Dietary Patterns and Cognitive Decline Among Chinese Older Adults

The circadian syndrome is a predictor for cognition impairment in middle-aged adults: Comparison with the metabolic syndrome

AIMS

Circadian syndrome (CircS) is considered a better predictor for cardiovascular disease than the metabolic syndrome (MetS). We aim to examine the associations between CircS and MetS with cognition in Chinese adults.

METHOD

We used the data of 8546 Chinese adults aged ≥40 years from the 2011 China Health and Retirement Longitudinal Study. MetS was defined using harmonised criteria. CircS included the components of MetS plus short sleep and depression. The cut-off for CircS was set as ≥4. Global cognitive function was assessed during the face-to-face interview.

RESULTS

CircS and MetS had opposite associations with the global cognition score and self-reported poor memory. Compared with individuals without the CircS and MetS, the regression coefficients (95%CI) for global cognition score were -1.02 (-1.71 to -0.34) for CircS alone and 0.52 (0.09 to 0.96) for MetS alone in men; -1.36 (-2.00 to -0.72) for CircS alone and 0.60 (0.15 to 1.06) for MetS alone in women. Having CircS alone was 2.53 times more likely to report poor memory in men (95%CI 1.80-3.55) and 2.08 times more likely in women (95%CI 1.54-2.81). In contrast, having MetS alone was less likely to report poor memory (OR 0.64 (0.49-0.84) in men and 0.65 (0.52-0.81) in women). People with CircS and MetS combined were more likely to have self-reported poor memory.

CONCLUSIONS

CircS is a strong and better predictor for cognition impairment than MetS in Chinese middle-aged adults. MetS without short sleep and depression is associated with better cognition.

Impact of vegetarianism on cognition and neuropsychological status among urban community-dwelling adults in Telangana, South India: a cross-sectional study

PURPOSE

The potential benefits of vegetarian diets in reducing cognitive impairment have garnered attention due to existing mixed results; hence, our study aims to examine the impact of vegetarianism on cognitive function and neuropsychological status among urban community-dwelling adults from Telangana.

METHODS

The dietary patterns were self-reported and dietary data collected using a Food Frequency Questionnaire while cognitive function was assessed using Mini-Mental State Examination (MMSE) and depression, anxiety, and stress (DASS-21) questionnaire for psychological measures. Adults (N = 304) aged 40 years and above, who followed either a vegetarian or non-vegetarian diet for at least 6 months prior to data collection, scored MMSE ≥ 19 indicating mild cognitive impairment, and were recruited using convenience sampling.

RESULTS

Among the participants, vegetarians (n = 155) exhibited significantly better mood states compared to non-vegetarians (n = 149), as indicated by lower scores on the DASS subscales for depression (10.0 ± 0.06 vs. 17.0 ± 0.07, p =  < 0.001), anxiety (4.0 ± 0.05 vs. 6.0 ± 0.07, p = 0.005), and stress (8.0 ± 0.02 vs. 10.0 ± 0.05, p = 0.007). Vegetarians also demonstrated superior cognitive functioning compared to non-vegetarians, as indicated by higher MMSE scores (26.0 ± 0.04 vs. 24.0 ± 0.03, p =  < 0.001). MMSE scores were inversely correlated with depression, anxiety, and stress for vegetarians (ρ = - 0.371, p = 0.000; ρ = - 0.027, p = 0.734; and ρ = - 0.105, p = 0.914), respectively. Similar to the vegetarians group, MMSE scores were negatively correlated with depression (ρ = - 0.059), but the correlation is not significant.

CONCLUSION

Vegetarianism exerted a positive influence on the cognitive and neuropsychological status of the investigated population. Nevertheless, additional research is required to comprehend the underlying mechanisms that elucidate the long-term effects of vegetarianism and plant-based nutritional interventions on brain health.

New Insights into the Relationship between Nutrition and Neuroinflammation in Alzheimer's Disease: Preventive and Therapeutic Perspectives

Neurodegenerative diseases are progressive brain disorders characterized by inexorable synaptic dysfunction and neuronal loss. Since the most consistent risk factor for developing neurodegenerative diseases is aging, the prevalence of these disorders is intended to increase with increasing life expectancy. Alzheimer's disease is the most common cause of neurodegenerative dementia, representing a significant medical, social, and economic burden worldwide. Despite growing research to reach an early diagnosis and optimal patient management, no disease-modifying therapies are currently available. Chronic neuroinflammation has been recognized as a crucial player in sustaining neurodegenerative processes, along with pathological deposition of misfolded proteins, including amyloid-β and tau protein. Modulating neuroinflammatory responses may be a promising therapeutic strategy in future clinical trials. Among factors that are able to regulate neuroinflammatory mechanisms, diet, and nutrients represent easily accessible and modifiable lifestyle components. Mediterranean diet and several nutrients, including polyphenols, vitamins, and omega-3 polyunsaturated fatty acids, can exert antioxidant and anti-inflammatory properties, impacting clinical manifestations, cognitive decline, and dementia. This review aims to provide an updated overview of the relationship between neuroinflammation, nutrition, gut microbiota, and neurodegeneration. We summarize the major studies exploring the effects of diet regimes on cognitive decline, primarily focusing on Alzheimer's disease dementia and the impact of these results on the design of ongoing clinical trials.

Higher Adherence to the AMED, DASH, and CHFP Dietary Patterns Is Associated with Better Cognition among Chinese Middle-Aged and Elderly Adults

The available evidence regarding the association between adherence to the Alternate Mediterranean Diet (AMED) and Dietary Approaches to Stop Hypertension (DASH) dietary patterns and cognitive performance exhibits inconsistency, and its applicability within the Asian population remains uncertain. The association between adherence to the Chinese Food Pagoda (CHFP) and cognitive function is also unknown. In this study, we aimed to assess the association between adherence to the AMED, DASH, and CHFP different dietary patterns and cognitive function. The study included 3353 Chinese adults aged 55 years and over from the China Health and Nutrition Survey (CHNS) in 2006. A 24 h dietary recall over three consecutive days was used to collect dietary information. Dietary patterns included AMED, DASH, and CHFP. A subset of items from the Telephone Interview for Cognitive Status-Modified was used for cognitive screening. Poor cognitive performance was defined as a global cognitive function score < 7. Binary logistic regression was used to estimate the association between adherence to the three different dietary patterns and cognitive function. Binary logistic regression analysis showed that there is a negative association between higher adherence to the AMED, DASH, and CHFP and poorer cognitive performance (AMED: OR = 0.594, 95% CI = 0.458-0.771, p < 0.001; DASH: OR = 0.652, 95% CI = 0.504-0.843, p = 0.001; CHFP: OR = 0.599, 95% CI = 0.417-0.861, p = 0.006). There was a significant interaction between each of the three dietary patterns and residential regions (AMED: p for interaction = 0.045; DASH: p for interaction = 0.003; CHFP: p for interaction < 0.001). Higher adherence to the AMED, DASH, and CHFP dietary patterns was inversely associated with poor cognition in Chinese middle-aged and elderly adults, particularly among urban residents.

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.

Nutrition and Healthy Ageing in Asia: A Systematic Review

BACKGROUND

Nutrition plays a key role in modulating the likelihood of healthy ageing. In the present study, we aimed to conduct a systematic review to assess the impact of nutrition on healthy ageing in Asia.

METHODS

The systematic review was registered in the International Prospective Register of Systematic Reviews database (CRD42023408936) and conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed, Web of Science, and Embase databases were searched up to February 2023 without language restrictions. We included prospective cohort studies that evaluated the associations of intake of a single food or consumption of a single nutrient at midlife; adherence to various dietary patterns at midlife; and improved adherence to dietary patterns from mid- to late life with the likelihood of healthy ageing and its components.

RESULTS

Out of 16,373 records, we included 71 papers comprising 24 cohorts from Singapore, China, Japan, and Thailand. The healthy ageing components included cognitive function, physical function, and depression. The majority of studies supported the observation that the likelihood of healthy ageing and its components in late life was positively increased by a higher consumption of healthy foods, such as vegetables, fruits, fish, nuts, legumes, tea, milk, and dairy, at midlife, and also by greater adherence to dietary patterns with high diversity scores or high total antioxidant capacities. Furthermore, improved adherence to healthy dietary patterns from mid- to late life also increased the likelihood of healthy ageing in late life.

CONCLUSION

Consuming healthy foods and adhering to healthy dietary patterns at midlife can promote the likelihood of healthy ageing. Moreover, improving diet quality from mid- to late life can still be beneficial.

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

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

MIND diet and cognitive function and its decline: A prospective study and meta-analysis of prospective cohort studies

BACKGROUND

Evidence on the association of the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet with cognitive aging is limited and inconsistent.

OBJECTIVE

We examined how the MIND diet is related to cognitive function and its decline among middle-aged and older adults.

METHODS

We included 4066 participants with baseline dietary assessment and at least one cognitive test from the China Health and Nutrition Survey (CHNS) in 1997, 2000, 2004, and 2006, with a median follow-up of 3 years. The modified MIND diet score (range: 0-12) was calculated based on nine healthy and three unhealthy food groups. Linear mixed-effect models were used to examine the association of adherence to the MIND diet with z-scores of cognitive function and cognitive decline. We also conducted a meta-analysis including our findings and seven other cohort studies.

RESULTS

At baseline, median MIND diet scores for the increasing tertile were 3.0, 4.0, and 5.5, respectively. Participants with higher MIND diet scores had significant better global cognitive function. The adjusted difference in global cognitive function z-score for every three-point increment of MIND diet scores was 0.11 (95% CI, 0.06, 0.16, p-trend<0.001), which was approximately equivalent to being one year younger in age. Consumption of nuts, fish, red meats, and tea showed independent positive associations with cognitive function, and fried food consumption exhibited negative associations. In the meta-analysis of 26,103 participants, one standardized deviation increment of the MIND score was associated with 0.042 (95 % CI 0.020, 0.065) units higher in global cognitive function z-score and 0.014 (95 % CI -0.010, 0.037) units slower in annual cognitive decline.

CONCLUSIONS

Our findings suggest that higher adherence to the MIND diet was associated with better cognitive function and potentially slower cognitive decline in later life. Further large-scale observational and interventional studies are warranted to elucidate the cognitive effects of the MIND diet.

PROSPERO REGISTRY NUMBER

This meta-analysis was registered at PROSPERO as CRD42022330417.

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

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

Whole Dietary Patterns, Cognitive Decline and Cognitive Disorders: A Systematic Review of Prospective and Intervention Studies

Dementia prevalence is a global public health concern. Adherence towards a healthy dietary pattern (DP) may reduce the risk of cognitive decline and dementia. This narrative systematic review aimed to synthesise prospective and intervention study data to evaluate the impact of a-posteriori and a-priori derived DPs on cognitive ageing, from cognitive decline to incident dementia. Ninety-three studies were included: 83 prospective studies and 10 randomised controlled trials (RCT). Most prospective studies (77%) examined a-priori DPs, with the Mediterranean diet examined most frequently. A total of 52% of prospective and 50% of RCTs reported a protective relationship between 'healthy' DPs and global cognitive decline. Overall, 59% of prospective studies reported positive associations between healthy DPs and risk of cognitive disorder. Incident cognitive disorder was examined by only one intervention study (subgroup analysis) which reported a beneficial effect of a low-fat diet on risk of probable dementia in women. Unhealthy DPs were examined less frequently (n = 17; 21%), with 41% of these studies reporting associations between adherence and poorer cognitive outcomes. Overall, there were mixed results for healthy and unhealthy DPs on cognition, likely due to between-study heterogeneity. Standardisation of diet exposure and cognitive outcome measurement would help to reduce this. Future research would benefit from investigating effects of culturally appropriate DPs on individual cognitive domains and incident cognitive disorders in diverse and high-risk populations.

Association of Dietary Quality with Cognitive Function in Chinese Adults Aged 55 Years and Above: A Longitudinal Study

OBJECTIVES

Diet is an important modifiable factor for brain health and aging. Present study aimed to explore association of dietary quality with cognitive function and poor cognition in middle-aged and older adults participating in the China Health and Nutrition Survey (CHNS).

DESIGN

A longitudinal study with a twenty-year follow-up.

SETTING AND PARTICIPANTS

Data were drawn from the CHNS 1997, 2000, 2004, 2006, 2015 and 2018. Subjects aged 55 years and more who participated in at least two waves and had completed data on socio-demographics, lifestyle, disease history, anthropometrics, dietary measure and cognitive assessment were eligible in present study.

METHODS

Baseline diet were assessed by 3-day 24-hour dietary recalls and used to evaluate diet quality via China Elderly Dietary Guidelines Index 2022 (CDGI 2022-E). Cognitive function was examined using part items of the Telephone Interview for Cognitive Status-modified. Three-level linear mixed effects models and three-level mixed effects logistic regression models were performed to estimate the association between diet quality and cognitive function and odds of poor cognition, respectively.

RESULTS

At baseline, 4173 subjects with median age of 63.7 years were recruited. Median of CDGI 2022-E total score was 44.7. Median score of global cognition was 16.0, and the proportion of people with poor cognitive function was 13.9%. Difference in global cognitive score was observed by tertiles of CDGI 2022-E (p<0.05). Significant associations of high diet quality with increment in global cognitive score [β (95%CI): 0.704 (0.394~1.015)], composite cognitive z score [0.086 (0.045~0.128)] and standardized verbal memory score [0.221 (0.122~0.320)] were observed in total subjects. Consistent associations were also found in those below 65 years at baseline. The likelihood of poor cognition in the highest tertile of CDGI 2022-E decreased by 18% (95%CI: 0.698~0.965) relative to the lowest tertile group in total population.

CONCLUSIONS

High diet quality may be beneficial for improving cognitive function and delaying cognitive decline in Chinese middle-aged and older population.

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.

Association between the mediterranean diet and cognitive health among healthy adults: A systematic review and meta-analysis

Background

An increasing prevalence of cognitive disorders warrants comprehensive systematic reviews on the effect of diet on cognitive health. Studies have suggested that the Mediterranean (MeDi) diet has protective effects against metabolic diseases. However, comprehensive systematic reviews on the effect of the MeDi diet on the cognitive decline are limited. We investigated whether adherence to the MeDi diet could lower the risk of the cognitive disorder or improve cognitive function in older adults.

Methods

In this systematic review and meta-analysis, PubMed, Web of Science, PsycINFO, Scopus, and Cochrane databases were searched from inception to June 2021. Cohort studies and randomized controlled trials (RCTs) were included. The effect sizes were estimated as log risk ratios and standard mean differences (SMDs) with 95% confidence intervals (CIs). The Newcastle–Ottawa score and Cochrane Collaboration’s tool were used to assess the risk of bias in cohort studies and RCTs, respectively.

Results

Of the 1,687 screened studies, 31 cohort studies and five RCTs met the eligibility criteria for qualitative analysis; 26 cohort studies and two RCTs were included in the meta-analysis. In the cohort studies, high adherence to the MeDi diet was associated with lower risk of mild cognitive impairment (MCI) [risk ratio (RR) = 0.75 (0.66–0.86)], and Alzheimer’s disease (AD) [RR = 0.71 (0.56–0.89)]. In the RCTs, high adherence to the MeDi diet was associated with better episodic [SMD = 0.20 (0.09–0.30)] and working memories [SMD = 0.17 (0.01–0.32)] than lowest group.

Conclusion

Adherence to the MeDi diet may reduce the risk of MCI and AD. However, other associations with cognitive outcomes (global cognition, working memory, and episodic memory) remain open to interpretation. Overall, the MeDi diet is recommended to prevent or delay cognitive disorders and improve cognitive function. Further, long-term RCTs are warranted to strengthen the evidence.

Systematic review registration

[https://www.crd.york.ac.uk], identifier [CRD42021276801].

The relationship between a fish-rich diet and poststroke cognitive impairment: A cross-sectional study with a follow-up in China

Whether a fish-rich diet is positively associated with cognitive function after stroke remains unclear; thus, the present study investigated the relationship between them.The present study was part of a prospective multicenter study, in which 920 individuals (609 males, mean age, 62.78 ± 11.79 years) were included from November 2013 to December 2015. The cognitive function of the patients was evaluated, and the diagnosis of poststroke cognitive impairment (PSCI) was made during their stay in the hospital. A subgroup of 439 patients from a single center was followed up for 4 to 6 years and was reassessed for cognitive function.According to the diagnostic criteria, the PSCI prevalence was lower in the fish-rich diet group (P < .05). After adjusting for demographic and clinical variables by logistic regression, patients with a habit of consuming a fish-rich diet had a lower risk of developing PSCI than patients without a fish-rich diet (odds ratio [OR]: 0.74; 95% confidence interval [CI]: 0.46-0.95). When MMSE score was considered the cognitive function outcome variable, the long-term cognitive function of the fish-rich diet group was better (28 [26-30] vs 27 [25-29], P < .01), but the statistical results were not significant after correcting for the related confounding factors (β: 0.13; 95% CI: -0.99-1.25; P = .82).There was a negative relationship between consuming a fish-rich diet and the prevalence of PSCI, and there was no statistically significant difference in the relationship of a fish-rich diet on long-term cognitive function after stroke, which requires further study.

MedDiet adherence score for the association between inflammatory markers and cognitive performance in the elderly: a study of the NHANES 2011-2014

Background

To explore the optimal Mediterranean diet (MedDiet) adherence score threshold for the association between inflammatory markers and cognitive performance among older adults.

Methods

In this cross-sectional study, we selected data of the elderly (≥ 60 years old) from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 (n = 2830). Participants completed at least one cognitive measurement and two 24-h food recalls. By analyzing the relation between inflammatory markers and cognitive performance using the subdivided MedDiet adherence score, we got the optimal MedDiet adherence score threshold. Then the optimal threshold was used to divide participants into high and low MedDiet adherence groups and multivariate logistic regression models were developed to examine the association between inflammatory markers and cognitive performance in each group. Subgroup analysis was conducted based on gender, race, BMI, physical activity level, and chronic diseases.

Results

We chose 4 as the optimal MedDiet adherence score threshold and included these participants whose MedDiet adherence score was 4 or above into the high MedDiet adherence group, while the MedDiet adherence score of the low adherence group was less than 4. We found that the increased white blood cell (WBC) count (OR = 1.44, 95% CI: 1.09–1.90, P = 0.008), neutrophil count (OR = 1.30, 95% CI: 1.03–1.65, P = 0.023), and neutrophil-albumin ratio (NAR) (OR = 1.34, 95% CI: 1.06–1.70, P = 0.012) were all related to a higher risk of low cognitive performance in the low MedDiet adherence group. A higher PLR was linked to a reduced risk of low cognitive performance (OR = 0.86, 95% CI: 0.74–1.00, P = 0.036) in the high MedDiet adherence group. Significant differences were found in the associations of WBC count, neutrophil count and NAR with low cognitive performance between the low and high MedDiet adherence groups (all P < 0.001). The weakened negative association between inflammatory markers and cognitive performance in the high MedDiet adherence group also existed among male, non-Hispanic white, normal-weight, overweight, moderate work activity, moderate recreational activity, non-depression, hypertension, non-hypertension, non-diabetes, non-stroke, non-heart failure, non-coronary heart disease, or non-heart attack subpopulations of older adults.

Conclusions

The optimal threshold for the MedDiet adherence score was 4, and the negative association between inflammation and cognitive performance could be weakened in older adults whose MedDiet adherence score was ≥ 4.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03140-1.

Association between the self-reported duration and quality of sleep and cognitive function among middle-aged and older adults in China

BACKGROUND

The World Alzheimer Report showed that 46.8 million people suffered from dementia in 2015. This study examined how the duration and quality of sleep are associated with cognition among older adults in China.

METHOD

Data were drawn from waves 2011, 2013, and 2015 of the China Health and Retirement Longitudinal Study (CHARLS), including noninstitutionalized adults aged 45 and older (n=10,768). Cognition was measured by interview-based assessments of mental status (TICS-10), episodic memory, and visuospatial abilities. Sleep duration was categorized as long, medium, or short and sleep quality was categorized as good, fair, or poor.

RESULTS

Sleep duration had an inverted U-shape relationship with cognitive scores (P <.001); and sleep quality had a positive linear relationship with cognitive scores (P <.001). Short and long sleep durations were associated with consistently lower cognition scores with increasing age (both P <.001); and fair and poor quality of sleep were associated with consistently lower levels of cognition (both P <.001). Tests of interactions between sleep duration and sleep quality showed that participants reporting long durations of sleep with poor quality of sleep had the lowest overall cognitive scores.

LIMITATIONS

Self-reported methods were used to measure sleep quality and duration and thus our findings underscore the need for more evidence-based research to improve prevention efforts and tailor interventions to reduce cognitive decline among Chinese older adults.

CONCLUSIONS

Suboptimal sleep duration and quality were associated with poor cognition. Cognitive scores were lowest among those who reported long durations of sleep that were of poor quality.

Patterns of lifestyle behaviours from mid- through later-life in relation to exceptional episodic memory performance in older women: the Nurses' Health Study

OBJECTIVES

to model and compare patterns from mid- to late-life of body mass index (BMI), alternate Mediterranean diet (A-MeDi) and physical activity, between women with exceptional episodic memory over age 80 and cognitively average controls. Our goal was to examine if lifestyle risk factors in early adulthood may be identified which promote exceptional memory status later in life.

METHODS

a case-control sample nested within the Nurses' Health Study (initiated in 1976), including 7,557 cognitively healthy participants who survived to age 80 and had a cognitive assessment at 80-87 years. We defined women with exceptional memory (n = 455) as those with a composite score of episodic memory ≥1.5 standard deviation above the mean. Then, we selected 2,275 cognitively average controls with a score within 1 standard deviation of the mean, matched by age and education. Patterns of BMI, A-MeDi and physical activity at 52-62 through age 82 years were estimated between groups using latent process mixed models.

RESULTS

In midlife, women with exceptional episodic memory had similar BMI (mean difference [MD] = -0.07 kg/m2 [95% confidence intervals {CI}:-0.41; 0.26]) but better adherence to A-MeDi (MD = +0.25 points [0.08; 0.43]) and more physical activity (MD = +3.50 metabolic-equivalent h/week [1.97; 5.09]) than controls. However, with ageing, both groups had similar patterns; both initially gained and later lost weight, had less activity and declining diet quality (all group-by-time interactions P > 0.07).

CONCLUSIONS

our findings suggest that lifestyle factors differ primarily at earlier ages for those with exceptional versus average episodic memory, thus lifestyle may be most important in earlier life to preserve high levels of memory.

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.

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

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

Trends of central obesity and associations with nutrients intake and daily behaviors among women of childbearing age in China

Background

Obesity among women of childbearing age has becoming an important public health concern. We aimed to describe the trends of central obesity among Chinese women of childbearing age from 2004 to 2011 and to examine its associations with nutrients intake and daily behaviors.

Methods

Longitudinal data were derived from the China Health and Nutrition Survey. Participants consisted of 2481 women aged 15–44 years old. WC (Waist circumference) and WHtR (Waist to height ratio) were adopted as indicators of central obesity. Generalized linear mixed model was performed to analyze the associations of nutrients intake and daily behaviors with central obesity.

Results

From 2004 to 2011, the prevalence of central obesity among Chinese women of childbearing age increased from 21.6 to 30.7% (WC as indice) or from 22.8 to 32.6% (WHtR as indice) (both p < 0.001). Protein intake above the AMDR (Acceptable macronutrient distribution range) (OR = 1.21, 95% CI 1.05–1.39, p < 0.01) and non-participation in LTPA (Leisure time physical activity) (OR = 1.45, 95% CI 1.17–1.80, p < 0.001) were risk factors for high WC, and the latter was also associated with high WHtR (OR = 1.36, 95% CI 1.10–1.67, p < 0.01). For those women who had high WC & high WHtR, the impacts of protein intake and LTPA became stronger, especial LTPA (OR = 1.53, 95% CI 1.21–1.94, p < 0.001). Age-stratified analyses found that non-participation in LTPA was key factor for central obesity in 15–34 age group, while protein intake above the AMDR was pronounced in the 35–44 age group.

Conclusions

Non-participation in LTPA and protein intake above the AMDR were significant contributors of central obesity, which could be intervention targets to deal with the growing trend of central obesity among women of childbearing age.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12905-022-01600-9.

Iron, Zinc and Copper from Cereal Food Sources and Cognitive Performance in Older Adults in China

BACKGROUND

We aimed to determine the risk factors associated with cognitive performance in older adults in China.

METHODS

A longitudinal study was conducted in a group of 1,898 adults aged 60 yr and over in China, Cognitive score was determined by a modified Telephone Interview for Cognitive Status (TICSM). The dietary intake of iron (Fe), zinc (Zn) and copper (Cu) from cereal source foods (CSF) were calculated by using Food Frequency Questionnaire (FFQ) and Chinese Food Composition Tables. Descriptive statistics and multivariate mixed regression models were utilized to explore the association between the intake of these elements and cognitive function.

RESULTS

The mean dietary intakes of Fe, Zn and Cu from CSF were 12.01, 6.90 and 1.30 mg/d respectively. Compared with participants in the high-cognitive group, those in the low-cognitive group had lower total dietary intakes of Fe, Zn and Cu. However, with respect to ratios of CSF-Zn, CSF-Fe and CSF-Cu to their respective total values, participants in the low-cognitive group had significantly higher ratios than those in the high-cognitive group. The results of multivariate mixed regression model revealed that although total dietary Zn intake was positively linked with cognitive function, the CSF-Zn/Zn ratio was negatively associated with cognitive performance.

CONCLUSION

Excessive intake of Zn from a specific food source, such as CSF, was found to be negatively associated with cognitive status. Avoiding over-intake of Zn from CSF foods and diversifying intake of Zn from different food sources seemed to protect individuals from cognitive decline.

Diet May Moderate the Relationship Between Arterial Stiffness and Cognitive Performance in Older Adults

BACKGROUND

Cognitive decline is influenced by various factors including diet, cardiovascular disease, and glucose control. However, the combined effect of these risk factors on cognitive performance is yet to be fully understood.

OBJECTIVE

The current study aimed to explore the inter-relationship between these risk factors and cognitive performance in older adults at risk of future cognitive decline.

METHODS

The sample comprised 163 (Age: M = 65.23 years, SD = 6.50) participants. Food Frequency Questionnaire data was used to score diet quality and adherence to the Western Style Diet (WSD) and Prudent Style Diet (PSD). Glucose control was gauged by serum levels of glycated hemoglobin (HbA1c) and arterial stiffness was measured using carotid to femoral pulse wave velocity. Cognitive performance was assessed using two subtests of the Swinburne University Computerized Cognitive Assessment Battery (SUCCAB) and Rey's Verbal Learning Test (RVLT).

RESULTS

Diet quality, adherence to the WSD or PSD, and glucose control were not significantly related to cognitive outcomes. However, a significant negative association was found between arterial stiffness and the spatial working memory subtest of SUCCAB (β= -0.21, p <  0.05). Arterial stiffness also significantly interacted with the PSD to impact total recall (F change (1,134) = 5.37, p <  0.05) and the composite score of RVLT (F change (1,134) = 4.03, p <  0.05).

CONCLUSION

In this sample of older adults at risk of cognitive decline, diet alone was not found to predict cognitive performance; however, it was found to moderate the relationship between arterial stiffness and cognition.

Associations of Dietary Pattern and Sleep Duration with Cognitive Decline in Community-Dwelling Older Adults: A Seven-Year Follow-Up Cohort Study

BACKGROUND

A few studies have linked dietary patterns and sleep to cognitive decline.

OBJECTIVE

To examine the independent and joint associations of dietary patterns and sleep with cognitive decline.

METHODS

Our analysis included 2,307 participants aged 55- 89 years at baseline from the China Health and Nutrition Survey. Dietary intake was assessed using weighing methods in combination with 24 h dietary recalls for three consecutive days. Exploratory factor analysis was applied to identify major dietary factors. Cognition was assessed in 1997, 2000, 2004, 2006, and 2015.

RESULTS

Five dietary patterns were identified: dairy-fruits-fast foods, grains-vegetables-pork, plant-based food, beans-mushroom, and beverages-nuts patterns. Beans-mushroom pattern and sleep duration of 8 h/day were defined as healthy habits. There was a positive association between the beans-mushroom pattern and change in the global cognitive Z-score over seven years (β (95% CI) for quintile 5 versus quintile 1:0.17 (0.05, 0.30)). Compared to individuals with sleep duration of 8 h/day, those with sleep duration of≤5 h/day (β (95% CI): - 0.23 (- 0.45, - 0.00)) or > 10 h/day (- 0.52 (- 0.73, - 0.32)) had a greater decrease in global cognitive Z-score. Compared to individuals with no healthy patterns, those with a healthy dietary pattern only (β (95% CI): 0.18 (0.08, 0.28)), healthy sleep pattern only (0.13 (0.04, 0.23), and both healthy dietary and sleep patterns (0.19 (0.08, 0.31)) had a relative increase in global cognitive Z-score.

CONCLUSION

Our findings highlight the importance of involving both diet and sleep as intervention priorities for the potential prevention of cognitive decline.

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.

Dietary patterns in middle age: effects on concurrent neurocognition and risk of age-related cognitive decline

Context

Diet plays a critical role in cognitive integrity and decline in older adults. However, little is known about the relationship between diet and cognitive integrity in middle age.

Objective

To investigate the relationship between dietary patterns in healthy middle-aged adults and neurocognition both in middle age and later in life.

Data Sources

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, the following electronic databases were searched: Web of Science, Scopus, PubMed, and PsychInfo.

Data Extraction

Data from eligible articles was extracted by 2 reviewers.

Data Analysis

Articles included in the systematic review were synthesized (based on the synthesis without meta-analysis reporting guidelines) and assessed for quality (using the Joanna Briggs Institute checklist for randomized controlled trials, cohort studies, and cross-sectional studies) by 2 reviewers.

Results

Of 1558 studies identified, 34 met the eligibility criteria for inclusion. These comprised 9 cross-sectional studies, 23 longitudinal or prospective cohort studies, and 2 randomized controlled trials. Findings were mixed, with some studies reporting a significant positive relationship between adherence to various “healthy” dietary patterns and neurocognition, but others reporting no such relationship.

Conclusion

This systematic review demonstrated that adherence to the Mediterranean diet and other healthy dietary patterns in middle age can protect neurocognition later in life.

Systematic Review Registration

PROSPERO registration no. CRD42020153179.

A Critical Review of the Study of Neuroprotective Diets to Reduce Cognitive Decline

Alzheimer’s disease (AD) and other dementias are now the seventh leading cause of death in the world and are projected to affect 115.4 million people by 2050. Delaying the onset of AD by just five years is estimated to reduce the cost and prevalence of the disease by half. There is no cure for AD nor any drug therapies to halt its progression once the disease begins. Lifestyle choices including diet are being seen as a viable complementary therapy to reduce cognitive decline, the hallmark of AD. Mediterranean, DASH (Dietary Approaches to Stop Hypertension), and MIND (Mediterranean-DASH Intervention for Neurodegenerative Delay) diets have biological mechanisms supporting their potential neuroprotective benefits, but the findings of study outcomes about these benefits have been inconsistent. This paper analyzed five Randomized Clinical Trials (RCTs) (from 2000 to 2021) and 27 observational studies (from 2010 to 2021) focused on the link between cognitive health and the Mediterranean/DASH/MIND diets to identify gaps and challenges that could lead to inconsistent results. These include a lack of accuracy in assessing food intake, multiple dietary pattern scoring systems, a shifting metric among studies focused on the Mediterranean diet, a lack of standards in the tools used to assess cognitive decline, and studies that were underpowered or had follow-up periods too short to detect cognitive change. Insights from these gaps and challenges are summarized in recommendations for future RCTs, including both pragmatic and explanatory RCTs.

The Role of Micronutrients in Ageing Asia: What Can Be Implemented with the Existing Insights

Life expectancy as a measure of population health does not reflect years of healthy life. The average life expectancy in the Asia-Pacific region has more than doubled since 1900 and is now above 70 years. In the Asia-Pacific region, the proportion of aged people in the population is expected to double between 2017 and 2050. Increased life expectancy leads to an increase in non-communicable diseases, which consequently affects quality of life. Suboptimal nutritional status is a contributing factor to the prevalence and severity of non-communicable diseases, including cardiovascular, cognitive, musculoskeletal, immune, metabolic and ophthalmological functions. We have reviewed the published literature on nutrition and healthy ageing as it applies to the Asia-Pacific region, focusing on vitamins, minerals/trace elements and omega-3 fatty acids. Optimal nutritional status needs to start before a senior age is reached and before the consequences of the disease process are irreversible. Based on the nutritional status and health issues in the senior age in the region, micronutrients of particular importance are vitamins A, D, E, C, B-12, zinc and omega-3 fatty acids. The present paper substantiates the creation of micronutrient guidelines and proposes actions to support the achievement of optimal nutritional status as contribution to healthy ageing for Asia-Pacific populations.

The role of diet on the risk of dementia in the oldest old: The Monzino 80-plus population-based study

BACKGROUND & AIMS

Longevity also carries its dark side of age-related chronic diseases, dementia being one of the worst and the most prevalent. Since dementia lacks effective treatments, preventing or delaying it is highly desirable. Dietary habits and nutrition have been found to be important modifiable risk factors for many chronic diseases, but evidence on the role of diet on the risk of dementia is still limited, particularly among the very old. Aim of the present work is to study the association of the Mediterranean diet and its components with prevalent and incident dementia in the oldest-old.

METHODS

We analyzed data from the Monzino 80-plus study, a population-based study in subjects 80 years or older in the Varese province, Italy. A validated food frequency questionnaire was used to collect information on 23 different foods consumed in the previous year. A Mediterranean diet score was calculated and its components were classified into tertiles. Multivariable models for dementia prevalence and incidence were adjusted for demographic and clinical characteristics.

RESULTS

Information on nutrition was available for 1390 subjects in the cross-sectional study and 512 subjects in the longitudinal study, mean respective ages 93 and 92. Greater adherence to Mediterranean diet, greater consumption of eggs, fruits and vegetables, carbohydrates, and greater food intake were associated with a lower prevalence of dementia. Increasing number of portions per week and consumption of legumes significantly decreased the incidence of dementia during the 3.6 year mean follow-up: corresponding hazard ratios of highest vs. lowest tertiles (95% confidence intervals) were 0.66 (0.46-0.95) and 0.68 (0.47-0.97), respectively.

CONCLUSION

Oldest-old eating less and having diets with less variety and nutrient density were more frequent among subjects with dementia. The longitudinal analysis confirmed oldest-old subjects who eat more portions, as well as those who have a higher intake of legumes, are at decreased risk of developing dementia even though reverse causality cannot be completely ruled out.

Trends and Urban-Rural Disparities of Energy Intake and Macronutrient Composition among Chinese Children: Findings from the China Health and Nutrition Survey (1991 to 2015)

The nutrition status of children is gaining more attention with a rapid nutrition transition. This study aimed to investigate trends and urban-rural differences in dietary energy and macronutrient composition among Chinese children. A total of 7565 participants aged 6 to 17 years were obtained from three rounds (1991, 2004 and 2015) of the Chinese Health and Nutrition Survey (CHNS). The individual diet was evaluated via three consecutive 24-hour dietary recalls and compared with the Chinese Dietary Reference Intakes (DRIs). From 1991 to 2015, there was a significant increase in children’s fat intake, the proportion of energy intake from fat, and the proportion of children with more than 30% of energy from fat and less than 50% of energy from carbohydrates (p < 0.001). Compared with the DRI, the proportion with higher fat and lower carbohydrate intakes were, respectively, 64.7% and 46.8% in 2015. The urban-rural disparities in fat and carbohydrate intake gradually narrowed, while the gap in protein intake increased notably over time (p < 0.001). Chinese children experienced a rapid transformation to a low-carbohydrate and high-fat diet. Urban-rural disparities persistently existed; further nutritional interventions and education were of great significance, so as to ensure a more balanced diet for Chinese children.

Dietary Diversity and Healthy Aging: A Prospective Study

Population aging is a global phenomenon. The present study determined the effects of dietary diversity score (DDS) and food consumption on healthy aging. A subset of the data of the China Health and Nutrition Survey was utilized in this study. DDSs were calculated using the dietary data collected in the years 2009 and 2011. A healthy aging score (HAS) was calculated by summing the standardized scores on physical functional limitation, comorbidity, cognitive function, and psychological stress based on the data collected in the year 2015, with a lower HAS indicating a healthier aging process. Life quality was self-reported in the year 2015. This study found that DDS was inversely associated with HAS (T3 vs. T1: β −0.16, 95%CI −0.20 to −0.11, p-trend <0.001). The consumption of meat and poultry, aquatic products, and fruits was inversely associated with HAS, and participants in the highest tertile of staple foods consumption had a higher HAS than those in the lowest tertile. HAS was inversely associated with good self-reported life quality and positively associated with bad life quality. In conclusion, food consumption may influence the aging process, and adherence to a diverse diet is associated with a healthier aging process in elderly people.

Social and Built Environments Related to Cognitive Function of Older Adults: A Multi-Level Analysis Study in Taiwan

The purpose of this study was to examine the associations between cognitive function, the city’s social environment, and individual characteristics of older adults. The individual data of older people were from the Nutrition and Health Survey in Taiwan 2013–2016. The participants who were aged 65 and above were included in the analysis (n = 1356). City-level data were obtained for twenty cities in Taiwan. The data of city-level indicators were from governmental open data and Taiwan’s Age Friendly Environment Monitor Study. A multilevel mixed-effect model was applied in the analysis. Population density, median income, safety in the community, barrier-free sidewalks, high education rate of the population, low-income population rate, household income inequality, and elderly abuse rate were related to cognitive function in the bivariate analysis. When controlling for individual factors, the city’s low-income population rate was still significantly related to lower cognitive function. In addition, the participants who were at younger age, had a higher education level, had a better financial satisfaction, had worse self-rated health, had higher numbers of disease, and had better physical function had better cognitive function. Social and built environments associated with cognitive function highlight the importance of income security and the age friendliness of the city for older adults. Income security for older people and age-friendly city policies are suggested.

A mixed methods pilot randomised controlled trial to develop and evaluate the feasibility of a Mediterranean diet and lifestyle education intervention 'THINK-MED' among people with cognitive impairment

BACKGROUND

Accumulating evidence supports the role of a Mediterranean diet (MD) in cognition, with a greater adherence to a MD associated with reduced dementia risk. It is important to understand how best to achieve behaviour change towards a MD, particularly in non-Mediterranean and high-risk populations. The aim of this study was to evaluate the feasibility of a MD and lifestyle education intervention (THINK-MED) among older adults with cognitive impairment.

METHODS

Qualitative interviews (Phase I), conducted with mild cognitive impairment (MCI) participants, evaluated the intervention materials to allow refinement before pilot testing. THINK-MED was a 12-month, pilot RCT (Phase II) whereby MCI participants were randomised into one of three groups: education on one occasion vs education staged and supported by a dietitian vs control. The primary outcome was a change in MD score. Secondary outcome measurements were collected to gather data on variability of the outcomes to inform a full trial power calculation and to test their acceptability. Slower recruitment rates necessitated a change in primary outcome to a revised focus primarily on feasibility. A sub-study of the same THINK-MED intervention and data collection measures was also conducted among community-dwelling participants with subjective cognitive impairment (SCI) (NCT03569319).

RESULTS

A total of 20 participants (n = 15 MCI; n = 5 SCI) were enrolled in the THINK-MED study. However, there were 10 (50%) participants (n = 9 MCI; n = 1 SCI) who withdrew from the study. Although, those who remained in the intervention rated and evaluated their experience as generally positive, recruitment and retention, especially from a MCI population, was extremely challenging. This highlights the complex needs of this heterogeneous clinical cohort. Recruiting participants from a community-based sample with SCI was more feasible, reaching a wider audience in a shorter time period. There were challenges relating to data collection and incompleteness, with the occurrence of missing data particularly among the questionnaire-based assessments.

CONCLUSIONS

Owing to the challenges with recruitment and retention of older adults with cognitive impairment in this study, it is difficult to confirm if this intervention is feasible. This research has highlighted considerations for a future trial, including a review of the recruitment strategies used and prioritisation of the outcome measures assessed.

TRIAL REGISTRATION

Clinical trials registration NCT03265522 / NCT03569319.

Is milk and dairy intake a preventive factor for elderly cognition (dementia and Alzheimer's)? A quality review of cohort surveys

Milk and dairy (M&D) is a longstanding human food with widespread use. Many studies showed the preventive capacity of M&D in several human health disorders, but its utility in others is under discussion. Aging has been associated to elderly cognitive decline including dementia-Alzheimer syndrome (Dem-AD). The absence of a therapy to impede or postpone Dem-AD determines the need for its prevention, including nutritional factors. To evaluate the preventive capacity of M&D consumption in elderly Dem-AD we performed a systematic review in the main biomedical databases and information resources, but we present this study as a narrative review to discuss better the complexity of this subject. The elderly Dem-AD has a long pre-symptomatic period and the M&D intake has a widespread use. These determinants and the quality flaws of published studies impeach us to answer whether M&D consumption is preventive for Dem-AD. Moreover, two long Japanese cohorts suggest that M&D intake could prevent Dem-AD. Prospective cohorts beginning in midlife (or early life) could answer this question in the future.

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

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

The association of dietary patterns with cognition through the lens of neuroimaging-a Systematic review

Despite the reported benefits of diet on cognition in older adults, randomized controlled trials (RCT) testing the impact of dietary interventions on cognitive scores have yielded less promising results when cognition was assessed via neuropsychological tests. More recently, neuroimaging has been used to identify more subtle brain-related changes associated to cognition. Hence, employing a combination of neuroimaging techniques with neuropsychological tests could clarify this controversy. To determine the effect of diet on cognitive performance, we conducted a systematic review of PubMed and Scopus databases for all studies, on middle-aged and older adults, combining neuroimaging, neuropsychological tests, and data on dietary patterns. The inclusion criteria were met by 14 observational studies and no RCTs. The range of brain measures assessed varied from volumes to white matter integrity, functional connectivity, brain glucose metabolism and beta-amyloid deposition. Given the variability of methods used in assessing cognitive performance, diet and brain correlates, conducting a meta-analysis was not possible. Here the evidence suggests that, in observational studies, dietary patterns may be associated with brain correlates that have been shown to precede cognitive decline. As such, neuroimaging should be included in future RCTs to identify any benefits of diet on brain measures linked with cognitive health.

Higher Adherence to the Mediterranean Diet Is Associated With Preserved White Matter Integrity and Altered Structural Connectivity

The Mediterranean diet (MedDiet) has been associated with cognitive performance. Yet, controlled trials have yielded contradictory results. To tackle this controversy, a comprehensive multimodal analysis of the association of the MedDiet with cognitive performance and brain structure in normative aging is still necessary. Here, community dwellers ≥50 years from a cohort study on normative aging (n = 76) underwent a (i) magnetic resonance imaging session with two acquisitions: structural and diffusion-weighted imaging (DWI); (ii) neuropsychological battery of tests focusing on memory and executive functioning; and (iii) dietary assessment through the Mediterranean Diet Assessment Screener (MEDAS, score range: 0-14, scores ≥10 indicate high adherence to the Mediterranean diet) 18 months prior to the brain imaging and neuropsychological assessment. We found that high adherence to the MedDiet (MEDAS ≥10) was associated with higher values of fractional anisotropy and lower diffusivity values in the brain white matter. Similarly, high adherence to the MedDiet was associated with higher structural connectivity between left hemisphere brain regions. Specifically, the amygdala, lingual, olfactory, middle occipital gyrus, and calcarine areas. No association was found between high adherence to the MedDiet and total brain volumes or hypointensities. Higher adherence to the MedDiet was positively associated with executive functioning scores. These results suggest that high adherence to the MedDiet positively associates with brain health, specifically with executive function scores and white matter integrity of bundles related to the processing and integration of taste, reward, and decision making. These findings seem to support the view that the MedDiet should be part of recommendations to promote a healthy brain.

Gender differences in the relationship between dietary energy and macronutrients intake and body weight outcomes in Chinese adults

BACKGROUND

To explore the gender differences in the relationship between dietary energy and macronutrients intake and body weight outcomes in Chinese adults.

METHODS

Data from the China Health and Nutrition Survey (CHNS, 2015) for10,898 participants aged 18-64 years. Three consecutive 24-h dietary recalls was used to assess the dietary intake. Quantile regression models for body mass index (BMI) and waist circumference (WC) were performed separately for each sex.

RESULTS

Adult males showed greater absolute intakes of energy and macronutrients as compared to females as per the body weight outcomes. A 10% increase in BMI resulted in an additional intake of 0.002-0.004 kcal/d of dietary energy, 0.032-0.057 g/d of fats, 0.039-0.084 g/d of proteins, and 0.018-0.028 g/d of carbohydrates across all quantiles in males (p <  0.05). A 10% increase in WC lead to an additional intake of 0.004-0.008 kcal/d of dietary energy, 0.051-0.052 g/d of carbohydrates across the entire quantile in males (p <  0.05), and an increased intake of 0.060-0.150 kcal/d of fat in females (p <  0.05).

CONCLUSIONS

Dietary fat intake could be the risk factor of abdominal obesity in women. The importance of gender-specific evidence should be considered before promoting macronutrient allocation for the prevention and treatment of obesity.

Markers of a plant-based diet relate to memory and executive function in older adults

Background: Although it is known that plant-based foods are important for physical health, little is known about the relationship between plant-based foods and cognitive health. Emerging evidence suggests that some macronutrients may influence cognition, but it is unclear which domains of cognition are involved; more importantly, it is unknown how a plant-based diet relates to cognition.Objective: To examine associations between a plant-based dietary pattern and cognitive functioning.Methods: Participants were 3,039 older adults who participated in the 2011-2014 waves of the National Health and Nutrition Examination Survey (NHANES). The present cross-sectional study used data on macronutrient intake from 24-hour dietary interviews, as well as performance on tests of long-term memory and executive function (i.e., delayed word recall, digit symbol substitution test, and animal fluency). Principal component analysis was used to extract a dietary pattern consistent with a plant-based diet.Results: Greater adherence to a dietary pattern consistent with a plant-based diet was related to better performance on all cognitive tasks. Secondary analyses indicated that the associations between a plant-based dietary pattern and executive function accounted for the association between a plant-based dietary pattern and memory. Furthermore, this same plant-based dietary pattern was associated with reduced baseline inflammation in a separate dataset.Conclusions: Experimental manipulations are needed to determine the potential causal relations of these associations, but these results suggest that a plant-based diet relates to better cognition, especially through improved executive control. Future work should also attempt to extend these results by examining potential mechanisms underlying these associations, such as reduced inflammation.

Dietary Patterns and Cognitive Health in Older Adults: A Systematic Review

While the role of diet and nutrition in cognitive health and prevention of dementia in older adults has attracted much attention, the efficacy of different dietary patterns remains uncertain. Previous reviews have mainly focused on the Mediterranean diet, but either omitted other dietary patterns, lacked more recent studies, were based on cross-sectional studies, or combined older and younger populations. We followed PRISMA guidelines, and examined the efficacy of current research from randomized controlled trials and cohort studies on the effects of different dietary patterns. We reviewed the Mediterranean diet, Dietary Approach to Stop Hypertension (DASH) diet, the Mediterranean-DASH diet Intervention for Neurodegenerative Delay (MIND) diet, Anti-inflammatory diet, Healthy diet recommended by guidelines via dietary index, or Prudent healthy diets generated via statistical approaches, and their impact on cognitive health among older adults. Of 38 studies, the Mediterranean diet was the most investigated with evidence supporting protection against cognitive decline among older adults. Evidence from other dietary patterns such as the MIND, DASH, Anti-inflammatory, and Prudent healthy diets was more limited but showed promising results, especially for those at risk of cardiovascular disease. Overall, this review found positive effects of dietary patterns including the Mediterranean, DASH, MIND, and Anti-inflammatory diets on cognitive health outcomes in older adults. These dietary patterns are plant-based, rich in poly- and mono-unsaturated fatty acids with lower consumption of processed foods. Better understanding of the underlying mechanisms and effectiveness is needed to develop comprehensive and practical dietary recommendations against age-related cognitive decline among older adult.

Effect of nutrition on neurodegenerative diseases. A systematic review

Neurodegenerative diseases are characterized by the progressive functional loss of neurons in the brain, causing cognitive impairment and motoneuron disability. Although multifactorial interactions are evident, nutrition plays an essential role in the pathogenesis and evolution of these diseases. A systematic literature search was performed, and the prevalence of studies evaluated the effect of the Mediterranean diet (MeDiet), nutritional support, EPA and DHA, and vitamins on memory and cognition impairment. The data showed that malnutrition and low body mass index (BMI) is correlated with the higher development of dementia and mortality. MeDiet, nutritional support, and calorie-controlled diets play a protective effect against cognitive decline, Alzheimer's disease (AD), Parkinson disease (PD) while malnutrition and insulin resistance represent significant risk factors. Malnutrition activates also the gut-microbiota-brain axis dysfunction that exacerbate neurogenerative process. Omega-3 and -6, and the vitamins supplementation seem to be less effective in protecting neuron degeneration. Insulin activity is a prevalent factor contributing to brain health while malnutrition correlated with the higher development of dementia and mortality.

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.

Dietary pattern in midlife and cognitive impairment in late life: a prospective study in Chinese adults

BACKGROUND

Prospective studies linking dietary pattern and cognitive function in the elderly are limited in Asian populations.

OBJECTIVE

We examined the associations between various healthful dietary patterns and risk of cognitive impairment in Chinese adults.

METHODS

We used data from the Singapore Chinese Health Study of 16,948 men and women who were aged 45-74 y at baseline (1993-1998) and reinterviewed at the third follow-up visit (2014-2016), ∼20 y later. Diet quality at baseline was assessed according to the alternate Mediterranean diet (aMED), the Dietary Approaches to Stop Hypertension (DASH) diet, the alternative Healthy Eating Index (AHEI)-2010, overall plant-based diet index (PDI), and healthful plant-based diet index (hPDI). Cognitive function was evaluated using a Singapore-modified Mini-Mental State Examination during the third follow-up visit when subjects were aged 61-96 y. Multivariable logistic regression models were used to compute ORs and 95% CIs associated with the risk of cognitive impairment defined using education-specific cut-offs.

RESULTS

Cognitive impairment was present in 2443 (14.4%) participants. The OR (95% CI) for cognitive impairment comparing the highest with the lowest quartile of diet quality scores was 0.67 (0.59, 0.77) for aMED, 0.71 (0.62, 0.81) for DASH, 0.75 (0.66, 0.85) for AHEI-2010, 0.82 (0.71, 0.94) for PDI, and 0.78 (0.68, 0.90) for hPDI (all P values for trend <0.001). Each SD increment in different diet quality scores was associated with 7-16% lower risk of cognitive impairment.

CONCLUSIONS

These results provide evidence that adherence to healthy dietary patterns in midlife is associated with a lower risk of cognitive impairment in late life in Chinese adults.

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.

Diet and Inflammation in Cognitive Ageing and Alzheimer's Disease

PURPOSE OF REVIEW

Nutrition is known to modulate the immune system and may alter neuroinflammatory processes implicated in the pathogenesis of Alzheimer's disease (AD) and progression of neurodegeneration. Here, we review the evidence for healthy dietary patterns and age-related cognition and discuss potential neuroinflammatory actions of diet on cognitive function.

RECENT FINDINGS

Anti-inflammatory dietary patterns such as the Mediterranean diet (MD) and dietary approaches to stop hypertension (DASH) may be neuroprotective. Several dietary components consumed in the MD and DASH (omega-3 fatty acids, antioxidants and polyphenols) can inhibit neuroinflammation associated with AD. Anti-inflammatory diets may also attenuate neuroinflammation via indirect immune pathways from the gut microbiome and systemic circulation. Diet may influence cognitive ageing via several inflammatory pathways. However, data from human studies are lacking and the exact mechanisms linking diet to cognitive function remain elusive. Further dietary intervention studies are required to investigate diet-associated neurological change from the earliest through to latest stages of cognitive decline. Furthermore, incorporation of neuroimaging measures in intervention studies would advance current understanding of the mechanistic effects of dietary modification on neuroinflammation in the ageing brain.

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.