MIND diet slows cognitive decline with aging

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.

The Role of Nutrition in Cognitive Function and Brain Ageing in the Elderly

PURPOSE OF REVIEW

The purposes of this review were to examine literature published over the last 5 years and to evaluate the role of nutrition in cognitive function and brain ageing, focussing on the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH), and Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diets.

RECENT FINDINGS

Results suggest that higher adherence to a healthy dietary pattern is associated with preservation of brain structure and function as well as slower cognitive decline, with the MIND diet substantially slowing cognitive decline, over and above the MeDi and DASH diets. Whilst results to-date suggest adherence to a healthy diet, such as the MeDi, DASH, or MIND, is an important modifiable risk factor in the quest to develop strategies aimed at increasing likelihood of healthy brain ageing, further work is required to develop dietary guidelines with the greatest potential benefit for public health; a research topic of increasing importance as the world's population ages.

Mediterranean Diet in Preventing Neurodegenerative Diseases

PURPOSE OF REVIEW

We reviewed the most recent literature examining the associations between the Mediterranean-style diet (MD), neurodegenerative diseases, and markers and mechanisms of neurodegeneration.

RECENT FINDINGS

Most, but not all, epidemiologic studies report a protective association between MD adherence, cognitive impairment, and brain health. Data from clinical trials supporting these observational findings are also emerging. Limited evidence suggests that MD adherence may be protective for Parkinson's disease risk. Mechanistically, plant polyphenols may activate similar molecular pathways as caloric restriction diets, which helps explain the neuroprotective properties of the MD. Evidence for cognitive disorders is abundant, but there is a dearth of literature for other neurodegenerative disorders and for markers of neurodegeneration. Further research is needed to elucidate the protective role of MD on neurodegeneration, the most salient components of the MD, and the most sensitive time periods over the lifecourse at which the MD may exert its effects.

Diet and Alzheimer's dementia - Nutritional approach to modulate inflammation

BACKGROUND

Alzheimer's disease (AD) is the most common neurodegenerative disease causing dementia in the elderly population. Due to the fact that there is still no cure for Alzheimer's dementia and available treatment strategies bring only symptomatic benefits, there is a pressing demand for other effective strategies such as diet. Since the inflammation hypothesis gained considerable significance in the AD pathogenesis, elucidating the modulatory role of dietary factors on inflammation may help to prevent, delay the onset and slow the progression of AD. Current evidence clearly shows that synergistic action of combined supplementation and complex dietary patterns provides stronger benefits than any single component considered separately. Recent studies reveal the growing importance of novel factors such as dietary advanced glycation end products (d-AGE), gut microbiota, butyrate and vitamin D₃ on inflammatory processes in AD.

CONCLUSION

This paper summarizes the available evidence of pro- and anti-inflammatory activity of some dietary components including fatty acids, vitamins, flavonoids, polyphenols, probiotics and d-AGE, and their potential for AD prevention and treatment.

N-of-1 Clinical Trials in Nutritional Interventions Directed at Improving Cognitive Function

Longer life expectancy has led to an increase in the prevalence of age-related cognitive decline and dementia worldwide. Due to the current lack of effective treatment for these conditions, preventive strategies represent a research priority. A large body of evidence suggests that nutrition is involved in the pathogenesis of age-related cognitive decline, but also that it may play a critical role in slowing down its progression. At a population level, healthy dietary patterns interventions, such as the Mediterranean and the MIND diets, have been associated with improved cognitive performance and a decreased risk of neurodegenerative disease development. In the era of evidence-based medicine and patient-centered healthcare, personalized nutritional recommendations would offer a considerable opportunity in preventing cognitive decline progression. N-of-1 clinical trials have emerged as a fundamental design in evidence-based medicine. They consider each individual as the only unit of observation and intervention. The aggregation of series of N-of-1 clinical trials also enables population-level conclusions. This review provides a general view of the current scientific evidence regarding nutrition and cognitive decline, and critically states its limitations when translating results into the clinical practice. Furthermore, we suggest methodological strategies to develop N-of-1 clinical trials focused on nutrition and cognition in an older population. Finally, we evaluate the potential challenges that researchers may face when performing studies in precision nutrition and cognition.

A systematic review of existing peripheral biomarkers of cognitive aging: Is there enough evidence for biomarker proxies in behavioral modification interventions?: An initiative in association with the nutrition, exercise and lifestyle team of the Canadian Consortium on Neurodegeneration in Aging

Peripheral biomarkers have shown significant value in predicting brain health and may serve as a useful proxy measurement in the assessment of evidence-based lifestyle behavior modification programs, including physical activity and nutrition programs, that aim to maintain cognitive function in late life. The aim of this systematic review was to elucidate which peripheral biomarkers are robustly associated with cognitive function among relatively healthy non-demented older adults. Following the standards for systematic reviews (PICO, PRIMSA), and employing MEDLINE and Scopus search engines, 222 articles were included in the review. Based on the review of biomarker proxies of cognitive health, it is recommended that a comprehensive biomarker panel, or biomarker signature, be developed as a clinical end point for behavior modification trials aimed at enhancing cognitive function in late life. The biomarker signature should take a multisystemic approach, including lipid, immune/inflammatory, and metabolic biomarkers in the biological signature index of cognitive health.

Sugar in mind: Untangling a sweet and sour relationship beyond type 2 diabetes

It is widely recognised that type 2 diabetes (T2D) represents a major disease burden but it is only recently that its role in neurodegeneration has attracted more attention. This research has shown that T2D is associated with impaired cerebral health, cognitive decline and dementia. However, the impact on the brain of progressive metabolic changes associated with the pre-clinical development of the disease is less clear. The aim of this review is to comprehensively summarise how the emergence of risk factors and co-morbid conditions linked to the development of T2D impact cerebral health. Particular attention is directed at characterising how normal but elevated blood glucose levels in individuals without T2D contribute to neurodegenerative processes, and how the main risk factors for T2D including obesity, physical activity and diet modulate these effects. Where available, evidence from the animal and human literature is contrasted, and sex differences in risk and outcomes are highlighted.

Association of changes in red meat consumption with total and cause specific mortality among US women and men: two prospective cohort studies

OBJECTIVE

To evaluate the association of changes in red meat consumption with total and cause specific mortality in women and men.

DESIGN

Two prospective cohort studies with repeated measures of diet and lifestyle factors.

SETTING

Nurses' Health Study and the Health Professionals Follow-up Study, United States.

PARTICIPANTS

53 553 women and 27 916 men without cardiovascular disease or cancer at baseline.

MAIN OUTCOME MEASURE

Death confirmed by state vital statistics records, the national death index, or reported by families and the postal system.

RESULTS

14 019 deaths occurred during 1.2 million person years of follow-up. Increases in red meat consumption over eight years were associated with a higher mortality risk in the subsequent eight years among women and men (both P for trend<0.05, P for heterogeneity=0.97). An increase in total red meat consumption of at least half a serving per day was associated with a 10% higher mortality risk (pooled hazard ratio 1.10, 95% confidence interval 1.04 to 1.17). For processed and unprocessed red meat consumption, an increase of at least half a serving per day was associated with a 13% higher mortality risk (1.13, 1.04 to 1.23) and a 9% higher mortality risk (1.09, 1.02 to 1.17), respectively. A decrease in consumption of processed or unprocessed red meat of at least half a serving per day was not associated with mortality risk. The association between increased red meat consumption and mortality risk was consistent across subgroups defined by age, physical activity, dietary quality, smoking status, or alcohol consumption.

CONCLUSION

Increases in red meat consumption, especially processed meat, were associated with higher overall mortality rates.

Dietary Protein and Amino Acid Intake: Links to the Maintenance of Cognitive Health

With the rapid growth in the aging population, there has been a subsequent increase in the rates of Alzheimer's disease and related dementias (ADRD). To combat these increases in ADRD, scientists and clinicians have begun to place an increased emphasis on preventative methods to ameliorate disease rates, with a primary focus area on dietary intake. Protein/amino acid intake is a burgeoning area of research as it relates to the prevention of ADRD, and consumption is directly related to a number of disease-related risk factors as such low-muscle mass, sleep, stress, depression, and anxiety. As a result, the role that protein/amino acid intake plays in affecting modifiable risk factors for cognitive decline has provided a robust area for scientific exploration; however, this research is still speculative and specific mechanisms have to be proven. The purpose of this review is to describe the current understanding of protein and amino acids and the preventative roles they play with regard to ADRD, while providing future recommendations for this body of research. Additionally, we will discuss the current recommendations for protein intake and how much protein older adults should consume in order to properly manage their long-term risk for cognitive decline.

Nutritional Intervention as a Preventive Approach for Cognitive-Related Outcomes in Cognitively Healthy Older Adults: A Systematic Review

The link diet-cognitive function/dementia has been largely investigated in observational studies; however, there was a lack of evidence from randomized clinical trials (RCTs) on the prevention of late-life cognitive disorders though dietary intervention in cognitively healthy older adults. In the present article, we systematically reviewed RCTs published in the last four years (2014-2017) exploring nutritional intervention efficacy in preventing the onset of late-life cognitive disorders and dementia in cognitively healthy subjects aged 60 years and older using different levels of investigation (i.e., dietary pattern changes/medical food/nutraceutical supplementation/multidomain approach and dietary macro- and micronutrient approaches) as well as possible underlying mechanisms of nutritional prevention. From the 35 included RCTs, there was moderate evidence that intervention through dietary pattern changes, medical food/nutraceutical supplementation, and multidomain approach improved specific cognitive domains or cognitive-related blood biomarkers. There was high evidence that protein supplementation improved specific cognitive domains or functional status in prefrail older adults without effect on cognitive function. For fatty acid supplementation, mainly long-chain polyunsaturated fatty acids, there was emerging evidence suggesting an impact of this approach in improving specific cognitive domains, magnetic resonance imaging (MRI) findings, and/or cognitive-related biomarkers also in selected subgroups of older subjects, although some results were conflicting. There was convincing evidence of an impact of non-flavonoid polyphenol and flavonoid supplementations in improving specific cognitive domains and/or MRI findings. Finally, there was only low evidence suggesting efficacy of intervention with homocysteine-related and antioxidant vitamins in improving cognitive functions, dementia incidence, or cognitive-related biomarkers in cognitively healthy older subjects.

Mediterranean and MIND Diets Containing Olive Biophenols Reduces the Prevalence of Alzheimer's Disease

The risk of Alzheimer’s disease (AD) increases with nonmodifiable conditions including age and lack of effective efficacious pharmacotherapy. During the past decades, the non-pharmacotherapy mode of treatment of dietary modification received extensive attention in AD research. In order to reduce the AD pathology and cognitive decline, various dietary patterns have been attempted including caloric restriction (CR), dietary approaches to stop hypertension (DASH), ketogenic diets (KD), Mediterranean diet (MedDi) and Mediterranean-DASH diet Intervention for Neurological Delay (MIND) diet. Higher adherence to the MedDi diet was associated with decreases in cardiovascular and neurological disorders including AD and related cognitive decline. However, another emerging healthy dietary pattern MIND diet has also been associated with slower rates of cognitive decline and significant reduction of AD rate. Olive serves as one of the building block components of MedDi and MIND diets and the exerted potential health beneficial might be suggested due to the presence of its bioactive constituents such as oleic acids and phenolic compounds (biophenols). A few trials using medical food showed an optimal result in presymptomatic or early stages of AD. The review supports the notion that MedDi and MIND diets display potential for maintaining the cognitive function as nonpharmacological agents against AD pathology and proposed preventative mechanism through the presence of olive biophenols and presents the gaps along with the future directions.

High fat diet alters gut microbiota but not spatial working memory in early middle-aged Sprague Dawley rats

As the global population ages, and rates of dementia rise, understanding lifestyle factors that play a role in the development and acceleration of cognitive decline is vital to creating therapies and recommendations to improve quality of later life. Obesity has been shown to increase risk for dementia. However, the specific mechanisms for obesity-induced cognitive decline remain unclear. One potential contributor to diet-induced cognitive changes is neuroinflammation. Furthermore, a source of diet-induced inflammation to potentially increase neuroinflammation is via gut dysbiosis. We hypothesized that a high fat diet would cause gut microbe dysbiosis, and subsequently: neuroinflammation and cognitive decline. Using 7-month old male Sprague Dawley rats, this study examined whether 8 weeks on a high fat diet could impact performance on the water radial arm maze, gut microbe diversity and abundance, and microgliosis. We found that a high fat diet altered gut microbe populations compared to a low fat, control diet. However, we did not observe any significant differences between dietary groups on maze performance (a measure of spatial working memory) or microgliosis. Our data reveal a significant change to the gut microbiome without subsequent effects to neuroinflammation (as measured by microglia characterization and counts in the cortex, hippocampus, and hypothalamus) or cognitive performance under the parameters of our study. However, future studies that explore duration of the diet, composition of the diet, age of animal model, and strain of animal model, must be explored.

Sex differences in Alzheimer's disease: Understanding the molecular impact

Alzheimer's disease (AD) is a common neurodegenerative disorder that presents with cognitive impairment and behavioral disturbance. Approximately 5.5 million people in the United States live with AD, most of whom are over the age of 65 with two-thirds being woman. There have been major advancements over the last decade or so in the understanding of AD neuropathological changes and genetic involvement. However, studies of sex impact in AD have not been adequately integrated into the investigation of disease development and progression. It becomes indispensable to acknowledge in both basic science and clinical research studies the importance of understanding sex-specific differences in AD pathophysiology and pathogenesis, which could guide future effort in the discovery of novel targets for AD. Here, we review the latest and most relevant literature on this topic, highlighting the importance of understanding sex dimorphism from a molecular perspective and its association to clinical trial design and development in AD research field.

Dietary Patterns Are Related to Clinical Characteristics in Memory Clinic Patients with Subjective Cognitive Decline: The SCIENCe Project

As nutrition is one of the modifiable risk factors for cognitive decline, we studied the relationship between dietary quality and clinical characteristics in cognitively normal individuals with subjective cognitive decline (SCD). We included 165 SCD subjects (age: 64 ± 8 years; 45% female) from the SCIENCe project, a prospective memory clinic based cohort study on SCD. The Dutch Healthy Diet Food Frequency Questionnaire (DHD-FFQ) was used to assess adherence to Dutch guidelines on vegetable, fruit, fibers, fish, saturated fat, trans fatty acids, salt and alcohol intake (item score 0-10, higher score indicating better adherence). We measured global cognition (Mini Mental State Examination), cognitive complaints (Cognitive Change Index self-report; CCI) and depressive symptoms (Center for Epidemiologic Studies Depression Scale; CES-D). Using principal component analysis, we identified dietary components and investigated their relation to clinical characteristics using linear regression models adjusted for age, sex and education. We identified three dietary patterns: (i) "low-Fat-low-Salt", (ii) "high-Veggy", and (iii) "low-Alcohol-low-Fish". Individuals with lower adherence on "low-Fat-low-Salt" had more depressive symptoms (β -0.18 (-2.27--0.16)). Higher adherence to "high-Veggy" was associated with higher MMSE scores (β 0.30 (0.21-0.64)). No associations were found with the low-Alcohol-low-Fish component. We showed that in SCD subjects, dietary quality was related to clinically relevant outcomes. These findings could be useful to identify individuals that might benefit most from nutritional prevention strategies to optimize brain health.

Development of a Multicomponent Intervention to Prevent Alzheimer's Disease

Recent advances in vascular risk management have successfully reduced the prevalence of Alzheimer's Disease (AD) in several epidemiologic investigations. It is now widely accepted that cerebrovascular disease is both directly and indirectly involved in AD pathogenesis. Herein, we review the non-pharmacological and pharmacological therapeutic approaches for AD treatment. MIND [Mediterranean and DASH (Dietary Approaches to Stop Hypertension) Intervention for Neurodegenerative Delay] diet is an important dietary treatment for prevention of AD. Multi domain intervention including diet, exercise, cognitive training, and intensive risk managements also prevented cognitive decline in the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) study. To confirm these favorable effects of life-style intervention, replica studies are being planned worldwide. Promotion of β-amyloid (Aβ) clearance has emerged as a promising pharmacological approach because insufficient removal of Aβ is more important than excessive Aβ production in the pathogenesis of the majority of AD patients. Most AD brains exhibit accompanying cerebral amyloid angiopathy, and Aβ distribution in cerebral amyloid angiopathy closely corresponds with the intramural periarterial drainage (IPAD) route, emphasizing the importance of Aβ clearance. In view of these facts, promotion of the major vascular-mediated Aβ elimination systems, including capillary transcytosis, the glymphatic system, and IPAD, have emerged as new treatment strategies in AD. In particular, the beneficial effects of cilostazol were shown in several clinical observation studies, and cilostazol facilitated IPAD in a rodent AD model. The COMCID (Cilostazol for prevention of Conversion from MCI to Dementia) trial, evaluating the efficacy of cilostazol for patients with mild cognitive impairment is currently ongoing in Japan. Such therapeutic approaches involving maintenance of cerebrovascular integrity and promotion of vascular-mediated Aβ clearance have the potential to be mainstream treatments for sporadic AD.

Associations between modifiable risk factors and white matter of the aging brain: insights from diffusion tensor imaging studies

There is increasing interest in factors that may modulate white matter (WM) breakdown and, consequentially, age-related cognitive and behavioral deficits. Recent diffusion tensor imaging studies have examined the relationship of such factors with WM microstructure. This review summarizes the evidence regarding the relationship between WM microstructure and recognized modifiable factors, including hearing loss, hypertension, diabetes, obesity, smoking, depressive symptoms, physical (in) activity, and social isolation, as well as sleep disturbances, diet, cognitive training, and meditation. Current cross-sectional evidence suggests a clear link between loss of WM integrity (lower fractional anisotropy and higher mean diffusivity) and hypertension, obesity, diabetes, and smoking; a relationship that seems to hold for hearing loss, social isolation, depressive symptoms, and sleep disturbances. Physical activity, cognitive training, diet, and meditation, on the other hand, may protect WM with aging. Preliminary evidence from cross-sectional studies of treated risk factors suggests that modification of factors could slow down negative effects on WM microstructure. Careful intervention studies are needed for this literature to contribute to public health initiatives going forward.

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Both aging and dementia are associated with breakdown of white matter (WM) microstructure.

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We review a range of modifiable factors that could prevent or slow age-related WM decline.

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Risk factors are consistently related with lower fractional anisotropy and higher mean diffusivity.

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Treatment of risk factors may slow WM decline.

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Careful longitudinal and intervention studies are now needed.

Association of dietary patterns with serum high-sensitivity C-reactive protein level in community-dwelling older adults

INTRODUCTION

Studies examining the association between dietary patterns and inflammatory markers are limited, in particular among Chinese older adults.

OBJECTIVE

We examined the association of various dietary patterns with serum high-sensitivity C-reactive protein (hsCRP) level in community-dwelling Chinese older adults, taking into account demographics and other lifestyle factors.

METHODS

We conducted ordinal regression analyses using baseline data based on 1332 older men and 1314 older women of Chinese origin from a cohort study of bone health in Hong Kong. Baseline interviewer administered questionnaires included dietary intake estimation and dietary pattern generation from the food frequency questionnaire, as well as demographic and lifestyle factors. Serum hsCRP was measured using a commercially available enzyme-linked immunosorbent assay.

RESULTS

In men, higher serum hsCRP level was associated with lower Diet Quality Index-International (DQI-I) score, the Mediterranean-DASH Intervention for Neurodegenerative Delay diet (MIND) score, Okinawan diet score, "vegetables-fruits" pattern score, and lower adherence to the Mediterranean diet. In women, serum hsCRP level was not associated with any dietary patterns.

CONCLUSION

Our cross-sectional analyses suggest that various dietary patterns were associated with a lower serum hsCRP level in community-dwelling Chinese older adults, and these associations were only observed in older men.

Cognitive decline: can diet be a preventive or treatment option?

Cognitive decline has been associated with and accepted as a consequence of ageing. Diets such as the Mediterranean diet have been investigated for their effect on abating cognitive decline. However, diet is not the only aspect of the Mediterranean life that may play a role - social interaction and cultural engagement may also be influential in preserving cognitive function through the ageing process. This article discusses the perspective on cognitive decline and the influence the Mediterranean diet may have. It highlights that no sole dietary regimen will prevent cognitive decline and the UK healthy eating guidelines reflect those foods included in the Mediterranean diet. The focus should instead be on the way in which people engage with food, society and culture to maintain a healthy body and mind.

MIND not Mediterranean diet related to 12-year incidence of cognitive impairment in an Australian longitudinal cohort study

INTRODUCTION

Associations between the Mediterranean-DASH diet Intervention for Neurological Delay (MIND) diet and incidence of cognitive impairment have not been evaluated outside the United States.

METHODS

We investigated MIND and Mediterranean diet relations with 12-year incidence of Alzheimer's disease/Vascular dementia (National Institute of Neurological Disorders criteria) and mild cognitive impairment (Winbald criteria) in the Personality and Total Health (PATH) Through Life cohort (n = 1220) set in Canberra, Australia: wave-1 2001-2002; wave-2 2005-2006; wave-3 2009-2010; and wave-4 2013-2014. MIND diet and two alternate Mediterranean diet scores were calculated from the baseline food frequency questionnaire responses. Higher dietary scores signified greater adherence.

RESULTS

In adjusted logistic regression models, MIND diet (OR = 0.47, 95% CI 0.24, 0.91), but not Mediterranean diet, was associated with reduced odds of 12-year cognitive impairment.

DISCUSSION

Preliminary evidence suggests that protective effects of the MIND diet are geographically generalizable. Additional prospective studies are needed in diverse samples to determine the relative effects of the MIND and the Mediterranean diets against cognitive decline.

Perspectives on ethnic and racial disparities in Alzheimer's disease and related dementias: Update and areas of immediate need

Alzheimer's disease and related dementias (ADRDs) are a global crisis facing the aging population and society as a whole. With the numbers of people with ADRDs predicted to rise dramatically across the world, the scientific community can no longer neglect the need for research focusing on ADRDs among underrepresented ethnoracial diverse groups. The Alzheimer's Association International Society to Advance Alzheimer's Research and Treatment (ISTAART; alz.org/ISTAART) comprises a number of professional interest areas (PIAs), each focusing on a major scientific area associated with ADRDs. We leverage the expertise of the existing international cadre of ISTAART scientists and experts to synthesize a cross-PIA white paper that provides both a concise "state-of-the-science" report of ethnoracial factors across PIA foci and updated recommendations to address immediate needs to advance ADRD science across ethnoracial populations.

How Dietary Patterns are Related to Inflammaging and Mortality in Community-Dwelling Older Chinese Adults in Hong Kong - A Prospective Analysis

INTRODUCTION

Studies examining dietary patterns and inflammageing in relation to mortality are limited.

OBJECTIVE

We examined the influence of various dietary patterns on all-cause and cardiovascular disease (CVD) mortality, taking into account demographics, lifestyle factors, and serum inflammatory markers.

METHODS

We conducted multivariate Cox regression analyses using data from a cohort of community-dwelling older Chinese adults (1,406 men, 1,396 women) in Hong Kong. Baseline interviewer administered questionnaires covered dietary intake estimation and dietary pattern generation from the food frequency questionnaire, demographic and lifestyle factors, cognitive function and depressive symptoms. Serum high-sensitivity C-reactive protein (hsCRP) and 25-hydroxyvitamin D (25OHD) were measured. All-cause and CVD mortality data at 14-year follow up were retrieved from an official database.

RESULTS

In men, higher hsCRP level was associated with lower Diet Quality Index-International (DQI-I) score, Mediterranean-DASH Intervention for Neurodegenerative Delay Diet (MIND) score, Okinawan diet score, "vegetables-fruits" pattern score and "snacks-drinks-milk" pattern score. Higher serum 25OHD level was associated with higher Mediterranean Diet Score (MDS) but lower "snacks-drinks-milk" pattern score. None of the dietary pattern scores was associated with all-cause or CVD mortality after adjusting for all covariates. In women, hsCRP level and serum 25OHD level were not associated with any dietary patterns. Higher DQI-I score (HR=0.77 (95% CIs: 0.59, 0.99) highest vs. lowest tertile, p-trend=0.038) and Okinawan diet score (HR=0.78 (95% CIs: 0.61, 1.00) highest vs lowest tertile, p-trend=0.046) was associated with a lower risk of all-cause mortality, whereas higher MIND score (HR=0.63 (95% CI: 0.36, 1.09) highest vs. lowest tertile, p-trend=0.045) was associated with a reduced risk of CVD morality in the multivariate adjusted model.

CONCLUSION

Higher DQI-I score and Okinawan diet score were associated with a lower risk of all-cause mortality, and higher adherence to the MIND diet was related to a reduced risk of CVD mortality in community-dwelling Chinese older women.

Advances in developing novel therapeutic strategies for Alzheimer's disease

Alzheimer's Disease (AD), the most prevalent neurodegenerative disease of aging, affects one in eight older Americans. Nearly all drug treatments tested for AD today have failed to show any efficacy. There is a great need for therapies to prevent and/or slow the progression of AD. The major challenge in AD drug development is lack of clarity about the mechanisms underlying AD pathogenesis and pathophysiology. Several studies support the notion that AD is a multifactorial disease. While there is abundant evidence that amyloid plays a role in AD pathogenesis, other mechanisms have been implicated in AD such as tangle formation and spread, dysregulated protein degradation pathways, neuroinflammation, and loss of support by neurotrophic factors. Therefore, current paradigms of AD drug design have been shifted from single target approach (primarily amyloid-centric) to developing drugs targeted at multiple disease aspects, and from treating AD at later stages of disease progression to focusing on preventive strategies at early stages of disease development. Here, we summarize current strategies and new trends of AD drug development, including pre-clinical and clinical trials that target different aspects of disease (mechanism-based versus non-mechanism based, e.g. symptomatic treatments, lifestyle modifications and risk factor management).

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.

Selenium Status Is Not Associated with Cognitive Performance: A Cross-Sectional Study in 154 Older Australian Adults

Selenium was suggested to play a role in modulating cognitive performance and dementia risk. Thus, this study aimed to investigate the association between selenium status and cognitive performance, as well as inflammatory and neurotrophic markers in healthy older adults. This cross-sectional study included 154 older adults (≥60 years) from Victoria, Australia. Participants were assessed for cognitive performance (Cogstate battery), dietary selenium intake (two 24-h food recalls), plasma selenium concentration, inflammatory markers (interleukin (IL)-6, -8, -10, tumor necrosis factor-alpha and adiponectin) and neurotrophic factors (brain-derived neurotrophic factor, vascular endothelial growth factor and insulin-like growth factor 1). Dietary selenium intake was adequate for 85% of all participants. The prevalence of selenium deficiency was low; only 8.4% did not have the minimum concentration in plasma required for optimization of iodothyronine 5' deiodinases activity. Multiple linear regression analysis revealed that plasma selenium was not associated with cognitive performance, inflammatory markers nor neurotrophic factors, independent of age, sex, body mass index (BMI), habitual physical activity, APOE status, education, and history of cardiovascular disease. The lack of association might be due to the optimization of selenoproteins synthesis as a result of adequate selenium intake. Future prospective studies are recommended to explore potential associations of selenium status with age-associated cognitive decline.

Redox proteomics and amyloid β-peptide: insights into Alzheimer disease

Alzheimer disease (AD) is a progressive neurodegenerative disorder associated with aging and characterized pathologically by the presence of senile plaques, neurofibrillary tangles, and neurite and synapse loss. Amyloid beta-peptide (1-42) [Aβ(1-42)], a major component of senile plaques, is neurotoxic and induces oxidative stress in vitro and in vivo. Redox proteomics has been used to identify proteins oxidatively modified by Aβ(1-42) in vitro and in vivo. In this review, we discuss these proteins in the context of those identified to be oxidatively modified in animal models of AD, and human studies including familial AD, pre-clinical AD (PCAD), mild cognitive impairment (MCI), early AD, late AD, Down syndrome (DS), and DS with AD (DS/AD). These redox proteomics studies indicate that Aβ(1-42)-mediated oxidative stress occurs early in AD pathogenesis and results in altered antioxidant and cellular detoxification defenses, decreased energy yielding metabolism and mitochondrial dysfunction, excitotoxicity, loss of synaptic plasticity and cell structure, neuroinflammation, impaired protein folding and degradation, and altered signal transduction. Improved access to biomarker imaging and the identification of lifestyle interventions or treatments to reduce Aβ production could be beneficial in preventing or delaying the progression of AD. This article is part of the special issue "Proteomics".

Impact of rye-based evening meals on cognitive functions, mood and cardiometabolic risk factors: a randomized controlled study in healthy middle-aged subjects

Background

Whole grain (WG) intake is associated with reduced risk of obesity, type 2 diabetes and cardiovascular disease, whereas type 2 diabetes increases the risk of cognitive decline and dementia. The purpose of this study was to investigate the effects of short-term intervention with WG rye on cognitive functions, mood and cardiometabolic risk markers in middle-aged test subjects.

Method

Rye-based breads were provided to 38 healthy test subjects (aged 52-70y) during three consecutive days in a crossover study design, using white wheat flour bread (WWB) as a reference. The rye-based bread consisted of a WG rye kernel/flour mixture (1:1 ratio) supplemented with resistant starch type 2 (RS2) (RB + RS2). The last bread portion was ingested at 2100 h, and cognitive function, mood and cardiometabolic risk markers were determined the following morning, 11 − 14 h post intake.

Results

In comparison to WWB, the RB + RS2 product increased ratings of mood parameters (valance, P < 0.001; activation P < 0.05). No differences were seen in the cognitive tests depending on intervention (P > 0.05). RB + RS2 increased insulin sensitivity (P < 0.05), fasting levels of gut hormones (PYY, P < 0.05; GLP-2, P < 0.01) and fasting concentrations of plasma acetate, butyrate and total SCFA (P < 0.001). In contrast, fasting levels of IL − 1β were decreased (P < 0.05). Insulin sensitivity was positively correlated with working memory test performance (P < 0.05).

Conclusions

This study display novel findings regarding effects of WG rye products on mood, and glucose and appetite regulation in middle-aged subjects, indicating anti-diabetic properties of WG rye. The beneficial effects are suggested to be mediated through gut fermentation of dietary fiber in the RB + RS2 product.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov, register number NCT03275948. Registered September 8 2017.

Cognitive Improvement in Healthy Older Adults Can Parallel That of Younger Adults Following Lifestyle Modification: Support for Cognitive Reserve During Aging

Executive function was assayed following a nutritional supplementation in healthy adults using the Trail Making Test. Comparison with published normative scores demonstrated that cohorts from 35-74 years of age displayed similar relative improvement compared to their own baseline performance. These findings support early, pro-active lifestyle modifications to maintain cognitive performance during aging and further demonstrate the persistence of cognitive reserve in healthy older adults.

Examining the relationship between nutrition and cerebral structural integrity in older adults without dementia

The proportion of adults aged 60 years and over is expected to increase over the coming decades. This ageing of the population represents an important health issue, given that marked reductions to cerebral macro- and microstructural integrity are apparent with increasing age. Reduced cerebral structural integrity in older adults appears to predict poorer cognitive performance, even in the absence of clinical disorders such as dementia. As such, it is becoming increasingly important to identify those factors predicting cerebral structural integrity, especially factors that are modifiable. One such factor is nutritional intake. While the literature is limited, data from available cross-sectional studies indicate that increased intake of nutrients such as B vitamins (for example, B6, B12 and folate), choline, n-3 fatty acids and vitamin D, or increased adherence to prudent whole diets (for example, the Mediterranean diet) predicts greater cerebral structural integrity in older adults. There is even greater scarcity of randomised clinical trials investigating the effects of nutritional supplementation on cerebral structure, though it appears that supplementation with B vitamins (B6, B12 and folic acid) or n-3 fatty acids (DHA or EPA) may be beneficial. The current review presents an overview of available research examining the relationship between key nutrients or adherence to select diets and cerebral structural integrity in dementia-free older adults.

An Active Lifestyle Reinforces the Effect of a Healthy Diet on Cognitive Function: A Population-Based Longitudinal Study

The joint effect of diet and leisure activity on cognitive function remains unknown. We aimed to verify the hypothesis that an active lifestyle reinforces the effect of the Nordic Prudent Dietary Pattern (NPDP) on cognitive function. A total of 2223 dementia-free Swedish adults aged ≥60 with Mini-Mental State Examination (MMSE) scores ≥27 were followed for an average of 6 years. MMSE was tested during follow-ups. Diet was assessed by food frequency questionnaire. The NPDP index was calculated and tertiled (low, moderate, and high adherence). Participation in physical, mental and social activities was trichotomised (low, moderate, and intense). An active lifestyle was defined based on the participation in each activity. Data were analyzed using mixed-effects models. Moderate-to-high adherence to NPDP was associated with a reduced decline in the MMSE score (β: 0.19, 95% Confidence Interval (CI): 0.14–0.24). This association became stronger when combined with moderate-to-intense physical (β: 0.34, 95% CI: 0.2–0.45), mental (β: 0.29, 95% CI: 0.21–0.37), or social (β: 0.27, 95% CI: 0.19–0.34) activities. An active lifestyle strengthened the effect of NPDP on cognitive function by two times, and further lowered risk of MMSE decline by 30%. Thus, an active lifestyle reinforces the effect of a healthy diet on preserved cognitive function, and further decreases the risk of cognitive decline.

Role of green tea catechins in prevention of age-related cognitive decline: Pharmacological targets and clinical perspective

Over the past decade, a wide range of scientific investigations have been performed to reveal neuropathological aspects of cognitive disorders; however, only limited therapeutic approaches currently exist. The failures of conventional therapeutic options as well as the predicted dramatic rise in the prevalence of cognitive decline in the coming future show the necessity for novel therapeutic agents. Recently, a wide range of research has focused on pharmacological activities of green tea catechins worldwide. Current investigations have clarified mechanistic effects of the catechins in inflammatory cascades, oxidative damages, different cellular transcription as well as transduction pathway in various body systems. It has been demonstrated that green tea polyphenols prevent age-related neurodegeneration through improvement of endogenous antioxidant defense mechanisms, modulation of neural growth factors, attenuation of neuroinflammatory pathway, and regulation of apoptosis. The catechins exhibited beneficial effects in cellular and animal models of neurodegenerative diseases including Alzheimer's disease, MS, and Parkinson's disease. The present review discusses the current pharmacological targets, which can be involved in the treatment of cognitive decline and addresses the action of catechin derivatives elicited from green tea on the multiple neural targets.

Predictors of cognitive stability or decline during aging: A longitudinal study in primary care

We aimed to identify the early predictors of cognitive decline, and primary care physicians' (PCP) ability to diagnose cognitively impaired subjects, in a cohort of individuals recruited in primary care centers. Independent adults, aged ≥50 years at inception, with an overall low level of education, undertook a prospective clinical and cognitive evaluation targeting memory, attention and executive functions. At follow-up subjects were classified as cognitively normal (CN) or impaired (CI). Of 275 subjects (70.4 ± 8.3 years old, 176 females, 7.5 ± 4.4 education, 162 with MRI), 31 (11.2%) presented CI 4.9 years later, the majority (64.5%) presenting subjective cognitive complaints. PCP could correctly identify 40% of CI individuals, particularly if they presented current cognitive complaints. Male sex (OR = 3.117; CI95%: 1.007-9.645), age (OR = 1.063; CI95%: 1.004-1.126) and baseline scores on TMT-B (OR = 0.225; CI95%: 0.073-0.688) and Vocabulary (OR =  0.940; 95% CI: 0.894-0.986) predicted CI. This study shows that measures indicating poor cognitive reserve and low executive performance (as shown by low vocabulary and executive test scores, respectively) can be early indicators of the risk of decline, stressing the role of cognitive assessment as part of prevention/early intervention programs. The results also underline the need to help PCP to improve the detection of subjects with cognitive decline.

A Remote Intervention to Prevent or Delay Cognitive Impairment in Older Adults: Design, Recruitment, and Baseline Characteristics of the Virtual Cognitive Health (VC Health) Study

Background

A growing body of evidence supports the use of lifestyle interventions for preventing or delaying the onset of Alzheimer disease and other forms of dementia in at-risk individuals. The development of internet-delivered programs would increase the scalability and reach of these interventions, but requires validation to ensure similar effectiveness to brick-and-mortar options.

Objective

We describe the study design, recruitment process, and baseline participant characteristics of the sample in the Virtual Cognitive Health (VC Health) study. Future analyses will assess the impact of the remotely delivered lifestyle intervention on (1) cognitive function, (2) depression and anxiety, and (3) various lifestyle behaviors, including diet, exercise, and sleep, in a cohort of older adults with subjective memory decline. Additional analyses will explore feasibility outcomes, as well as the participants’ engagement patterns with the program.

Methods

Older adults (aged 60-75 years) with subjective memory decline as measured by the Subjective Cognitive Decline 9-item (SCD-9) questionnaire, and who reported feeling worried about their memory decline, were eligible to participate in this single-arm pre-post study. All participants enrolled in the yearlong digital intervention, which consists of health coach-guided lifestyle change for improving diet, exercise, sleep, stress, and cognition. All components of this study were conducted remotely, including the collection of data and the administration of the intervention. We assessed participants at baseline, 12 weeks, 24 weeks, and 52 weeks with online surveys and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) test. We will conduct intention-to-treat analysis on all outcomes.

Results

A total of 85 participants enrolled in the intervention and 82 are included in the study sample (3 participants withdrew). The study cohort of 82 participants comprises 61 (74%) female, 72 (88%) white, and 64 (78%) overweight or obese participants, and 55 (67%) have at least a college degree. The average baseline RBANS score was 95.9 (SD 11.1), which is within age-adjusted norms. The average SCD-9 score was 6.0 (SD 2.0), indicating minor subjective cognitive impairment at the beginning of the study. The average baseline Generalized Anxiety Disorder 7-item scale score was 6.2 (SD 4.5), and the average Patient Health Questionnaire 9-item score was 8.5 (SD 4.9), indicating mild levels of anxiety and depression at baseline.

Conclusions

Internet-delivered lifestyle interventions are a scalable solution for the prevention or delay of Alzheimer disease. The results of this study will provide the first evidence for the effectiveness of a fully remote intervention and lay the groundwork for future investigations.

Trial Registration

ClinicalTrials.gov NCT02969460; http://clinicaltrials.gov/ct2/show/NCT02969460 (Archived by WebCite at http://www.webcitation.org/71LkYAkSh)

Registered Report Identifier

RR1-10.2196/11368

Cognitive impairment in Parkinson's disease: a report from a multidisciplinary symposium on unmet needs and future directions to maintain cognitive health

People with Parkinson's disease (PD) and their care partners frequently report cognitive decline as one of their greatest concerns. Mild cognitive impairment affects approximately 20-50% of people with PD, and longitudinal studies reveal dementia in up to 80% of PD. Through the Parkinson's Disease Foundation Community Choice Research Award Program, the PD community identified maintaining cognitive function as one of their major unmet needs. In response, a working group of experts across multiple disciplines was organized to evaluate the unmet needs, current challenges, and future opportunities related to cognitive impairment in PD. Specific conference goals included defining the current state in the field and gaps regarding cognitive issues in PD from patient, care partner, and healthcare professional viewpoints; discussing non-pharmacological interventions to help maintain cognitive function; forming recommendations for what people with PD can do at all disease stages to maintain cognitive health; and proposing ideas for how healthcare professionals can approach cognitive changes in PD. This paper summarizes the discussions of the conference, first by addressing what is currently known about cognitive dysfunction in PD and discussing several non-pharmacological interventions that are often suggested to people with PD. Second, based on the conference discussions, we provide considerations for people with PD for maintaining cognitive health and for healthcare professionals and care partners when working with people with PD experiencing cognitive impairment. Furthermore, we highlight key issues and knowledge gaps that need to be addressed in order to advance research in cognition in PD and improve clinical care.

Nutritional prevention of cognitive decline and dementia

Cognitive impairment results from a complex interplay of many factors. The most important independent predictor of cognitive decline is age but other contributing factors include demographic, genetic, socio-economic, and environmental parameters, including nutrition. The number of persons with cognitive decline and dementia will increase in the next decades in parallel with aging of the world population. Effective pharmaceutical treatments for age-related cognitive decline are lacking, emphasizing the importance of prevention strategies. There is extensive evidence supporting a relationship between diet and cognitive functions. Thus, nutritional approaches to prevent or slow cognitive decline could have a remarkable public health impact. Several dietary components and supplements have been examined in relation to their association with the development of cognitive decline. A number of studies have examined the role of dietary patterns on late-life cognition, with accumulating evidence that combinations of foods and nutrients may act synergistically to provide stronger benefit than those conferred by individual dietary components. Higher adherence to the Mediterranean dietary pattern has been associated with decreased cognitive decline and incident AD. Another dietary pattern with neuroprotective actions is the Dietary Approach to Stop Hypertension (DASH). The combination of these two dietary patterns has been associated with slower rates of cognitive decline and significant reduction in incident AD. This review evaluates the evidence for the effects of some dietary components, supplements, and dietary patterns as neuroprotective, with potential to delay cognitive decline and the onset of dementia. (www.actabiomedica.it)

Better diet quality relates to larger brain tissue volumes: The Rotterdam Study

OBJECTIVE

To investigate the relation of diet quality with structural brain tissue volumes and focal vascular lesions in a dementia-free population.

METHODS

From the population-based Rotterdam Study, 4,447 participants underwent dietary assessment and brain MRI scanning between 2005 and 2015. We excluded participants with an implausible energy intake, prevalent dementia, or cortical infarcts, leaving 4,213 participants for the current analysis. A diet quality score (0-14) was calculated reflecting adherence to Dutch dietary guidelines. Brain MRI was performed to obtain information on brain tissue volumes, white matter lesion volume, lacunes, and cerebral microbleeds. The associations of diet quality score and separate food groups with brain structures were assessed using multivariable linear and logistic regression.

RESULTS

We found that better diet quality related to larger brain volume, gray matter volume, white matter volume, and hippocampal volume. Diet quality was not associated with white matter lesion volume, lacunes, or microbleeds. High intake of vegetables, fruit, whole grains, nuts, dairy, and fish and low intake of sugar-containing beverages were associated with larger brain volumes.

CONCLUSIONS

A better diet quality is associated with larger brain tissue volumes. These results suggest that the effect of nutrition on neurodegeneration may act via brain structure. More research, in particular longitudinal research, is needed to unravel direct vs indirect effects between diet quality and brain health.

Effect of the NU-AGE Diet on Cognitive Functioning in Older Adults: A Randomized Controlled Trial

Background: Findings from animal and epidemiological research support the potential neuroprotective benefits from healthy diets. However, to establish diet-neuroprotective causal relations, evidence from dietary intervention studies is needed. NU-AGE is the first multicenter intervention assessing whether a diet targeting health in aging can counteract the age-related physiological changes in different organs, including the brain. In this study, we specifically investigated the effects of NU-AGE's dietary intervention on age-related cognitive decline.

Materials and Methods: NU-AGE randomized trial (NCT01754012, clinicaltrials.gov) included 1279 relatively healthy older-adults, aged 65–79 years, from five European centers. Participants were randomly allocated into two groups: “control” (n = 638), following a habitual diet; and, “intervention” (n = 641), given individually tailored dietary advice (NU-AGE diet). Adherence to the NU-AGE diet was measured over follow-up, and categorized into tertiles (low, moderate, high). Cognitive function was ascertained at baseline and at 1-year follow-up with the Consortium to Establish a Registry for Alzheimer's Disease (CERAD)-Neuropsychological Battery and five additional domain-specific single cognitive tests. The raw scores from the CERAD subtests [excluding the Mini-Mental State Examination (MMSE)] and the single tests were standardized into Z-scores. Global cognition (measured with MMSE and CERAD-total score), and five cognitive domains (perceptual speed, executive function, episodic memory, verbal abilities, and constructional praxis) were created. Cognitive changes as a function of the intervention were analyzed with multivariable mixed-effects models.

Results: After the 1-year follow-up, 571 (89.1%) controls and 573 (89.8%) from the intervention group participated in the post-intervention assessment. Both control and intervention groups showed improvements in global cognition and in all cognitive domains after 1 year, but differences in cognitive changes between the two groups were not statistically significant. However, participants with higher adherence to the NU-AGE diet showed statistically significant improvements in global cognition [β 0.20 (95%CI 0.004, 0.39), p-value = 0.046] and episodic memory [β 0.15 (95%CI 0.02, 0.28), p-value = 0.025] after 1 year, compared to those adults with lower adherence.

Discussion: High adherence to the culturally adapted, individually tailored, NU-AGE diet could slow down age-related cognitive decline, helping to prevent cognitive impairment and dementia.

Integrative Medicine Strategies for Changing Health Behaviors: Support for Primary Care

Until system reforms allow adequate time and reimbursement for primary care providers to focus on lifestyle change to prevent and mitigate chronic disease, primary care providers need a manageable, defined role to support lifestyle change. The authors suggest this role is to serve as a catalyst, priming the patient for change; educating and pointing the patient to appropriate, evidence-based resources for additional guidance and hands-on support; and providing ongoing encouragement throughout the long journey of change while patients work more intensely with health coaches or allied health providers.