groups according to the quartile of circulating TC (total cholesterol), High Density Lipoprotein Cholesterol (HDL-c), Low Density Lipoprotein Cholesterol (LDL-c) levels and HDLc/ LDL-c ratio. The difference in cognitive performance among the groups was compared. Logistic regression model was used to determine the association of circulating cholesterol level with the risk of Mild Cognitive Impairment (MCI).

Results:

Mild increase of serum LDL-c level correlated with better visual and executive, language, memory and delayed recall abilities. Higher circulating TC and HDL-c levels were found to be associated with poorer cognitive function, especially in aging female subjects. Higher circulating TC, HDL-c and HDL/LDL ratio indicated an increased risk of MCI, especially in female subjects.

Conclusion:

Slight increase in circulating LDL-c level might benefit cognitive function in aging adults. However, higher circulating TC and HDL-c levels might indicate a decline of cognitive function, especially in aging female subjects.

"Influence of diet on mood and social cognition: a pilot study"

Recently, a relationship has been observed between nutrition and social cognition. In this aspect, several dietary patterns, or even some probiotics, have been reported as social cognition modulators. However, to date, no studies have reported the effects of specific nutrients. Our aim was to evaluate the relationship between dietary macronutrients and the processing of social and affective information. Participants were undergraduates from the University of Extremadura (Badajoz, Spain) aged 21.3 ± 2.9 years., with a BMI of 22.8 ± 3.9 (kg m-2). The students' social cognition and diet were analysed through questionnaires and a dietary record. The diets were analysed with DIAL v.1.18® software (Alce Ingeniería®). The participants filled out the WHO-5 well-being index, Beck's anxiety inventory, Beck's depression inventory, ruminative response scale (RSS), Leiden index of depression sensitivity (LEIDS-r), empathy quotient (EQ), and interpersonal reactivity index (IRI). To analyse the data, nutrients were grouped through principal component analysis (PCA) into lipids, carbohydrates and proteins. Additionally, we assayed if these principal components were associated with psychological questionnaire scores using multiple linear regression analyses. The dietary pattern differed from the traditional Mediterranean diet due to high intake of proteins and saturated fatty acids. Regarding social cognition and macronutrients, we found a positive association between lipids, specifically cholesterol, and the Perspective-Taking Scale (an IRI component). Carbohydrates influenced the RSS, indicating that complex carbohydrates may be a risk factor for depression. Moreover, the brooding factor, a component of the RRS, was negatively affected by dietary carbohydrates and proteins, specifically by fiber and aspartate. Diet may influence several variables related to social cognition and mood. Particularly, a low-cholesterol diet rich in fiber, complex carbohydrates, and aspartate apparently provides benefits, improving the processing of social and affective information and psychic well-being.

Dietary patterns are related to cognitive functioning in elderly enriched with individuals at increased risk for Alzheimer's disease

Purpose

To investigate cross-sectional associations between dietary patterns and cognitive functioning in elderly free of dementia.

Methods

Data of 389 participants from the German DELCODE study (52% female, 69 ± 6 years, mean Mini Mental State Score 29 ± 1) were included. The sample was enriched with elderly at increased risk for Alzheimer’s disease (AD) by including participants with subjective cognitive decline, mild cognitive impairment (MCI) and siblings of AD patients. Mediterranean and MIND diets were derived from 148 Food Frequency Questionnaire items, and data-driven patterns by principal component analysis (PCA) of 39 food groups. Associations between dietary patterns and five cognitive domain scores were analyzed with linear regression analyses adjusted for demographics (model 1), and additionally for energy intake, BMI, other lifestyle variables and APOe4-status (model 2). For PCA-derived dietary components, final model 3 included all other dietary components.

Results

In fully adjusted models, adherence to Mediterranean and MIND diet was associated with better memory. The ‘alcoholic beverages’ PCA component was positively associated with most cognitive domains. Exclusion of MCI subjects (n = 60) revealed that Mediterranean and MIND diet were also related to language functions; associations with the alcoholic beverages component were attenuated, but most remained significant.

Conclusion

In line with data from elderly population samples, Mediterranean and MIND diet and some data-derived dietary patterns were related to memory and language function. Longitudinal data are needed to draw conclusions on the putative effect of nutrition on the rate of cognitive decline, and on the potential of dietary interventions in groups at increased risk for AD.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02257-6) contains supplementary material, which is available to authorized users.

Meat Consumption, Cognitive Function and Disorders: A Systematic Review with Narrative Synthesis and Meta-Analysis

Cognitive impairment, Alzheimer's disease, and other forms of dementia are increasing in prevalence worldwide, while global dietary patterns are transitioning to a 'western type' with increasing meat consumption. Studies which have explored the associations between cognitive function and meat intakes have produced inconsistent findings. The aim of this systematic review was to explore the evidence linking meat intake with cognitive disorders. Twenty-nine studies were retrieved, including twelve cohort, three case-control, thirteen cross-sectional studies, and one intervention study. The majority (21/29) showed that meat consumption was not significantly associated with cognitive function or disorders. Meta-analysis of five studies showed no significant differences in meat consumption between cases with cognitive disorders and controls (standardized mean difference = -0.32, 95% CI: -1.01, 0.36); however, there was considerable heterogeneity. In contrast, a meta-analysis of five studies showed reduced odds of cognitive disorders by consuming meat weekly or more (OR = 0.73, 95% CI: 0.57, 0.88); however, potential publication bias was noted in relation to this finding. Overall, there was no strong association between meat intake and cognitive disorders. However, the evidence base was limited, requiring more studies of high quality to isolate the specific effect of meat consumption from dietary patterns to confirm these associations.

Association between physical activity and cognition in Mexican and Korean older adults

Introduction:

As the world’s population ages, the prevalence of cognitive impairment associated with age increases. This increase is particularly pronounced in Asia and South-America. The objective of this study was to investigate separately the longitudinal association of physical activity and cognitive function in; older adults in Mexico and South Korea.

Materials and Methods:

This is a secondary analysis of two surveys, The Mexican Health and aging Study (MHAS) (n = 5853) and Korean Longitudinal Study of aging (KLoSA) (n = 5188), designed to study the aging process of older adults living in Mexico and South Korea. Participants older than 50 years were selected from rural and urban areas achieving a representative sample. Physical activity was assessed using self-report. Cognition was assessed using Cross-Cultural Cognitive Examination (CCCE) and Minimental state examination (MMSE) in Mexico and South Korea respectively. Here we investigate the longitudinal association between physical activity and cognition during 3 years for MHAS and 4 years for KLoSA using multiple linear regression analyses.

Results:

The prevalence of physical activity was 40.68 % in MHAS and 35.57 % in KLoSA. In the adjusted longitudinal multivariate analysis, an independent association was found between physical activity and MMSE score OR 0.0866 (CI 0.0266-0.1467 p-value 0.0047) in the Korean older adults, while there was no significant association in MHAS.

Conclusions:

Physical activity could have a protective effect on the cognitive decline associated with aging in the Korean population.

Association of Circulating Retinol and α-TOH Levels with Cognitive Function in Aging Subject with Type 2 Diabetes Mellitus

OBJECTIVES

Malnutrition of vitamin A (retinol) and vitamin E (α-tocopherol, α-TOH) was observed in type 2 diabetes mellitus (T2DM) or dementia patients. However, how these vitamins affect cognitive function of subjects with T2DM was seldom reported. The objective of this study was to determine the association of circulating retinol and α-TOH with cognition in aging subjects with T2DM.

METHODS

A total of 448 T2DM subjects and 448 age, gender and education matched control subjects (aged 55-75 years) were included in the study. Demographic characters of the participants were collected. Food frequency questionnaire (FFQ) method was used to collect dietary intake information. To assess the status of cognition, the MoCA test was used. Circulating retinol and α-TOH levels were compared between T2DM and non-T2DM subjects. Correlation of circulating retinol and α-TOH levels with cognitive function was analyzed in T2DM subjects. The effect of serum retinol and α-TOH levels on the risk of MCI in T2DM patients was explored.

RESULTS

We found that T2DM-MCI subjects demonstrate lower serum retinol level than T2DM-nonMCI subjects (P < 0.01). Serum retinol level was positively correlated to cognitive function in T2DM subject (P < 0.05). T2DM subjects with higher circulating retinol level demonstrate higher cognitive scores in visual and executive, attention, language, memory and delayed recall domains (P < 0.05).

CONCLUSION

Diminished circulating retinol predicts an increased risk of MCI in T2DM patients. Our findings provide suggestions that optimal retinol nutritional status might benefit cognition and decrease the risk of MCI in aging subjects with T2DM.

A healthy diet and physical activity are important to promote healthy ageing among older Chinese people

Objective

To examine the associations between multiple health behaviours and health outcomes among older Chinese adults.

Methods

Data from the World Health Organization’s Study on global AGEing and adult health Wave 1 (2007–2010), collected among the older Chinese population, were included in this study. Smoking, diet, and physical activity were analysed by linear regression for any associations with depressive symptoms, quality of life (QoL), cognitive function, and physical function.

Results

A total of 13 367 participants aged >49 years were included in the analyses. After controlling for key socioeconomic factors, healthy diet was significantly associated with higher QoL (β = 0.099) and better cognitive function (β = 0.023). Physical activity was significantly associated with fewer depressive symptoms (β = –0.020), higher QoL (β = 0.086), better cognitive function (β = 0.072), and better physical function (β = –0.155 [higher scores = poorer physical function]). No relationship was found between smoking and any health-related outcome included in this study.

Conclusion

This study demonstrates the importance of healthy diet and physical activity for health outcomes in the older Chinese population.

Associations of dietary choline intake with risk of incident dementia and with cognitive performance: the Kuopio Ischaemic Heart Disease Risk Factor Study

BACKGROUND

Moderate egg intake has been associated with better cognitive performance in observational studies. This association may be due to the rich content of choline, especially phosphatidylcholine, in eggs because choline has been suggested to have a role in the prevention of cognitive decline.

OBJECTIVES

We investigated the associations of dietary choline intake with the risk of incident dementia and with cognitive performance in middle-aged and older men in the prospective, population-based Kuopio Ischaemic Heart Disease Risk Factor Study.

METHODS

A population-based sample of 2497 dementia-free men aged 42-60 y was examined in 1984-1989. A subset of 482 men completed 5 different cognitive performance tests 4 y later. Dementia and Alzheimer disease diagnoses were retrieved from Finnish health registers. Dietary intakes were assessed with the use of 4-d food records at baseline. Cox regression and ANCOVA were used for the analyses. All analyses were also stratified by the apolipoprotein E phenotype (APOE-ε4 compared with other phenotypes). These data were available for 1259 men.

RESULTS

The mean ± SD total choline intake was 431 ± 88 mg/d, of which 188 ± 63 mg/d was phosphatidylcholine. During a 21.9-y follow-up, 337 men were diagnosed with dementia. Those in the highest compared with the lowest phosphatidylcholine intake quartile had 28% (95% CI: 1%, 48%; P-trend = 0.02 across quartiles) lower multivariable-adjusted risk of incident dementia. Total choline intake had no association with the risk of incident dementia. However, both total choline and phosphatidylcholine intakes were associated with better performance in cognitive tests assessing frontal and temporal lobe functioning. For example, higher intakes were associated with better performance in verbal fluency and memory functions. The APOE phenotype had little or no impact on the associations.

CONCLUSION

Higher phosphatidylcholine intake was associated with lower risk of incident dementia and better cognitive performance in men in eastern Finland. This trial was registered at clinicaltrials.gov as NCT03221127.

[Nut consumption and cognitive function: a systematic review]

Introduction

Antioxidant-rich diet patterns could contribute to the prevention and treatment of early stages of dementia. Nuts have an appreciable antioxidant load and there is evidence of their positive effects on several chronic diseases incidence and death rates. Moreover, they are rich in polyunsaturated fatty acids, which might also play a positive role in neurogenesis. The aim of this systematic review was to summarize the evidence from studies related to the effects of nut consumption on cognitive function among adults. We conducted a systematic search of articles published in PubMed, Scopus and Web of Science. A total of 19 articles met the inclusion criteria (seven cross-sectional, four prospective cohorts and eight experimental); these were independently extracted and reviewed by two reviewers. The evidence from the cross-sectional and cohort studies was uncertain, due to the disparity of results and risk of bias. However, in most experimental studies a protective effect of nut consumption on some dimension of cognitive function was observed and the methodological quality of these studies was acceptable. In addition, the effects appear to be independent of nut type, amount of intake, age and baseline status of subjects. In summary, these results suggest that the inclusion of daily nut consumption in the healthy diet pattern of adults could have positive effects on their cognitive function. Nevertheless, more well-designed longitudinal and experimental studies are needed to provide strength to this suggestive evidence.

Dietary Intake of Riboflavin and Unsaturated Fatty Acid Can Improve the Multi-Domain Cognitive Function in Middle-Aged and Elderly Populations: A 2-Year Prospective Cohort Study

Objective

This study was aimed to explore the effects of dietary nutrients on cognitive function among the middle-aged and elderly populations.

Methods

A prospective cohort study of 1,385 middle-aged and elderly people was conducted from January 2014 to December 2017. Dietary nutrients were assessed according to the food frequency questionnaire (FFQ) and China Food Composition Database (CFCD). Montreal cognitive assessment (MoCA) was used to evaluate the participants’ global cognitive function. Six other neuropsychological measures [auditory verbal learning test-immediate recall (AVLT-IR), auditory verbal learning test-short recall (AVLT-SR), auditory verbal learning test-long recall (AVLT-LR), logical memory test (LMT), digit span forward (DST-F), and digit span backward (DST-B)] were used to assess the verbal memory domain and the attention domain by principal component analysis (PCA). Multiple linear regressions were conducted to explore associations between nutrients and cognition. Sensitivity analyses were performed to confirm the results.

Results

Dietary riboflavin was protective for global cognitive function (β = 1.31, 95% CI: 0.26, 2.35) and the verbal memory domain (β = 0.37, 95% CI: 0.02, 0.71). Unsaturated fatty acid (USFA) played a protective role in global cognitive function (β = 1.15, 95% CI: 0.16, 2.14). The protective effects of riboflavin and USFA on cognitive function were consistent and reliable when different confounders were adjusted during sensitivity analyses. During the follow-up, neuropsychological measure scores revealed a reduced decline in the high-riboflavin group (d-MoCA, P = 0.025; d-AVLT-IR, P = 0.001; d-DST-B, P = 0.004; and d-composite score, P = 0.004) and the high-USFA group (d-AVLT-IR, P = 0.007; d-LMT, P = 0.032; d-DST-B, P = 0.002; and d-composite score, P = 0.008).

Conclusion

Higher intake of riboflavin and USFA can improve multi-dimensional cognitive functioning in middle-aged and elderly people. These findings were consistent in different models of sensitivity analyses.

Health Benefits of Nut Consumption in Middle-Aged and Elderly Population

Aging is considered the major risk factor for most chronic disorders. Oxidative stress and chronic inflammation are two major contributors for cellular senescence, downregulation of stress response pathways with a decrease of protective cellular activity and accumulation of cellular damage, leading in time to age-related diseases. This review investigated the most recent clinical trials and cohort studies published in the last ten years, which presented the influence of tree nut and peanut antioxidant diets in preventing or delaying age-related diseases in middle-aged and elderly subjects (≥55 years old). Tree nut and peanut ingestion has the possibility to influence blood lipid count, biochemical and anthropometric parameters, endothelial function and inflammatory biomarkers, thereby positively affecting cardiometabolic morbidity and mortality, cancers, and cognitive disorders, mainly through the nuts’ healthy lipid profile and antioxidant and anti-inflammatory mechanisms of actions. Clinical evidence and scientific findings demonstrate the importance of diets characterized by a high intake of nuts and emphasize their potential in preventing age-related diseases, validating the addition of tree nuts and peanuts in the diet of older adults. Therefore, increased consumption of bioactive antioxidant compounds from nuts clearly impacts many risk factors related to aging and can extend health span and lifespan.

Health Biomarkers in Adults Are More Closely Linked to Diet Quality Attributes Than to Plant-Based Diet Categorization

Although plant-based diets are promoted for healthy outcomes, these diets are not synonymous with high-quality diets. Plant-based diets can include highly processed, less healthful foods, including savory snacks, pastries, and sugary fruit drinks. This cross-sectional study examined the diet quality of vegetarian and omnivorous adults, matched for gender, age, and adiposity, and related diet quality to standard health biomarkers. Diet quality was assessed using the Rapid Eating and Activity Assessment for Participants Short Version questionnaire. Participants (17 vegetarians and 16 omnivores; 28.2 ± 8.9 years; 22.5 ± 2.7 kg/m²) were non-smokers and healthy by self-report. The median duration of adherence to the vegetarian diet was 27 months. Physical activity level and diet quality did not differ significantly between diet groups. Moreover, health biomarkers did not differ by diet groups. When participants were regrouped by low versus high diet quality, health biomarkers differed significantly between groups for fasting insulin, HOMA-IR, triglyceride (TG)/HDL ratio, and blood folate, with more favorable levels in the group with high diet quality. These data suggest that health biomarkers more closely align with diet quality attributes than with plant-based diet categorization. Thus, messaging focused on healthy diet attributes may lead to better health outcomes than the simple promotion of plant-based diets.

Diminished circulating retinol and elevated α-TOH/retinol ratio predict an increased risk of cognitive decline in aging Chinese adults, especially in subjects with ApoE2 or ApoE4 genotype

OBJECTIVE

The current study evaluated the relationship between circulating fat soluble vitamin status and cognition in aging Chinese population.

METHODS

A cross-sectional study was carried out in 1754 community residents aged 55-80 years aiming to evaluate the relationship between circulating α-tocopherol and retinol status and cognition. The effect of ApoE genetic polymorphism on the relationship between vitamins and cognition was also explored.

RESULTS

Our results indicated that serum retinol status positively correlated with cognitive performance; while, serum α-tocopherol (α-TOH)/retinol ratio negatively correlated with cognitive performance. Mild cognitive impairment (MCI) subject demonstrated higher serum α-TOH status (P < 0.05), α-TOH/retinol ratio (P < 0.01) and lower retinol status (P < 0.01) than normal subjects. Subjects with ApoE4 genotype have lower serum retinol level (P < 0.05) and higher α-TOH/retinol ratio (P < 0.01) than subjects with ApoE3 genotype. MCI-ApoE4 carriers demonstrated the worst cognitive performance (P < 0.05) and exhibited higher serum TC, α-TOH and α-TOH/retinol ratio levels (P < 0.05), and lower LDL-C, retinol and lipid-adjusted retinol status (P < 0.05). MCI-ApoE2 subjects showed higher serum TC, HDL-C content and α-TOH/retinol ratio (P < 0.05); and lower serum retinol and lipid-adjusted retinol status (P < 0.05).

CONCLUSION

Lower circulating retinol and higher α-TOH/retinol ratio potentially predicts an increased risk for the development of cognitive decline in aging Chinese adults. ApoE2 or E4 carriers with higher circulating α-TOH/retinol ratio infer poor cognitive performance and an increased risk of developing MCI.

Association between diets and mild cognitive impairment in adults aged 50 years or older

BACKGROUND/OBJECTIVE

As aging progresses, the number of patients with cognitive impairment also increases. Cognitive function is not generally correlated with diet, and there is debate over that association. Thus, the present study aimed to investigate the association between dietary intake and cognitive function among adults aged 50 years or older.

SUBJECTS/METHODS

Between July 2017 and March 2018, 324 adults aged over 50 years from Gwangju Sun-Han hospital participated in a dietary survey. The frequency of food intake and related information were collected using a semi-quantitative food frequency questionnaire (SQ-FFQ) and determining the mini-mental state examination (MMSE) level for 276 participants. The association between dietary intake and cognitive function was assessed by performing logistic regression analysis.

RESULTS

Depending on the MMSE score, the participants' age, education level, inhabitation status, medications, alcohol consumption, sleep duration, physical activity, and short geriatric depression scale score were significantly different (P < 0.05). Moreover, those participant characteristics were associated with either decreased or increased odds ratios (OR) for the risk of mild cognitive impairment (MCI). Based on analysis of the participants' intake of 112 detailed food items, which were categorized into 20 food types, intakes of cooked white rice (< 2 times/day compared with ≥ 3 times/day) (P < 0.05), properly cooked rice with other grains and legumes (P < 0.001), fruits (P < 0.05), milk (low fat and normal) (P = 0.044), liquid-type yogurt (P = 0.019), and curd-type yogurt (P = 0.015) were found to significantly decrease the OR for the risk of MCI.

CONCLUSIONS

Associations were significant between the risk of MCI and the intake of certain food types. Specifically, a moderate intake of cooked white rice and an adequate intake of whole grains, fruits, milk, and dairy products were associated with reduced risks of MCI among adults aged over 50 years.

The mediating role of depression on the relationship between housebound status and cognitive function among the elderly in rural communities: A cross-sectional study

OBJECTIVE

To explore the relationship among housebound status, depression and cognitive function, and further to study whether depression can take on a mediator among elders in rural communities.

METHODS

A cross-sectional survey was conducted among 720 community residents aged ≥60 years from March to May in 2016 in Hebei province, China. We used the Chinese version of Housebound scale, the Rasch-Derived of the Center for Epidemiological studies Depression scale (CES-D-R), and the Minimental State Examination Scale (MMSE) to estimate housebound status, depression, and cognitive function separately. Correlation, multiple linear regression, and structural equation modeling was used to data analyses.

RESULTS

712 completely replied questionnaires were finally used in the data analyses among 720 questionnaires, which indicated that effective response rate was 98.9%. Results indicated that the scores of housebound status were positively correlated with the MMSE scores. Being housebound correlated negatively with MMSE scores. Housebound status and three dimensions of CES-D-R (i.e. negative affect, positive affect, and interpersonal problems) were deemed as significant predictors of cognitive function among rural elders. The effect of housebound status on cognitive function was fully mediated by depression.

CONCLUSIONS

Not all subscales of CES-D-R can affect MMSE scores among rural elders. There may be full mediation effects of depression within the impact of housebound status on cognitive function, mainly through negative affect, positive affect and interpersonal problems. It indicates that preventing the elderly from housebound status could relieve the decline of cognitive function by the intermediary role of depression.

The association between macronutrient intake and cognition in individuals aged under 65 in China: a cross-sectional study

OBJECTIVE

The aim of this retrospective study was to explore the correlation between daily energy intake from macronutrients and cognitive functions in a Chinese population aged less than 65 years.

DESIGN

This is a cross-sectional study to explore the relationships between macronutrients' intake and cognitive function. The analysis of variance (ANOVA) and χ² test were used to compare the demographic and physical characteristics, lifestyle and laboratory parameters with the intake of macronutrients among different quartiles of % fat/energy. Multivariate logistic regression analysis was applied to identify the potential risk factors of mild cognitive impairment (MCI).

PARTICIPANTS

Young and middle-aged participants (age <65 years) were recruited from Beijing, China. The Montreal cognitive assessment (MoCA) and mini-mental state examination (MMSE) were used to evaluate the cognitive functions, and the dietary intake of the participants was estimated with a semi-quantitative food frequency questionnaire (FFQ).

RESULTS

Among the 661 participants, 80 (12.1%) had MCI, while 581 (87.9%) had normal cognitive functions. On evaluating the data based on the age group, educational background, and conditions of hyperlipidaemia and total energy intake, the results revealed that high % fat (upper quartile: adjusted OR (aOR) 3.90, 95% CI1.53 to 9.89, P=0.004), and high % protein intake (upper quartile: aOR 2.77, 95% CI 1.24 to 6.15) were greatly associated with increased frequency of MCI, while high % carbohydrate intake (upper quartile: aOR0.30, 95% CI 0.12 to 0.72) was correlated with decreased prevalence of MCI.

CONCLUSION

The dietary pattern with high percentage of energy intake from fat and protein, and low-energy intake from carbohydrate might have been associated with cognitive decline in a Chinese population under 65 years of age.

Dietary Intake is Positively Associated with Cognitive Function of a Chinese Older Adults Sample

OBJECTIVE

The relationship between cognitive function and dietary intake in older adults was under-studied in China. This study examined this relationship in a Chinese sample while controlling for the effects of sleep quality and socio demographic confounders.

METHODS

The sample consisted of 340 Chinese older adults (age > 60) who were randomly selected from Wuhan city in central China. Cognitive function was assessed by the Mini-mental State Examination [MMSE], sleep quality by the Pittsburgh Sleep Quality Index [PSQI], and dietary intake by frequencies of intake of meat products, fruits, fish/seafood/aquatic products, nuts and mushroom/algae over the past year. First, confirmatory factor analysis (CFA) was conducted to evaluate the measurement properties of cognitive function, dietary intake, and sleep quality. Second, structural equation modeling (SEM) was conducted to examine the relations of cognitive function, dietary intake, and sleep quality.

RESULTS

Dietary intake was found to be positively related to cognitive function. Older age, lower education status, monthly income, and living alone or without a spouse were significantly associated with poorer cognitive function. SES status had an indirect effect on cognitive function via dietary intake.

CONCLUSION

Dietary intake may be critical to maintain normal cognitive function of older adults in China.

An acute bout of housework activities has beneficial effects on executive function

PURPOSE

Although acute bouts of exercise reportedly have beneficial effects on executive function, inactive people may find it difficult to start exercising. In this study, we focused on housework activities (HAs) that generate a sense of accomplishment and require a mild intensity of physical activity. We examined the impact of an acute bout of HA on executive function and oxygenated hemoglobin (oxy-Hb) flow to related cortical regions.

MATERIALS AND METHODS

Twenty-five participants (age, 18-21 years; mean, 19.88±0.60 years; six males and 19 females) underwent two experiments, ie, HA and control experiments, which were conducted on different days. Participants vacuumed a dirty floor in the HA experiment and mimicked the same motion with an unplugged vacuum cleaner on a clean floor in the control experiment.

RESULTS

Heart rate recorded during the experiments showed no significant difference in the intensity of physical activity between control and HA groups. A questionnaire revealed a sense of accomplishment after completing the HA experiment. Participants performed the Stroop color-word task (SCWT) pre- and post-experiments; cortical hemodynamic changes were simultaneously monitored using functional near-infrared spectroscopy. Variation in Stroop interference scores for SCWT total response between pre- and post-experiments was signifi-cantly higher in the HA group than in the control group, and that for SCWT correct response showed a similar trend. Variation in the Stroop interference score for oxy-Hb flow to the right ventrolateral prefrontal cortex (R-VLPFC) showed the same trend.

CONCLUSION

Thus, HAs may have a greater beneficial effect on executive function than other physical activities through the activation of PFC, including R-VLPFC.

The Role of ApoE Polymorphism in the Relationship between Serum Steroid Hormone Levels and Cognition in Older Chinese Adults: A Cross-Sectional Study

BACKGROUND

Epidemiology studies have indicated an association of apolipoprotein E (ApoE) genetic polymorphism and circulating steroid hormone levels with the risk of Alzheimer's disease. The established physiologic relationship between apolipoproteins and steroid hormone indicate an important role of ApoE polymorphism in impacting the relationship between serum steroid hormones and cognition in the elderly.

STUDY DESIGN

A total of 500 Chinese adults aged between 50 and 75 participated in this community-based cross-sectional study. Blood samples were collected in the morning for ApoE genotyping and serum parameter assessment. Cognitive performance of participants was evaluated by Montreal Cognitive Assessment test.

RESULTS

Age, gender, educational level, smoking, and physical activity levels are factors associated with cognitive performance in this older Chinese adults. Compared to the control subjects, MCI subjects demonstrated higher serum total cholesterol, HDL-C, and estradiol status (P < 0.05). ApoE genotype difference of serum lipid profile was observed with a relatively higher mean serum triglyceride levels in ApoE2 and ApoE4 carriers (P < 0.05), and lower mean serum HDL-C level in ApoE4 carriers (P < 0.05). Memory and delayed recall ability was serum estradiol level related; and subjects with higher circulating estradiol concentration exhibited lower memory and delayed recall ability (P < 0.05). The association of serum estradiol and cortisol concentration with cognitive performance was ApoE genotypes dependent. Poor cognitive performance was observed in ApoE2 and ApoE4 carriers with higher serum estradiol level (P < 0.05). Moreover, ApoE2 and ApoE4 carriers with higher serum cortisol status demonstrated decreased language ability (P < 0.05). Multiple logistic regression analysis indicates that subjects with higher serum estradiol status may have an increased risk for MCI [OR = 2.004, 95% confidence interval (CI): 1.135, 3.540; P = 0.017]. ApoE2 carriers with higher serum steroid levels may be potentially predisposed to an increased risk of MCI (OR = 3.353; 95% CI: 1.135, 9.907; P = 0.029).

CONCLUSION

Cognitive outcomes in older Chinese adults are associated with serum steroid hormone status. Higher serum steroid levels in ApoE2 carriers might pose an increased risk of MCI in the elderly.

The Relationship between the Lifestyle of the Elderly in Shanghai Communities and Mild Cognitive Impairment

Background

Those with mild cognitive impairment (MCI) are ten times more like to develop Alzheimer’s disease (AD) than the general population. MCI diagnosis and early intervention are helpful for the diagnosis and treatment of AD in its early stages, thus delaying its development and improving the quality of life for those with MCI.

Aims

To analyze the relationship between the lifestyle of the elderly in Shanghai communities and mild cognitive impairment and to look for preventative lifestyle measures for the elderly with mild cognitive impairment.

Methods

1005 elderly persons were randomly selected from the community in Shanghai. Study participants were 265 people with an MCI diagnosis and 607 non-MCI elderly persons. The demographic and lifestyle data of these elderly people were collected for univariate and multivariate analysis to search for statistically significant indicators.

Results

The univariate analysis revealed that smoking (χ²= 10.808, p=0.001), tea drinking (χ²=11.74, p= 0.001), having hobbies (χ²= 20.815, p<0.001), reading (χ²=28.670, p= 0.001), surfing the internet (χ²=12.623, p= 0.001), and photography (χ²=4.470, p= 0.034) were protective factors for MCI. The binary logistic regression, a multivariate analysis, revealed that smoking, reading, and surfing the internet had statistical significance. Their OR values were 0.562 (0.358-0.883), 0.428 (0.253-0.726), and 0.238 (0.071-0.797) respectively. Thus, smoking, reading, and surfing the internet were protective factors for MCI.

Conclusions

Lifestyle is associated with the onset of MCI. Good life habits and behaviors are significant in the prevention of MCI developing into Alzheimer’s.