Association between dietary patterns and cognitive function among 70-year-old Japanese elderly: a cross-sectional analysis of the SONIC study

A review of the effects of mushrooms on mood and neurocognitive health across the lifespan

Mushrooms contain bioactive compounds with documented antioxidant and anti-inflammatory actions. Here, we present a systematic evaluation of epidemiological and clinical studies that investigate the role of mushrooms, either as a separate or integral dietary component, on neurocognition and mood. Following a search of four databases, a total of 34 human studies examining the effect of different mushrooms across varying age cohorts and health statuses were selected for inclusion. Epidemiological studies included in this review (n = 24) revealed a significant benefit of dietary patterns that included mushrooms of any species on cognition and mood in both healthy and compromised populations. However, the results obtained from intervention studies (n = 10) were mixed. Studies mainly investigated Lion's Mane (Hericium erinaceus), showing some enhancement of mood and cognitive function in middle-aged and older adults. Further acute and chronic human intervention studies are needed, using adequate sample sizes, employing appropriately sensitive neurocognitive tests, and investigating a range of dietary mushrooms, to confirm the effects of mushroom supplementation on neurocognition and mood in humans.

Comparison of Eating Habits, Body Composition and Densitometric Parameters between Subjects with Normal Cognitive Function and Mild Cognitive Impairment: An Observational Study

The role of nutrition in the ageing process of the brain is pivotal. Therefore, the study aimed to compare eating habits, body composition and densitometric parameters between subjects with normal cognitive function (NCF) and mild cognitive impairment (MCI). A total of 95 subjects with NCF (74% of women) and 95 individuals with MCI (77% of women) aged 50-70 years were studied. Densitometric parameters were evaluated using dual-energy X-ray absorptiometry methods. Eating habits were assessed using the food frequency questionnaire and 3-day diary records, and advanced glycation end products (AGEs) intake was calculated. Significant differences between groups were detected for the %fat in the right arm (NCF vs. MCI: 38.4 (30.4-46.8) vs. 43.5 (35.5-49.2)%, p = 0.0407). Moreover, the MCI group had a significantly lower intake of calcium (p = 0.0010), phosphor (p = 0.0411), vitamins B2 (p = 0.0138) and B12 (p = 0.0024) compared to the NCF group, with both groups also differing in the frequency of butter (p = 0.0191) and fermented milk beverages (p = 0.0398) intake. Analysis restricted to women showed significant differences between groups in right arm %fat, VAT mass, calcium, vitamins B2, B12, butter and fermented milk products intake, while in men, differences were detected in the intake of calcium, iodine, vitamin B1, water and AGEs. In conclusion, subjects with NCF and MCI have comparable densitometric variables but differ significantly in some body composition parameters and the intake of some food groups and nutrients.

The Relationship between Mushroom Intake and Cognitive Performance: An Epidemiological Study in the European Investigation of Cancer-Norfolk Cohort (EPIC-Norfolk)

The previous literature suggests that regular consumption of edible mushrooms may confer neuroprotective cognitive health benefits. To further investigate the possible association between mushrooms and brain function during ageing, data from a population-based study of diet and chronic disease (EPIC-Norfolk cohort) were analysed. Changes in mushroom intake were measured using a food frequency questionnaire at three health check (HC) points over an 18-year period, with participants categorised based on their consumption frequency. Cognitive performance was assessed at the final health check (3HC) via a battery of validated tests assessing a range of different cognitive domains. The findings revealed a significant reduction in mushroom intake over time, with 4.12% of the cohort giving up mushrooms after previously consuming them. At 3HC, mushroom consumers displayed better cognitive performance than non-consumers across multiple cognitive domains. This relationship was observed to be dose-dependent, with those consuming 1 or more portions per week showing the highest cognitive scores. These findings suggest that regular mushroom consumption may be beneficial for cognitive function during aging. Further randomised controlled trials will be needed to confirm any potential benefits of mushrooms on long-term cognitive health, alongside public health initiatives to promote mushroom consumption in this older-adult demographic.

Association between dietary patterns and subjective and objective measures of physical activity among Japanese adults aged 85 years and older: a cross-sectional study

A healthy diet and regular physical activity (PA) are delineated as healthy behaviours. Their implementation is associated with better health outcomes and improved quality of life. There is less evidence of a relationship between dietary patterns (DP) and PA, especially in adults aged ≥ 85. Hence, this cross-sectional study investigates the association between DP and PA in people of this age group, using the data from The Kawasaki Aging and Well-Being Project. Brief-type self-administered diet history questionnaire was used to estimate the intake of fifty-eight types of food. After energy adjustment, principal component analysis was performed to identify DP. PA was measured objectively using an accelerometer and subjectively using a questionnaire validated for this age group. Thousand participants (median age: 86·9 years, men: 49·9 %) were included in the analysis. Three major DP (DP1 'various foods', DP2 'red meats and coffee', DP3 'bread and processed meats') were identified. DP1 'various foods' was similar to DP previously named 'healthy' or 'prudent' and showed a positive association with PA time (PAT) as measured by accelerometer (B, 6·25; 95 % CI 0·13, 12·37) and relatively shorter sedentary behaviour (SB) time. DP2 'red meats and coffee' and DP3 'bread and processed meats' were negatively associated with PAT and positively associated with SB time. This study observed the relationship between diet and PA behaviours in adults aged ≥ 85, with healthier and more food-diverse DP associated with longer PAT and relatively unhealthy DP with shorter PAT.

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

Purpose

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

Methods

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

Results

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

Conclusion

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

Systematic review registration

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

Empirically derived dietary patterns and postpartum depression symptoms in a large sample of Iranian women

BACKGROUND

Postpartum Depression (PPD) is a major depressive disorder that mainly begins within one month after delivery. The present study aimed to determine the relationship between dietary patterns and the occurrence of high PPD symptoms in women participating in the initial phase of the Maternal and Child Health cohort study, Yazd, Iran.

METHODS

This cross-sectional study was carried out in the years 2017-2019 included 1028 women after childbirth The Food Frequency Questionnaire (FFQ) and the Edinburgh Postnatal Depression Scale (EPDS) were study tools. The EPDS questionnaire was used to measure postpartum depression symptoms and a cut-off score of 13 was considered to indicate high PPD symptoms. The baseline data related to dietary intake was collected at the beginning of the study at the first visit after pregnancy diagnosis and the data related to depression, were collected in the second month after delivery. Dietary patterns were extracted by exploratory factor analysis (EFA). Frequency (percentage) and mean (SD) were used for description. Chi-square test, Fisher's exact test, independent sample t-test, and multiple logistic regression (MLR) were used for data analysis.

RESULTS

The incidence of high PPD symptoms was 24%. Four posterior patterns were extracted including prudent pattern, sweet and dessert pattern, junk food pattern and western pattern. A high adherence to the western pattern was associated with a higher risk of high PPD symptoms than a low adherence (OR_T3/T1: 2.67; p < 0.001). A high adherence to the Prudent pattern was associated with a lower risk of high PPD symptoms than a low adherence (OR_T3/T1: 0.55; p = 0.001). There are not any significant association between sweet and dessert and junk food patterns and high PPD symptoms risk (p > 0.05).

CONCLUSION

High adherence to prudent patterns was characterized by high intake of vegetables, fruit and juice, nuts and beans, low-fat dairy products, liquid oil, olive, eggs, fish, whole grains had a protective effect against high PPD symptoms, but the effect of western pattern was characterized by high intake of red and processed meats and organs was reverse. Therefore, it is suggested that health care providers have a particular emphasis on the healthy food patterns such as the prudent pattern.

Relationship between dietary patterns and physical performance in the very old population: a cross-sectional study from the Kawasaki Aging and Wellbeing Project

OBJECTIVES

As the world's population is ageing, improving the physical performance (PP) of the older population is becoming important. Although diets are fundamental to maintaining and improving PP, few studies have addressed the role of these factors in adults aged ≥ 85 years, and none have been conducted in Asia. This study aimed to determine the dietary patterns (DP) and examine their relationship with PP in this population.

DESIGN

This cross-sectional study (Kawasaki Aging and Wellbeing Project) estimated food consumption using a brief-type self-administered diet history questionnaire. The results were adjusted for energy after aggregating into thirty-three groups, excluding possible over- or underestimation. Principal component analysis was used to identify DP, and outcomes included hand grip strength (HGS), timed up-and-go test, and usual walking speed.

SETTING

This study was set throughout several hospitals in Kawasaki city.

PARTICIPANTS

In total, 1026 community-dwelling older adults (85-89 years) were enrolled.

RESULTS

Data of 1000 participants (median age: 86·9 years, men: 49·9 %) were included in the analysis. Three major DP (DP1: various foods, DP2: red meats and coffee, DP3: bread and processed meats) were identified. The results of multiple regression analysis showed that the trend of DP2 was negatively associated with HGS (B, 95 % CI -0·35, -0·64, -0·06).

CONCLUSIONS

This study suggests a negative association between HGS and DP characterised by red meats and coffee in older adults aged ≥ 85 years in Japan.

Increased Intake of Vegetables and Fruits Improves Cognitive Function among Chinese Oldest Old: 10-Year Follow-Up Study

BACKGROUND

In view of the rapidly accelerating aging process in China, this study looked at the associations between vegetables and fruits intake pattens and cognitive function among the oldest old in China using the genetic sub study from the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

METHODS

This study screened respondents who participated in all four surveys of longitudinal data from the CLHLS, and a total of 2454 participants were ultimately included. The relationships of cognitive function with vegetables and fruits intake patterns were examined using Generalized-estimating equations.

RESULTS

The prevalence range of mild cognitive impairment (MCI) was 14.3% to 16.9% at T1 to T3 and 32.7% at T4. There was a significant increase in the prevalence of MCI from T1 to T4 (β = 0.054; 95% CI, 0.037 to 0.070; p < 0.001; adjusted). The V+/F+ pattern significantly improved cognitive function in Chinese older adults compared with the V-/F- pattern (OR, 1.026; 95% CI, 1.001-1.053; p < 0.05).

CONCLUSION

Older adults who frequently consume both fruits and vegetables experience a reduction in MCI risk relative to those consuming these food groups infrequently-emphasizing the critical importance of the regular intake of both fruits and vegetables in maintaining cognitive function.

The Association between Dietary Iron Intake and Incidence of Dementia in Adults Aged 60 Years or over in the UK Biobank

Background Several studies have investigated the association between dietary iron intake and cognitive impairment, but little is known about the relationship between iron intake and dementia incidence. Objectives This study explored the association between dietary iron intake and incident dementia in males and females. Whether this association was modified by factors such as age and medical diseases was also examined. Methods We included 41,213 males and 48,892 females aged 60 years or over, from the UK-Biobank cohort. Dietary iron intake was measured using a web-based 24-h dietary recall questionnaire from between 2009 and 2012. Incident dementia was ascertained using hospital inpatient records and death registers until April 2021. Cox proportional regression models examined the association between iron intake and incident dementia, and hazard ratio curves were constructed with knots from the analysis indicating insufficient or excessive iron intake. Results During a mean follow-up of 11.8 years, 560 males and 492 females developed dementia. A non-linear relationship between iron intake and incident dementia was observed in both males and females. The lowest incidence rates were observed in the higher iron intake quintile (Q4: ≥15.73, <17.57 mg/day) for males, and the intermediate iron intake quintile (Q3: ≥12.4, <13.71 mg/day) for females. Among those aged 60 and above, all-cause dementia in males was associated with deficient iron intake (Q1 versus Q4: Hazard ratio [HR]: 1.37, 95% Confidence interval [95%CI]: 1.01−1.86, p = 0.042) and excessive iron intake (Q5 versus Q4: HR: 1.49, 95%CI: 1.14−1.96, p = 0.003), whilst significant associations between all-cause dementia and deficient iron intake were only observed in females without hypertension. Smoking status was a significant moderator (p-value for trend = 0.017) for dementia in males only. Conclusions Excessive iron intake (≥17.57 mg/day) is associated with a higher incidence of all-cause dementia in males and smoking status modified this association amongst males. Deficient iron intake (<10.93 mg/day) was associated with a higher incidence of all-cause dementia in females without a history of hypertension.

Correlation between dietary patterns and cognitive function in older Chinese adults: A representative cross-sectional study

Objective

The objective of this study was to investigate the relationship between dietary patterns and cognitive function in older adults (≥60 years old).

Methods

Food intake was quantitatively assessed by the Food Frequency Questionnaire (FFQ), and cognitive function was assessed by the Chinese version of the Simple Mental State Examination Scale (MMSE). Four major dietary patterns were identified by the factor analysis (FA) method. The relationship between dietary patterns and cognitive function was evaluated by logistic regression.

Results

A total of 884 participants were included in the study. Four dietary patterns (vegetable and mushroom, oil and salt, seafood and alcohol, and oil tea dietary patterns) were extracted. In the total population, Model III results showed that the fourth quartile of dietary pattern factor scores for the vegetable and mushroom pattern was 0.399 and 7.056. The vegetable and mushroom dietary pattern may be a protective factor for cognitive function, with p-value = 0.033, OR (95% CI): 0.578 (0.348, 0.951) in Model III (adjusted for covariates: sex, ethnic, marital, agricultural activities, smoking, drinking, hypertension, diabetes, dyslipidemia, BMI, and dietary fiber). In the ethnic stratification analysis, the scores of dietary pattern factors of the vegetable and mushroom among the Yao participants were 0.333 and 5.064. The Vegetable and mushroom diet pattern may be a protective factor for cognitive function, p-value = 0.012, OR (95% CI): 0.415 (0.206, 0.815).

Conclusion

The fourth quartile of the vegetable and mushroom dietary pattern scores showed dose-dependent and a strong correlation with cognitive function. Currently, increasing vegetable and mushroom intake may be one of the effective ways to prevent and mitigate cognitive decline. It is recommended to increase the dietary intake of vegetables and mushroom foods.

Cognitive Decline Related to Diet Pattern and Nutritional Adequacy in Alzheimer's Disease Using Surface-Based Morphometry

Dietary pattern (DP) results in nutrition adequacy and may influence cognitive decline and cortical atrophy in Alzheimer's disease (AD). The study explored DP in 248 patients with AD. Two neurobehavioral assessments (intervals 13.4 months) and two cortical thickness measurements derived from magnetic resonance images (intervals 26.5 months) were collected as outcome measures. Reduced rank regression was used to assess the groups of DPs and a linear mixed-effect model to explore the cortical neurodegenerative patterns. At screening, underweight body mass index (BMI) was related to significant higher lipid profile, impaired cognitive function, smaller cortical thickness, lower protein DP factor loading scores and the non-spouse caregiver status. Higher mini-mental state examination (MMSE) scores were related to the DP of coffee/tea, compared to the lipid/sugar or protein DP group. The underweighted-BMI group had faster cortical thickness atrophy in the pregenual and lateral temporal cortex, while the correlations between cortical thickness degeneration and high HbA1C or low B12 and folate levels were localized in the medial and lateral prefrontal cortex. The predictive model suggested that factors related to MMSE score were related to the caregiver status. In conclusion, normal or overweight BMI, coffee/tea DP group and living with a spouse were considered as protective factors for better cognitive outcomes in patients with AD. The influence of glucose, B12 and folate on the cortical degeneration was spatially distinct from the pattern of AD degeneration.

The role of dietary patterns and erythrocyte membrane fatty acid patterns on mild cognitive impairment

Background

Dietary fatty acids have been shown to be associated with the development of cognition. However, research on the role of fatty acid intake in dietary patterns and fatty acid patterns (FAPs) in the development of cognitive function is limited. The aim of this study was to explore the correlation between dietary patterns and FAPs and to provide available evidence for preventing mild cognitive impairment (MCI) through these patterns.

Materials and methods

The 973 participants aged between 65 and 85 were recruited from 2020 to 2021 for this multicenter research in Beijing. Neuropsychological tests were used for cognitive evaluation, and data of dietary intake in the past 12 months were collected with semi-quantitative food frequency questionnaire. The erythrocyte membrane fatty acid profile was tested by chromatography and mass spectrometry lipid profiling. Factor analysis was used to derive the main dietary patterns and FAPs. Pearson’s correlation or Spearman’s correlation was used to explore the association between dietary patterns and FAPs. Binary logistic regression was applied to examine the relationship between patterns and cognitive function.

Results

Six dietary patterns and six FAPs were identified, explaining 53.4 and 80.9% of the total variance separately. After adjusting all potential confounders, T3 of the pattern 1 and FAP2 were the independent protect factors for MCI, respectively (OR 0.601, 95% CI [0.395, 0.914]; OR 0.108, 95% CI [0.019, 0.623]). Rich of SM (26:0), SM (24:1), and SM (26:1) is the characteristic of FAP2. A positive correlation was found between component scores of dietary pattern1 and FAP2 (r = 0.441, p = 0.001). People who adhered to a reasonable intake of animal flesh consumed more various long-chain fatty acids as well.

Conclusion

The erythrocyte membrane metabolites, SM (26:0), SM (24:1), and SM (26:1), might function as early biomarkers for predicting or monitoring of cognitive aging in the elderly. The dietary pattern with recommended animal flesh consumption was significantly associated with FAP characterized by very long-chain SMs. This dietary pattern affected FAP, which might achieve the ultimate goal of neuroprotection through the very long-chain SMs. A rational intake of dietary fatty acids might be an effective way on preventing MCI in the elderly.

[Identification of dietary patterns and their relationship with physical performance in adults of 85 years of age and older -A cross sectional study from The Tokyo Oldest Old survey on Total Health study]

AIM

While the proportion of people of ≥85 years of age is expected to increase, there is limited research on the dietary patterns and physical performance of this population in Japan. The purpose of this study was to identify the dietary patterns of people of ≥85 years of age who live in Tokyo and to examine the relationship with their physical performance.

METHODS

Using data from the baseline survey (conducted in 2008-2009) of The Tokyo Oldest Old survey on Total Health study, the estimated 58 food intake items were aggregated into 33 items after energy adjustment, and a principal component analysis was performed. For physical performance, the results of grip strength, chair standing test, and 3 m timed up and go test conducted at normal walking speed were used. A multiple regression analysis was used to adjust for confounders and to examine the relationship between each dietary pattern and physical performance.

RESULTS

The subjects of the analysis were 87.3 (86.2-88.8) years of age (median [25-75th percentile] ). From the principal component analysis, three dietary patterns were identified: "various vegetable foods", "fish and mushrooms", and "cooked rice and miso soup". A higher propensity for the "fish and mushrooms" dietary pattern was significantly associated with grip strength (partial regression coefficient, B (95% confidence interval): 0.48 (0.13-0.83) ).

CONCLUSIONS

In a population of people of ≥85 years of age in Tokyo, a positive association was observed between hand grip strength and a dietary pattern characterized by fish and mushroom intake.

Protein Intake and Oral Health in Older Adults-A Narrative Review

Oral health is vital to general health and well-being for all ages, and as with other chronic conditions, oral health problems increase with age. There is a bi-directional link between nutrition and oral health, in that nutrition affects the health of oral tissues and saliva, and the health of the mouth may affect the foods consumed. Evidence suggests that a healthy diet generally has a positive impact on oral health in older adults. Although studies examining the direct link between oral health and protein intake in older adults are limited, some have explored the relationship via malnutrition, which is also prevalent among older adults. Protein-energy malnutrition (PEM) may be associated with poor oral health, dental caries, enamel hypoplasia, and salivary gland atrophy. This narrative review presents the theoretical evidence on the impact of dietary protein and amino acid composition on oral health, and their combined impact on overall health in older adults.

Impulsiveness in children with attention-deficit/hyperactivity disorder after an 8-week intervention with the Mediterranean diet and/or omega-3 fatty acids: A randomised clinical trial

INTRODUCTION

The Barratt Impulsiveness Scale (BIS) is a self-administered instrument designed to assess the personality/behavioural construct of impulsiveness. Impulsiveness has been associated with several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). This study assesses the progression of impulsive behaviour in children with ADHD after an 8-week dietary intervention with the Mediterranean diet and/or omega-3 fatty acid supplementation, by using a version of the 11-item BIS adapted for children (BIS-11c).

METHODS

This cross-sectional study includes 60 children with ADHD from the region of Madrid, Spain. Participants were divided into 4 groups, with one control group (G1) and 3 intervention groups (Mediterranean diet [G2]; omega-3 supplementation [G3]; and Mediterranean diet plus omega-3 supplementation [G4]). A personalised Mediterranean diet was designed for members of groups 2 and 4. The BIS-11c was administered to determine the level of impulsiveness, and the KIDMED test was used to assess adherence to the Mediterranean diet.

RESULTS

The supplementation group showed a fairly significant decrease in the total BIS-11c (P=.049). Total cognitive score slightly decreased in the diet and supplementation groups. Only the control group showed a considerable decrease in the total motor score. Total nonplanning scores were lower in all groups after the intervention. Baseline and final BIS-11c scores were positively correlated with treatments (r>0.9).

CONCLUSION

An intake of 550mg EPA fatty acid and 225mg DHA fatty acid per day for 8 weeks is associated with less marked impulsive behaviour in children with ADHD. A Mediterranean diet may improve BIS scores, although our results are not conclusive in this population.

Relationship between Dietary Patterns and Subjectively Measured Physical Activity in Japanese Individuals 85 Years and Older: A Cross-Sectional Study

High-quality diets and regular physical activity (PA) are considered healthy behaviors (HBs). HBs are associated with many health outcomes and are expected to improve quality of life. Although implementing HBs is important, the relationship between dietary patterns (DPs) and PA has not been well investigated, especially among those aged ≥ 85. This study used data from the Tokyo Oldest Old survey on Total Health study to examine the relationship between DPs and PA in a cross-sectional study. The dietary survey used the brief self-administered diet history questionnaire to estimate the intake of 58 foods. After energy adjustment, principal component analysis was performed to identify major DPs. A validated questionnaire was used to evaluate PA, and linear regression analysis was used to investigate the association between DPs and PA, considering confounders. A total of 519 participants were included. Three major DPs (‘Various plant foods’, ‘Fish and mushrooms’, ‘Cooked rice and miso soup’) were identified. ‘Various plant foods’ was similar to DPs previously named ‘Healthy’ or ‘Prudent’, and its trend was positively associated with higher PA. This study observed the implementation of HBs even among those aged ≥ 85, suggesting that a trend toward a healthier diet is associated with higher PA.

Association of food groups with the risk of cognitive impairment in Chinese older adults

OBJECTIVE

To investigate the impact of 10 common foods (including staple foods, fruits, vegetables, sugar, meat, fish, eggs, beans, salt-preserved vegetables, and garlic) on cognitive function in Chinese older adults.

METHODS

Cross-sectional data on demographic characteristics, lifestyle, and dietary habits were taken from the 2018 Chinese Longitudinal Healthy Longevity Survey (CLHLS). Cognition was assessed using the Mini-Mental State Examination (MMSE). Food consumption was measured by participants reporting the frequency of their food consumption. Association between food groups and cognitive function was evaluated using mixed-effect regression model analysis.

RESULTS

Compared with those who rarely or never consumed vegetables, meat, fruits, beans, and garlic, older adults who consumed these foods almost daily were 56%, 30%, 23%, 34%, and 29% less likely to have cognitive impairment, respectively. No associations between staple foods, sugar, fish, and eggs consumption and cognitive impairment were found. Low-frequency consumption of salt-preserved vegetables may be associated with cognitive function. Regular vegetables consumption had the greatest associated risk reduction of all food types. Interactions indicated that the co-ingestion of vegetables and beans or sugar, meat and beans may have antagonistic effect, while the co-ingestion of salt-preserved vegetables and garlic may have synergistic effect. Subgroup analyses showed that sex and age were the significant effect modifiers for meat and fish, respectively.

CONCLUSIONS

Cognitive function of Chinese older adults may be related to food groups. Future research should measure food types and consumption level with greater granularity.

The Lifelong Health Support 10: a Japanese prescription for a long and healthy life

Background

Although the age-adjusted incidence and mortality of cancer and cardiovascular disease (CVD) have been decreasing steadily in Japan, both diseases remain major contributors to morbidity and mortality along with the aging society. Herein, we aim to provide a prescription of 10 health tips for long and healthy life named the “Lifelong Health Support 10 (LHS10).”

Method

The LHS10 was developed by the preventive medicine specialists at the National Cerebral and Cardiovascular Center in Suita, where it has been used for health guidance to prevent CVD, cancer, and cognitive decline in addition to their major risk factors such as hypertension, diabetes, and obesity. It consisted of the lifestyle modification recommendations of the 2014 Japanese Society of Hypertension guidelines and the 2017 Japan Atherosclerosis Society Guidelines for preventing atherosclerotic CVD. Further, it came in line with other international lifestyle modification guidelines. In this narrative review, we summarized the results of several Japanese epidemiological studies investigating the association between the LHS10 items and the risk of cancer, CVD, and other chronic diseases including dementia, diabetes, and chronic kidney disease.

Results

The LHS10 included avoiding smoking and secondhand smoke exposure, engaging in physical activity, refraining from excessive alcohol drinking, reducing fried foods and sugary soft drinks, cutting salt in food, consuming more vegetables, fruits, fish, soy foods, and fibers, and maintaining proper body weight. All items of the LHS10 were shown to reduce the risk of cancer, CVD, and other chronic diseases.

Conclusions

The LHS10 can be a helpful tool for health guidance.

Supplementary information

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.22-00085.

Are dietary patterns becoming more processed? The effects of different dietary patterns on cognition: A review

Background: Identifying dietary patterns that promote healthy aging has become increasingly important due to changes in food processing and consumption of processed foods. Recently, the effects of these foods and unhealthy dietary patterns on cognitive function have become more widely recognized. Aim: The aim of this review is to discuss the association between various dietary patterns and cognition in older age, while also highlighting growing evidence that ultra processed food (UPF) may negatively impact healthy aging. Methods: We have performed a non-systematic literature review searches in Google Scholar electronic database with pre-defined terms relating to UPF, diet, dietary patterns, cognition and ageing. Results: The most prevalent diets in the literature include the Western, Mediterranean, Dietary Approach to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurogenerative Delay (MIND), Japanese, Nordic, and plant-based diets. Based on the findings, higher intakes of fresh fruit and vegetables, wholegrains and oily fish are common components of dietary patterns that are positively associated with better cognitive function. In contrast, the characteristics of a Western style dietary pattern, consisting of high amounts of UPF's, are increasing in many countries even where the staple dietary pattern was identified as healthy (i.e. Japan). Conclusion: The consumption of UPF, classified by the NOVA food classification system as industrially manufactured foods containing high levels of starches, vegetable oils, sugar, emulsifiers, and foods additives, has a negative impact on the overall nutritional quality of individual diets.

Dietary Patterns Are Associated With Multi-Dimensional Cognitive Functions Among Adults Aged 55 and Older in China

Background

The intake of certain food and nutrients may play a crucial role in cognitive health. However, research on the relationship between dietary patterns and cognitive function is limited. This study aims to investigate the associations between dietary patterns and multi-dimensional cognitive functions, such as global cognitive status and related domain profiles, mild cognitive impairment (MCI), and four major subtypes of Chinese adults.

Methods

Using the baseline data from the Community-based Cohort Study on Nervous System Diseases (2018–2019), we selected 4,309 Chinese adults aged 55 years and older as subjects with complete diet, cognition, and other related data. We collected food data for the past 12 months with a valid semi-quantitative food frequency questionnaire. Diving 49 food items into 13 subgroups, we used factor analysis to derive the main dietary patterns. We evaluated cognitive functions based on the scores of the Montreal Cognitive Assessment (MoCA) and used quantile regression and multivariable logistic regression to examine the relationship between dietary patterns and cognitive-related outcomes.

Results

We identified four dietary patterns, explaining 50.11% of the total variance: “meat-preferred” pattern, “plant-preferred” pattern, “eggs- and dairy-preferred” pattern, and “grain-preferred” pattern. After adjusting for all potential confounders, the “meat-preferred” pattern and the “plant-preferred” pattern were associated with higher scores of global cognition and several cognitive domains (p &lt;0.05), while the “grain-preferred” pattern was associated with lower scores of global cognition (β = −0.36, p &lt;0.05), execution (β = −0.19, p &lt;0.05), visuospatial (β = −0.09, p &lt;0.05), and language (β = −0.05, p &lt;0.05). Adults adhering to the “meat-preferred” pattern and the “plant-preferred” pattern had decreased odds of MCI and some MCI subtypes (p-trend &lt;0.05); in contrast, those in the top quartiles of the “grain-preferred” pattern had increased odds of MCI [adjusted odds ratio (AOR) = 1.34, 95% CI: 1.11–1.63, p-trend = 0.003].

Conclusions

Adhering to the “plant-preferred” pattern and the “meat-preferred” pattern may help improve the multi-dimensional cognitive functions; on the contrary, adhering to the “grain-preferred” pattern may worse cognitive health. More prospective studies in this field are needed to strengthen the evidence.

Soy consumption, cognitive function, and dementia

PURPOSE OF REVIEW

With the rising number of people living with dementia, the interest in modifiable risk factors including dietary intake for dementia is increasing. Although there is a growing body of evidence investigating soy's health effects, the direction and strength of the association between soy consumption and risk of dementia and cognitive decline are still uncertain. Thus, we aimed to review the evidence linking soy consumption to dementia and cognitive function.

RECENT FINDINGS

Some studies showed that higher intake of total soy products was associated with a lower risk or prevalence of cognitive impairment. Some studies pointed to an inverse association between higher tofu consumption and cognitive function, whereas a higher intake of soybean was associated with better cognitive function.

SUMMARY

Previous studies are scarce and have provided contradictory results. Soy is a high-protein alternative to red meat and processed meat. Further studies are needed to clarify the safety and potential preventive effects particularly in healthy populations before clinical disease manifestation and irreversible injury have occurred.

Effect of the Intake of Brown Rice for Six Months on the Cognitive Function in Healthy Elderly Persons: A Study Protocol for a Pilot, Non-Randomized Controlled Trial

The nutritional components of brown rice have been reported to be effective against diabetes mellitus. Recent animal studies have suggested that it is also effective in maintaining cognitive function. Therefore, in this study, we examined the effect of a brown rice diet on cognitive function in individuals aged over 60 years. The study participants were recruited from a pool of individuals aged ≥60 years who were using elderly care facilities. The participants were provided with four servings of brown or white rice per week for 6 months, and their cognitive function was measured before and after the intervention period. Prior to the intervention, participants tasted the white and brown rice to determine which type they would like to be offered over the 6-month period. Since rice is the staple food of the participants in this study, they were allowed to decide whether they wanted to eat white or brown rice.

Impulsiveness in children with attention-deficit/hyperactivity disorder after an 8-week intervention with the Mediterranean diet and/or omega-3 fatty acids: a randomised clinical trial

INTRODUCTION

The Barratt Impulsiveness Scale (BIS) is a self-administered instrument designed to assess the personality/behavioural construct of impulsiveness. Impulsiveness has been associated with several psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). This study assesses the progression of impulsive behaviour in children with ADHD after an 8-week dietary intervention with the Mediterranean diet and/or omega-3 fatty acid supplementation, by using a version of the 11-item BIS adapted for children (BIS-11c).

METHODS

This cross-sectional study includes 60 children with ADHD from the region of Madrid, Spain. Participants were divided into 4 groups, with one control group and 3 intervention groups (Mediterranean diet; omega-3 supplementation; and Mediterranean diet plus omega-3 supplementation). A personalised Mediterranean diet was designed for members of groups 2 and 4. The BIS-11c was administered to determine the level of impulsiveness, and the KIDMED test was used to assess adherence to the Mediterranean diet.

RESULTS

The supplementation group showed a fairly significant decrease in the total BIS-11c (P = .049). Total cognitive score slightly decreased in the diet and supplementation groups. Only the control group showed a considerable decrease in the total motor score. Total nonplanning scores were lower in all groups after the intervention. Baseline and final BIS-11c scores were positively correlated with treatments (r > 0.9).

CONCLUSION

An intake of 550 mg EPA fatty acid and 225 mg DHA fatty acid per day for 8 weeks is associated with less marked impulsive behaviour in children with ADHD. A Mediterranean diet may improve BIS scores, although our results are not conclusive in this population.

Changes in Diet Quality from Mid- to Late Life Are Associated with Cognitive Impairment in the Singapore Chinese Health Study

BACKGROUND

Although higher diet quality at mid-life has been associated with better cognitive function in late adulthood, it is unclear whether dietary improvement after mid-life may reduce the risk of cognitive impairment.

OBJECTIVES

We examined associations between changes in diet quality and risk of cognitive impairment in the Singapore Chinese Health Study cohort.

METHODS

We used data from 14,683 Chinese men and women who were recruited at ages 45 to 74 y from 1993 to 1998 and re-interviewed after 20 y at ages 61 to 96 y during follow-up 3 (2014-2016). Diet quality was measured using the Dietary Approaches to Stop Hypertension (DASH) scores at baseline and follow-up 3 interviews. Cognitive impairment was defined using scores from the Singapore-modified Mini-Mental State Examination at the follow-up 3 interview. Multivariable logistic regression models were used to estimate ORs and 95% CIs for the associations between change in DASH scores and cognitive impairment.

RESULTS

Higher quintiles in DASH scores at baseline and follow-up 3 interviews were associated with lower odds of cognitive impairment in a dose-dependent manner (both: P-trend < 0.001). Compared with participants with consistently low DASH scores, the OR (95% CI) of cognitive impairment was lowest, at 0.64 (0.51, 0.79), in those with consistently high DASH scores. Those with small (OR: 0.80, 95% CI: 0.65, 0.98) or moderate-large (OR: 0.72, 95% CI: 0.59, 0.86) increases in DASH scores were associated with significantly lower odds of cognitive impairment than those with consistently low DASH scores. Associations were consistent across subgroups by sex, BMI (kg/m2; <23 or ≥23), and age (<60 y, ≥60 y) at baseline.

CONCLUSIONS

Although maintaining high diet quality confers the lowest risk, improving diet quality from mid- to late life was still associated with a lower risk of cognitive impairment in late adulthood.

Interplay between cognition and weight reduction in individuals following a Mediterranean Diet: Three-year follow-up of the PREDIMED-Plus trial

BACKGROUND & AIMS

Some cognitive profiles might facilitate successful weight loss and its maintenance. Also, weight reductions may result in cognitive benefits. However, little work to date has examined the interactions between cognition and weight changes in the context of interventions with the Mediterranean diet (MedDiet). We studied the within-subject longitudinal relationships between cognition, body mass index (BMI), physical activity (PA), and quality of life (QoL), in older adults following a MedDiet.

METHODS

The PREDIMED-Plus is a primary prevention trial testing the effect of a lifestyle intervention program with an energy-restricted MedDiet (er-MedDiet), weight-loss goals and PA promotion on cardiovascular disease. The PREDIMED-Plus-Cognition sub-study included 487 participants (50% women, mean age 65.2 ± 4.7 years), with overweight/obesity, metabolic syndrome and normal cognitive performance at baseline. A comprehensive neurocognitive test battery was administered at baseline and after 1 and 3 years.

RESULTS

Baseline higher performance in verbal memory (OR = 1.5; 95%CI 1.0, 2.1), visuoconstructive praxis and attention (OR = 1.5; 95%CI 0.9, 2.3), and inhibition (OR = 1.3; 95%CI 0.9, 1.9) were associated with a higher odd of achieving at least 8% weight loss after 3 years follow-up in participants randomized to the intervention group. There were moderate improvements in specific tests of memory and executive functions during follow-up. Higher adherence to the er-MedDiet was associated with greater improvements in memory. Women exhibited lower rates of change in global cognition, PA and QoL. Moreover, improvements in memory correlated with reductions in BMI after 1 year (β_STD = -0.14) and with improvements in PA after 3 years (β_STD = 0.13). Finally, participants who experienced greater improvements in executive functions and global cognition also experienced greater improvements in their QoL.

CONCLUSIONS

This study refines the understanding of the determinants and mutual interrelationships between longitudinally-assessed cognitive performance and weight loss, adding further evidence to the cognitive benefits associated with better adherence to a MedDiet. Our results also suggest that weight loss interventions tailored to the cognitive profile and gender of participants are promising avenues for future studies.

Green Tea Suppresses Brain Aging

Epidemiological studies have demonstrated that the intake of green tea is effective in reducing the risk of dementia. The most important component of green tea is epigallocatechin gallate (EGCG). Both EGCG and epigallocatechin (EGC) have been suggested to cross the blood–brain barrier to reach the brain parenchyma, but EGCG has been found to be more effective than EGC in promoting neuronal differentiation. It has also been suggested that the products of EGCG decomposition by the intestinal microbiota promote the differentiation of nerve cells and that both EGCG and its degradation products act on nerve cells with a time lag. On the other hand, the free amino acids theanine and arginine contained in green tea have stress-reducing effects. While long-term stress accelerates the aging of the brain, theanine and arginine suppress the aging of the brain due to their anti-stress effect. Since this effect is counteracted by EGCG and caffeine, the ratios between these green tea components are important for the anti-stress action. In this review, we describe how green tea suppresses brain aging, through the activation of nerve cells by both EGCG and its degradation products, and the reductions in stress achieved by theanine and arginine.

The Effect of Mediterranean Diet on Cognitive Functions in the Elderly Population

At present, due to the demographic changes and the rise of senior population worldwide, there is effort to prolong an active life of these people by both pharmacological and non-pharmacological strategies. The purpose of this article is, on the basis of the literature review of recent clinical studies, to discuss one of such strategy, i.e., the effect of Mediterranean Diet (MedDiet) on the cognitive functions among both the cognitively unimpaired and impaired elderly people. The methodology includes a literature review of full-text, peer-reviewed journal studies written in English and published in Web of Science and PubMed between 1 January 2016 and 28 February 2021. The findings indicate that the adherence to MedDiet has a positive effect on both cognitively impaired and unimpaired older population, especially on their memory, both in the short and long run. The results show that the higher adherence to MedDiet proves to have a better effect on global cognitive performance of older people. In addition, the adherence to MedDiet offers other benefits to older people, such as reduction of depressive symptoms, lowered frailty, as well as reduced length of hospital stays.

Association of APOE ε4 genotype and lifestyle with cognitive function among Chinese adults aged 80 years and older: A cross-sectional study

BACKGROUND

Apolipoprotein E (APOE) ε4 is the single most important genetic risk factor for cognitive impairment and Alzheimer disease (AD), while lifestyle factors such as smoking, drinking, diet, and physical activity also have impact on cognition. The goal of the study is to investigate whether the association between lifestyle and cognition varies by APOE genotype among the oldest old.

METHODS AND FINDINGS

We used the cross-sectional data including 6,160 oldest old (aged 80 years old or older) from the genetic substudy of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) which is a national wide cohort study that began in 1998 with follow-up surveys every 2-3 years. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score less than 18. Healthy lifestyle profile was classified into 3 groups by a composite measure including smoking, alcohol consumption, dietary pattern, physical activity, and body weight. APOE genotype was categorized as APOE ε4 carriers versus noncarriers. We examined the associations of cognitive impairment with lifestyle profile and APOE genotype using multivariable logistic regressions, controlling for age, sex, education, marital status, residence, disability, and numbers of chronic conditions. The mean age of our study sample was 90.1 (standard deviation [SD], 7.2) years (range 80-113); 57.6% were women, and 17.5% were APOE ε4 carriers. The mean MMSE score was 21.4 (SD: 9.2), and 25.0% had cognitive impairment. Compared with those with an unhealthy lifestyle, participants with intermediate and healthy lifestyle profiles were associated with 28% (95% confidence interval [CI]: 16%-38%, P < 0.001) and 55% (95% CI: 44%-64%, P < 0.001) lower adjusted odds of cognitive impairment. Carrying the APOE ε4 allele was associated with 17% higher odds (95% CI: 1%-31%, P = 0.042) of being cognitively impaired in the adjusted model. The association between lifestyle profiles and cognitive function did not vary significantly by APOE ε4 genotype (noncarriers: 0.47 [0.37-0.60] healthy versus unhealthy; carriers: 0.33 [0.18-0.58], P for interaction = 0.30). The main limitation was the lifestyle measurements were self-reported and were nonspecific. Generalizability of the findings is another limitation because the study sample was from the oldest old in China, with unique characteristics such as low body weight compared to populations in high-income countries.

CONCLUSIONS

In this study, we observed that healthier lifestyle was associated with better cognitive function among the oldest old regardless of APOE genotype. Our findings may inform the cognitive outlook for those oldest old with high genetic risk of cognitive impairment.

The association between major dietary patterns at dinner and obesity in adults living in Tehran: A population-based study

Introduction: Findings of studies on the association between evening meal and obesity are inconclusive. Thus, we sought to investigate the association between major dietary patterns at evening meal and obesity among apparently healthy adults in Tehran. Methods: This cross-sectional research was conducted using 833 adult men and women who lived in Tehran (age range: 20-59 years). Their dietary intake was evaluated by three, 24-h dietary recalls(24hDRs), and major patterns were identified using exploratory factor analysis. The association between major dietary patterns at dinner with general and central obesity was assessed using logistic regression analysis. Results: We identified 3 major dietary patterns at dinner including "prudent", "potatoes and eggs" and"Western" patterns. There was no significant relationship between prudent and general obesity (OR:0.76, 95% CI = 0.21, 1.15, P value = 0.20), and, a significant association was not observed between potatoes and eggs and general obesity (OR: 0.89, 95% CI = 0.60, 1.32, P value = 0.57) also, there was no significant relationship between Western dietary pattern and general obesity in this study (OR: 0.95,95% CI = 0.63, 1.43, P value = 0.82). Further analyses showed that there was no significant relationship between central obesity with any of the dietary patterns. Conclusion: The results of this study do not support a possible relationship between major dietary patterns at dinner with general and central obesity. However, the presented findings should be confirmed in prospective studies.

Dysbiosis and Alzheimer's Disease: Cause or Treatment Opportunity?

Recent investigations have increased the interest on the connection between the microorganisms inhabiting the gut (gut microbiota) and human health. An imbalance of the intestinal bacteria representation (dysbiosis) could lead to different diseases, ranging from obesity and diabetes, to neurological disorders including Alzheimer's disease (AD). The term "gut-brain axis" refers to a crosstalk between the brain and the gut involving multiple overlapping pathways, including the autonomic, neuroendocrine, and immune systems as well as bacterial metabolites and neuromodulatory molecules. Through this pathway, microbiota can influence the onset and progression of neuropathologies such as AD. This review discusses the possible interaction between the gut microbiome and AD, focusing on the role of gut microbiota in neuroinflammation, cerebrovascular degeneration and Aβ clearance.

Changes in a specific dietary pattern and incident dementia: A prospective cohort study

BACKGROUND & AIMS

Previous studies have reported that the Japanese diet is associated with a lower risk of dementia; however, whether changes in adherence to the Japanese diet affects incident dementia remains unknown. We aimed to evaluate the association between long-term changes in adherence to the Japanese diet and risk of incident dementia among older Japanese individuals.

METHODS

We collected dietary information from community-dwelling older individuals living in Ohsaki city, Japan using a validated 39-item food frequency questionnaire in 1994 and 2006. Adherence to the Japanese diet was assessed using the 8-item Japanese Diet Index (JDI8) score (range: 0 to 8 points). Changes in adherence to the Japanese diet were defined as changes in the JDI8 score from 1994 to 2006. Next, the participants were classified into five groups: great decrease, moderate decrease, no changes [ref.], moderate increase, or great increase. Then, 3146 Japanese adults aged ≥65 years in 2006 were followed-up for 5.7 years. Incident dementia was retrieved from the long-term care insurance database. The Cox proportional hazards model was used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident dementia.

RESULTS

During 14,336 person-years of follow up, 231 cases of dementia were ascertained. Compared with no changes in the JDI8 score, the multivariable-adjusted HRs (95%CIs) were 1.72 (1.13, 2.62) for great decrease, 1.10 (0.73, 1.66) for moderate decrease, 0.82 (0.54, 1.25) for moderate increase, and 0.62 (0.38, 1.02) for great increase (p-trend <0.0001).

CONCLUSIONS

An increase in adherence to the Japanese diet was associated with a reduced risk of incident dementia, whereas a decrease in adherence was associated with an elevated risk among older Japanese individuals.

Association of healthy lifestyle with cognitive function among Chinese older adults

BACKGROUND/OBJECTIVES

Dietary patterns and daily life habits have been reported to be associated with cognitive function in European populations. We aimed to examine the associations of dietary patterns and daily life habits with cognitive function among Chinese old people.

SUBJECTS/METHODS

We used 2011-2014 longitudinal data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) comprising 5716 participants with an average age of 82 years. Cognitive function was measured in 2014 based on the results of Mini-Mental Status Examination. Data on participants' dietary patterns and daily life habits were collected during baseline survey. Logistic regression models and general linear models were adopted to estimate the associations of dietary pattern and daily life habit with cognitive function.

RESULTS

Compared with participants in the lowest quartile of lifestyle score, those in the highest quartile had a lower risk of cognitive impairment after controlling for all covariates (OR = 0.52, 95% confidence interval (CI), 0.41-0.65, P < 0.001). Higher lifestyle score was associated with better cognitive function (β = 0.74, 95% CI, 0.55-0.93, P < 0.001). Participants with top quartile of dietary pattern had a lower risk of cognitive impairment (OR = 0.65, 95% CI, 0.51-0.81, P < 0.001). Similar trends were observed in daily life habit, showing that more exercises, moderate alcohol consumption, and non-smoking were associated with improved cognition status (OR = 0.64, 95% CI, 0.53-0.77, P < 0.001).

CONCLUSIONS

Our findings suggest that maintaining a healthy dietary pattern and carrying out outdoor exercises is associated with a lower risk of cognitive impairment among Chinese old people.

The Effect of Healthy Diet on Cognitive Performance Among Healthy Seniors - A Mini Review

At present, a healthy diet appears to be one of the suitable strategies in slowing down cognitive decline in the process of aging. A number of evidence-based studies confirm its efficacy, safety, and cost-effectiveness. The aim of this mini review is to evaluate and describe recent randomized clinical and cohort studies exploring the effect of healthy diet on cognitive performance among healthy seniors, as well as to update the existing information on this research issue. For these reasons, the authors reviewed full-text, peer-reviewed journal articles written in English and available in Web of Science and PubMed between September 2017 and February 2020. Altogether nine original studies were detected. The results indicate that healthy diet and healthy diet components generally have a positive impact on the enhancement of cognitive functions. Furthermore, the findings reveal that dietary patterns, as well as single nutrients might have a significant effect on specific cognitive domains, such as memory in general, episodic memory, or processing speed. It also seems that a strict adherence to the dietary patterns and a higher diet variety have a more significant effect on the improvement of cognitive functions. Nevertheless, there seem to be gender differences in dietary behavior. More recently, personalized dietary interventions started to be used in delaying cognitive decline among healthy seniors. Therefore, more randomized control trials or N-of-1 trials should be performed in this research area in order to detect the most suitable dietary pattern or nutrients, which would, together with other modifiable lifestyle factors, contribute to the improvement of quality of life of the aging population.

Dietary Inflammatory Potential and the Risk of Neurodegenerative Diseases in Adults

Nutrition and diet have been suggested to enhance or inhibit cognitive performance and the risk of several neurodegenerative diseases. We conducted a systematic review to elucidate the relationship between the inflammatory capacity of a person's diet and the risk of incident neurodegenerative diseases. We searched major medical databases for articles published through June 30, 2018. Original, full-text, English-language articles on studies with human participants which investigated the link between dietary inflammatory potential and risk of developing neurodegenerative diseases were included. Duplicate and irrelevant studies were removed, and data were compiled through critical analysis. Initially, 457 articles were collected via the searching method, of which 196 studies remained after removal of duplicates. Fourteen articles were screened and found to be relevant to the scope of the review. After critical analysis, 10 were included in the final review. In all studies but one, a higher dietary inflammatory index (DII) was related to higher risk of developing neurodegenerative disease symptoms, including memory and cognition decline and multiple sclerosis. Of 3 studies that assessed the association of DII with levels of circulating inflammation markers, 2 indicated that DII was positively correlated with inflammatory marker levels. Low literacy, an unhealthy lifestyle, and individual nutritional status were the factors involved in a diet with inflammatory potential. These findings enhance confidence that DII is an appropriate tool for measurement of dietary inflammatory potential and validate the role of diets with inflammatory potential in the pathophysiology of neurodegenerative diseases. DII may be correlated with levels of circulating inflammatory markers.

Diet, inflammation and the gut microbiome: Mechanisms for obesity-associated cognitive impairment

Poor diet and obesity are associated with cognitive impairment throughout adulthood, and increased dementia risk in aging. Here we review the current literature interrogating the mechanisms by which diets high in fat, or fat and sugar lead to cognitive impairment, focusing on changes to gut microbiome composition, inflammatory signalling and blood-brain barrier integrity. Preclinical studies indicate weight gain is not necessary for diet-induced cognitive impairment. Rather, gut microbiome composition, and systemic and central inflammatory processes appear to contribute to diet-induced cognitive impairment. While both obese humans and rodents exhibit reduced blood-brain barrier integrity, cognitive impairments precede these changes, suggesting other mechanisms may underly diet-induced cognitive changes. Other potential candidates include hormone, glucoregulatory and cardiovascular changes. Poor diet and obesity act through multiple mechanisms to affect cognitive health and the challenge for future research is to identify key processes that can be reversed to improve cognition and quality of life.

A Suboptimal Diet is Associated with Poorer Cognition: The NUDAD Project

Nutrition is one of the modifiable risk factors for cognitive decline and Alzheimer’s disease (AD) dementia, and is therefore highly relevant in the context of prevention. However, knowledge of dietary quality in clinical populations on the spectrum of AD dementia is lacking, therefore we studied the association between dietary quality and cognitive impairment in Alzheimer’s disease (AD) dementia, mild cognitive impairment (MCI) and controls. We included 357 participants from the NUDAD project (134 AD dementia, 90 MCI, 133 controls). We assessed adherence to dietary guidelines (components: vegetables, fruit, fibers, fish, saturated fat, trans-fat, salt, and alcohol), and cognitive performance (domains: memory, language, visuospatial functioning, attention, and executive functioning). In the total population, linear regression analyses showed a lower vegetable intake is associated with poorer global cognition, visuospatial functioning, attention and executive functioning. In AD dementia, lower total adherence to dietary guidelines and higher alcohol intake were associated with poorer memory, a lower vegetable intake with poorer global cognition and executive functioning, and a higher trans-fat intake with poorer executive functioning. In conclusion, a suboptimal diet is associated with more severely impaired cognition—this association is mostly attributable to a lower vegetable intake and is most pronounced in AD dementia.

Effects of soy isoflavones on cognitive function: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

The results of preclinical and observational studies support the beneficial effect of soy isoflavones on cognition.

OBJECTIVE

This review aimed to evaluate the effects of soy isoflavones on cognition in adults.

DATA SOURCES

The PUBMED, EMBASE, Ovid Medline, Cochrane Library, and clinicaltrials.gov databases were searched.

STUDY SELECTION

Two researchers independently screened 1955 records, using the PICOS criteria: participants were adults; intervention was dietary sources with soy isoflavones or isolated soy isoflavones; comparator was any comparator; outcome was cognitive function; study type was randomized controlled trials (RCTs). A third researcher was consulted to resolve any discrepancies. Sixteen RCTs were included and their quality assessed.

DATA EXTRACTION

Information on study design, characteristics of participants, and outcomes was extracted. PRISMA guidelines were followed.

DATA ANALYSIS

A random-effects meta-analysis was used to pool estimates across studies. In the 16 RCTs (1386 participants, mean age = 60 y), soy isoflavones were found to improve overall cognitive function (standardized mean difference [SMD], 0.19; 95% confidence interval [CI], 0.07-0.32) and memory (SMD, 0.15; 95%CI, 0.03-0.26).

CONCLUSION

The results showed that soy isoflavones may improve cognitive function in adults.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42018082070.

Plant-Based Dietary Patterns, Plant Foods, and Age-Related Cognitive Decline

The aging population is expanding, as is the prevalence of age-related cognitive decline (ARCD). Of the several risk factors that predict the onset and progression of ARCD, 2 important modifiable risk factors are diet and physical activity. Dietary patterns that emphasize plant foods can exert neuroprotective effects. In this comprehensive review, we examine studies in humans of plant-based dietary patterns and polyphenol-rich plant foods and their role in either preventing ARCD and/or improving cognitive function. As yet, there is no direct evidence to support the benefits of a vegetarian diet in preventing cognitive decline. However, there is emerging evidence for brain-health-promoting effects of several plant foods rich in polyphenols, anti-inflammatory dietary patterns, and plant-based dietary patterns such as the Mediterranean diet that include a variety of fruits, vegetables, legumes, nuts, and whole grains. The bioactive compounds present in these dietary patterns include antioxidant vitamins, polyphenols, other phytochemicals, and unsaturated fatty acids. In animal models these nutrients and non-nutrients have been shown to enhance neurogenesis, synaptic plasticity, and neuronal survival by reducing oxidative stress and neuroinflammation. In this review, we summarize the mounting evidence in favor of plant-centered dietary patterns, inclusive of polyphenol-rich foods for cognitive well-being. Randomized clinical trials support the role of plant foods (citrus fruits, grapes, berries, cocoa, nuts, green tea, and coffee) in improving specific domains of cognition, most notably frontal executive function. We also identify knowledge gaps and recommend future studies to identify whether plant-exclusive diets have an added cognitive advantage compared with plant-centered diets with fish and/or small amounts of animal foods.

Iron-related dietary pattern increases the risk of poor cognition

INTRODUCTION

High iron intake has been shown to be associated with poor cognition. We aimed to examine the association between iron-related dietary pattern (IDP) and cognitive function in Chinese adults.

METHOD

Longitudinal study data from the China Health and Nutrition Survey (CHNS) during 1991-2006 were used (N = 4852, ≥55 years old). Dietary intake was obtained from a 3-day food record during home visits. Reduced rank regression was used to construct IDP with iron intake as a response variable. Cognitive function was assessed in 1997, 2000, 2004 and 2006. Multivariable mixed linear regression and logistic regression were used in the analyses.

RESULTS

IDP was characterised by high intake of fresh vegetable, wheat, legume, beverage, offal, rice and whole grain. High IDP intake was associated with poor cognition. In fully adjusted models, across the quartiles of IDP, the odds ratio (95% CI) for poor cognitive function were: 1.00, 1.06 (0.86-1.30), 1.24 (0.99-1.54), and 1.50 (1.17-1.93), respectively. There was a borderline significant interaction between IDP and meat intake (p interaction 0.085). The association between high IDP and poor cognition was only observed among those with no or low intake of meat. With the adjustment of carbohydrate or iron intake, the IDP and cognition association became non-significant. IDP was positively associated with lead intake. The association between IDP and poor cognition was partly mediated by lead intake.

CONCLUSIONS

Iron-related dietary pattern is associated with poor cognition in Chinese adults, partly due to high intake of carbohydrate, iron and lead.

Study protocol: associations between dietary patterns, cognitive function and metabolic syndrome in older adults - a cross-sectional study

BACKGROUND

Loss of cognitive function is a significant issue as the world's population ages. Preserving cognitive function maintains independence in older adults bringing major societal and financial benefits. Lifestyle factors such as diet are modifiable risk factors, which may help preserve cognitive function. Most nutrition research aimed at preserving cognitive function and metabolic health has focussed on individual nutrients and foods, not allowing for food combinations and interactions. A dietary pattern approach considers the entire diet including its complexity. Previous research investigating dietary patterns and cognitive function has not always considered relevant covariates such as physical activity and the Apolipoprotein E genotype, which are known to have associations with cognitive function. The aim of the REACH (Researching Eating, Activity and Cognitive Health) study is to investigate associations between dietary patterns, cognitive function and metabolic syndrome, accounting for a range of covariates.

METHODS

This cross-sectional study design will recruit older, community-living adults (65-74 years) from Auckland, New Zealand. Dietary data will be collected via a 109-item food frequency questionnaire validated using a 4-day food record. Cognitive function will be assessed using the Montreal Cognitive Assessment (paper based) and the Computerised Mental Performance Assessment System (COMPASS) - a testing suite covering six domains. Additional data will include genetic (Apolipoprotein E ε4) and biochemical markers (fasting glucose, HbA1c, lipids profile), anthropometric measurements (weight, height, waist and hip circumference, body composition using dual X-ray absorptiometry), blood pressure, physical activity (International Physical Activity Questionnaire - short form) and health and demographics (questionnaire). Dietary patterns will be derived by principal component analysis. Associations between cognitive function and dietary patterns will be examined using multiple regression analysis. Covariates and interaction factors will include age, education, socio-economic status, physical activity, Apolipoprotein E ε4 genotype, family history of dementia or cognitive impairment, and lifestyle factors. Differences between participants with and without metabolic syndrome will also be examined.

DISCUSSION

This study will bring new knowledge regarding associations between dietary patterns and cognitive function and metabolic health in older adults living in New Zealand. This is important for developing nutrition related recommendations to help older adults maintain cognitive function.

A Systematic Review of Principal Component Analysis-Derived Dietary Patterns in Japanese Adults: Are Major Dietary Patterns Reproducible Within a Country?

Principal component analysis (PCA) has been widely used in nutritional epidemiology to derive dietary patterns. However, although PCA-derived dietary patterns are population-dependent, their reproducibility in different populations is largely unexplored. We aimed to investigate whether major dietary patterns are consistently identified among different populations within a country and, if so, how similar these dietary patterns are. We conducted a systematic review of PCA-derived dietary patterns in Japanese adults using PubMed and Web of Science for English articles and Ichushi-Web and CiNii databases for Japanese articles. We assessed the reproducibility of major dietary patterns using congruence coefficients (CCs), with values ≥0.80 considered to represent fair similarity. From 65 articles (80 studies) included in this review, 285 different dietary patterns were identified. Based on the names of these patterns, major dietary patterns were Western (n = 34), Japanese (n = 12), traditional (n = 10), traditional Japanese (n = 9), healthy (n = 18), and prudent (n = 9) patterns. When assessment was limited to high-quality data (i.e., studies based on a sample size ≥200 and use of a validated dietary assessment questionnaire or multiple-day dietary record), the median CC was low for Western (0.44), traditional (0.59), and traditional Japanese (0.31) patterns. Conversely, the median CC was 0.89 for healthy, 0.86 for prudent, and 0.80 for Japanese patterns; and the proportion of pairs with a CC ≥0.80 was 87.3%, 64.3%, and 50.0%, respectively. Characteristics shared among these 3 dietary patterns included higher intakes of mushrooms, seaweeds, vegetables, potatoes, fruits, pulses, and pickles. In conclusion, this systematic review showed that some of the major dietary patterns are relatively reproducible in different populations within a country, whereas others are not. This highlights the importance of careful interpretation of PCA-derived dietary patterns. Our findings in Japan should be confirmed in different countries and globally. This study was registered at https://www.crd.york.ac.uk/prospero/ as CRD42018087669.

Effect of S-equol and Soy Isoflavones on Heart and Brain

BACKGROUND

Observational studies in Asia show that dietary intake of soy isoflavones had a significant inverse association with coronary heart disease (CHD). A recent randomized controlled trial (RCT) of soy isoflavones on atherosclerosis in the US, however, failed to show their benefit. The discrepancy may be due to the much lower prevalence of S-equol producers in Westerners: Only 20-30% of Westerners produce S-equol in contrast to 50-70% in Asians. S-equol is a metabolite of dietary soy isoflavone daidzein by gut microbiome and possesses the most antiatherogenic properties among all isoflavones. Several short-duration RCTs documented that soy isoflavones improves arterial stiffness. Accumulating evidence shows that both atherosclerosis and arterial stiffness are positively associated with cognitive decline/dementia. Therefore, potentially, soy isoflavones, especially S-equol, are protective against cognitive decline/dementia.

METHODS/RESULTS

This narrative review of clinical and epidemiological studies provides an overview of the health benefits of soy isoflavones and introduces S-equol. Second, we review recent evidence on the association of soy isoflavones and S-equol with CHD, atherosclerosis, and arterial stiffness as well as the association of atherosclerosis and arterial stiffness with cognitive decline/ dementia. Third, we highlight recent studies that report the association of soy isoflavones and S-equol with cognitive decline/dementia. Lastly, we discuss the future directions of clinical and epidemiological research on the relationship of S-equol and CHD and dementia.

CONCLUSIONS

Evidence from observational studies and short-term RCTs suggests that S-equol is anti-atherogenic and improves arterial stiffness and may prevent CHD and cognitive impairment/ dementia. Well-designed long-term (≥ 2years) RCTs should be pursued.

The Association Between Eating Green Vegetables Every Day And Mild Cognitive Impairment: A Community-Based Cross-Sectional Study In Shanghai

BACKGROUND

Emerging evidence has suggested that green vegetables may prevent cognitive decline.

METHODS

We examined the cross-sectional association between green vegetables intake and mild cognitive impairment (MCI) using data from 525 participants aged 55 years and above from the China Longitudinal Aging Study (CLAS) in Shanghai.

RESULTS

Compared with participants who did not eat green vegetables every day, those who had consumed green vegetables every day had a significantly lower risk of mild cognitive impairment (MCI) (OR = 0.218, 95% CI, 0.116-0.411, p < 0.001), and this association was independent of age, education, having hobbies, surfing the Internet, sleep time per night (youth), long-term residency and consumption of specific red food, such as meat, bread, bean curd, and ginger.

CONCLUSION

In summary, using community-based data in Shanghai, we found out that subjects who eat green vegetables every day have significantly lower odds of MCI than those who do not eat every day. Based on current evidence, we propose that eating green vegetables every day might be a potential preventive measure to slow cognitive decline and neurodegeneration in the elderly.

Dietary patterns derived by factor analysis are associated with cognitive function among a middle-aged and elder Chinese population

The aim of this study was to assess the association of empirically derived dietary patterns with cognitive function among a middle-aged and elder Chinese population. This study comprised 1676 Chinese adults ≥45 years of age, who participated in a Health Survey and completed semi-quantitative food frequency questionnaire (FFQ) and cognitive screening test in the city of Linyi.We performed factor analysis using the principal component analysis method to identify the major dietary patterns. Binary logistic regression models were used to estimate odds ratio(OR) and 95% confidence interval(CI) for cognitive impairment according to quartiles of each dietary pattern score. Three dietary patterns were identified, namely traditional Chinese, Western-style and grains-fruits-vegetable patterns. A total of 362 participants (101 men and 261 women) were classified as cognitive impaired. After controlling for potential confounders, participants in the highest quartile of the Western-style pattern had a greater OR for incident cognitive impairment, compared to participants in the lowest quartile. Compared with the lowest quartile of grains-fruits-vegetable pattern, the highest quartile had a lower OR for incident cognitive impairment. Conclusions: Our findings demonstrate that the Western-style pattern is associated with an elevated risk and the grains-fruits-vegetables pattern is associated with a decreased risk of cognitive impairment.

Hardness of the habitual diet and its relationship with cognitive function among 70-year-old Japanese elderly: Findings from the SONIC Study

BACKGROUND

There is increasing evidence of causal links between poor mastication and cognitive impairment, but possible effects of dietary hardness, which clearly affects mastication, on cognitive function are unknown.

OBJECTIVE

We investigated the hypothesis that hardness of the habitual diet would be associated with cognitive function among older Japanese adults.

METHODS

The subjects of this cross-sectional study were 635 Japanese community-dwelling people aged 69-71 years. The masticatory muscle activity required for the habitual diet was used to determine dietary hardness. Consumption of 38 foods was assessed by a validated, brief-type, self-administered diet history questionnaire. A published database was then used to estimate the masticatory muscle activity involved in the ingestion of these foods. The Japanese version of the Montreal Cognitive Assessment (MoCA-J) was used for the measurement of cognitive function.

RESULTS

The principal contributors to dietary hardness were cooked rice (28.0%), green leafy vegetables (5.1%), dried fish (4.9%), and pork and beef (4.6%). There was a positive association between dietary hardness and MoCA-J score that was robust to adjustment for potential confounders (MoCA-J score per 100-unit increase in dietary hardness: β = 0.83 [95% CI: 0.08, 1.59], P = 0.03). These results did not change materially even after exclusion of subjects who reported substantial changes in their diet for any reason (β = 0.94 [95% CI: 0.02, 1.86], P = 0.04).

CONCLUSION

This preliminary cross-sectional study suggests that dietary hardness might have a beneficial effect on cognitive function in older Japanese people. Further prospective studies with more accurate measurements are needed to confirm this finding.

Lack of a meaningful association between dietary patterns and in vitro fertilization outcome among Japanese women

PURPOSE

The purpose of this study was to examine whether preconception maternal dietary pattern is associated with in vitro fertilization (IVF) outcome among Japanese women.

METHODS

This prospective study included 140 Japanese women who underwent conventional-IVF/intracytoplasmic sperm injection. The patients' diets during the previous month before egg retrieval were assessed with validated brief-type self-administered diet history questionnaire. Dietary patterns from 33 predefined food groups [energy-adjusted food (g/1000 kcal)] were extracted by factor analysis. The primary outcome measure was clinical pregnancy rate after IVF.

RESULTS

Thirty-six women had confirmed clinical pregnancy. Three dietary patterns were identified: "Vegetable and seafood," "Western," and "Rice and miso soup." The "Vegetables and seafood" dietary pattern (high intakes of green and other vegetables, mushrooms, seasoning, fish, soy products, chicken, and potatoes) was not associated with clinical pregnancy ([odds ratio per one-quartile increase in dietary pattern: 0.94 (95% confidence interval: 0.67-1.32), P = 0.73]. This relationship was unaltered after controlling for potential confounders. Furthermore, no association was seen between the other two dietary patterns and clinical pregnancy.

CONCLUSIONS

The three maternal preconception dietary patterns identified revealed no meaningful association with IVF outcome in Japanese women. Further studies in various populations with different dietary patterns are needed to confirm these findings.