A cross sectional study to examine the association between dietary patterns and cognitive impairment in older Chinese people in Hong Kong

Association between Mediterranean diet and dementia and Alzheimer disease: a systematic review with meta-analysis

BACKGROUND

Dementia affects 5-8% of the population aged over 65 years (~50 million worldwide). Several factors are associated with increased risk, including diet. The Mediterranean diet (MedDiet) has shown potential protective effects against several chronic diseases.

AIMS

This systematic review with meta-analysis aim was to assess the association between adherence to the MedDiet and the risk of dementia in the elderly.

METHODS

PRISMA-2020 guidelines were followed. PubMed/MEDLINE and Scopus were searched on 17 July 2023. The Newcastle-Ottawa Scale tool was used to assess the risk of bias. The protocol was pre-registered in PROSPERO (registration number: CRD 42023444368). Heterogeneity was assessed using the I2 test. Publication bias was assessed by visual inspection of the funnel plot and by Egger's regression asymmetry test. The final effect size was reported as OR or HR, depending on the study design of the included studies.

RESULTS

Out of 682 records, 21 were included in the analysis. The pooled OR was 0.89 (95% CI = 0.84-0.94) based on 65,955 participants (I2 = 69.94). When only cohort studies were included, HR was 0.84 (95% CI = 0.76-0.94) based on 55,205 participants (I2 = 89.70). When only Alzheimer Disease was considered OR was 0.73 (95% CI = 0.62-0.85) based on 38,292 participants (I2 = 63.85).

DISCUSSION

Despite the relatively low risk reduction associated with higher adherence to MedDiet among elderly, it should be considered that this population is the most affected.

CONCLUSIONS

Adherence to MedDiet could be an effective non-pharmacological measure to reduce the burden of dementia, even among elderly.

Nutritional Status and Physical Exercise Are Associated with Cognitive Function in Chinese Community-Dwelling Older Adults: The Role of Happiness

We aim to assess the relationship between nutrition status, physical exercise, and cognitive function and particularly examine how happiness modifies and mediates the relationship, among 699 seniors aged 60 and above in Shanghai, China. Linear regression models were used to validate the effects of nutrition and exercise on cognitive function and to test their interaction effects with happiness. When the interactions were significant, stratified analyses in sub-groups were conducted. Mediation effects of happiness were examined using two-step causal mediation models. We confirmed that better nutrition (p < 0.001) and exercise (p = 0.009) were significantly associated with less cognitive decline. Furthermore, the effects of nutrition and exercise on cognitive decline were significant in the unhappy (happiness < 20) (p < 0.001) and younger (age < 74) sub-groups (p = 0.015). Happiness partially mediated 11.5% of the negative association of cognitive decline with nutrition (p = 0.015) and 23.0% of that with exercise (p = 0.017). This study suggests that happiness moderates and partially mediates the effects of exercise and nutrition on cognitive status. The beneficial effects of exercise and nutrition were stronger in less happy or younger seniors. Future intervention studies are required to confirm this path relationship.

Association of dietary variety with the risk for dementia: the Yabu cohort study

OBJECTIVE

The consumption of various foods is internationally recommended in healthy diet although the association between dietary variety and incident dementia is unknown. We aimed to examine the association between dietary variety and the incidence of disabling dementia in older Japanese adults.

DESIGN

We conducted a prospective cohort study. Dietary variety was assessed based on the Dietary Variety Score (DVS). DVS was assessed by counting the number of ten food components (meat, fish/shellfish, eggs, milk, soyabean products, green/yellow vegetables, potatoes, fruit, seaweed and fats/oils) that were consumed almost daily using a FFQ. Participants were categorised into low (0-2 points), middle (3-4 points) and high (5-10 points) groups based on the DVS. Data on newly diagnosed disabling dementia were retrieved from the public long-term care insurance database. Cox proportional hazards regression was used to estimate hazard ratios (HR) with 95 % CI.

SETTING

Yabu cohort study, Japan.

PARTICIPANTS

A total of 4972 community-dwelling adults aged 65 years or older.

RESULTS

During the median follow-up of 6·8 years, 884 participants were newly diagnosed with disabling dementia. After adjusting for confounders, the multivariable-adjusted HR for incident disabling dementia was 0·82 (95 % CI, 0·69, 0·97) for participants in the highest DVS category compared with those in the lowest DVS category (Pfor trend = 0·019).

CONCLUSIONS

A higher dietary variety is associated with a reduced risk of disabling dementia in older Japanese adults. These results have potential implications for the development of effective public nutritional approaches to prevent dementia in older adults.

Association between Dietary Patterns and Cognitive Function among Qatari Adults: A Cross-Sectional Analysis of the Qatar Biobank Study

This study aimed to assess the association between dietary patterns and cognitive function among Qatari adults. In a cross-sectional analysis, data on 1000 Qatari adults attending the Qatar Biobank Study (QBB) aged ≥18 years were obtained. Using factor analysis, dietary patterns were constructed based on habitual dietary intake assessed by food frequency questionnaires (FFQs). The mean reaction time (MRT) derived from self-administered touch screen tests was used as an indicator of cognitive function. The association between dietary patterns and MRT was investigated using linear regression. The mean age of the participants was 35.8 (SD 10.3) years, and the mean MRT was 715.3 (SD 204.1) milliseconds. Three dietary patterns were identified. The "traditional" dietary pattern, characterized by high intakes of white rice, mixed dishes and soups/starters possibly high in saturated fat and sodium, was positively associated with MRT. In the multivariable model, comparing the highest to lowest quartiles of the traditional pattern, the regression coefficient for MRT was 50.0 (95% CI 16.9, 83.1; p for trend 0.001). There was an effect modification of diabetes and age on the association between the "modern" dietary pattern and MRT. The "convenient" dietary pattern was not associated with cognition. In conclusion, the traditional rice-based dietary pattern may be associated with poor cognitive function.

Dietary Patterns and Alzheimer's Disease: An Updated Review Linking Nutrition to Neuroscience

Alzheimer's disease (AD) is a growing concern for the aging population worldwide. With no current cure or reliable treatments available for AD, prevention is an important and growing area of research. A range of lifestyle and dietary patterns have been studied to identify the most effective preventive lifestyle changes against AD and related dementia (ADRD) pathology. Of these, the most studied dietary patterns are the Mediterranean, DASH, MIND, ketogenic, and modified Mediterranean-ketogenic diets. However, there are discrepancies in the reported benefits among studies examining these dietary patterns. We herein compile a narrative/literature review of existing clinical evidence on the association of these patterns with ADRD symptomology and contemplate their preventive/ameliorative effects on ADRD neuropathology in various clinical milieus. By and large, plant-based dietary patterns have been found to be relatively consistently and positively correlated with preventing and reducing the odds of ADRD. These impacts stem not only from the direct impact of specific dietary components within these patterns on the brain but also from indirect effects through decreasing the deleterious effects of ADRD risk factors, such as diabetes, obesity, and cardiovascular diseases. Importantly, other psychosocial factors influence dietary intake, such as the social connection, which may directly influence diet and lifestyle, thereby also impacting ADRD risk. To this end, prospective research on ADRD should include a holistic approach, including psychosocial considerations.

Dietary patterns and the risk of Alzheimer's disease in an elderly Iranian population: a case-control study

BACKGROUND

An increasing number of studies in Western countries have shown that healthy eating patterns have a protective effect against cognitive decline and dementia, however, information about this relationship among non-western populations with different cultural environments is scarce. The present study investigated the association between dietary patterns (DPs) and cognitive function in the Iranian elderly.

METHODS

In this case-control study, the data of 290 elderly people in two groups of case and control (Mean age in case: 74.2 ± 8.6, in control: 67.3 ± 7.3 year) were analyzed. Two DPs of healthy and unhealthy were extracted from a 142-item dish-based food frequency questionnaire, and patterns driven by principal components analysis (PCA) of 25 food groups. Multivariate binary logistic regression calculated the odds ratio (OR) of cognitive impairment with adjustment for potential confounding factors.

RESULTS

A healthy DP, characterized by high consumption of fruits and vegetables, legumes, and nuts, was related to a decrease in the odds of Alzheimer's disease in Iranian elderly people. Also, moderate adherence to an unhealthy food pattern was associated with an increase in the probability of the disease; however, the association was not statistically significant.

CONCLUSION

In this elderly population, a healthy eating pattern was associated with reducing the risk of Alzheimer's disease. Further prospective studies are recommended.

The Prevalence and Trends of Instrumental Activities of Daily Living Impairments in the United States from 2008-2018

Background

Instrumental activities of daily living (IADL) are neuropsychological-driven tasks that are linked to cognitive dysfunction. Examining population-based IADL deficits may reveal insights for the presence of these impairments in the United States.

Objective

This investigation sought to evaluate the prevalence and trends of IADL impairments in Americans.

Methods

A secondary analysis of data from the 2006-2018 waves of the Health and Retirement Study was conducted. The overall unweighted analytic sample included 29,764 Americans aged≥50 years. Respondents indicated their ability to perform six IADLs: manage money, manage medications, use a telephone, prepare hot meals, shop for groceries, and use a map. Persons reporting difficulty or an inability to complete an individual IADL were considered as having a task-specific impairment. Similarly, those indicating difficulty or an inability to perform any IADL were classified as having an IADL impairment. Sample weights were utilized to generate nationally-representative estimates.

Results

Having an impairment in using a map (2018 wave: 15.7% (95% confidence interval (CI): 15.0-16.4) had the highest prevalence in individual IADLs regardless of wave examined. The overall prevalence of IADL impairments declined during the study period (p < 0.001) to 25.4% (CI: 24.5-26.2) in the 2018 wave. Older Americans and women had a consistently higher prevalence of IADL impairments compared to middle-aged Americans and men, respectively. The prevalence of IADL impairments was also highest among Hispanics and non-Hispanic Blacks.

Conclusion

IADL impairments have declined over time. Continued surveillance of IADLs may help inform cognitive screening, identify subpopulations at risk of impairment, and guide relevant policy.

Mediterranean diet and structural neuroimaging biomarkers of Alzheimer's and cerebrovascular disease: A systematic review

Previous studies have demonstrated an association between adherence to the Mediterranean diet (MedDiet) and better cognitive performance, lower incidence of dementia and lower Alzheimer's disease biomarker burden. The aim of this systematic review was to evaluate the evidence base for MedDiet associations with hippocampal volume and white matter hyperintensity volume (WMHV). We searched systematically for studies reporting on MedDiet and hippocampal volume or WMHV in MedLine, EMBASE, CINAHL and PsycInfo. Searches were initially carried out on 21st July 2021 with final searches run on 23rd November 2022. Risk of bias was assessed using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Of an initial 112 papers identified, seven papers were eligible for inclusion in the review reporting on 21,933 participants. Four studies reported on hippocampal volume, with inconclusive or no associations seen with MedDiet adherence. Two studies found a significant association between higher MedDiet adherence and lower WMHV, while two other studies found no significant associations. Overall these results highlight a gap in our knowledge about the associations between the MedDiet and AD and cerebrovascular related structural neuroimaging findings.

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.

Adherence to High Dietary Diversity and Incident Cognitive Impairment for the Oldest-Old: A Community-Based, Nationwide Cohort Study

BACKGROUND AND AIMS

Dietary diversity change is associated with cognitive function, however, whether the effect still exists among the oldest-old (80+) is unclear. Our aim was to examine the effect of dietary diversity changes on cognitive impairment for the oldest-old in a large prospective cohort.

METHODS

Within the Chinese Longitudinal Healthy Longevity Study, 6237 adults older than 80 years were included. The dietary diversity score (DDS) was assessed by a simplified food frequency questionnaire (FFQ). Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score lower than 18 points. Cognitive decline was defined as a reduction of total MMSE score ≥3 points, and cognitive decline of different subdomains was defined as a reduction of ≥15% in the corresponding cognitive domain. The multivariate-adjusted Cox proportional hazard model evaluated the effects of DDS change on cognitive decline. The linear mixed-effect model was used to test subsequent changes in MMSE over the years.

RESULTS

During 32,813 person-years of follow-up, 1829 participants developed cognitive impairment. Relative to the high-high DDS change pattern, participants in the low-low and high-low patterns were associated with an increased risk of cognitive impairment with a hazard ratio (95% confidential interval, CI) of 1.43 (1.25, 1.63) and 1.44 (1.24, 1.67), and a faster decline in the MMSE score over the follow-up year. Participants with the low-high pattern had a similar incidence of cognitive impairment with HRs (95% CI) of 1.03 (0.88, 1.20). Compared with the stable DDS status group (-1-1), the risk of cognitive impairment was higher for those with large declines in DDS (≤-5) and the HR was 1.70 (95% CI: 1.44, 2.01).

CONCLUSIONS

Even for people older than 80, dietary diversity change is a simple method to identify those who had a high risk of cognitive decline. Keeping high dietary diversity is beneficial for cognitive function and its subdomain even in the final phase of life, especially for females and the illiterate oldest-old.

A healthy plant-based diet was associated with slower cognitive decline in African American older adults: a biracial community-based cohort

BACKGROUND

African American (AA) adults have about twice the risk of developing dementia compared with white adults. However, evidence on dietary modification in preventing cognitive decline from diverse populations focusing on AA adults is minimal.

OBJECTIVES

We aimed to evaluate the association between a plant-based diet and the rate of cognitive decline in a population-based sample of AA and white adults.

METHODS

This study consisted of 3337 participants from the Chicago Health and Aging Project (60% AA participants, 64% female). Plant-based diet quality was evaluated by the overall plant-based diet index (PDI), the healthful PDI (hPDI), and the unhealthful PDI (uPDI). Global cognition was assessed using a composite score of 4 individual tests of cognition. We used mixed models to examine the associations of PDI, hPDI, and uPDI with the rates of decline in global cognition, perceptual speed, and episodic memory. Models were adjusted for age, sex, presence of apoE e4 allele, lifestyle factors including education, cognitive activities, smoking status, calorie intake, risk factors for cardiovascular disease, time, and the interaction terms of time × each covariate.

RESULTS

AA and white participants had various dietary patterns. Higher hPDI was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AA participants but not white participants. AA study participants in the highest quintile of hPDI had significantly slower rates of global cognitive decline (β: 0.0183 ± 0.0086; P = 0.032), perceptual speed (β: 0.0179 ± 0.0088; P = 0.04), and episodic memory (β: 0.0163 ± 0.0118; P = 0.04) than individuals in the lowest quintile of hPDI. There were no associations of either PDI or uPDI with the rate of cognitive decline in either racial group.

CONCLUSIONS

A healthy plant-based diet was associated with a slower rate of decline in global cognition, perceptual speed, and episodic memory in AA adults.

Fruit and Vegetable Consumption and Cognitive Disorders in Older Adults: A Meta-Analysis of Observational Studies

Objectives

The aim of this meta-analysis was to assess the quantitative associations between fruit and vegetable intake and cognitive disorders in older adults.

Design

A meta-analysis.

Setting and Participants

We used the PubMed, Web of Science and Scopus databases for a literature search to 12 April 2022. We preliminarily retrieved 11,759 studies, 16 of which met the inclusion criteria including six cross-sectional studies, nine cohort studies and one case-control study, incorporating 64,348 participants and 9,879 cases.

Methods

Using the three databases, we identified observational studies exploring the association. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model.

Results

Sixteen studies were included in the meta-analysis, and the results showed that increased fruit and vegetable consumption in older adults was associated with a decline in the prevalence of cognitive disorders (OR: 0.79, 95% CI: 0.76–0.83). Moreover, intake of fruits (OR: 0.83, 95% CI: 0.77–0.89) and vegetables (OR: 0.75, 95% CI: 0.70–0.80) alone were both associated with a lower prevalence of cognitive disorders. Subgroup analyses indicated that the intake of fruits and vegetables was associated with the prevalence of cognitive impairment (OR: 0.72, 95% CI: 0.76–0.80) and dementia (OR: 0.84, 95% CI: 0.78–0.91) but not Alzheimer’s disease (OR: 0.88, 95% CI: 0.76–1.01).

Conclusion and Implications

Our meta-analysis provides evidence that the intake of fruits and vegetables is inversely proportional and linearly associated with the prevalence of cognitive disorders in older adults. Future research is required to further investigate the preventive effects of the frequency, quantity, and duration of eating vegetables and fruits on cognitive disorders in older adults.

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.

Higher fruit and vegetable variety associated with lower risk of cognitive impairment in Chinese community-dwelling older men: a 4-year cohort study

PURPOSE

Few studies have examined the variety in fruit and vegetable (FV) intake with cognitive impairment in older adults. This study examined the associations of variety in fruit, vegetable and combined FV with 4-year incident cognitive impairment in Chinese community-dwelling older adults.

METHODS

Data was derived from a cohort study among Chinese community-dwelling older adults aged ≥ 65 years in Hong Kong. At baseline, a validated food frequency questionnaire was used to assess variety in fruit, vegetable and combined FV. Cognitive impairment was defined as a Community Screening Instrument of Dementia score of < 29.5 points and/or Mini-Mental State Examination score of < 27 points. Adjusted multiple logistic regression was performed to examine the associations. Results are presented as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Of the 1518 participants [median age: 70 years (IQR 68-74), 32.7% women] included at baseline, 300 men and 111 women were newly identified as cognitively impaired at the 4-year follow-up. In men, higher variety in vegetable (adjusted OR: 0.97, 95% CI 0.95-0.99, p = 0.029) and combined FV (adjusted OR: 0.98, 95% CI 0.96-0.98, p = 0.039) were significantly associated with a lower risk of cognitive impairment. Fruit variety was not associated with cognitive impairment. In women, there were no associations between variety in fruit, vegetable and combined FV with cognitive impairment in the adjusted model.

CONCLUSION

Independent of FV quantity, higher variety in vegetable and combined FV were associated with lower risk of cognitive impairment in Chinese community-dwelling older adults, and these associations were only observed in men.

A China Healthy Diet Index-Based Evaluation of Dietary Quality among Pregnant Women in Shanghai across Trimesters and Residential Areas

Good dietary quality among pregnant women is critical for maternal and fetal health. The primary objective of our study was to analyze the dietary quality of pregnant woman and its influencing factors. Pregnant women were enrolled using a multistage, stratified, random-sampling method in Shanghai. We used a personal food frequency questionnaire and a household condiment weighing method for dietary assessments. Participants' scores on the China Healthy Diet Index (CHDI) were analyzed to evaluate diet quality. Significant differences in the median daily intake of almost all food types were found across all trimesters, and all food types were found across all residential areas (urban, suburban and rural). The median of total CHDI score was 71.6 in all subjects, 71.1 in early pregnancy, 71.5 in middle pregnancy and 72.3 in late pregnancy. The results of uni-variate analysis showed that significant differences in CHDI scores were found across trimesters and residential areas. Eighty one point six percent of participants scored below 80 points, indicating general or poor dietary quality. Logistic regression models showed that participants in early and middle pregnancy had lower scores than those in late pregnancy. Women in urban areas had higher scores than those in suburban and rural areas. Most of pregnant women living in Shanghai suffer from a general or poor dietary quality. Education on balance diet should be strengthened to guide pregnant women in making reasonable food choices and intake, especially those living in suburban and rural areas and those in their first and second trimesters.

Adherence to Mediterranean Diet and Cognitive Abilities in the Greek Cohort of Epirus Health Study

The Mediterranean diet is commonly proposed as a major modifiable protective factor that may delay cognitive impairment in the elderly. The aim of the study was to investigate the cross-sectional association of adherence to the Mediterranean diet with cognitive abilities in a younger Greek population. A total of 1201 healthy adults aged 21-77 years (mean: 47.8) from the Epirus Health Study cohort were included in the analysis. Adherence to the Mediterranean diet was measured using the 14-point Mediterranean Diet Adherence Screener (MEDAS) and cognition was measured using the Trail Making Test, the Verbal Fluency test and the Logical Memory test. Statistical analysis was performed using multiple linear regression models adjusted for age, sex, education, body mass index, smoking status, alcohol consumption and physical activity. Overall, no association was found between the MEDAS score and cognitive tests, which could be explained by the young mean age and high level of education of the participants. Future studies should target young and middle-aged individuals to gain further understanding of the association between Mediterranean diet and cognition in this age group.

Cross-sectional and longitudinal associations between adherence to Mediterranean diet with physical performance and cognitive function in older adults: A systematic review and meta-analysis

OBJECTIVES

The present study investigated the association between adherence to Mediterranean diet (MeDi) and physical performance and cognitive function in older adults.

METHODS

We conducted a systematic review and meta-analysis of cross-sectional and longitudinal studies that investigated older adults aged 60+ years and assessed adherence to MeDi diet using validated composite scores. Observational studies, including cross-sectional, case-control, and longitudinal cohort studies, if crude baseline data was available, which investigated as a primary or secondary outcome the association of MeDi diet adherence with physical performance and/or cognitive function in non-demented older adults were included in the cross-sectional analysis. For the longitudinal analysis, case-control and longitudinal cohort studies that investigated the longitudinal associations between adherence to MeDi diet with the incidence of mild cognitive impairment (MCI), dementia, and/or Alzheimer's disease (AD), and/or changes in physical performance and cognition in non-demented older adults were included. Studies published in other languages than English were excluded. Studies were retrieved from MEDLINE, SCOPUS, CINAHL, and AgeLine databases until May 19, 2021. The risk of bias was evaluated using the Newcastle - Ottawa Quality Assessment Scale (NOS). A pooled effect size was calculated based on standard mean differences (SMD), log odds ratio (OR) and log risk ratio (RR). This study is registered on PROSPERO (CRD42021250254).

RESULTS

Nineteen cross-sectional studies that investigated 19.734 community-dwelling and institutionalized older adults free of disability and dementia were included. A high adherence to MeDi was cross-sectionally associated with better walking speed (SMD = 0.42; 95 % Confidence Interval (CI) = 0.12-0.72, P = 0.006; I² = 65 %, P = 0.06), knee muscle strength speed (SMD = 0.26; 95 % CI = 0.17-0.36, P < 0.00001; I² = 0 %, P = 0.69), global cognition (SMD = 0.24; 95 % CI = 0.15-0.33, P < 0.00001; I² = 85 %, P < 0.00001), and memory (SMD = 0.18; 95 % CI = 0.13-0.25, P < 0.00001; I² = 100 %, P < 0.00001). The association between MeDi adherence and global cognition remained significant after stratifying the analysis by the region where the study was conducted, MeDi diet adherence composite score, and Mini Mental State Examination (MMSE). Studies had a moderate to low risk of bias. In relation to longitudinal analysis, thirty-four prospective studies with an average follow-up period that varied from 3.0 to 12.6 years and investigated 98.315 community-dwellers were included. Results indicated that older adults with high MeDi scores had a lower decline in global cognition RR = 0.26; 95 % CI = 0.23-0.29, P < 0.00001; I² = 100 %, P < 0.00001). In contrast, no significant associations between MeDi and mobility, MCI, dementia were found. A low risk of bias was found in the longitudinal studies.

DISCUSSION

Findings of the present study indicated that high adherence to MeDi was cross-sectionally associated with physical performance and cognitive function. Results of the pooled analysis of longitudinal studies revealed that high adherence to MeDi reduced the risk of global cognitive decline in non-demented older adults. However, no significant associations between MeDi adherence and the incidence of mobility problems, MCI, and dementia were found. Although important, our findings should be carefully interpreted due to the presence of heterogeneity and publication bias.

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.

Carotenoid-Rich Brain Nutrient Pattern Is Positively Correlated With Higher Cognition and Lower Depression in the Oldest Old With No Dementia

Background: Healthy dietary patterns are related to better cognitive health in aging populations. While levels of individual nutrients in neural tissues are individually associated with cognitive function, the investigation of nutrient patterns in human brain tissue has not been conducted. Methods: Brain tissues were acquired from frontal and temporal cortices of 47 centenarians from the Georgia Centenarian Study. Fat-soluble nutrients (carotenoids, vitamins A, E, K, and fatty acids [FA]) were measured and averaged from the two brain regions. Nutrient patterns were constructed using principal component analysis. Cognitive composite scores were constructed from cognitive assessment from the time point closest to death. Dementia status was rated by Global Deterioration Scale (GDS). Pearson's correlation coefficients between NP scores and cognitive composite scores were calculated controlling for sex, education, hypertension, diabetes, and APOE ε4 allele. Result: Among non-demented subjects (GDS = 1-3, n = 23), a nutrient pattern higher in carotenoids was consistently associated with better performance on global cognition (r = 0.38, p = 0.070), memory (r = 0.38, p = 0.073), language (r = 0.42, p = 0.046), and lower depression (r = -0.40, p = 0.090). The findings were confirmed with univariate analysis. Conclusion: Both multivariate and univariate analyses demonstrate that brain nutrient pattern explained mainly by carotenoid concentrations is correlated with cognitive function among subjects who had no dementia. Investigation of their synergistic roles on the prevention of age-related cognitive impairment remains to be performed.

Race/ethnicity and gender modify the association between diet and cognition in U.S. older adults: National Health and Nutrition Examination Survey 2011-2014

INTRODUCTION

It is unclear whether the association between Mediterranean-type Diet (MeDi) and cognition is similar across different racial/ethnic groups or between women and men.

METHODS

The current study included 2435 participants (≥60 years of age) of the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Linear regression models were applied to examine the association between diet and cognition, adjusted for multiple demographic variables. Interaction between MeDi and race/ethnicity (non-Hispanic White, non-Hispanic Black, Hispanic, other), and between MeDi and gender, were examined, followed by stratified analyses.

RESULTS

One score increase in MeDi was associated with 0.039 (95%confidence interval [CI] = 0.016-0.062) higher global cognitive z-score. Significant associations between MeDi and global cognition and between MeDi and immediate recall were found in the non-Hispanic Whites only (P-interaction = 0.057 and 0.059, respectively). MeDi was associated with increased score of animal fluency score in men but not in women (P-interaction = 0.082).

DISCUSSION

The positive association between MeDi and cognition might be dependent on race/ethnicity and gender.

Association Between Dietary Fish and PUFA Intake in Midlife and Dementia in Later Life: The JPHC Saku Mental Health Study

BACKGROUND

The relationship between midlife dietary habits and risk of dementia remains unclear.

OBJECTIVE

To investigate the association between dietary fish and n-3 polyunsaturated fatty acid (PUFA) consumption in midlife and risk of dementia in later life.

METHODS

This population-based cohort study assessed food frequency (average intake in 1995 and 2000) and cognition (2014-2015) in 1,127 participants (aged 45-64 in 1995). We used logistic regression analyses to calculate odds ratios (ORs) for dementia and mild cognitive impairment (MCI) diagnoses for consumption quartiles of fish, PUFA-rich fish, total n-3 PUFAs, total n-6 PUFAs, types of PUFAs, and n-3/n-6 PUFA ratio. Estimated ORs were adjusted for age; sex; education; smoking status; alcohol consumption frequency; physical activity; histories of cancer, myocardial infarction, and diabetes mellitus; and depression.

RESULTS

Significantly reduced risks of dementia over non-dementia (MCI plus cognitively normal) were observed in the second (OR = 0.43 (95% CI = 0.20-0.93)), third (OR = 0.22 (95% CI = 0.09-0.54)), and highest quartiles (OR = 0.39 (95% CI = 0.18-0.86)) for fish; the third (OR = 0.39 (95% CI = 0.16-0.92)) and highest quartiles (OR = 0.44 (95% CI = 0.19-0.98)) for eicosapentaenoic acid (EPA); the second (OR = 0.39 (95% CI = 0.18-0.84)), third (OR = 0.30 (95% CI = 0.13-0.70)), and highest quartiles (OR = 0.28 (95% CI = 0.12-0.66)) for docosahexaenoic acid (DHA); and the third (OR = 0.36 (95% CI = 0.16-0.85)) and highest quartiles (OR = 0.42 (95% CI = 0.19-0.95)) for docosapentaenoic acid (DPA).

CONCLUSION

High intake of fish in midlife might aid in preventing dementia.

Can Healthy Diets, Regular Exercise, and Better Lifestyle Delay the Progression of Dementia in Elderly Individuals?

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and multiple cognitive impairments. Current healthcare costs for over 50 million people afflicted with AD are about $818 million and are projected to be $2 billion by 2050. Unfortunately, there are no drugs currently available that can delay and/or prevent the progression of disease in elderly individuals and in AD patients. Loss of synapses and synaptic damage are largely correlated with cognitive decline in AD patients. Women are at a higher lifetime risk of developing AD encompassing two-thirds of the total AD afflicted population. Only about 1-2% of total AD patients can be explained by genetic mutations in APP, PS1, and PS2 genes. Several risk factors have been identified, such as Apolipoprotein E4 genotype, type 2 diabetes, traumatic brain injury, depression, and hormonal imbalance, are reported to be associated with late-onset AD. Strong evidence reveals that antioxidant enriched diets and regular exercise reduces toxic radicals, enhances mitochondrial function and synaptic activity, and improves cognitive function in elderly populations. Current available data on the use of antioxidants in mouse models of AD and antioxidant(s) supplements in diets of elderly individuals were investigated. The use of antioxidants in randomized clinical trials in AD patients was also critically assessed. Based on our survey of current literature and findings, we cautiously conclude that healthy diets, regular exercise, and improved lifestyle can delay dementia progression and reduce the risk of AD in elderly individuals and reverse subjects with mild cognitive impairment to a non-demented state.

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.

Dietary patterns and risk of mild cognitive impairment among Chinese elderly: A cross-sectional study

Objective

To investigate the relationship between food patterns and mild cognitive impairment (MCI) among Chinese elderly to provide evidence for risk prevention and control of MCI among elderly population.

Methods

Between February 2017 to October 2018, a stratified multistage cluster sampling method was used to select participants from 760 communities of six districts in Xi’an, China, for 49-item food frequency questionnaire survey. A total of 2311 participants aged 60 to 88 years were included in the study with 444 (19.2%) participants of MCI among Chinese community-dwelling elderly adults. Food patterns associated with risk of dementia were assessed by using a reduced rank regression (RRR) analysis, and the multivariate linear regression was used to test trends of risk factors across scores for the food pattern.

Results

Four dietary patterns were extracted which explained 88.65% of the total variation in food intakes. Furthermore, the food pattern 1 (FP1) accounted for 60.25% of the total variation of all responsible variables and as a target dietary pattern in the study, which was related with high intake of legumes, vegetables, fruits, milk and dairy products, nuts and a low intake of noodles and cereals (p<0.05). Multivariate linear regression analysis showed that participants with a high score for FP1 had higher direction, memory and language function and FP1 can improve the ability of cognitive function (p<0.05).

Conclusion

The FP1 of Chinese dietary patterns was significantly correlated with higher cognitive function which can reduce the risk of MCI among Chinese elderly.

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.

Higher ultra-processed food intake is associated with higher DNA damage in healthy adolescents

Ultra-processed food is one of the main contributors to energy supply and consumption in food systems worldwide, and evidence of their detrimental health outcomes in humans is emerging. This study aimed to assess ultra-processed food intake and its association with urinary levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker of DNA oxidative damage, in 139 healthy adolescents in Karaj City in Iran. Usual dietary intake was measured using a 168-item validated FFQ. The daily intake of ultra-processed food consumption was determined through the classification of NOVA, and general linear models were used to compare the urinary levels of 8-OHdG/creatinine (ng/mg creatinine) within tertiles of ultra-processed food intake. Adolescents in the higher tertile of ultra-processed food consumption had a significantly higher mean level of urinary 8-OHdG/creatinine in comparison with the lower tertiles in the crude model (Pfor trend: 0·003) and after adjustment for confounding variables, including total energy intake, sex, age, BMI for age Z-score, obesity and physical activity (Pfor trend: 0·004). This association was still significant after adjusting for dietary intake of whole grains, nuts, legumes, the ratio of MUFA:SFA (g/d) and Mediterranean dietary score (Pfor trend: 0·002). More studies are needed to explore the determinants of ultra-processed food supply, demand, consumption and health effects; such studies should be applied to develop evidence-informed policies and regulatory mechanisms to improve children’s and adolescents’ food environment policymaking and legislation with special attention to ultra-processed food.

Dietary Patterns and Cognitive Decline: key features for prevention

The decline in cognitive function is generally the result of the complex interaction of several factors. First of all, age, but also demographic, educational, genetic, socio-economic, and environmental determinants, including nutrition. Cognitive decline and dementia prevalence are increasing, and they are projected to continue increasing in the next decades due to the aging of the world population. Currently, there are no effective pharmacological treatments for these devastating and disabling conditions, which emphasize the key role of preventive strategies. There is compelling evidence of the role of diet and lifestyle on cognitive function. Therefore, dietary/ nutritional approaches that contribute to prevent, or slow cognitive decline may have a remarkable public health impact. Numerous studies have explored the role of dietary components and patterns on age-associated cognitive decline, with accruing evidence that combinations of foods and nutrients can have synergistic effects beyond those attributable to individual foods or nutrients. Dietary patterns show the strongest evidence for slowing the development of cognitive decline, Alzheimer's disease and other dementias including the Mediterranean diet, the Dietary Approaches to Stop Hypertension diet, and their combination (the MedDiet-DASH Intervention for Neurodegenerative Delay - MIND), among others with few positive results. There are also dietary patterns with no evidence of such effects. This review examines the evidence for the effects of some dietary patterns as neuroprotective with a potential to delay cognitive decline and the onset of dementia.

The Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) Diets Are Associated with Less Cognitive Decline and a Lower Risk of Alzheimer's Disease-A Review

As there is currently no cure for dementia, there is an urgent need for preventive strategies. The current review provides an overview of the existing evidence examining the associations of the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets and their dietary components with cognitive decline, dementia, and Alzheimer's disease (AD). A systematic search was conducted within Ovid Medline for studies published up to 27 March 2019 and reference lists from existing reviews and select articles were examined to supplement the electronic search results. In total, 56 articles were included. Higher adherence to the Mediterranean diet was associated with better cognitive scores in 9 of 12 cross-sectional studies, 17 of 25 longitudinal studies, and 1 of 3 trials. Higher adherence to the DASH diet was associated with better cognitive function in 1 cross-sectional study, 2 of 5 longitudinal studies, and 1 trial. Higher adherence to the MIND diet was associated with better cognitive scores in 1 cross-sectional study and 2 of 3 longitudinal studies. Evidence on the association of these dietary patterns with dementia in general was limited. However, higher adherence to the Mediterranean diet was associated with a lower risk of AD in 1 case-control study and 6 of 8 longitudinal studies. Moreover, higher adherence to the DASH or MIND diets was associated with a lower AD risk in 1 longitudinal study. With respect to the components of these dietary patterns, olive oil may be associated with less cognitive decline. In conclusion, current scientific evidence suggests that higher adherence to the Mediterranean, DASH, or MIND diets is associated with less cognitive decline and a lower risk of AD, where the strongest associations are observed for the MIND diet.

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.

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 impact of nutrient-based dietary patterns on cognitive decline in older adults

BACKGROUND & AIMS

The impact of nutrient patterns on cognitive decline is complex and findings are still inconclusive. We aimed to identify major nutrient patterns and to explore their association with cognitive decline over time among older adults.

METHODS

In a population-based cohort, 2250 cognitively healthy people aged ≥60 years were identified at baseline (2001-2004), and followed-up to 9 years. Global cognitive function was tested with the Mini-Mental State Examination (MMSE) at baseline and follow-ups. Nutrients intake was assessed on the basis of food intake using a 98-semi-quantitative food frequency questionnaire at baseline, and nutrient-based patterns were identified by principal components analysis based on 30 nutrients. Mixed-effects linear regression models were used to determine their association with change in cognitive function taking into account potential confounders.

RESULTS

Four major patterns (the plant-, animal-, dairy-derived nutrients and animal/plants-derived fats) were identified. Over the follow-up time, each one unit increment in plant- (β = 0.081, P = 0.002) and animal-derived nutrients pattern scores (β = 0.098, P < 0.001) was associated with slower decline in MMSE score. On the other hand, one-unit higher in dairy-derived nutrients pattern was related to a faster decline in global cognitive function (β = -0.064, P = 0.014). No significant association between animal/plants fats pattern and cognitive decline was observed. In stratified analyses, the association of high scores of plants- and animal-derived nutrient pattern with slower cognitive decline was stronger in APOE ε4 carriers than in ε4 non-carriers.

CONCLUSIONS

Plant- and animal -derived nutrients are associated with preserved cognitive function, especially among the APOE ε4 carriers, whereas nutrients derived from dairy products may accelerate cognitive decline in older adults.

A comprehensive overview on osteoporosis and its risk factors

Osteoporosis is a bone disorder with remarkable changes in bone biologic material and consequent bone structural distraction, affecting millions of people around the world from different ethnic groups. Bone fragility is the worse outcome of the disease, which needs long term therapy and medical management, especially in the elderly. Many involved genes including environmental factors have been introduced as the disease risk factors so far, of which genes should be considered as effective early diagnosis biomarkers, especially for the individuals from high-risk families. In this review, a number of important criteria involved in osteoporosis are addressed and discussed.

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.

Study of community-living Alzheimer's patients' adherence to the Mediterranean diet and risks of malnutrition at different disease stages

Background

Alzheimer’s disease (AD) is a neurodegenerative disease that is characterized by deficits in episodic memory. It is the most common form of dementia and affects 50–70% of patients with cognitive impairments over the age of 65. Elderly people are particularly susceptible to malnutrition and that risk is even higher in patients with AD. This study assessed the nutritional status of patients with AD at different stages of AD and explored how that status correlated with cognitive, functional and behavioural variables and caregiver overburden. The characteristics of the diet and the degree of adherence to the Mediterranean diet were also analysed.

Methods

This was a cross-sectional study that was representative of the general population and it was carried out in the Unit of Cognitive Disorders, Lleida, Spain. The participants were 111 subjects with AD who were aged 65 and over and still living at home. The subjects’ nutritional status was assessed using the Mini Nutritional Assessment (MNA) and Controlling Nutritional Status system. The monthly food intake was estimated using the short Food Frequency Questionnaire and adherence to the Mediterranean diet was evaluated using the Mediterranean Diet Score. The Mini Mental State Examination (MMSE), Global Deterioration Scale, Neuropsychiatric Inventory (NPI) and Zarit Burden Interview (ZBI) were also used.

Results

We found that 68% of the subjects presented with a risk of malnutrition and 19% were malnourished according to the MNA scale. Patients ate a higher quantity of meat and dairy products than recommended and fewer products from the remaining healthier food groups. Of the 111 subjects, 73% showed low adherence to the Mediterranean diet and 27% showed moderate adherence. There was a partial correlation between nutritional status and the MMSE when the data were adjusted for age and sex (r = 0, 318; p = 0.001) and inverse correlations were found for functional status (r =  − 0.283; p = 0.004) and the NPI (r =  − 0.409; p = 0.000) and ZBI scales (r =  − 0.433; p = 0.000) when they were adjusted using the same variables. The ZBI scale (OR 1.08, 95% CI [1.01–1.15]) showed an increase in the risk of malnutrition in the multivariate analysis.

Discussion

Alterations in nutritional status were more common during the advanced stages of AD and were also associated with behavioural changes and caregiver overburden. Low adherence to traditional healthy diets in Mediterranean countries and food intake profiles should be considered when managing patients with AD. Other countries can use the results to examine diets in people with AD that are high in meat and dairy and low in healthy food groups like fruit and vegetables.

An exploration of the role of a fish-oriented diet in cognitive decline: a systematic review of the literature

Epidemiological studies have presented inconsistent evidence of the correlation between a fish-oriented dietary intake (FDI) and the risk of cognitive decline. To address these controversies, we performed this systematic review of prospective studies published in December 2016 and earlier using PubMed, Embase, and Web of Science. Two independent researchers conducted the eligibility assessment and data extraction; all discrepancies were solved by discussion with a third researcher. The pooled relative risks (RRs) focused on the incidence of events were estimated with 95% confidence intervals (CIs). Overall, nine studies containing 28,754 subjects were analyzed. When the highest and lowest categories of fish consumption were compared, the summary RR for dementia of Alzheimer type (DAT) was 0.80 (95%CI = 0.65–0.97); i.e., people with a higher intake of fish had a 20% (95%CI = 3–35%) decreased risk of DAT. Additionally, the dose-response synthesized data indicated that a 100-g/week increase in fish intake reduced the risk of DAT by an additional 12% (RR = 0.88, 95%CI = 0.79–0.99). Non-significant results were observed for the risk of dementia of all causes (DAC) and mild cognitive impairment (MCI). Limited evidence involving heterogeneity was found within subgroups or across studies. In conclusion, this review confirmed that a higher intake of fish could be correlated with a reduced risk of DAT. Further research, especially prospective studies that specifically quantify FDI, will help find a more accurate assessment of the different levels of dietary intake.

Dietary Patterns Associated with Cognitive Function among the Older People in Underdeveloped Regions: Finding from the NCDFaC Study

Although dietary patterns are crucial to cognitive function, associations of dietary patterns with cognitive function have not yet been fully understood. This cross-sectional study explored dietary patterns associated with cognitive function among the older adults in underdeveloped regions, using 1504 community-dwelling older adults aged 60 and over. Diet was assessed using a food frequency questionnaire and 24-h dietary recall. Factor analysis was used to extract dietary patterns. Global cognitive function was assessed using the Mini-Mental State Examination (MMSE). Two dietary patterns, a “mushroom, vegetable, and fruits” (MVF) pattern and a “meat and soybean products” (MS) pattern, were identified. The MVF pattern, characterized by high consumption of mushrooms, vegetables, and fruits was significantly positively associated with cognitive function (p < 0.05), with an odds ratio of (95% CIs) 0.60 (0.38, 0.94) for cognitive impairment and β (95% CIs) 0.15 (0.02, 0.29) for –log (31-MMSE score). The MS pattern, characterized by high consumption of soybean products and meat, was also associated with better cognitive function, with an odds ratio of 0.47 (95% CIs 0.30, 0.74) for cognitive impairment and β (95% CIs) 0.34 (0.21, 0.47) for –log (31-MMSE score). Our results suggested that both the MVF and MS patterns were positively associated with better cognitive function among older adults in underdeveloped regions.

Mediterranean Diet and Cognitive Status in Free-Living Elderly: A Cross-Sectional Study in Northern Italy

OBJECTIVE

Few data are available on the Italian elderly population with regard to adherence to the Mediterranean diet (MD) and cognitive impairment. Our aim was to investigate adherence to the MD and its association with cognitive function in an Italian urban sample.

METHODS

A cross-sectional study of 279 participants aged ≥ 65 years (80 men, 199 women) was carried out at a nutritional center. Adherence to the MD was evaluated using a 14-item questionnaire. Cognitive function was assessed with the Mini-Mental State Examination (MMSE).

RESULTS

The clinical and nutritional assessments performed revealed 30.1% to have a dietary pattern in accordance with the MD; 13.6% had suspected or mild cognitive impairment (MMSE score ≤ 23). The MD pattern was associated with a lower risk of cognitive impairment (odds ratio [OR] = 0.39; 95% confidence interval [CI], 0.15-0.99; p = 0.045), as was the consumption of wine (OR = 0.37; 95% CI, 0.16-0.84; p = 0.018) and nuts (OR = 0.30; 95% CI, 0.13-0.69, p = 0.005). No association was found with other food groups.

CONCLUSION

A closer adherence to the MD was associated with a better cognitive status. Further cohort studies and randomized controlled trials are warranted.

Dietary inflammatory index and memory function: population-based national sample of elderly Americans

The objective of this study was to examine the association between dietary inflammatory potential and memory and cognitive functioning among a representative sample of the US older adult population. Cross-sectional data from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Survey were utilised to identify an aggregate sample of adults 60-85 years of age (n 1723). Dietary inflammatory index (DII®) scores were calculated using 24-h dietary recall interviews. Three memory-related assessments were employed, including the Consortium to Establish a Registry for Alzheimer's disease (CERAD) Word Learning subset, the Animal Fluency test and the Digit Symbol Substitution Test (DSST). Inverse associations were observed between DII scores and the different memory parameters. Episodic memory (CERAD) (b adjusted=-0·39; 95 % CI -0·79, 0·00), semantic-based memory (Animal Fluency Test) (b adjusted=-1·18; 95 % CI -2·17, -0·20) and executive function and working-memory (DSST) (b adjusted=-2·80; 95 % CI -5·58, -0·02) performances were lowest among those with the highest mean DII score. Though inverse relationships were observed between DII scores and memory and cognitive functioning, future work is needed to further explore the neurobiological mechanisms underlying the complex relationship between inflammation-related dietary behaviour and memory and cognition.

Effect of the replacement of dietary vegetable oils with a low dose of extravirgin olive oil in the Mediterranean Diet on cognitive functions in the elderly

BACKGROUND

Numerous studies have investigated the role of the monounsaturated fatty acid and other dietary factors in the prevention of cognitive decline but the short-term effect of a low dose of extravirgin olive oil on cognitive performances in the elderly have not still been investigated. Our aim was to investigate whether the replacement of all vegetable oils with a lower amount of extravirgin olive oil, in the contest of a Mediterranean Diet, would improve cognitive performances, among elderly Italian individuals.

METHODS

180 elderly individuals were randomly assigned to these treatment groups for 1 year: (1) MedDiet plus extravirgin OO, 20-30 g/day; (2) control MedDiet. The cognitive sub-test of ADAScale was used to detect cognitive decline progression over 12 months.

RESULTS

ADAS-cog score variation after 1 year, adjusted for food groups which were different between groups, was - 1.6 ± 0.4 and - 3.0 ± 0.4 in the MedDiet and MedDiet plus extravirgin OO groups, respectively (p = 0.024). Extravirgin OO intake was 30 g ± 12 and 26 g ± 6 in the MedDiet and MedDiet plus extravirgin OO groups, respectively (p = 0.044).

CONCLUSIONS

We demonstrated the higher short-term improvement of cognitive functions scores in individuals of the MedDiet plus low dose of extravirgin olive oil rather than MedDiet alone. Extravirgin olive oil is the best quality oil and may have a neuroprotective effect.

Identifying Dietary Patterns Associated with Mild Cognitive Impairment in Older Korean Adults Using Reduced Rank Regression

Diet plays a crucial role in cognitive function. Few studies have examined the relationship between dietary patterns and cognitive functions of older adults in the Korean population. This study aimed to identify the effect of dietary patterns on the risk of mild cognitive impairment. A total of 239 participants, including 88 men and 151 women, aged 65 years and older were selected from health centers in the district of Seoul, Gyeonggi province, and Incheon, in Korea. Dietary patterns were determined using Reduced Rank Regression (RRR) methods with responses regarding vitamin B6, vitamin C, and iron intakes, based on both a one-day 24-h recall and a food frequency questionnaire. Cognitive function was assessed using the Korean-Mini Mental State Examination (K-MMSE). Multivariable logistic regression models were used to estimate the association between dietary pattern score and the risk of mild cognitive impairment. A total of 20 (8%) out of the 239 participants had mild cognitive impairment. Three dietary patterns were identified: seafood and vegetables, high meat, and bread, ham, and alcohol. Among the three dietary patterns, the older adult population who adhered to the seafood and vegetables pattern, characterized by high intake of seafood, vegetables, fruits, bread, snacks, soy products, beans, chicken, pork, ham, egg, and milk had a decreased risk of mild cognitive impairment compared to those who did not (adjusted odds ratios 0.06, 95% confidence interval 0.01-0.72) after controlling for gender, supplementation, education, history of dementia, physical activity, body mass index (BMI), and duration of sleep. The other two dietary patterns were not significantly associated with the risk of mild cognitive impairment. In conclusion, high consumption of fruits, vegetables, seafood, and protein foods was significantly associated with reduced mild cognitive impairment in older Korean adults. These results can contribute to the establishment of dietary guidelines targeting older Korean adults to reduce mild cognitive impairments. Future prospective cohort studies are warranted to examine the effect of the seafood and vegetable dietary pattern on reducing mild cognitive impairment to prove the cause-effect relationship between dietary patterns and cognitive function.

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.

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

BACKGROUND

An increasing number of studies in Western countries have shown that healthy dietary patterns may have a protective effect against cognitive decline and dementia. However, information on this relationship among non-Western populations with different cultural settings is extremely limited. We aim to examine the relationship between dietary patterns and cognitive function among older Japanese people.

METHODS

This cross-sectional study included 635 community-dwelling people aged 69-71 years who participated in the prospective cohort study titled Septuagenarians, Octogenarians, Nonagenarians Investigation with Centenarians (SONIC). Diet was assessed over a one-month period with a validated, brief-type, self-administered diet history questionnaire. Dietary patterns from thirty-three predefined food groups [energy-adjusted food (g/d)] were extracted by factor analysis. Cognitive function was assessed using the Japanese version of the Montreal Cognitive Assessment (MoCA-J). Multivariate regression analysis was performed to examine the relationship between dietary patterns and cognitive function.

RESULTS

Three dietary patterns were identified: the 'Plant foods and fish', 'Rice and miso soup', and 'Animal food' patterns. The 'Plant foods and fish' pattern, characterized by high intakes of green and other vegetables, soy products, seaweeds, mushrooms, potatoes, fruit, fish, and green tea, was significantly associated with a higher MoCA-J score [MoCA-J score per one-quartile increase in dietary pattern: β = 0.56 (95% CI: 0.33, 0.79), P for trend <0.001]. This association was still evident after adjustment for potential confounding factors [β = 0.41 (95% CI: 0.17, 0.65), P for trend <0.001]. In contrast, neither the 'Rice and miso soup' nor the 'Animal food' pattern was related to cognitive function. To confirm the possibility of reverse causation we also conducted a sensitivity analysis excluding 186 subjects who reported substantial changes in their diet for any reason, but the results did not change materially.

CONCLUSION

This preliminary cross-sectional study suggests that a diet with high intakes of vegetables, soy products, fruit, and fish may have a beneficial effect on cognitive function in older Japanese people. Further prospective studies are needed to confirm this finding.

The Association between the Mediterranean Dietary Pattern and Cognitive Health: A Systematic Review

The ageing population is accompanied by increased rates of cognitive decline and dementia. Not only does cognitive decline have a profound impact on an individual's health and quality of life, but also on that of their caregivers. The Mediterranean diet (MD) has been known to aid in reducing the risk of cardiovascular diseases, cancer and diabetes. It has been recently linked to better cognitive function in the elderly population. The purpose of this review was to compile evidence based data that examined the effect of adherence to the MD on cognitive function and the risk of developing dementia or Alzheimer's disease. This review followed PRISMA guidelines and was conducted using four databases and resulted in 31 articles of interest. Cross-sectional studies and cohort studies in the non-Mediterranean region showed mixed results. However, cohort studies in the Mediterranean region and randomized controlled trials showed more cohesive outcomes of the beneficial effect of the MD on cognitive function. Although more standardized and in-depth studies are needed to strengthen the existing body of evidence, results from this review indicate that the Mediterranean diet could play a major role in cognitive health and risk of Alzheimer's disease and dementia.

The Role of Dietary and Lifestyle Factors in Maintaining Cognitive Health

Concern over loss of cognitive function, including descent into Alzheimer's disease or dementia, grips a growing percentage of men and women worldwide as the global population ages. Many studies, though not all, suggest that maintaining cognitive health, as well as slowing and even preventing cognitive decline, dementia, and Alzheimer's disease, can be achieved by consuming healthy diets over a long enough period of time. This appears to be the case even for those who initiated dietary changes later in life, as evidenced by an intervention study assessing consumption of a healthy diet among those who were >50 years of age. All such diets share the common traits of being rich in fruits, vegetables, whole grains, and fish or seafood, while also being low in red meat and sweets. A Mediterranean-style diet shares these characteristics and has been associated with an estimated 40% lower risk of cognitive impairment, including mild cognitive impairment, dementia, and Alzheimer's disease in prospective studies, in addition to being associated with both a 65% lower risk of mild cognitive impairment and improved cognitive performance in a notable randomized controlled trial.

Increased Consumption of Fruit and Vegetables Is Related to a Reduced Risk of Cognitive Impairment and Dementia: Meta-Analysis

Background: Increased consumption of fruit and vegetables has been shown to be associated with a reduced risk of cognitive impairment and dementia in many epidemiological studies. The purpose of this study was to assess the strength of this association in a meta-analysis.

Methods: We identified relevant studies by searching Medline, Embase, and Cochrane Library electronic databases (from 1970 to January 2016). Study were included if they reported relative risks and corresponding 95% confidence intervals (CIs) of cognitive impairment and dementia with respect to frequency of fruit and vegetable intake.

Results: Nine studies (five cohort studies and four cross-sectional studies) met the inclusion criteria and were included in the meta-analysis. There were a total of 31,104 participants and 4,583 incident cases of cognitive impairment and dementia. The meta-analysis showed that an increased consumption of fruit and vegetables was associated with a significant reduction in the risk of cognitive impairment and dementia (OR = 0.80, 95% CI 0.71–0.89). Subgroup analysis indicated this inverse association was only found among participants with mean age over 65 years and combined sexes. Dose–response meta-analysis showed that an increment of 100 g per day of fruit and vegetable consumption was related to an approximately 13% (OR = 0.87, 95% CI 0.77–0.99) reduction in cognitive impairment and dementia risk. There was no potential publication bias in the meta-analysis and the dose–response meta-analysis.

Conclusion: The increased consumption of fruit and vegetables is associated with a reduced risk of cognitive impairment and dementia.