Dietary patterns during adulthood and cognitive performance in midlife: The CARDIA study

Cognitive function and bladder health among midlife adult women in the Coronary Artery Risk Development in Young Adults (CARDIA) study

OBJECTIVE

The aim of this study was to examine whether different aspects of women's cognitive function are associated with lower urinary tract symptoms (LUTS) and their impact.

METHODS

In 2010-2011, women aged 42 to 57 years in the Coronary Artery Risk Development in Young Adults study completed different tests of cognitive function, including the Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, and Stroop test. Two years later, data on LUTS and their impact were collected. LUTS/impact, a four-level composite variable ranging from bladder health to mild, moderate, and severe LUTS/impact, was regressed on each cognitive test separately, as well as a cognitive function composite variable. The analytic sample was composed of 1,021 women with complete data.

RESULTS

When adjusting for sociodemographic variables (age, race, education) and gynecologic/obstetric variables (parity, menopausal status, hysterectomy, hormonal use), better performance on the cognitive function composite and Digit Symbol Substitution Test were both associated with lower odds of membership to a more severe LUTS/impact category (odds ratio, 0.90 [95% confidence interval, 0.83-0.98] and 0.89 [95% confidence interval, 0.82-0.97], respectively). These associations became nonsignificant when additionally adjusting for mechanisms that might explain an association between cognitive function and LUTS/impact, including health behaviors and health conditions that may covary with cerebral and peripheral vascular health and cognitive function.

CONCLUSIONS

In this sample of midlife adult women, a modest association was found between better cognitive function and lower likelihood of LUTS/impact. Longitudinal studies are needed to further investigate the association between cognitive function and LUTS/impact, as well as potential explanatory mechanisms, particularly as women age and cognitive function varies to a greater degree.

Trajectories in depressive symptoms and midlife brain health

Depressive symptoms may either be a risk factor or prodromal to dementia. Investigating this association in midlife may help clarify the role of depression in cognitive aging. We aimed to identify trajectories in depressive symptoms in early to mid-life and related cognitive and brain outcomes in midlife. This study includes 3944 Black and White participants (ages 26-45 years at baseline) from the Coronary Artery Risk Development in Young Adults (CARDIA) study with 20 years of follow-up. Depressive symptoms were assessed using the Center for Epidemiological Studies Depression scale at five time points over 20 years. Growth mixture modeling (GMM) was used to identify depressive symptom trajectories. Participants completed a neuropsychological battery 20 years after baseline, including the Digit Symbol Substitution Test (DSST), Rey-Auditory Verbal Learning Test (RAVLT), Stroop Test, Montreal Cognitive Assessment (MoCA), and category and letter fluency tests. A sub-sample of participants (n = 662) underwent brain magnetic resonance imaging (MRI) to characterize gray matter volumes and white matter hyperintensities (WMHs). We identified four classes of depressive symptom trajectories: a "declining" class (n = 286, 7.3%) with initially high symptoms and subsequent decline, a class with consistently high symptoms ("steady high"; n = 264, 6.7%), a class with late increases in symptoms ("increasing"; n = 277, 7%), and a class with consistently low symptoms ("steady low"; n = 3117, 79.0%). The steady high and the increasing classes had poorer performance on all cognitive tests, while the declining class had poorer performance on the DSST, verbal fluency, and MoCA. Compared to the steady low symptom class, the steady high class had lower volumes in the entorhinal cortex (β: -180.80, 95% CI: -336.69 to -24.91) and the amygdala (β: -40.97, 95% CI: -74.09 to -7.85), the increasing class had more WMHs (β: 0.55, 95% CI: 0.22 to 0.89), and the declining class was not significantly different in any brain measures. Trajectories in depressive symptoms in young to mid-adulthood show distinct cognitive and brain phenotypes in midlife. Steady high depressive symptoms may represent a group that is at risk for dementia, whereas increasing symptoms in midlife may be associated with white matter damage.

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

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

Diet patterns and cognitive performance in a UK Female Twin Registry (TwinsUK)

BACKGROUND

Plant-based diets may provide protection against cognitive decline and Alzheimer's disease, but observational data have not been consistent. Previous studies include early life confounding from socioeconomic conditions and genetics that are known to influence both cognitive performance and diet behaviour. This study investigated associations between Mediterranean (MED) diet and MIND diets and cognitive performance accounting for shared genotype and early-life environmental exposures in female twins.

METHODS

Diet scores were examined in 509 female twins enrolled in TwinsUK study. The Cambridge Neuropsychological Test Automated Battery was used to assess cognition at baseline and 10 years later (in n = 275). A co-twin case-control study for discordant monozygotic (MZ) twins examined effects of diet on cognitive performance independent of genetic factors. Differences in relative abundance of taxa at 10-year follow-up were explored in subsamples.

RESULTS

Each 1-point increase in MIND or MED diet score was associated with 1.75 (95% CI: - 2.96, - 0.54, p = 0.005 and q = 0.11) and 1.67 (95% CI: - 2.71, - 0.65, p = 0.002 and q = 0.02) fewer respective errors in paired-associates learning. Within each MZ pair, the twin with the high diet score had better preservation in spatial span especially for MED diet (p = 0.02). There were no differences between diet scores and 10-year change in the other cognitive tests. MIND diet adherence was associated with higher relative abundance of Ruminococcaceae UCG-010 (0.30% (95% CI 0.17, 0.62), q = 0.05) which was also associated with less decline in global cognition over 10 years (0.22 (95% CI 0.06, 0.39), p = 0.01).

CONCLUSIONS

MIND or MED diets could help to preserve some cognitive abilities in midlife, particularly episodic and visuospatial working memory. Effects may be mediated by high dietary fibre content and increased abundance of short-chain fatty acid producing gut bacteria. Longer follow-up with repeated measures of cognition will determine whether diet can influence changes in cognition occurring in older age.

Effects of PROtein enriched MEDiterranean Diet and EXercise on nutritional status and cognition in adults at risk of undernutrition and cognitive decline: the PROMED-EX Randomised Controlled Trial

INTRODUCTION

Undernutrition leading to unplanned weight loss is common in older age and has been linked to increased dementia risk in later life. Weight loss can precede dementia by a decade or more, providing a unique opportunity for early intervention to correct undernutrition and potentially prevent or delay cognitive impairment. The combined effects of diet and exercise on undernutrition have not yet been evaluated. The objective of this trial is to determine the effect of a protein-enriched Mediterranean diet, with and without exercise, on nutritional status and cognitive performance in older adults at risk of undernutrition and cognitive decline.

METHODS

One hundred and five participants aged 60 years and over at risk of undernutrition and with subjective cognitive decline will be recruited to participate in a 6-month, single-blind, parallel-group randomised controlled trial. Participants will be block randomised into one of three groups: group 1-PROMED-EX (diet+exercise), group 2-PROMED (diet only) and group 3-standard care (control). The primary outcome is nutritional status measured using the Mini Nutritional Assessment. Secondary outcomes include cognitive function, nutritional intake, body composition, physical function and quality of life. Mechanistic pathways for potential diet and exercise-induced change in nutritional status and cognition will be explored by measuring inflammatory, metabolic, nutritional and metabolomic biomarkers.

ETHICS AND DISSEMINATION

The study is approved by the UK Office for Research Ethics Committee (ref: 21/NW/0215). Written informed consent will be obtained from participants prior to recruitment. Research results will be disseminated to the public via meetings and media and the scientific community through conference presentations and publication in academic journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05166564).

Measures of MRI Brain Biomarkers in Middle Age According to Average Modified Mediterranean Diet Scores Throughout Young and Middle Adulthood

BACKGROUND

The Mediterranean diet (MedDiet) has been linked with better cognitive function and brain integrity.

OBJECTIVE

To examine the association of modified Mediterranean diet (mMedDiet) scores from early through middle adulthood in relation to volumetric and microstructural midlife MRI brain measures. Assess the association of mMedDiet and brain measures with four cognitive domains. If variables are correlated, determine if brain measures mediate the relationship between mMedDiet and cognition.

METHODS

618 participants (mean age 25.4±3.5 at year 0) of the Coronary Artery Risk Development in Young Adults (CARDIA) study were included. Cumulative average mMedDiet scores were calculated by averaging scores from years 0, 7, and 20. MRI scans were obtained at years 25 and 30. General linear models were used to examine the association between mMedDiet and brain measures.

RESULTS

Higher cumulative average mMedDiet scores were associated with better microstructural white matter (WM) integrity measured by fractional anisotropy (FA) at years 25 and 30 (all ptrend <0.05). Higher mMedDiet scores at year 7 were associated with higher WM FA at year 25 (β= 0.003, ptrend = 0.03). Higher mMedDiet scores at year 20 associated with higher WM FA at years 25 (β= 0.0005, ptrend = 0.002) and 30 (β= 0.0003, ptrend = 0.02). mMedDiet scores were not associated with brain volumes. Higher mMedDiet scores and WM FA were both correlated with better executive function, processing speed, and global cognition (all ptrend <0.05). WM FA did not mediate the association between mMedDiet scores and cognition.

CONCLUSIONS

mMedDiet scores may be associated with microstructural WM integrity at midlife.

Exploring the Effects of a Mediterranean Diet and Weight Loss on the Gut Microbiome and Cognitive Performance in Older, African American Obese Adults: A Post Hoc Analysis

African American adults have a higher prevalence of Alzheimer's dementia (AD) than non-Hispanic Whites. The impact of a Mediterranean Diet (Med Diet) and intentional weight loss (IWL) on the gut microbiome may alter AD risk. A post hoc analysis of the Building Research in Diet and Cognition (BRIDGE) trial was performed to determine whether participation in an 8-month Med Diet lifestyle intervention with (n = 35) or without IWL (n = 31) was associated with changes in gut microbiota structure, abundance, and function and whether these changes were related to changes in cognitive performance. The results showed that family and genus alpha diversity increased significantly in both groups combined (p = 0.0075 and p = 0.024, respectively). However, there were no other significant microbially related within- or between-group changes over time. Also, an increase in Med Diet adherence was significantly associated with a decrease in alpha diversity at the phylum level only (p = 0.049). Increasing alpha diversity was associated with decreasing cognitive performance, but this association was attenuated after controlling for Med Diet adherence. In sum, an 8-month Med Diet lifestyle intervention with or without IWL did not appreciably alter the gut microbiome.

Longitudinal Dietary Trajectories With Cognitive and Psychosocial Well-Being in Chinese Adults Aged 85 Years and Older in Singapore

Background and Objectives

Studies on longitudinal trajectories of diet and the influence on aging in older adults are limited. We characterized diet quality trajectories over the past 2 decades among adults aged ≥85 years and examined their associations with cognitive and psychosocial outcomes.

Research Design and Methods

We used data from 861 participants in the population-based Singapore Chinese Health Study. Dietary intakes were assessed at baseline (mean age [range]: 65 [60-74] years) and at follow-ups 3 (85 [81-95]) and 4 (88 [85-97]) years. Diet quality was measured by adherence to the Dietary Approaches to Stop Hypertension pattern, and group-based trajectory modeling was used to derive diet quality trajectories. At Follow-up 4, we assessed cognition using the Singapore-modified Mini-Mental State Examination, depressive symptoms using the 15-item Geriatric Depression Scale, social engagement, and self-rated health. Multivariable logistic regression models examined associations of diet quality trajectories with these outcomes.

Results

About 49.7% had a trajectory with consistently low diet quality scores, whereas 50.3% had a trajectory with consistently high diet quality scores. Compared to the "consistently low" trajectory, the "consistently high" trajectory had 29% and 26% lower likelihoods of cognitive impairment and depressive symptoms, respectively (odds ratio, 95% confidence interval: 0.71 [0.51, 0.99] and 0.74 [0.55, 0.99], respectively); as well as 47% higher likelihood of social engagement (1.47 [1.09, 1.98]). No statistically significant association was observed between the trajectories and self-rated health.

Discussion and Implications

Maintaining high diet quality throughout the older adult life course was associated with better cognitive and psychosocial well-being in adults aged ≥85 years.

The biological role of prolyl oligopeptidase and the procognitive potential of its peptidic inhibitors from food proteins

Prolyl oligopeptidase (POP) is a conserved serine protease belonging to proline-specific peptidases. It has both enzymatic and non-enzymatic activity and is involved in numerous biological processes in the human body, playing a role in e.g., cellular growth and differentiation, inflammation, as well as the development of some neurodegenerative and neuropsychiatric disorders. This article describes the physiological and pathological aspects of POP activity and the state-of-art of its peptidic inhibitors originating from food proteins, with a particular focus on their potential as cognition-enhancing agents. Although some milk, meat, fish, and plant protein-derived peptides have the potential to be applied as natural, procognitive nutraceuticals, their effectiveness requires further evaluation, especially in clinical trials. We demonstrated that the important features of the most promising POP-inhibiting peptides are very short sequence, high content of hydrophobic amino acids, and usually the presence of proline residue.

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 Between Dietary Habits in Midlife With Dementia Incidence Over a 20-Year Period

BACKGROUND AND OBJECTIVES

Dementia cases are expected to triple during the next 30 years, highlighting the importance of finding modifiable risk factors for dementia. The aim of this study was to investigate whether adherence to conventional dietary recommendations or to a modified Mediterranean diet are associated with a subsequent lower risk of developing all-cause dementia, Alzheimer disease (AD), vascular dementia (VaD), or with future accumulation of AD-related β-amyloid (Aβ) pathology.

METHODS

Baseline examination in the prospective Swedish population-based Malmö Diet and Cancer Study took place in 1991-1996 with a follow-up for incident dementia until 2014. Nondemented individuals born 1923-1950 and living in Malmö were invited to participate. Thirty thousand four hundred forty-six were recruited (41% of all eligible). Twenty-eight thousand twenty-five had dietary data and were included in this study. Dietary habits were assessed with a 7-day food diary, detailed food frequency questionnaire, and 1-hour interview. Main outcomes were incident all-cause dementia, AD, or VaD determined by memory clinic physicians. Secondary outcome was Aβ-accumulation measured using CSF Aβ42 (n = 738). Cox proportional hazard models were used to examine associations between diet and risk of developing dementia (adjusted for demographics, comorbidities, smoking, physical activity, and alcohol).

RESULTS

Sixty-one percent were women, and the mean (SD) age was 58.1 (7.6) years. One thousand nine hundred forty-three (6.9%) were diagnosed with dementia (median follow-up, 19.8 years). Individuals adhering to conventional dietary recommendations did not have lower risk of developing all-cause dementia (hazard ratio [HR] comparing worst with best adherence, 0.93, 95% CI 0.81-1.08), AD (HR 1.03, 0.85-1.23), or VaD (HR 0.93, 0.69-1.26). Neither did adherence to the modified Mediterranean diet lower the risk of developing all-cause dementia (HR 0.93 0.75-1.15), AD (HR 0.90, 0.68-1.19), or VaD (HR 1.00, 0.65-1.55). The results were similar when excluding participants developing dementia within 5 years or those with diabetes. No significant associations were found between diet and abnormal Aβ accumulation, conventional recommendations (OR 1.28, 0.74-2.24) or modified Mediterranean diet (OR 0.85, 0.39-1.84).

DISCUSSION

In this 20-year follow-up study, neither adherence to conventional dietary recommendations nor to modified Mediterranean diet were significantly associated with subsequent reduced risk for developing all-cause dementia, AD dementia, VaD, or AD pathology.

Adherence to the Dietary Approaches to Stop Hypertension (DASH) Eating Pattern Reduces the Risk of Head and Neck Cancer in American Adults Aged 55 Years and Above: A Prospective Cohort Study

OBJECTIVES

Dietary Approaches to Stop Hypertension (DASH) pattern has been found to aid in the reduction of obesity, oxidative stress, and chronic inflammation, which are all strongly linked to the development of head and neck cancer (HNC). Nevertheless, no epidemiological studies have investigated the association between this dietary pattern and HNC risk. This study was conducted with the purpose of bridging this gap in knowledge.

DESIGN

A prospective cohort study involving 98,459 American adults aged 55 years and older.

SETTING AND PARTICIPANTS

Data were drawn from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Trial. In the present study, participants with dependable energy intake data who furnished baseline and dietary history information were identified as the study population.

METHODS

Diet was assessed by food frequency questionnaires and the DASH score was calculated to assess each participant's adherence to DASH eating pattern. Cox proportional hazards models were used to calculate multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the occurrence of HNC. To visualize the variation in cancer risk for HNC and its subtypes across the entire spectrum of DASH scores, restricted cubic spline plots were utilized. Additionally, a series of predefined subgroup analyses were performed to identify potential effect modifiers, and several sensitivity analyses were conducted to assess the stability of the findings.

RESULTS

During a follow-up period of 871,879.6 person-years, 268 cases of HNC were identified, comprising 161 cases pertaining to oral cavity and pharynx cancers, as well as 96 cases of larynx cancer. In the fully adjusted model, adherence to the DASH diet was associated with a remarkable 57% reduction in the risk of HNC when comparing extreme quartiles (HR quartile 4 vs 1: 0.43; 95% CI: 0.28, 0.66; P for trend < 0.001). The restricted cubic spline plots demonstrated a linear dose-response relationship between the DASH score and the risk of HNC as well as its subtypes. Subgroup analysis revealed that the protective effect of the DASH diet against HNC was particularly pronounced in individuals with lower daily energy intake. The primary association remained robust in the sensitivity analysis.

CONCLUSIONS

In American middle-aged and older population, adherence to the DASH diet may help prevent HNC, particularly for individuals with lower daily energy intake.

Meeting report: plant-rich dietary patterns and health

Dietary patterns (DP) rich in plant foods are associated with improved health and reduced non-communicable disease risk. In October 2021, the Nutrition Society hosted a member-led conference, held online over 2 half days, exploring the latest research findings examining plant-rich DP and health. The aim of the present paper is to summarise the content of the conference and synopses of the individual speaker presentations are included. Topics included epidemiological analysis of plant-rich DP and health outcomes, the effects of dietary interventions which have increased fruit and vegetable (FV) intake on a range of health outcomes, how adherence to plant-rich DP is assessed, the use of biomarkers to assess FV intake and a consideration of how modifying behaviour towards increased FV intake could impact environmental outcomes, planetary health and food systems. In conclusion, although there are still considerable uncertainties which require further research, which were considered as part of the conference and are summarised in this review, adopting a plant-rich DP at a population level could have a considerable impact on diet and health outcomes, as well as planetary health.

Association between changes in diet quality from mid-life to late-life and healthy ageing: the Singapore Chinese Health Study

BACKGROUND

Few studies have evaluated the association between changes in diet quality from mid-life to late-life and healthy ageing.

METHODS

We included 12,316 Chinese adults aged 45-74 years at baseline (1993-1998) from the Singapore Chinese Health Study. Diet quality was measured using the Dietary Approaches to Stop Hypertension (DASH) scores at baseline and follow-up 3 interviews (2014-2016). Healthy ageing was assessed at follow-up 3 interviews, and was defined as absence of specific chronic diseases, good mental and overall self-perceived health, good physical functioning and absence of cognitive impairment, limitations in instrumental activities of daily living or function-limiting pain. Multivariable-adjusted logistic regression models were applied to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between changes in DASH scores and healthy ageing.

RESULTS

Compared with participants who maintained relatively stable DASH scores, a >10% decrease in DASH score was associated with a 16% (95% CI, 4-26%) lower likelihood of healthy ageing, whereas a >10% increase in DASH score was associated with a 19% (95% CI, 3-37%) higher likelihood of healthy ageing. Compared with participants who were in the low-score group consistently, participants who increased their DASH scores from moderate-score at baseline to high-score at follow-up 3 had a 53% (95% CI, 21-92%) higher likelihood of healthy ageing, whereas those who were in the high-score group consistently had 108% (95% CI, 71-152%) higher likelihood of healthy ageing.

CONCLUSIONS

Improving diet quality from mid- to late-life was associated with a higher likelihood of healthy ageing.

A Phenome-wide Association and Mendelian Randomization Study for Alzheimer's Disease: A Prospective Cohort Study of 502,493 Participants From the UK Biobank

BACKGROUND

Considerable uncertainty remains regarding associations of multiple risk factors with Alzheimer's disease (AD). We aimed to systematically screen and validate a wide range of potential risk factors for AD.

METHODS

Among 502,493 participants from the UK Biobank, baseline data were extracted for 4171 factors spanning 10 different categories. Phenome-wide association analyses and time-to-event analyses were conducted to identify factors associated with both polygenic risk scores for AD and AD diagnosis at follow-up. We performed two-sample Mendelian randomization analysis to further assess their potential causal relationships with AD and imaging association analysis to discover underlying mechanisms.

RESULTS

We identified 39 factors significantly associated with both AD polygenic risk scores and risk of incident AD, where higher levels of education, body size, basal metabolic rate, fat-free mass, computer use, and cognitive functions were associated with a decreased risk of developing AD, and selective food intake and more outdoor exposures were associated with an increased risk of developing AD. The identified factors were also associated with AD-related brain structures, including the hippocampus, entorhinal cortex, and inferior/middle temporal cortex, and 21 of these factors were further supported by Mendelian randomization evidence.

CONCLUSIONS

To our knowledge, this is the first study to comprehensively and rigorously assess the effects of wide-ranging risk factors on AD. Strong evidence was found for fat-free body mass, basal metabolic rate, computer use, selective food intake, and outdoor exposures as new risk factors for AD. Integration of genetic, clinical, and neuroimaging information may help prioritize risk factors and prevention targets for AD.

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.

Twenty-Five-Year Change in Cardiac Structure and Function and Midlife Cognition: The CARDIA Study

BACKGROUND AND OBJECTIVE

The goal of this work was to determine whether midlife cardiac structure and function and their 25-year change from early to middle adulthood are associated with lower midlife cognition.

METHODS

We studied 2,653 participants from the Coronary Artery Risk Development in Young Adults (CARDIA) study (57% women, 46% Black). Echocardiograms were obtained at year 5, 25, and 30 visits (participant mean age 30, 50, and 55 years) to assess left ventricular (LV) mass (LVM), LV systolic function with LV ejection fraction (LVEF), and LV diastolic function with left atrial volume (LAV) and early peak mitral velocity (E)/early peak mitral annular velocity (e') ratio. LVM and LAV were indexed to body surface area (LVMi and LAVi). At year 30, 5 cognitive domains were measured: global cognition, processing speed, executive function, delayed verbal memory, and verbal fluency. We investigated the association between midlife (year 30) and 25-year change in cardiac structure and function on midlife cognition using linear regressions.

RESULTS

Over 25 years, LVMi and LAVi increased with mean change (SD) per year of 0.27 (0.28) g/m² and 0.42 (0.15) mL/m², while LVEF decreased by 0.11% (0.02%). After adjustment for demographics and education, 25-year increase (≥1 SD) in LVMi was associated with lower cognition on most tests (p ≤ 0.02); 25-year increase in LAVi was associated with lower global cognition (p = 0.04), but 25-year decrease in LVEF was not associated with cognition. Further adjustment for cardiovascular risk factors led to similar results. In addition, unlike year 30 E/e' ratio and LVEF, higher year 30 LVMi and LAVi were significantly associated with worse cognition on most cognitive tests.

DISCUSSION

Midlife cardiac structure and its change from early to middle adulthood are associated with lower midlife cognition even after accounting for confounders. Unlike systolic function, midlife LV diastolic function and its 25-year change were also linked to cognition. Our results provide information linking early to midlife cardiac structure and function to cognition.

Multisite Medical Student-Led Community Culinary Medicine Classes Improve Patients' Diets: Machine Learning-Augmented Propensity Score-Adjusted Fixed Effects Cohort Analysis of 1381 Subjects

Background. Healthy diet represents one of the largest single modifiable risk factors proven to decrease rates of obesity and associated chronic disease, but practical approaches to improving dietary habits through nutritional intervention are limited. Objective. To evaluate the effectiveness of a medical student-led, 6-week culinary course on participants' dietary knowledge and behaviors, particularly focusing on the tenets of the Mediterranean diet (MedDiet). Design. This study is a prospective multisite cohort study evaluating the effects of a 6-week, hands-on community culinary education course offered at 3 sites. Participants' knowledge of cooking skills, eating habits, and adherence to the MedDiet were evaluated using a survey prior to beginning and 6 weeks after the completion of the course. Analysis was conducted using multivariable regression to assess subjects' diets, associated behaviors, and nutrition beliefs according to the number of classes to which they were exposed (0 to >6). Statistical results were then compared with the machine learning results to check statistical validity after selection of the top-performing algorithm from 43 supervised algorithms using 10-fold cross-validation with performance assessed according to accuracy, root relative square error, and root mean square error. Results. Among the 1381 participants, cooking classes significantly improved patients' overall 9-point MedDiet adherence (β = 0.62, 95% CI 0.23-1.00, P = .002). Participants were more likely to meet MedDiet point requirements for fruit intake (odds ratio [OR] 2.77, 95% CI 1.46-5.23, P = .002), vegetable intake (OR 4.61, 95% CI 1.85-11.53, P = .001), legume intake (OR 2.48, 95% CI 1.45-4.26, P = .001), and olive oil use (OR 2.87, 95% CI 1.44-5.74, P = .003), and were less likely to believe that cooking takes excessive time (OR 0.31, 95% CI 0.16-0.59, P < .001). Conclusion. Hands-on culinary education courses were associated with increased MedDiet adherence and improved knowledge of healthful eating. Such interventions thus represent a cost-effective option for addressing rates of obesity and obesity-related chronic illness.

Subjective cognitive decline and total energy intake: Talk too much?

The increasing longevity of the population has resulted in dementia becoming a leading cause of both death and disability. Dementia is not a single disease. Studies of rare Mendelian disorders have documented that Alzheimer's disease, the most common cause of dementia, is associated with a long incubation period from amyloid deposition to neurodegeneration to mild cognitive impairment and dementia. There are three broad hypotheses related to the causes of Alzheimer's dementia: (1) an aging process; (2) brain vascular disease; and (3) metabolic abnormalities associated with either increased production of amyloid-β or decreased clearance from the brain. Therefore, research on the early stages of the dementia process are of high priority. This paper reports that higher energy intake in both the Nurses' Health Study and Health Professionals Follow-up Study is associated with very early symptoms that lead to mild cognitive impairment and dementia. The results are very interesting but hard to interpret because they also show that higher energy intake is not related to body mass index, a very unusual observation. A likely hypothesis is that there is an association between reporting of dietary intake and subjective symptoms, i.e. reporting bias, accounting for their results.

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.

Adherence to a MIND-Like Dietary Pattern, Long-Term Exposure to Fine Particulate Matter Air Pollution, and MRI-Based Measures of Brain Volume: The Women's Health Initiative Memory Study-MRI

BACKGROUND

Previous studies suggest that certain dietary patterns and constituents may be beneficial to brain health. Airborne exposures to fine particulate matter [particulate matter with aerodynamic diameter ≤ 2.5 μ m (PM 2.5 )] are neurotoxic, but the combined effects of dietary patterns and PM 2.5 have not been investigated.

OBJECTIVES

We examined whether previously reported association between PM 2.5 exposure and lower white matter volume (WMV) differed between women whose usual diet during the last 3 months before baseline was more or less consistent with a Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND)-like diet, a dietary pattern that may slow neurodegenerative changes.

METHODS

This study included 1,302 U.S. women who were 65-79 y old and free of dementia in the period 1996-1998 (baseline). In the period 2005-2006, structural brain magnetic resonance imaging (MRI) scans were performed to estimate normal-appearing brain volumes (excluding areas with evidence of small vessel ischemic disease). Baseline MIND diet scores were derived from a food frequency questionnaire. Three-year average PM 2.5 exposure prior to MRI was estimated using geocoded participant addresses and a spatiotemporal model.

RESULTS

Average total and temporal lobe WMVs were 0.74   cm 3 [95% confidence interval (CI): 0.001, 1.48) and 0.19   cm 3 (95% CI: 0.002, 0.37) higher, respectively, with each 0.5-point increase in the MIND score and were 4.16   cm 3 (95% CI: - 6.99 , - 1.33 ) and 1.46   cm 3 (95% CI: - 2.16 , - 0.76 ) lower, respectively, with each interquartile range (IQR) (IQR = 3.22   μ g / m 3 ) increase in PM 2.5 . The inverse association between PM 2.5 per IQR and WMV was stronger (p -interaction < 0.001 ) among women with MIND scores below the median (for total WMV, - 12.47   cm 3 ; 95% CI: - 17.17 , - 7.78 ), but absent in women with scores above the median (0.16   cm 3 ; 95% CI: - 3.41 , 3.72), with similar patterns for WMV in the frontal, parietal, and temporal lobes. For total cerebral and hippocampus brain volumes or WMV in the corpus callosum, the associations with PM 2.5 were not significantly different for women with high MIND scores and women with low MIND scores.

DISCUSSION

In this cohort of U.S. women, PM 2.5 exposure was associated with lower MRI-based WMV, an indication of brain aging, only among women whose usual diet was less consistent with the MIND-like dietary pattern at baseline. https://doi.org/10.1289/EHP8036.

Healthy Diet for Healthy Aging

Extending healthspan is a major public health challenge. Diet is one of the modifiable factors for preventing age-related diseases and preserving overall good health status during aging. Optimizing individuals’ intrinsic capacity, including domains in cognition, psychological, sensory function, vitality, and locomotion, has been proposed as a model of healthy aging by the World Health Organization. To better understand the relationships between a healthy diet and healthy aging, this review summarizes the recent epidemiologic and clinical data for dietary patterns that have been shown to play a role in (domains of) healthy aging. Regardless of priori or posteriori dietary patterns, it appears that dietary patterns centered on plant-based foods have a beneficial role in (domains of) healthy aging. Our review identified a knowledge gap in dietary patterns and multidimensional concepts of healthy aging. More epidemiological studies should consider intrinsic capacity as an outcome measure to further our understanding of a healthy diet and multidimensional concepts of healthy aging. When a sufficient number of epidemiological studies is available, evidence can be synthesized and clinical trials can be designed to evaluate a healthy diet as a strategy for healthy aging to further our progress in translating evidence to practice and promoting healthy aging.

Current Alzheimer disease research highlights: evidence for novel risk factors

Alzheimer disease (AD) is the most common type of dementia characterized by the progressive cognitive and social decline. Clinical drug targets have heavily focused on the amyloid hypothesis, with amyloid beta (Aβ), and tau proteins as key pathophysiologic markers of AD. However, no effective treatment has been developed so far, which prompts researchers to focus on other aspects of AD beyond Aβ, and tau proteins. Additionally, there is a mounting epidemiologic evidence that various environmental factors influence the development of dementia and that dementia etiology is likely heterogenous. In the past decades, new risk factors or potential etiologies have been widely studied. Here, we review several novel epidemiologic and clinical research developments that focus on sleep, hypoxia, diet, gut microbiota, and hearing impairment and their links to AD published in recent years. At the frontiers of AD research, these findings and updates could be worthy of further attention.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Lifestyle-dependent microglial plasticity: training the brain guardians

Lifestyle is one of the most powerful instruments shaping mankind; the lifestyle includes many aspects of interactions with the environment, from nourishment and education to physical activity and quality of sleep. All these factors taken in complex affect neuroplasticity and define brain performance and cognitive longevity. In particular, physical exercise, exposure to enriched environment and dieting act through complex modifications of microglial cells, which change their phenotype and modulate their functional activity thus translating lifestyle events into remodelling of brain homoeostasis and reshaping neural networks ultimately enhancing neuroprotection and cognitive longevity.

Towards a More Sustainable Nutrition: Complementary Feeding and Early Taste Experiences as a Basis for Future Food Choices

The concept of sustainable nutrition considers different fields: from human health to environmental, economic and socio-cultural aspects. Currently, in Europe, the diets that reflect the assumptions of the sustainable diet are the Mediterranean Diet and the New Nordic Diet. They both encourage the consumption of vegetable, organic and minimally processed foods, as well as regional, seasonal and Fair-Trade products, reducing the ecological impact of the production chain. These eating habits could be established starting from the prenatal period and from infancy during the complementary feeding stage, aiding children to accept of a more variable diet in terms of flavor, taste and texture. In particular, the positive parental role model is an effective method for improving a child’s diet and behaviors. Two healthy plates representing a sustainable diet in early infancy, at 6 and 24 months, are here proposed, in line with the “Planetary Health Diet” approved by the EAT-Lancet Commission. Our work aims to highlight how a sustainable diet is possible since infancy, since the introduction of solid foods.

Mediterranean diet scoring systems: understanding the evolution and applications for Mediterranean and non-Mediterranean countries

The Mediterranean diet (MedD) is a flexible dietary pattern which has such variability that has led to inconsistencies in definitions and assessment. The purpose of this narrative review is to evaluate scoring systems in a cultural and geographic context, from Mediterranean and non-Mediterranean countries, for comparison and application. The early MedD scoring systems (i.e. Trichopoulou's MedD Scale (T-MDS) and alternative MedD Scale (aMed)) are widely applied throughout the world but use population-specific median cut-offs which limit interpretation and cross-study comparisons. The T-MDS and aMed also do not account for non-traditional MedD foods which are consumed in greater quantities than when the scoring systems were developed. Scoring systems developed after the MedD pyramid publication in 2011 have generally used these recommendations as a basis for food group intake cut-offs, incorporating more foods/food groups as negative components, and some have included dietary and lifestyle behaviours. The different approaches to MedD assessment have created much variability in the foods/food group components included in scoring systems. Assessments that include dietary and lifestyle behaviours may reflect the nutrition transition occurring in Mediterranean countries and better guide clinical intervention approaches. While the new scoring systems are theorised to better capture MedD adherence and behaviours, comparisons are sparse in the literature and none exists outside of Europe. Consensus on food and dietary behaviours to include as well as the methodology for assigning points in MedD scoring systems is needed to advance our understanding of MedD and health relationships to promote public health messaging and clinical application.

The Coronary Artery Risk Development In Young Adults (CARDIA) Study: JACC Focus Seminar 8/8

The CARDIA (Coronary Artery Risk Development in Young Adults) study began in 1985 to 1986 with enrollment of 5,115 Black or White men and women ages 18 to 30 years from 4 US communities. Over 35 years, CARDIA has contributed fundamentally to our understanding of the contemporary epidemiology and life course of cardiovascular health and disease, as well as pulmonary, renal, neurological, and other manifestations of aging. CARDIA has established associations between the neighborhood environment and the evolution of lifestyle behaviors with biological risk factors, subclinical disease, and early clinical events. CARDIA has also identified the nature and major determinants of Black-White differences in the development of cardiovascular risk. CARDIA will continue to be a unique resource for understanding determinants, mechanisms, and outcomes of cardiovascular health and disease across the life course, leveraging ongoing pan-omics work from genomics to metabolomics that will define mechanistic pathways involved in cardiometabolic aging.

Polyphenols of the Mediterranean Diet and Their Metabolites in the Prevention of Colorectal Cancer

The Mediterranean diet is a central element of a healthy lifestyle, where polyphenols play a key role due to their anti-oxidant properties, and for some of them, as nutripharmacological compounds capable of preventing a number of diseases, including cancer. Due to the high prevalence of intestinal cancer (ranking second in causing morbidity and mortality), this review is focused on the beneficial effects of selected dietary phytophenols, largely present in Mediterranean cooking: apigenin, curcumin, epigallocatechin gallate, quercetin-rutine, and resveratrol. The role of the Mediterranean diet in the prevention of colorectal cancer and future perspectives are discussed in terms of food polyphenol content, the effectiveness, the plasma level, and the importance of other factors, such as the polyphenol metabolites and the influence of the microbiome. Perspectives are discussed in terms of microbiome-dependency of the brain-second brain axis. The emergence of polyphenol formulations may strengthen the efficiency of the Mediterranean diet in the prevention of cancer.

In Pursuit of Healthy Aging: Effects of Nutrition on Brain Function

Consuming a balanced, nutritious diet is important for maintaining health, especially as individuals age. Several studies suggest that consuming a diet rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and fish may reduce age-related cognitive decline and the risk of developing various neurodegenerative diseases. Numerous studies have been published over the last decade focusing on nutrition and how this impacts health. The main objective of the current article is to review the data linking the role of diet and nutrition with aging and age-related cognitive decline. Specifically, we discuss the roles of micronutrients and macronutrients and provide an overview of how the gut microbiota-gut-brain axis and nutrition impact brain function in general and cognitive processes in particular during aging. We propose that dietary interventions designed to optimize the levels of macro and micronutrients and maximize the functioning of the microbiota-gut-brain axis can be of therapeutic value for improving cognitive functioning, particularly during aging.

Mediterranean diet adherence is associated with better cognitive status and less depressive symptoms in a Greek elderly population

PURPOSE

To evaluate the Mediterranean diet (MD) adherence of an elderly Greek population, and its association with the grade of cognitive decline and psychological status.

METHODS

Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Mediterranean diet score (MedDietScore) questionnaires were used to assess the impact of MD adherence on cognitive abilities and psychological state of a Greek elderly population.

PARTICIPANTS

2092 men and women over 65 years old (mean age 74.97 ± 8.41 years) from seven different Greek cities RESULTS: 34.4% of the study population showed cognitive impairment, while 32.3% of the participants had depressive symptoms. More than half of the participants (52.1%) showed very low or low MD adherence. Higher MD adherence was significantly associated with better MMSE and GDS scores. Moreover, higher MD adherence was significantly associated with younger age, female gender, higher educational level, and better anthropometric parameters. MD adherence was independently associated with cognitive and psychological status, and gender after adjustment for potential confounders.

CONCLUSION

Higher MD adherence is strongly associated with better cognitive status and less depressive symptomatology. Public health policies are recommended to focus on the promotion of the MD, as a crucial strategy to reduce the risk of cognitive impairment and depression.

Early-but Not Late-Onset Hypertension Is Related to Midlife Cognitive Function

Hypertension is related to increased risk of cognitive decline in a highly age-dependent manner. However, conflicting evidence exists on the relation between age of hypertension onset and cognition. Our goal was to investigate the association between early- versus late-onset hypertension and midlife cognitive performance in 2946 CARDIA study (Coronary Artery Risk Development in Young Adults) participants (mean age 55±4, 57% women). The participants underwent 9 repeat examinations, including blood pressure measurements, between 1985 to 1986 and 2015 to 2016. The participants underwent brain magnetic resonance imaging and completed Digit Symbol Substitution Test, Rey Auditory Verbal Learning Test, Stroop interference test, and the Montreal Cognitive Assessment to evaluate cognitive function at the year 30 exam. We assessed the relation between age of hypertension onset and cognitive function using linear regression models adjusted for cognitive decline risk factors, including systolic blood pressure. We observed that individuals with early-onset hypertension (onset at <35 years) had 0.24±0.09, 0.22±0.10, 0.27±0.09, and 0.19±0.07 lower standardized Z-scores in Digit Symbol Substitution Test, Stroop test, Montreal Cognitive Assessment, and a composite cognitive score than participants without hypertension (P<0.05 for all). In contrast, hypertension onset at ≥35 years was not associated with cognitive function (P >0.05 for all). In a subgroup of 559 participants, neither early- nor late-onset hypertension was related to macrostructural brain alterations (P >0.05 for all). Our results indicate that early-onset hypertension is a potent risk factor for midlife cognitive impairment. Thus, age of hypertension onset assessment in clinical practice could improve risk stratification of cognitive decline in patients with hypertension.

Non-alcoholic fatty liver disease and cognitive function in middle-aged adults: the CARDIA study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with cardiovascular disease (CVD) risk factors that have been linked to cognitive decline. Whether NAFLD is associated with cognitive performance in midlife remains uncertain.

METHODS

Coronary Artery Risk Development in Young Adults study participants with CT examination and cognitive assessment at Y25 (2010-2011; n = 2809) were included. Cognitive function was reassessed at Y30. NAFLD was defined according to liver attenuation and treated both continuously and categorically (using ≤ 40 and ≤ 51 Hounsfield units to define severity) after exclusion for other causes of liver fat. Cognitive tests including the Digit Symbol Substitution (processing speed), Rey Auditory Verbal Learning (verbal memory), and Stroop (executive function) were analyzed with standardized z-scores. Linear models were constructed to (a) examine the cross-sectional associations of NAFLD with cognitive scores and (b) evaluate its predictive role in 5-year change in cognitive performance.

RESULTS

Participants' mean age (Y25) was 50.1 (SD 3.6) years (57% female; 48% black), with 392 (14%) having mild NAFLD and 281 (10%) having severe NAFLD. NAFLD was positively associated with CVD risk factors and inversely associated with cognitive scores. However, after adjustment for CVD risk factors, no associations were shown between NAFLD and cognitive scores (all βs ≈ 0). Similarly, no associations were observed with 5-year cognitive decline. CVD history, hypertension, smoking, diabetes and hypertriglyceridemia showed stronger associations with baseline cognitive scores and were predictive of subsequent cognitive decline (all P ≤ .05).

CONCLUSION

Among middle-aged adults, inverse associations between NAFLD and cognitive scores were attenuated after adjustment for CVD risk factors, with the latter predictive of poorer cognitive performance both at baseline and follow-up.

Building research in diet and cognition (BRIDGE): Baseline characteristics of older obese African American adults in a randomized controlled trial to examine the effect of the Mediterranean diet with and without weight loss on cognitive functioning

•

The MedDiet is correlated with slower cognitive decline in longitudinal studies.

•

Self-reported MedDiet adherence positively associated with select cognitive domains.

•

Women outperformed men across verbal tasks, including learning and memory.

•

Younger participants outperformed older participants on cognitive assessments.

In the United States, >5.4 million people age 65 and older are affected by cognitive impairment and dementia, including Alzheimer’s disease. African Americans are more likely than non-Hispanic whites to suffer from these disorders. Obesity is linked to accelerated age-related cognitive decline, and weight loss through caloric restriction is a potential strategy to prevent this cognitive impairment. Adherence to a healthful dietary pattern, such as the Mediterranean Diet (MedDiet), has also shown positive effects on reducing risk for dementia. African Americans are disproportionately affected by obesity and have less healthful diets than non-Hispanic whites. We present baseline characteristics from a three-arm randomized controlled trial that randomized 185 obese (BMI ≥ 30 kg/m² and ≤ 50 kg/m²) healthy older adults (55–85 years of age) to: 1) Typical Diet Control (TDC); 2) MedDiet alone (MedDiet-A) intervention; or 3) MedDiet caloric restricted intervention to promote weight loss (MedDiet-WL). The majority of the sample was African American (91.4%) and female (85.9%). The two active interventions (MedDiet-A and MedDiet-WL) met once weekly for 8 months, and the TDC received weekly general health newsletters. Baseline data were collected between January 2017 and July 2019 in Chicago, IL. In our sample, closer adherence to a MedDiet pattern was associated with higher attention and information processing (AIP) and higher executive functioning (EF). Consistent with the literature, we saw that older participants performed more poorly on the cognitive assessments than younger participants, and women outperformed men across verbally mediated tasks, especially ones related to learning and memory.

Racial Differences in Dietary Relations to Cognitive Decline and Alzheimer's Disease Risk: Do We Know Enough?

The elderly population in the US is increasing and projected to be 44% minority by 2060. African Americans and Hispanics are at increased risk of cognitive impairment and Alzheimer’s disease compared to non-Hispanic whites. These conditions are associated with many other adverse health outcomes, lower quality of life, and substantial economic burden. In the past few decades, diet has been identified as an important modifiable risk factor for cognitive decline and Alzheimer’s disease. Some studies report poor diet quality among African American and Hispanic older adult populations compared to their white counterparts. We have a limited understanding of how diet affects brain health in different racial-ethnic groups. One primary reason for our lack of knowledge is that most cohort studies are of majority non-Hispanic white participants. Moreover, those that do include minority participants do not publish their findings stratified by racial-ethnic groups, and likely have a less accurate measurement of dietary intake among minority groups. In this review, we summarize the current, albeit limited, literature on racial/ethnic differences in dietary relations to dementia outcomes. We will also discuss methodological issues in conducting nutrition studies in diverse cultures, and suggestions for future research directions. Overcoming the gaps will make it possible to make dietary recommendations for Alzheimer’s prevention that are more relevant for different racial/ethnic groups and set us on a faster track to reduce health disparities.

The Mediterranean diet and menopausal health: An EMAS position statement

INTRODUCTION

Globally, 985 million women are aged 50 and over, leading to increasing concerns about chronic conditions such as cardiovascular disease, osteoporosis, dementia, and cognitive decline, which can adversely affect quality of life and independent living.

AIM

To evaluate the evidence from observational studies and randomized trials on the effects of the Mediterranean diet on short- and long-term menopausal health: estrogen deficiency symptoms, cardiovascular disease, osteoporosis, cognitive and mental health, breast cancer, and all-cause mortality.

MATERIALS AND METHODS

Literature review and consensus of expert opinion.

SUMMARY RECOMMENDATIONS

The Mediterranean diet is a non-restrictive dietary pattern common in the olive-growing areas of the Mediterranean basin. It may improve vasomotor symptoms, cardiovascular risk factors such as blood pressure, cholesterol and blood glucose levels, as well as mood and symptoms of depression. Long-term adherence may: improve cardiovascular risk and events, and death; improve bone mineral density; prevent cognitive decline; and reduce the risk of breast cancer and all-cause mortality.

Food Insecurity and Cognitive Function in Middle to Older Adulthood: A Systematic Review

Food insecurity (FI) may limit cognitive functioning during aging. The goal of this systematic review was to summarize existing evidence linking FI and general or specific cognitive functions in middle and older adulthood. A systematic search of human studies published between 1 January 2000 and 30 April 2018 was conducted in PubMed, PsycINFO, and CAB Direct. Four independent reviewers assessed the eligibility of identified articles and conducted data extraction and data quality assessment. Ten studies were included in the review, including 1 cluster-randomized controlled trial, 2 longitudinal studies, and 7 cross-sectional studies. Three studies reported the association between early-life FI experience and a global cognitive function measure. Nine studies reported later-life FI experience in relation to global or specific cognitive functions. The results suggest an adverse association between FI experienced in early or later life and global cognitive function; and between later-life FI and executive function and memory. Findings from the review are preliminary because of sparse data, heterogeneity across study populations, exposure and outcome assessments, and potential risk of bias across studies. Future studies are recommended to better understand the role of FI in cognitive function, with the goal of identifying possible critical windows for correction of FI in vulnerable subpopulations to prevent neurocognitive deficit in adulthood.

Mediterranean diet and health: A systematic review of epidemiological studies and intervention trials

Diet is a crucial variable for a healthy life. A rapidly growing number of studies in recent years support the hypothesis that the Mediterranean diet (MedDiet) has a beneficial effect on certain body systems, but the highly varied objectives and quality of these publications warrants an updated assessment. In the present review we performed a comprehensive evaluation of current evidence on the impact of the MedDiet on human health, assessing its effect on the incidence or progression of the main non-communicable diseases and their intermediate outcomes and risk factors. We scrutinised the clinical evidence from observational studies and randomised controlled trials. Cardiovascular disease was the condition with most information. The MedDiet showed a general preventive effect, which was reproduced to varying degrees for certain intermediate cardiovascular outcomes such as blood pressure, lipids, obesity, metabolic syndrome and diabetes. Benefits were also found for several types of cancer, brain function (including cognition, mood and to a lesser extent Parkinson's disease) and mortality. The quality of the published evidence was, however, generally moderate or low. In conclusion, the MedDiet shows a favourable impact on health. General adoption of a MedDiet is concordant with current policies promoting healthy and sustainable nutrition worldwide. Nonetheless, more high-quality research is needed to improve the consistency of the findings.

America's Health Care System Is Broken: What Went Wrong and How We Can Fix It. Part 6: Social Factors

Although previous articles in the series have focused on the key players in our health care system, even larger factors that impact the cost and outcome of the nation's health lie in areas that are not traditionally thought of as "health care." Diet and exercise play a huge role in longevity and well-being. The best health care systems are unable to do much to lower deaths from firearms and motor vehicle crashes. Changing our focus from health care institutions to how to better support patients in the community will both lower cost and improve satisfaction. We need to learn how to better integrate patients' wishes into end-of-life care to provide more humanistic as well as less expensive care.