Healthy eating and reduced risk of cognitive decline: A cohort from 40 countries

Select Dietary Components Are Associated With Better Global Cognition in U.S. Adults With HIV: A Pilot Study

ABSTRACT

People with HIV (PWH) are at an increased risk for cognitive impairment. Lifestyle factors can have protective effects on cognition; little work has examined diet and cognitive function in PWH. In this cross-sectional pilot study, 86 PWH (mean age 56 years) completed diet recalls and a neurocognitive assessment. Correlations were conducted between diet and cognitive function, adjusting for total calories, sex, and education (multiple comparison correction p values are reported). Diet quality of the sample was poor. Greater calories per day ( r = 0.28, p =.08) and greater percentage of calories from saturated fatty acids (SFAs; r = 0.26, p = 0.08) were associated with better cognition. Higher intake of SFAs ( r s 0.30-0.31, p s = 0.07), amino acids ( r s = 0.27, p s = 0.08), and phosphorus ( r = 0.29, p = .07) and magnesium ( r = 0.25, p = .08) were associated with better cognition. A diet reflecting higher protein and fat relative to carbohydrates was associated with better cognition. Targeting individual nutrients, improving diet quality, and adequate caloric intake may preserve cognition in PWH.

Enhancing Brain Health and Well-Being in Older Adults: Innovations in Lifestyle Interventions

PURPOSE OF REVIEW

This article will provide clinicians with guidance on helping older adult patients make lifestyle changes to enhance brain health and well-being.

RECENT FINDINGS

Evidence suggests that physical activity might be helpful in improving cognitive functioning. The data on the benefits of cognitive activity is inconsistent and not as robust. The MediDiet, DASH, and MIND diets have been associated with better cognitive health. Sleep hygiene and cognitive behavioral therapies are considered first line evidence-based treatments for insomnia and the maintenance of healthy sleep patterns. Mindfulness based interventions have been shown to reduce anxiety, depression, and stress, and can help some older adults manage pain more constructively. Evidence-based information regarding the four topics of exercise, nutrition, sleep, and mindfulness is reviewed, so that clinicians may be better able to optimize care for their older adult patients.

Dietary Adherence and Cognitive Performance in Older Adults by Nativity Status: Results from the National Health and Nutrition Examination Survey (NHANES), 2011-2014

Although adherence to dietary guidelines is associated with better cognitive performance, there may be differences by nativity status. This study aimed to investigate the association between adherence to the healthy eating index (HEI) and cognitive performance (CP) among United States (US)-born and foreign-born older adults (60+ years). Data were obtained from the 2011-2014 NHANES (n = 3065). Dietary adherence was assessed with HEI quintiles. CP (adequate vs. low) was examined using word listing (CERAD), animal naming (AFT), and the digit symbol substitution test (DSST). Weighted multivariable logistic regressions were used to examine associations. The US-born participants in higher dietary quintiles had adequate CP when compared to foreign-born participants. In adjusted models, the US-born participants in the highest HEI quintile had increased odds of adequate DSST scores (odds ratio: 1.95, 95% confidence interval: 1.15-3.28) compared with those in the lowest quintile. Patterns of association were generally reversed for foreign-born participants and were non-statistically significant. Future research should consider the influence of diets in delaying or preventing decline in cognition and evaluate nutritional factors that contribute to cognitive outcomes for the foreign-born population.

Existing and Future Strategies to Manipulate the Gut Microbiota With Diet as a Potential Adjuvant Treatment for Psychiatric Disorders

Nutrition and diet quality play key roles in preventing and slowing cognitive decline and have been linked to multiple brain disorders. This review compiles available evidence from preclinical studies and clinical trials on the impact of nutrition and interventions regarding major psychiatric conditions and some neurological disorders. We emphasize the potential role of diet-related microbiome alterations in these effects and highlight commonalities between various brain disorders related to the microbiome. Despite numerous studies shedding light on these findings, there are still gaps in our understanding due to the limited availability of definitive human trial data firmly establishing a causal link between a specific diet and microbially mediated brain functions and symptoms. The positive impact of certain diets on the microbiome and cognitive function is frequently ascribed with the anti-inflammatory effects of certain microbial metabolites or a reduction of proinflammatory microbial products. We also critically review recent research on pro- and prebiotics and nondietary interventions, particularly fecal microbiota transplantation. The recent focus on diet in relation to brain disorders could lead to improved treatment outcomes with combined dietary, pharmacological, and behavioral interventions.

Gut microbiota, nutrition, and mental health

The human brain remains one of the greatest challenges for modern medicine, yet it is one of the most integral and sometimes overlooked aspects of medicine. The human brain consists of roughly 100 billion neurons, 100 trillion neuronal connections and consumes about 20-25% of the body's energy. Emerging evidence highlights that insufficient or inadequate nutrition is linked to an increased risk of brain health, mental health, and psychological functioning compromise. A core component of this relationship includes the intricate dynamics of the brain-gut-microbiota (BGM) system, which is a progressively recognized factor in the sphere of mental/brain health. The bidirectional relationship between the brain, gut, and gut microbiota along the BGM system not only affects nutrient absorption and utilization, but also it exerts substantial influence on cognitive processes, mood regulation, neuroplasticity, and other indices of mental/brain health. Neuroplasticity is the brain's capacity for adaptation and neural regeneration in response to stimuli. Understanding neuroplasticity and considering interventions that enhance the remarkable ability of the brain to change through experience constitutes a burgeoning area of research that has substantial potential for improving well-being, resilience, and overall brain health through optimal nutrition and lifestyle interventions. The nexus of lifestyle interventions and both academic and clinical perspectives of nutritional neuroscience emerges as a potent tool to enhance patient outcomes, proactively mitigate mental/brain health challenges, and improve the management and treatment of existing mental/brain health conditions by championing health-promoting dietary patterns, rectifying nutritional deficiencies, and seamlessly integrating nutrition-centered strategies into clinical care.

Multi-nutrient interventions and cognitive ageing: are we barking up the right tree?

As we continue to elucidate the mechanisms underlying age-related brain diseases, the reductionist strategy in nutrition–brain function research has focused on establishing the impact of individual foods. However, the biological processes connecting diet and cognition are complex. Therefore, consideration of a combination of nutritional compounds may be most efficacious. One barrier to establishing the efficacy of multi-nutrient interventions is that the area lacks an established set of evidence-based guidelines for studying their effect on brain health. This review is an output of the International Life Sciences Institute (ILSI) Europe. A multi-disciplinary expert group was assembled with the aim of developing a set of considerations to guide research into the effects of multi-nutrient combinations on brain functions. Consensus recommendations converged on six key issues that should be considered to advance research in this area: (1) establish working mechanisms of the combination and contributions of each individual compound; (2) validate the relevance of the mechanisms for the targeted human condition; (3) include current nutrient status, intake or dietary pattern as inclusion/exclusion criteria in the study design; (4) select a participant population that is clinically and biologically appropriate for all nutritional components of the combination; (5) consider a range of cognitive outcomes; (6) consider the limits of reductionism and the ‘gold standard’ randomised controlled trial. These guiding principles will enhance our understanding of the interactive/complementary activities of dietary components, thereby strengthening the evidence base for recommendations aimed at delaying cognitive decline.

Dietary pattern, food, and nutritional supplement effects on cognitive outcomes in mild cognitive impairment: a systematic review of previous reviews

CONTEXT

Nutritional interventions may benefit cognition in people with mild cognitive impairment (MCI). However, evidence is yet to be synthesized in a way that can inform recommendations for clinical and public health settings.

OBJECTIVE

To systematically review evidence on the effect of dietary patterns, foods, and nutritional supplements on cognitive decline in individuals with MCI.

DATA SOURCES

Guided by the Preferred Reporting items for Systematic Review and Meta-Analysis Protocols 2015 statement, the Medline, EMBASE, and CINAHL databases, the JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were searched (publication years 2005 to 2020). Included studies were English-language systematic reviews and meta-analyses of randomized controlled trials and cohort studies reporting on the effectiveness of nutritional interventions on cognition of individuals with MCI.

DATA EXTRACTION

Two reviewers independently selected studies and extracted data on cognitive outcomes and adverse events. Review quality was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews-2). Primary study overlap was managed following Cochrane Handbook guidelines.

DATA ANALYSIS

Of the 6677 records retrieved, 20 reviews were included, which, in turn, reported on 43 randomized controlled trials and 1 cohort study that, together, addressed 18 nutritional interventions. Most reviews were limited by quality and the small number of primary studies with small sample sizes. Reviews were mostly positive for B vitamins, omega-3 fatty acids, and probiotics (including 12, 11 and 4 primary studies, respectively). Souvenaid and the Mediterranean diet reduced cognitive decline or Alzheimer's disease progression in single trials with <500 participants. Findings from studies with a small number of participants suggest vitamin D, a low-carbohydrate diet, medium-chain triglycerides, blueberries, grape juice, cocoa flavanols, and Brazil nuts may improve individual cognitive subdomains, but more studies are needed.

CONCLUSIONS

Few nutritional interventions were found to convincingly improve cognition of individuals with MCI. More high-quality research in MCI populations is required to determine if nutritional treatments improve cognition and/or reduce progression to dementia.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework protocol identifier DOI:10.17605/OSF.IO/BEP2S.

Potential Neuroprotective Effects of Dietary Omega-3 Fatty Acids on Stress in Alzheimer's Disease

BACKGROUND

A large number of individual potentially modifiable factors are associated with risk for Alzheimer's disease (AD). However, less is known about the interactions between the individual factors.

METHODS

In order to begin to examine the relationship between a pair of factors, we performed a pilot study, surveying patients with AD and controls for stress exposure and dietary omega-3 fatty acid intake to explore their relationship for risk of AD.

RESULTS

For individuals with the greatest stress exposure, omega-3 fatty acid intake was significantly greater in healthy controls than in AD patients. There was no difference among those with low stress exposure.

CONCLUSIONS

These initial results begin to suggest that omega-3 fatty acids may mitigate AD risk in the setting of greater stress exposure. This will need to be examined with larger populations and other pairs of risk factors to better understand these important relationships. Examining how individual risk factors interact will ultimately be important for learning how to optimally decrease the risk of AD.

Dietary flavanols restore hippocampal-dependent memory in older adults with lower diet quality and lower habitual flavanol consumption

Dietary flavanols are food constituents found in certain fruits and vegetables that have been linked to cognitive aging. Previous studies suggested that consumption of dietary flavanols might specifically be associated with the hippocampal-dependent memory component of cognitive aging and that memory benefits of a flavanol intervention might depend on habitual diet quality. Here, we tested these hypotheses in the context of a large-scale study of 3,562 older adults, who were randomly assigned to a 3-y intervention of cocoa extract (500 mg of cocoa flavanols per day) or a placebo [(COcoa Supplement and Multivitamin Outcomes Study) COSMOS-Web, NCT04582617]. Using the alternative Healthy Eating Index in all participants and a urine-based biomarker of flavanol intake in a subset of participants [n = 1,361], we show that habitual flavanol consumption and diet quality at baseline are positively and selectively correlated with hippocampal-dependent memory. While the prespecified primary end point testing for an intervention-related improvement in memory in all participants after 1 y was not statistically significant, the flavanol intervention restored memory among participants in lower tertiles of habitual diet quality or habitual flavanol consumption. Increases in the flavanol biomarker over the course of the trial were associated with improving memory. Collectively, our results allow dietary flavanols to be considered in the context of a depletion-repletion paradigm and suggest that low flavanol consumption can act as a driver of the hippocampal-dependent component of cognitive aging.

Longitudinal trajectories of dietary quality and cognitive performance in older adults: Results from a 6-year cohort study

BACKGROUND

Diet affects cognitive performance, but most previous studies only assessed diet once. Trajectory analysis of diet measured at multiple timepoints can identify subpopulations requiring more interventional efforts. We thus assessed associations between dietary trajectories and cognitive performance in older adults.

METHODS

This was a 6-year prospective cohort study involving 356 ethnically Chinese, non-demented, community-dwelling older adults recruited between 2011 and 2013. At baseline and at 4th- and 6th-year follow-ups, dietary intakes of the participants were assessed using food frequency questionnaires. Dietary quality was graded using the modified Alternative Healthy Eating Index (mAHEI) with seven components; longitudinal trajectories of dietary quality were derived using latent growth mixture modelling. Outcomes were global- and domain-specific cognitive performance (attention, memory, executive functions, and verbal fluency). Multivariable regressions adjusting for important covariates (sex, age, energy intake, APOE risk alleles, depressive symptoms, and body mass index (BMI)) assessed associations between the dietary trajectories and cognitive outcomes.

RESULTS

Included participants had a mean age of 71.6 years and a mean BMI of 23.8 kg/m2. Three mutually exclusive dietary quality trajectories, namely "deteriorating", "improving", and "stable-high", were derived. Compared with the stable-high trajectory, the improving trajectory was associated with a lower z-score for the memory domain (β: -0.403; 95% CI: -0.656, -0.151; P = 0.002), which was consistently observed for the four individual tests of the domain (β range: -0.324 to -0.448; all P < 0.05). In unadjusted analysis, the deteriorating trajectory was associated with a 0.369 lower z-score for the verbal fluency domain (95% CI: -0.700, -0.039 P = 0.028), though attenuated to borderline significance with adjustment for covariates. Sex and BMI modified some of these associations. No other associations were observed for global cognition or other cognitive domains.

CONCLUSIONS

In Taiwanese older adults, consistently high dietary quality is associated with better cognitive performance. Interventions to promote and sustain better dietary quality over time can have substantial impacts on cognitive function.

Nutrition and cognitive health: A life course approach

Multiple factors affect cognitive health, such as age-related changes in the brain, injuries, mood disorders, substance abuse, and diseases. While some cannot be changed, evidence exists of many potentially possibly modifiable lifestyle factors: diet, physical activity, cognitive and social engagement, smoking and alcohol consumption which may stabilize or improve declining cognitive function. In nutrition, the focus has been mainly on its role in brain development in the early years. There is a strong emerging need to identify the role of diet and nutrition factors on age-related cognitive decline, which will open up the use of new approaches for prevention, treatment or management of age-related disorders and maintaining a good quality of life among older adults. While data on effect of high protein diets is not consistent, low-fat diets are protective against cognitive decline. Several micronutrients like B group vitamins and iron, as well as many polyphenols play a crucial role in cognitive health. Mediterranean, Nordic, DASH, and MIND diets are linked to a lower risk of cognitive decline and dementia. The relationship between the gut microbiome and brain function through the gut-brain axis has led to the emergence of data on the beneficial effects of dietary fibers and probiotics through the management of gut microbes. A “whole diet” approach as well as macro- and micro-nutrient intake levels that have protective effects against cardiovascular diseases are most likely to be effective against neurodegenerative disorders too. Young adulthood and middle age are crucial periods for determining cognitive health in old age. The importance of cardio metabolic risk factors such as obesity and hypertension, smoking and physical inactivity that develop in middle age suggest that preventive approaches are required for target populations in their 40s and 50s, much before they develop dementia. The commonality of dementia risk with cardiovascular and diabetes risk suggests that dementia could be added to present non-communicable disease management programs in primary healthcare and broader public health programs.

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.

Complementary and Alternative Medicine Approaches in Alzheimer Disease and Other Neurocognitive Disorders

As our population ages, there is interest in delaying or intervening in cognitive decline. While newer agents are under development, agents in mainstream use do not impact the course of diseases that cause cognitive decline. This increases interest in alternative strategies. Even as we welcome possible new disease-modifying agents, they are likely to remain costly. Herein, we review the evidence behind other complementary and alternative strategies for cognitive enhancement and prevention of cognitive decline.

The Effect of Nighttime Snacking on Cognitive Function in Older Adults: Evidence from Observational and Experimental Studies

Evidence shows that supplementary snacking could provide older adults with nutrients that cannot be obtained through three meals a day. However, whether and how supplementary snacking, especially nighttime snacking, affects older adults' cognitive function remain unclear. The present study examined the effect of nighttime snacking on cognitive function for older adults. In study 1, we investigated the association between nighttime snacking and cognitive function based on data from 2618 community-dwelling older adults from the China health and nutrition survey (CHNS). In study 2, we conducted an experiment (n = 50) to explore how nighttime acute energy intake influences older adults' performance on cognitive tasks (immediate recall, short-term delayed recall, and long-term delayed recall). Both the observational and experimental studies suggested that nighttime snacking facilitated older adults' cognitive abilities, such as memory and mathematical ability, as indicated by subjective measures (study 1) and objective measures (studies 1 and 2). Moreover, this beneficial effect was moderated by cognitive load. These findings bridge the gap in the literature on the relationships between older adults' nighttime snacking and cognitive function, providing insight into how to improve older adults' dietary behaviors and cognitive function.

Association between dietary quality and executive functions in school-aged children with autism spectrum disorder

Background

It is well known that children with autism spectrum disorder (ASD) had executive functions deficit. However, it is still unclear whether the poor dietary quality is related to the impairment of executive functions. The current study aimed to explore the association between dietary quality and executive functions in children with ASD.

Methods

A total of 106 children with ASD (7.7 ± 1.3 years) and 207 typically developing (TD) children (7.8 ± 1.3 years) were enrolled from Guangzhou, China. The Chinese version of Behavior Rating Scale of Executive function (BRIEF), the working memory subscales of the Chinese version of Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV), and the Stroop Color-Word Test (SCWT) were used to measure the participant's executive functions. The food frequency questionnaire (FFQ) was used to collect the dietary intake information, and the Chinese Diet Balance Index (DBI_16) was used to evaluate the dietary quality. Generalized linear models were used to estimate the association between dietary quality and executive functions.

Results

In children with ASD, Low Bound Score (LBS) was positively correlated with the working memory subscale score of BRIEF (β = 0.23, 95% CI: 0.02–0.44, P < 0.05), while High Bound Score (HBS) and LBS were positively correlated with the organizable subscale score of BRIEF (β = 0.44, 95% CI: 0.11–0.77, P < 0.01; β = 0.19, 95% CI: 0.01–0.37, P < 0.05). Compared to TD children, children with ASD had a higher proportion of moderate and high levels of insufficient dietary intake (moderate level, 37.7% vs. 23.2%, high level, 4.7% vs. 1.4%) and moderate level of unbalanced dietary intake (36.8% vs.21.3%), higher scores on all subscales of BRIEF (P < 0.01), and lower score on the working memory (81.3 ± 32.3 vs. 104.6 ± 12.5, P < 0.01), while there was no difference on the SCWT.

Conclusion

Poor dietary quality was associated with the impairment of working memory and organizational capacity in children with ASD. This study emphasized the importance of dietary quality in executive functions among children with ASD, and attention should be paid to improving their dietary quality.

The Relationship between Alternative Healthy Diet Index and Cognitive Function in the Older Adults: The Mediating Effect of Depressive Symptoms

This study aimed to investigate the association between the alternative healthy eating index-2010 (AHEI-2010) with cognitive function and the mediating role of depressive symptoms in older adults using the data from the 2011–2014 National Health and Nutrition Examination Survey (NHANES). The AHEI-2010 was calculated from NHANES individual food data and Food Patterns Equivalents Database (FPED) diet data. Cognitive function was assessed by the Consortium to Establish a Registry for Alzheimer’s disease (CERAD, memory function indicator), Word Learning sub-test, digital symbol substitution test (DSST, processing speed indicator), animal fluency test (AFT, executive function indicator), and the comprehensive z-score (global cognition indicator). A weighted multiple linear regression model was used to explore the relationship between AHEI-2010 and cognitive function, and Karlson–Holm–Breen (KHB) method was used to explore the mediating effect of depressive symptoms. A total of 2644 participants were included in this study. Participants with higher AHEI-2010 scores were more likely to have higher scores in DSST, AFT, and comprehensive z-score compared with the lowest quartile. Depressive symptoms play a significant mediating role between AHEI-2010 and cognitive function. The proportion of mediating in CERAD, DSST, AFT, and comprehensive z-score was 14.14%, 9.10%, 9.15%, and 10.47%, respectively. This study found that higher dietary quality was associated with better cognitive function. In addition, depressive symptoms may be an important pathway linking diet and cognitive function.

Role of diet and its effects on the gut microbiome in the pathophysiology of mental disorders

There is emerging evidence that diet has a major modulatory influence on brain-gut-microbiome (BGM) interactions with important implications for brain health, and for several brain disorders. The BGM system is made up of neuroendocrine, neural, and immune communication channels which establish a network of bidirectional interactions between the brain, the gut and its microbiome. Diet not only plays a crucial role in shaping the gut microbiome, but it can modulate structure and function of the brain through these communication channels. In this review, we summarize the evidence available from preclinical and clinical studies on the influence of dietary habits and interventions on a selected group of psychiatric and neurologic disorders including depression, cognitive decline, Parkinson's disease, autism spectrum disorder and epilepsy. We will particularly address the role of diet-induced microbiome changes which have been implicated in these effects, and some of which are shared between different brain disorders. While the majority of these findings have been demonstrated in preclinical and in cross-sectional, epidemiological studies, to date there is insufficient evidence from mechanistic human studies to make conclusions about causality between a specific diet and microbially mediated brain function. Many of the dietary benefits on microbiome and brain health have been attributed to anti-inflammatory effects mediated by the microbial metabolites of dietary fiber and polyphenols. The new attention given to dietary factors in brain disorders has the potential to improve treatment outcomes with currently available pharmacological and non-pharmacological therapies.

Neuroticism predicts informant reported cognitive problems through health behaviors

OBJECTIVE

Personality traits have been linked to cognitive impairment, though work is needed to understand the mechanisms involved. Research also needs to consider alternative markers of cognitive impairment, such as informant report measures. The aim of the current study was to examine the role of health behaviors and social engagement as mediators for the relationship between personality and informant reported cognitive problems. It was expected that neuroticism would predict cognitive problems through negative health behaviors, while conscientiousness might predict cognitive problems through positive health behaviors.

METHODS

Using data from the St. Louis Personality and Aging Network study at three time points, spanning approximately 2.27 years (N = 829, M age = 65.95), correlations were computed between the Big Five personality traits and health behaviors at wave 1, social engagement at wave 2, and informant reported cognitive problems at wave 3. Mediation tests examined whether health behaviors and social engagement explained the relationships found between personality and informant reported cognitive problems.

RESULTS

Findings showed that neuroticism at wave 1 significantly predicted informant reported cognitive problems at wave 3 and that health behaviors, specifically wellness maintenance, partially explained this relationship. No significant associations were found between informant reported cognitive problems and conscientiousness, agreeableness, extraversion, openness, or social engagement.

CONCLUSION

This study supports claims that neuroticism predicts later cognitive problems and expands on previous literature by demonstrating this relationship using an informant report measure. Furthermore, we found that health behaviors, and specifically wellness maintenance, account for some of the relationship between neuroticism and informant reported cognitive problems.

Mediterranean diet and cognitive function: From methodology to mechanisms of action

The traditional Mediterranean diet (MedDiet), rich in minimally processed plant foods and fish, has been widely recognized to be one of the healthiest diets. Data from multiple randomized clinical trials have demonstrated its powerful effect against oxidative stress, inflammation and the development and progression of cardiovascular disease, type 2 diabetes, and other metabolic conditions that play a crucial role in the pathogenesis of neurodegenerative diseases. The protecting effects of the MedDiet against cognitive decline have been investigated in several observational and experimental studies. Data from observational studies suggest that the MedDiet may represent an effective dietary strategy for the early prevention of dementia, although these findings require further substantiation in clinical trials which have so far produced inconclusive results. Moreover, as we discuss in this review, accumulating data emphasizes the importance of: 1) maintaining an optimal nutritional and metabolic status for the promotion of healthy cognitive aging, and 2) implementing cognition-sparing dietary and lifestyle interventions during early time-sensitive windows before the pathological cascades turn into an irreversible state. In summary, components of the MedDiet pattern, such as essential fatty acids, polyphenols and vitamins, have been associated with reduced oxidative stress and the current evidence from observational studies seems to assign to the MedDiet a beneficial role in promoting brain health; however, results from clinical trials have been inconsistent. While we advocate for longitudinal analyses and for larger and longer clinical trials to be conducted, we assert our interim support to the use of the MedDiet as a protective dietary intervention for cognitive function based on its proven cardiovascular and metabolic benefits.

Association of adherence to the Australian Dietary Guidelines with cognitive performance and cognitive decline in the Sydney Memory and Ageing Study: a longitudinal analysis

This study investigated associations of adherence to the Australian Dietary Guidelines (ADG) with cognitive performance and cognitive decline over 6 years. We used longitudinal data from the Sydney Memory and Aging Study comprising 1037 community-dwelling non-demented participants aged 70–90 years. Dietary intake was assessed at baseline using the Dietary Questionnaire for Epidemiological Studies Version 2. Adherence to the ADG was scored using the Dietary Guideline Index 2013 (DGI-2013). Cognition was assessed using neuropsychological tests in six cognitive domains and global cognition at baseline and 2, 4 and 6 years later. Linear mixed models analysed the association between adherence to the ADG and cognitive function and cognitive decline over 6 years. Results indicated that overall adherence to the ADG was suboptimal (DGI-2013 mean score 43⋅8 with a standard deviation of 10⋅1; median score 44, range 12–73 with an interquartile range of 7). The percent of participants attaining recommended serves for the five food groups were 30⋅2 % for fruits, 11⋅2 % for vegetables, 54⋅6 % for cereals, 28⋅9 % for meat and alternatives and 2⋅1 % for dairy consumption. Adherence to the ADG was not associated with overall global cognition over 6 years (β = 0⋅000; 95 % CI: −0⋅007, 0⋅007; P = 0⋅95). Neither were DGI-2013 scores associated with change in global cognitive performance over 6 years (β = 0⋅002; 95 % CI: −0⋅002, 0⋅005; P = 0⋅41) nor in any individual cognitive domains. In conclusion, adherence to the ADG was not associated with cognitive health over time in this longitudinal analysis of older Australians. Future research is needed to provide evidence to support specific dietary guidelines for neurocognitive health among Australian older adults.

Nutrition and exercise interventions could ameliorate age-related cognitive decline: a meta-analysis of randomized controlled trials

OBJECTIVE

To evaluate the effect of nutrition combined physical exercise interventions on age-related cognitive decline by a systematic review and meta-analysis.

METHODS

We searched 9 databases, including PubMed, EMbase, The Cochrane Library, Web of Science, Science Direct, China National Knowledge Infrastructure (CNKI), VIP Information, China Biological Medical Database (CBM) and Wanfang for studies published until the end of December 2019. The selected trials should meet the following criteria, study objects: healthy adults aged 65 and over with cognitive dysfunction or diagnosed as MCI, but not meet the diagnostic criteria for dementia as well as no restriction on follow-up time, race or gender. Study interventions: multiple interventions including nutrition and exercise.

EXCLUSION CRITERIA

(1) studies included elderly people with any type of dementia or patients with cognitive impairment induced by secondary causes, including drug, alcohol, severe organic brain diseases, mental disorders. (2) Republished literature. (3) Studies with significant differences in baseline data between groups. (4) The data in the study cannot be converted into the required data format. We reviewed and extracted information and assessed the risk of bias of recruited studies independently. Meta-analysis was performed using STATA v.15.1 software. The bias of publication was estimated by Egger test.

RESULTS

A total of six RCTs representing 1039 participates were included in our meta-analysis. In terms of global cognitive function that has been assessed by neuropsychological test in different combinations, the result showed that the beneficial effect of nutrition combined exercise interventions was statistically significant [SMD = 0.23, 95% CI (0.1, 0.36), P = 0.0004]. There were no statistical differences from assays on MMSE scores, Memory, Executive Function, Attention, and Information Processing Speed across groups.

CONCLUSIONS

The current study shows that nutrition combined exercise interventions can improve global cognitive function in the aged with cognitive decline. Further researches emphasizing on longer follow-up time, experimental randomness, credibility and scale would better elucidate the effect of nutrition combined exercise interventions on cognitive function, particularly in older adults. (registration number: CRD42020159291, date of registration: 28/04/2020).

Microglia and modifiable life factors: Potential contributions to cognitive resilience in aging

Given the increasing prevalence of age-related cognitive decline, it is relevant to consider the factors and mechanisms that might facilitate an individual's resiliency to such deficits. Growing evidence suggests a preeminent role of microglia, the prime mediator of innate immunity within the central nervous system. Human and animal investigations suggest aberrant microglial functioning and neuroinflammation are not only characteristic of the aged brain, but also might contribute to age-related dementia and Alzheimer's Disease. Conversely, accumulating data suggest that modifiable lifestyle factors (MLFs), such as healthy diet, exercise and cognitive engagement, can reliably afford cognitive benefits by potentially suppressing inflammation in the aging brain. The present review highlights recent advances in our understanding of the role for microglia in maintaining brain homeostasis and cognitive functioning in aging. Moreover, we propose an integrated, mechanistic model that postulates an individual's resiliency to cognitive decline afforded by MLFs might be mediated by the mitigation of aberrant microglia activation in aging, and subsequent suppression of neuroinflammation.

Eating Alone and Cognitive Decline in Korean Older Adults: A 3-Year Prospective Study

BACKGROUND

Eating alone is a critical factor in nutritional risk screening among older adults. We investigated whether changes in eating status (eating alone or with others) in late-life affected cognitive decline in community-dwelling older adults.

METHODS

We used data from the Survey of the Living Conditions and Welfare Needs of Korean Older Persons. Nutritional risk, including eating status, was assessed using seven questions from the Nutrition Screening Initiative checklist, and cognitive function was measured using the Mini-Mental State Examination (MMSE). On the basis of changes in eating status between baseline (2008) and the 3-year follow-up (2011), the subjects were divided into four groups: group 1 (eating with others at both visits), group 2 (eating alone in 2008 and eating with others in 2011), group 3 (eating with others in 2008 and eating alone in 2011), and group 4 (eating alone at both visits). Generalized linear models were used to compare the changes in MMSE scores over the 3-year period among the four groups.

RESULTS

Among older women, group 2 had the least decline in MMSE scores (-0.55±0.46), whereas group 3 had the greatest decline (-1.76±0.37) (p=0.034). We observed no difference in the change in MMSE scores among the four eating groups in older men.

CONCLUSION

Deprivation of mealtime partners in late life enhanced cognitive decline compared with gaining mealtime partners. Eating alone may be a risk factor for cognitive impairment; thus, meal programs reinforcing social integration might help preserve cognitive function.

Association between Intake of Energy and Macronutrients and Memory Impairment Severity in US Older Adults, National Health and Nutrition Examination Survey 2011-2014

Without a cure, dementia affects about 50 million people worldwide. Understanding the effects of dietary habits, a key lifestyle behavior, on memory impairment is critical to inform early behavioral modification to delay further memory loss and progression to dementia. We examined the associations of total energy intake and energy intake from macronutrients with memory impairment among older US adults using data from the nationally representative National Health and Nutrition Examination Survey study 2011-2014. A total of 3623 participants aged ≥60 years were analyzed. Comparing to those with low total energy intake, individuals with high intake were more likely to have severe memory impairment (OR: 1.52, 95% CI: 1.15 to 2.02; ptrend = 0.005). Specifically, higher energy intake from carbohydrate (OR: 1.59, 95% CI: 1.12 to 2.26) and sugar (OR: 1.54, 95% CI: 1.11 to 2.16) were both significantly associated with the presence of memory impairment. Additionally, higher energy intake from fat, carbohydrate and sugar were significantly associated with more server memory impairment (fat: ptrend = 0.04; carbohydrate: ptrend = 0.03; sugar: ptrend = 0.02). High energy intake, either total or from carbohydrates, fat or sugar, is associated with memory impairment severity in the older US population. No such association was found in energy intake from protein.

Toward an Affective Political Ecology of Obesity

This article argues for an affective approach to obesity that destabilizes the conceptual boundaries between the biological and the social aspects of food, eating, and fatness. Its approach foregrounds visceral experience, attends to food both inside and outside the body, and explores how bodies labeled “obese” consume their political, economic, and material environments. This approach is termed affective political ecology. The authors’ aim is to draw attention to how the entanglements between the physiological and social aspects of eating tend to be absented from antiobesity public health rhetoric. By exploring a range of ethnographic examples in high-income countries, they illuminate how such interventions often fail to account for the complex interplays between subjective corporeal experience and political economic relations and contend that overlooking an individual’s visceral relationship with food counterproductively augments social stigma, stresses, and painful emotions. They demonstrate, then, how an approach that draws together political economic and biomedical perspectives better reflects the lived experience of eating. In so doing, the authors aim to indicate how attending to affective political ecologies can further our understanding of the consumption practices of those in precarious and stressful social contexts, and they offer additional insight into how the entanglement of the biological and the social is experienced in everyday life.

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

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

Using network science tools to identify novel diet patterns in prodromal dementia

OBJECTIVE

To use network science to model complex diet relationships a decade before onset of dementia in a large French cohort, the 3-City Bordeaux study.

METHODS

We identified cases of dementia incident to the baseline food frequency questionnaire over 12 years of follow-up. For each case, we randomly selected 2 controls among individuals at risk at the age at case diagnosis and matched for age at diet assessment, sex, education, and season of the survey. We inferred food networks in both cases and controls using mutual information, a measure to detect nonlinear associations, and compared food consumption patterns between groups.

RESULTS

In the nested case-control study, the mean (SD) duration of follow-up and number of visits were 5.0 (2.5) vs 4.9 (2.6) years and 4.1 (1.0) vs 4.4 (0.9) for cases (n = 209) vs controls (n = 418), respectively. While there were few differences in simple, average food intakes, food networks differed substantially between cases and controls. The network in cases was focused and characterized by charcuterie as the main hub, with connections to foods typical of French southwestern diet and snack foods. In contrast, the network of controls included several disconnected subnetworks reflecting diverse and healthier food choices.

CONCLUSION

How foods are consumed (and not only the quantity consumed) may be important for dementia prevention. Differences in predementia diet networks, suggesting worse eating habits toward charcuterie and snacking, were evident years before diagnosis in this cohort. Network methods, which are designed to model complex systems, may advance our understanding of risk factors for dementia.

Dietary Patterns and Cognitive Decline: key features for prevention

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

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.

Nutritional psychiatry: Towards improving mental health by what you eat

Does it matter what we eat for our mental health? Accumulating data suggests that this may indeed be the case and that diet and nutrition are not only critical for human physiology and body composition, but also have significant effects on mood and mental wellbeing. While the determining factors of mental health are complex, increasing evidence indicates a strong association between a poor diet and the exacerbation of mood disorders, including anxiety and depression, as well as other neuropsychiatric conditions. There are common beliefs about the health effects of certain foods that are not supported by solid evidence and the scientific evidence demonstrating the unequivocal link between nutrition and mental health is only beginning to emerge. Current epidemiological data on nutrition and mental health do not provide information about causality or underlying mechanisms. Future studies should focus on elucidating mechanism. Randomized controlled trials should be of high quality, adequately powered and geared towards the advancement of knowledge from population-based observations towards personalized nutrition. Here, we provide an overview of the emerging field of nutritional psychiatry, exploring the scientific evidence exemplifying the importance of a well-balanced diet for mental health. We conclude that an experimental medicine approach and a mechanistic understanding is required to provide solid evidence on which future policies on diet and nutrition for mental health can be based.

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.

The Interplay of Diet Quality and Alzheimer's Disease Genetic Risk Score in Relation to Cognitive Performance Among Urban African Americans

We examined the interactive associations of poor diet quality and Alzheimer’s Disease (AD) genetic risk with cognitive performance among 304 African American adults (mean age~57 years) from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. In this cross-sectional study, selected participants had complete predictors and covariate data with 13 cognitive test scores as outcomes. Healthy Eating Index-2010 (HEI-2010), Dietary Approaches to Stop Hypertension (DASH), and mean adequacy ratio (MAR) were measured. A genetic risk score for AD in HANDLS (hAlzScore) was computed from 12 selected single nucleotide polymorphisms (SNPs). Our key hypotheses were tested using linear regression models. The hAlzScore was directly associated with poor performance in verbal memory (−0.4 ± 0.2, 0.01) and immediate visual memory (0.4 ± 0.2, 0.03) measured in seconds, in women only. The hAlzScore interacted synergistically with poorer diet quality to determine lower cognitive performance on a test of verbal fluency. Among numerous SNP × diet quality interactions for models of cognitive performance as outcomes, only one passed correction for multiple testing, namely verbal fluency. Our results suggest that improved diet quality can potentially modify performance on cognitive tests of verbal fluency among individuals with higher AD genetic risk.

The Mediterranean Diet and 2-Year Change in Cognitive Function by Status of Type 2 Diabetes and Glycemic Control

OBJECTIVE

To determine associations of a Mediterranean diet score (MeDS) with 2-year change in cognitive function by type 2 diabetes and glycemic control status and contrast it against other diet quality scores.

RESEARCH DESIGN AND METHODS

We used data from the longitudinal Boston Puerto Rican Health Study (n = 913; 42.6% with type 2 diabetes at 2 years). Glycemic control at baseline was categorized as uncontrolled (hemoglobin A1c ≥7% [53 mmol/mol]) versus controlled. Two-year change in glycemic control was defined as stable/improved versus poor/declined. We defined MeDS, Healthy Eating Index, Alternate Healthy Eating Index, and Dietary Approaches to Stop Hypertension scores. Adjusted mixed linear models assessed 2-year change in global cognitive function z score, executive and memory function, and nine individual cognitive tests.

RESULTS

Higher MeDS, but no other diet quality score, was associated with higher 2-year change in global cognitive function in adults with type 2 diabetes (β ± SE = 0.027 ± 0.011; P = 0.016) but not in those without (P = 0.80). Similar results were noted for Mini-Mental State Examination, word recognition, digit span, and clock drawing tests. Results remained consistent for individuals under glycemic control at baseline (0.062 ± 0.020; P = 0.004) and stable/improved over 2 years (0.053 ± 0.019; P = 0.007), but not for individuals with uncontrolled or poor/declined glycemic control. All diet quality scores were associated with higher 2-year memory function in adults without type 2 diabetes.

CONCLUSIONS

Both adhering to a Mediterranean diet and effectively managing type 2 diabetes may support optimal cognitive function. Healthy diets, in general, can help improve memory function among adults without type 2 diabetes.

Association of Diet Quality and Vegetable Variety with the Risk of Cognitive Decline in Chinese Older Adults

Diet quality plays an important role in dementia prevention. It remains unclear how the joint effect of vegetable variety and diet quality affects cognition. This study aimed to explore the association of diet quality and vegetable variety with cognitive decline in older adults. This prospective cohort study (2011–2015) included 436 community-dwelling elders in Taipei. Diet quality, assessed by the modified Alternative Healthy Eating Index (mAHEI), was computed from a food frequency questionnaire at baseline (2011–2013). Vegetable variety indicated the number of different vegetable groups, adjusted for vegetable quantity. Multivariable linear and logistic regression models were used to explore the association of diet quality and vegetable variety with the decline of global and domain-specific cognition over two years. Our findings suggest that high diet quality (the highest tertile of mAHEI) was associated with a lower risk of both global cognitive decline (adjusted odds ratio (AOR) = 0.54, confidence interval (CI) = 0.31–0.95) and decline of attention domain (AOR = 0.56, CI = 0.32–0.99) compared with low diet quality. In elders with high vegetable variety, high diet quality was associated with a lower risk of global cognitive decline (AOR = 0.49, CI = 0.26–0.95). We therefore concluded that high diet quality along with diverse vegetable intake was associated with a lower risk of cognitive decline in older adults.

Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

OBJECTIVE

To evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults.

DESIGN

International prospective cohort study.

SETTING

18 high, middle, and low income countries, sampled from urban and rural communities.

PARTICIPANTS

103 570 people who provided morning fasting urine samples.

MAIN OUTCOME MEASURES

Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day).

RESULTS

Mean estimated sodium and potassium urinary excretion were 4.93 g/day and 2.12 g/day, respectively. After a median follow-up of 8.2 years, 7884 (6.1%) participants had died or experienced a major cardiovascular event. Increasing urinary sodium excretion was positively associated with increasing potassium excretion (unadjusted r=0.34), and only 0.002% had a concomitant urinary excretion of <2.0 g/day of sodium and >3.5 g/day of potassium. A J-shaped association was observed of sodium excretion and inverse association of potassium excretion with death and cardiovascular events. For joint sodium and potassium excretion categories, the lowest risk of death and cardiovascular events occurred in the group with moderate sodium excretion (3-5 g/day) and higher potassium excretion (21.9% of cohort). Compared with this reference group, the combinations of low potassium with low sodium excretion (hazard ratio 1.23, 1.11 to 1.37; 7.4% of cohort) and low potassium with high sodium excretion (1.21, 1.11 to 1.32; 13.8% of cohort) were associated with the highest risk, followed by low sodium excretion (1.19, 1.02 to 1.38; 3.3% of cohort) and high sodium excretion (1.10, 1.02 to 1.18; 29.6% of cohort) among those with potassium excretion greater than the median. Higher potassium excretion attenuated the increased cardiovascular risk associated with high sodium excretion (P for interaction=0.007).

CONCLUSIONS

These findings suggest that the simultaneous target of low sodium intake (<2 g/day) with high potassium intake (>3.5 g/day) is extremely uncommon. Combined moderate sodium intake (3-5 g/day) with high potassium intake is associated with the lowest risk of mortality and cardiovascular events.

A high methionine, low folate and vitamin B6/B12 containing diet can be associated with memory loss by epigenetic silencing of netrin-1

Memory-epigenetics which is the loss of memory due to epigenetic modifications can be due to the silencing of genes involved in cognitive functions and this is the basis of the current study. We hypothesize that a diet containing high methionine and low vitamins can lead to memory impairment by increasing global DNA methylation and therefore, silencing the netrin-1 gene, which encodes the glycoprotein involved in neurogenesis, axonal guidance and maintenance of the synaptic plasticity. Wild type (C57BL/6J) mice were fed with a diet containing excess methionine (1.2%), low-folate (0.08 mg/kg), vitamin B₆ (0.01 mg/kg), and B₁₂ (10.4 mg/kg) for 6 weeks. Mice were examined weekly for the long-term memory function, using a passive avoidance test, which determined loss of fear-motivated long-term memory starting from the fourth week of diet. Similarly, an increase in brain %5-methyl cytosine was observed starting from the 4^th week of diet in mice. Mice fed with a high methionine, low folate and vitamins containing diet showed a decrease in netrin-1 protein expression and an increase in netrin-1 gene promotor methylation, as determined by methylation-sensitive restriction enzyme-polymerase chain reaction analysis. The increase in methylation of netrin-1 gene was validated by high-resolution melting and sequencing analysis. Furthermore, the association of netrin-1 with memory was established by administering netrin that considerably restored long-term fear motivated memory. Taken together, these results suggest that a diet rich in methionine and lacking in folate and vitamin B₆/B₁₂ can induce defects in learning and memory. Furthermore, the data indicates that decrease in netrin-1 expression due to hyper-methylation of its gene can be associated with memory loss. The animal procedures were approved by the Institutional Animal Care and Use Committee, University of Louisville, USA (No. A3586-01) on February 2, 2018.

Dietary changes and cognition over 2 years within a multidomain intervention trial-The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER)

INTRODUCTION

Association between healthy diet and better cognition is well established, but evidence is limited to evaluate the effect of dietary changes adopted in older age.

METHODS

We investigated the role of dietary changes in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) with 1260 at-risk participants (60-77 years) who were randomized to intensive multidomain intervention (including dietary counseling) or regular health advice for 2 years. Parallel process latent growth curves of adherence to dietary recommendations and cognitive performance were analyzed.

RESULTS

Adherence to healthy diet at baseline predicted improvement in global cognition, regardless of intervention allocation (P = .003). Dietary improvement was associated with beneficial changes in executive function, especially in the intervention group (P = .008; P = .051 for groups combined).

DISCUSSION

Dietary changes initiated during the intervention were related to changes in executive function in 2 years. Long-term diet appeared more influential for global cognition.

Dietary Patterns and Cognitive Function among Older Community-Dwelling Adults

Diet may be an important modifiable risk factor for maintenance of cognitive health in later life. This study aimed at examining associations between common dietary indices and dietary patterns defined by factor analysis and cognitive function in older community-dwelling adults. Dietary information for 1499 participants from the Rancho Bernardo Study was collected in 1988–1992 and used to calculate the alternate Mediterranean diet score, Alternate Healthy Eating Index (AHEI)-2010 score and factor scores derived from factor analysis of nutrients. Global cognitive function, executive function, verbal fluency and episodic memory were assessed at approximate four-year intervals from 1988–2016. Linear mixed models were used to examine associations between dietary patterns and cognitive trajectories. Estimates for the highest vs. lowest tertile in models adjusting for age, sex, education, energy intake, lifestyle variables and retest effect showed greater adherence to the Mediterranean score was associated with better baseline global cognitive function (β (95% CI) = 0.33 (0.11, 0.55)). The AHEI-2010 score was not significantly associated with cognitive performance. Higher loading on a plant polyunsaturated fatty acid (PUFA)/vitamin E factor was associated with better baseline global cognitive function and executive function (β = 0.22 (0.02, 0.42) and β = −7.85 (−13.20, −2.47)). A sugar/low protein factor was associated with poorer baseline cognitive function across multiple domains. Dietary patterns were not associated with cognitive decline over time. Adherence to a healthy diet with foods high in PUFA and vitamin E and a low sugar to protein ratio, as typified by a Mediterranean diet, may be beneficial for cognitive health in late life.

Nutritional Interventions as Beneficial Strategies to Delay Cognitive Decline in Healthy Older Individuals

Current demographic trends indicate that the population is aging. The aging process is inevitably connected with cognitive decline, which manifests itself in worsening working memory, processing speed, and attention. Therefore, apart from pharmacological therapies, non-pharmacological approaches which can influence cognitive performance (such as physical activities or healthy diet), are being investigated. The purpose of this study is to explore the types of nutritional interventions and their benefits in the prevention and delay of cognitive delay in healthy older individuals. The methods used in this study include a literature review of the available studies on the research topic found in Web of Science, Scopus, and MEDLINE. The findings show that nutritional intervention has a positive impact on cognitive function in healthy older people. However, it seems that the interactions between more than one nutrient are most effective. The results reveal that specifically the Mediterranean diet appears to be effective in this respect. Moreover, the findings also indicate that multi-domain interventions including diet, exercise, cognitive training, and vascular risk monitoring have a far more significant effect on the enhancement of cognitive functions among healthy older individuals.

Dietary Patterns and Physical Activity Correlate With Total Cholesterol Independently of Lipid-Lowering Drugs and Antiretroviral Therapy in Aging People Living With Human Immunodeficiency Virus

Background

Hypercholesterolemia is a well established risk factor for coronary heart disease and is highly prevalent among human immunodeficiency virus (HIV)-positive persons. Antiretroviral therapy (ART) can both directly modify total cholesterol and have drug-drug interactions with statins. This makes investigating modifiable behavioral predictors of total cholesterol a pertinent task.

Methods

To explore the association between diet and physical activity with cross-sectionally measured total cholesterol, we administered a validated Food-Frequency-Questionnaire to participants of the Swiss HIV Cohort Study ≥45 years old. Linear mixed-effects models were applied to explore the associations between dietary patterns and physical activity with total cholesterol, after adjustment for clinical and demographic covariates.

Results

In total, 395 patients were included. Forty percent (158 of 395) had elevated total cholesterol (>5.2 mmol/L), and 41% (164 of 395) were not regularly physically active. In multivariable analysis, 2 factors were positively associated with total cholesterol; female sex (β = 0.562; 95% confidence interval [CI], 0.229–0.896) and the combined consumption of meat, refined/milled grains, carbonated beverages, and coffee (β = 0.243; 95% CI, 0.047–0.439). On the other hand, regular physical activity (β = −0.381; 95% CI, −0.626 to −0.136), lipid-lowering drugs (β = −0.443; 95% CI −0.691 to −0.196), ART containing tenofovir (β = −0.336; 95% CI −0.554 to −0.118), and black ethnicity (β = −0.967; 95% CI −1.524 to −0.410) exhibited a negative association.

Conclusions

We found independent associations between certain dietary patterns and physical activity with total cholesterol. Increasing physical activity might achieve cardiovascular and other health benefits in HIV-positive individuals. The clinical relevance of the identified dietary patterns requires further investigation in prospective cohort studies and randomized controlled trials.

Effect of the Mediterranean diet on cognition and brain morphology and function: a systematic review of randomized controlled trials

Background

Observational studies of the Mediterranean diet suggest cognitive benefits, potentially reducing dementia risk.

Objective

We performed the first published review to our knowledge of randomized controlled trials (RCTs) investigating Mediterranean diet effects on cognition or brain morphology and function, with an additional focus on intervention diet quality and its relation to "traditional" Mediterranean dietary patterns.

Design

We searched 9 databases from inception (final update December 2017) for RCTs testing a Mediterranean compared with alternate diet for cognitive or brain morphology and function outcomes.

Results

Analyses were based on 66 cognitive tests and 1 brain function outcome from 5 included studies (n = 1888 participants). The prescribed Mediterranean diets varied considerably between studies, particularly with regards to quantitative food advice. Only 8/66 (12.1%) of individual cognitive outcomes at trial level significantly favored a Mediterranean diet for cognitive performance, with effect sizes (ESs) ranging from small (0.32) to large (1.66), whereas 2 outcomes favored controls. Data limitations precluded a meta-analysis. Of 8 domain composite cognitive scores from 2 studies, the 3 (Memory, Frontal, and Global function) from PREDIMED (PREvención con DIeta MEDiterránea) were significant, with ESs ranging from 0.39 to 1.29. A posttest comparison at a second PREDIMED site found that the Mediterranean diet modulates the effect of several genotypes associated with dementia risk for some cognitive outcomes, with mixed results. Finally, the risk of low-plasma brain-derived neurotrophic factor was reduced by 78% (OR = 0.22; 95% CI: 0.05, 0.90) in those who consumed a Mediterranean diet compared to control diet at 3 y in this trial. There was no benefit of the Mediterranean diet for incident cognitive impairment or dementia.

Conclusions

Five RCTs of the Mediterranean diet and cognition have been published to date. The data are mostly nonsignificant, with small ESs. However, the significant improvements in cognitive domain composites in the most robustly designed study warrant additional research.

Symptom Management and Lifestyle Modifications in Multiple Sclerosis

PURPOSE OF REVIEW

This article reviews the rationale and approach to symptom management and lifestyle modifications in multiple sclerosis (MS).

RECENT FINDINGS

MS symptoms are important to treat because they affect quality of life and daily activity. Appreciation of cluster symptoms (where one symptom contributes to another), changes over time, and multimodality therapeutic approaches are guiding optimized symptom management. Equally important are lifestyle modifications that enhance central nervous system reserve and function. These modifications are the foundation for a health maintenance, wellness, and vascular risk factor control program.

SUMMARY

Symptom management and lifestyle modifications are important therapeutic targets to improve the lives of patients with MS.

Diet Quality as Assessed by the Healthy Eating Index, Alternate Healthy Eating Index, Dietary Approaches to Stop Hypertension Score, and Health Outcomes: An Updated Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

Diets of the highest quality have been associated with a significantly lower risk of noncommunicable diseases.

OBJECTIVE

It was the aim of this study to update a previous systematic review investigating the associations of diet quality as assessed by the Healthy Eating Index (HEI), Alternate Healthy Eating Index (AHEI), and Dietary Approaches to Stop Hypertension (DASH) score and multiple health outcomes. As an additional topic, the associations of these diet quality indices with all-cause mortality and cancer mortality among cancer survivors were also investigated.

DESIGN

A literature search for prospective cohort studies that were published up to May 15, 2017 was performed using the electronic databases PubMed, Scopus, and Embase. Summary risk ratios (RRs) and 95% CIs were estimated using a random effects model for high vs low adherence categories.

RESULTS

The updated review process showed 34 new reports (total number of reports evaluated=68; including 1,670,179 participants). Diets of the highest quality, as assessed by the HEI, AHEI, and DASH score, resulted in a significant risk reduction for all-cause mortality (RR 0.78, 95% CI 0.77 to 0.80; I²=59%; n=13), cardiovascular disease (incidence or mortality) (RR 0.78, 95% CI 0.76 to 0.80; I²=49%; n=28), cancer (incidence or mortality) (RR 0.84, 95% CI 0.82 to 0.87; I²=66%; n=31), type 2 diabetes (RR 0.82, 95% CI 0.78 to 0.85; I²=72%; n=10), and neurodegenerative diseases (RR 0.85, 95% CI 0.74 to 0.98; I²=51%; n=5). Among cancer survivors, the association between diets for the highest quality resulted in a significant reduction in all-cause mortality (RR 0.88, 95% CI 0.81 to 0.95; I²=38%; n=7) and cancer mortality (RR 0.90, 95% CI 0.83 to 0.98; I²=0%; n=7).

CONCLUSIONS

In the updated meta-analyses, diets that score highly on the HEI, AHEI, and DASH were associated with a significant reduction in the risk of all-cause mortality, cardiovascular disease, cancer, type 2 diabetes, and neurodegenerative disease by 22%, 22%, 16%, 18%, and 15%, respectively. Moreover, high-quality diets were inversely associated with overall mortality and cancer mortality among cancer survivors.

Comparability of a short food frequency questionnaire to assess diet quality: the DISCOVER study

This study aims to assess comparability of a short food frequency questionnaire (SFFQ) used in the Determinants of Suicide: Conventional and Emergent Risk Study (DISCOVER Study) with a validated comprehensive FFQ (CFFQ). A total of 127 individuals completed SFFQ and CFFQ. Healthy eating was measured using Healthy Eating Score (HES). Estimated food intake and healthy eating assessed by SFFQ was compared with the CFFQ. For most food groups and HES, the highest Spearman's rank correlation coefficients between the two FFQs were r > .60. For macro-nutrients, the correlations exceeded 0.4. Cross-classification of quantile analysis showed that participants were classified between 46% and 81% into the exact same quantiles, while 10% or less were misclassified into opposite quantiles. The Bland-Altman plots showed an acceptable level of agreement between the two dietary measurement methods. The SFFQ can be used for Canadian with psychiatric disorders to rank them based on their dietary intake.

Healthy eating patterns associated with acculturation, sex and BMI among Mexican Americans

OBJECTIVE

Examine relationships of healthy and unhealthy dietary patterns with BMI, sex, age and acculturation among Mexican Americans.

DESIGN

Cross-sectional. Participants completed culturally tailored Healthy and Unhealthy Eating Indices. Multivariable mixed-effect Poisson regression models compared food pattern index scores and dietary intake of specific foods by BMI, sex, age and acculturation defined by language preference and generational status.

SETTING

Participants recruited from the Cameron County Hispanic Cohort study, Texas-Mexico border region, between 2008 and 2011.

SUBJECTS

Mexican-American males and females aged 18-97 years (n 1250).

RESULTS

Participants were primarily female (55·3 %), overweight or obese (85·7 %), preferred Spanish language (68·0 %) and first-generation status (60·3 %). Among first-generation participants, bilingual participants were less likely to have a healthy eating pattern than preferred Spanish-speaking participants (rate ratio (RR)=0·79, P=0·0218). This association was also found in males (RR=0·81, P=0·0098). Preferred English-speaking females were less likely to consume healthy foods than preferred Spanish-speaking females (RR=0·84, P=0·0293). Among second-generation participants, preferred English-speaking participants were more likely to report a higher unhealthy eating pattern than preferred Spanish-speaking participants (RR=1·23, P=0·0114). Higher unhealthy eating patterns were also found in females who preferred English v. females who preferred Spanish (RR=1·23, P=0·0107) or were bilingual (RR=1·26, P=0·0159). Younger, male participants were more likely to have a higher unhealthy eating pattern. BMI and diabetes status were not significantly associated with healthy or unhealthy eating patterns.

CONCLUSIONS

Acculturation, age, sex and education are associated with healthy and unhealthy dietary patterns. Nutrition interventions for Mexican Americans should tailor approaches by these characteristics.

Memory loss: Five new things

PURPOSE OF REVIEW

Memory loss can be due to a wide variety of causes. We provide new information about the biology of common genetic and acquired causes of memory loss in older adults.

RECENT FINDINGS

New data are available about the genetics of Alzheimer disease (AD), dementia with Lewy bodies (DLB), and frontotemporal dementia. Amyloid PET, FDG-PET, and MRI have improved our understanding of how mild cognitive impairment evolves to AD. Several studies have shown links between concussion and chronic traumatic encephalopathy. Healthy eating and regular exercise have been demonstrated to slow cognitive decline in older adults. Randomized trials continue to show benefits for cholinesterase inhibitors and memantine in patients with AD and DLB.

SUMMARY

New causes of memory loss are still being identified. More sophisticated diagnostic tools have improved our ability to make earlier diagnoses in older adults with memory loss.