Food combination and Alzheimer disease risk: a protective diet

Dietary patterns are related to cognitive functioning in elderly enriched with individuals at increased risk for Alzheimer's disease

Purpose

To investigate cross-sectional associations between dietary patterns and cognitive functioning in elderly free of dementia.

Methods

Data of 389 participants from the German DELCODE study (52% female, 69 ± 6 years, mean Mini Mental State Score 29 ± 1) were included. The sample was enriched with elderly at increased risk for Alzheimer’s disease (AD) by including participants with subjective cognitive decline, mild cognitive impairment (MCI) and siblings of AD patients. Mediterranean and MIND diets were derived from 148 Food Frequency Questionnaire items, and data-driven patterns by principal component analysis (PCA) of 39 food groups. Associations between dietary patterns and five cognitive domain scores were analyzed with linear regression analyses adjusted for demographics (model 1), and additionally for energy intake, BMI, other lifestyle variables and APOe4-status (model 2). For PCA-derived dietary components, final model 3 included all other dietary components.

Results

In fully adjusted models, adherence to Mediterranean and MIND diet was associated with better memory. The ‘alcoholic beverages’ PCA component was positively associated with most cognitive domains. Exclusion of MCI subjects (n = 60) revealed that Mediterranean and MIND diet were also related to language functions; associations with the alcoholic beverages component were attenuated, but most remained significant.

Conclusion

In line with data from elderly population samples, Mediterranean and MIND diet and some data-derived dietary patterns were related to memory and language function. Longitudinal data are needed to draw conclusions on the putative effect of nutrition on the rate of cognitive decline, and on the potential of dietary interventions in groups at increased risk for AD.

Electronic supplementary material

The online version of this article (10.1007/s00394-020-02257-6) contains supplementary material, which is available to authorized users.

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.

Serum Magnesium and Cognitive Function Among Qatari Adults

Background: Previous studies found that low blood magnesium increases the risk of several diseases such as cardiovascular diseases (CVD), diabetes, and hypertension. These ailments are associated with declined cognitive function.

Objective: We aimed to examine the association between serum magnesium and cognitive function among Qatari adults. In addition, we assessed the interaction relation between low serum magnesium, hypertension, and diabetes in relation to cognitive function.

Method: Data from 1,000 Qatari participants aged ≥20 years old who participated in the Qatar Biobank (QBB) Study were analyzed. Serum magnesium was measured by an automated calorimetric method and suboptimal magnesium was characterized by <0.85 mmol/l. Cognitive function was determined by measuring the mean reaction time (MRT) based on a computer-based, self-administered test. Multivariable linear regression was used to examine the relation between serum magnesium concentrations and cognitive function.

Results: The prevalence of suboptimal magnesium was 57.1%. Across the four quartiles of serum magnesium from the lowest to the highest, the regression coefficients (95% CI) for MRT were 0 (reference), −17.8, −18.3, and −31.9 (95% CI 2.4–3.1; p for trend 0.05). The presence of hypertension and diabetes significantly increased the MRT. Women with suboptimal magnesium and hypertension had the highest MRT.

Conclusion: The prevalence of suboptimal magnesium is high in Qatar. There was a direct association between serum magnesium and cognitive function. Low magnesium concentrations were associated with a longer MRT.

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.

Associations between cognitive performance and Mediterranean dietary pattern in patients with type 1 or type 2 diabetes mellitus

Diabetes mellitus has been associated with impaired cognitive performance, particularly in verbal memory. Mediterranean diets (MedD) may lead to improvements in overall and single cognitive functions. We hypothesised that adherence to MedD associates with better performance in verbal memory in patients with type 1 or type 2 diabetes. Thus, we performed a cross-sectional analysis including patients with recently diagnosed type 1 (n = 75) or type 2 diabetes (n = 118), metabolically healthy individuals (n = 41) and individuals with type 1 (n = 44) or type 2 diabetes (n = 62) of at least five years after diagnosis. Participants underwent comprehensive metabolic phenotyping and cognitive testing. Adherence to the Modified Mediterranean diet scale (MMDS) was computed from a food frequency questionnaire. Among patients with type 2 diabetes with a known diabetes duration ≥5 years, closer adherence to the MMDS was associated with higher score in verbal memory after adjustment for potential confounders (P = 0.043). Adherence to the MMDS did not relate to verbal memory in recently diagnosed type 2 diabetes (P = 0.275), recently diagnosed or longer-standing type 1 diabetes (P = 0.215 and P = 0.626, respectively) or metabolically healthy individuals (P = 0.666). In conclusion, closer adherence to MedD may exert beneficial effects on cognitive performance in the course of type 2 diabetes.

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.

Gut Microbiota in Neurological Disorders

The incidence of neurological disorders such as multiple sclerosis (MS), Alzheimer's disease (AD) and Parkinson's disease (PD) is increasing throughout the world, but their pathogenesis remains unclear and successful treatment remains elusive. Bidirectional communications between the central nervous system and gut microbiota may play some role in the pathogenesis of the above disorders. Up to a thousand bacterial species reside in human intestine; they colonize the gut shortly after birth and remain for life. Numerous studies point to the role of microbiota composition in the development, course and treatment of MS, AD and PD.

Sex and Gender Driven Modifiers of Alzheimer's: The Role for Estrogenic Control Across Age, Race, Medical, and Lifestyle Risks

Research indicates that after advanced age, the major risk factor for late-onset Alzheimer’s disease (AD) is female sex. Out of every three AD patients, two are females with postmenopausal women contributing to over 60% of all those affected. Sex- and gender-related differences in AD have been widely researched and several emerging lines of evidence point to different vulnerabilities that contribute to dementia risk. Among those being considered, it is becoming widely accepted that gonadal steroids contribute to the gender disparity in AD, as evidenced by the “estrogen hypothesis.” This posits that sex hormones, 17β-estradiol in particular, exert a neuroprotective effect by shielding females’ brains from disease development. This theory is further supported by recent findings that the onset of menopause is associated with the emergence of AD-related brain changes in women in contrast to men of the same age. In this review, we discuss genetic, medical, societal, and lifestyle risk factors known to increase AD risk differently between the genders, with a focus on the role of hormonal changes, particularly declines in 17β-estradiol during the menopause transition (MT) as key underlying mechanisms.

Diet quality and risk of multiple sclerosis in two cohorts of US women

OBJECTIVE

To determine the association between measures of overall diet quality (dietary indices/patterns) and risk of multiple sclerosis (MS).

METHODS

Over 185,000 women in the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII) completed semiquantitative food frequency questionnaires every 4 years. There were 480 MS incident cases. Diet quality was assessed using the Alternative Healthy Eating Index-2010 (AHEI-2010), Alternate Mediterranean Diet (aMED) index, and Dietary Approaches to Stop Hypertension (DASH) index. Principal component analysis was used to determine major dietary patterns. We calculated the hazard ratio (HR) of MS with Cox multivariate models adjusted for age, latitude of residence at age 15, body mass index at age 18, supplemental vitamin D intake, and cigarette smoking.

RESULTS

None of the dietary indices, AHEI-2010, aMED, or DASH, at baseline was statistically significantly related to the risk of MS. The principal component analysis identified "Western" and "prudent" dietary patterns, neither of which was associated with MS risk (HR, top vs bottom quintile: Western, 0.81 (p = 0.31) and prudent, 0.96 (p = 0.94)). When the analysis was repeated using cumulative average dietary pattern scores, the results were unchanged.

CONCLUSION

There was no evidence of an association between overall diet quality and risk of developing MS among women.

Nutrient Patterns, Cognitive Function, and Decline in Older Persons: Results from the Three-City and NuAge Studies

Dietary patterns, or the combination of foods and beverages intake, have been associated with better cognitive function in older persons. To date, no study has investigated the link between a posteriori nutrient patterns based on food intake, and cognitive decline in longitudinal analyses. The aim of this study was to evaluate the relationship between nutrient patterns and cognitive function and decline in two longitudinal cohorts of older persons from France and Canada. The study sample was composed of participants from the Three-City study (3C, France) and the Quebec Longitudinal Study on Nutrition and Successful Aging (NuAge, Quebec, Canada). Both studies estimated nutritional intakes at baseline, and carried out repeated measures of global cognitive function for 1,388 and 1,439 individuals, respectively. Nutrient patterns were determined using principal component analysis methodology in the two samples, and their relation with cognitive function and decline was estimated using linear mixed models. In 3C, a healthy nutrient pattern, characterized by higher intakes of plant-based foods, was associated with a higher global cognitive function at baseline, as opposed to a Western nutrient pattern, which was associated with lower cognitive performance. In NuAge, we also found a healthy nutrient pattern and a Western pattern, although no association was observed with either of these patterns in the Canadian cohort. No association between any of the nutrient patterns and cognitive decline was observed in either cohort. There is a need for longitudinal cohorts focusing on nutrient patterns with substantial follow-up, in order to evaluate more accurately associations between nutrition and cognition in older persons.

Impact of Flavonoids on Cellular and Molecular Mechanisms Underlying Age-Related Cognitive Decline and Neurodegeneration

Purpose of Review

This review summarises the most recent evidence regarding the effects of dietary flavonoids on age-related cognitive decline and neurodegenerative diseases.

Recent Findings

Recent evidence indicates that plant-derived flavonoids may exert powerful actions on mammalian cognition and protect against the development of age-related cognitive decline and pathological neurodegeneration. The neuroprotective effects of flavonoids have been suggested to be due to interactions with the cellular and molecular architecture of brain regions responsible for memory.

Summary

Mechanisms for the beneficial effects of flavonoids on age-related cognitive decline and dementia are discussed, including modulating signalling pathways critical in controlling synaptic plasticity, reducing neuroinflammation, promoting vascular effects capable of stimulating new nerve cell growth in the hippocampus, bidirectional interactions with gut microbiota and attenuating the extracellular accumulation of pathological proteins. These processes are known to be important in maintaining optimal neuronal function and preventing age-related cognitive decline and neurodegeneration.

Infectious Agents in Bovine Red Meat and Milk and Their Potential Role in Cancer and Other Chronic Diseases

Red meat and dairy products have frequently been suggested to represent risk factors for certain cancers, chronic neurodegenerative diseases, and autoimmune and cardiovascular disorders. This review summarizes the evidence and investigates the possible involvement of infectious factors in these diseases. The isolation of small circular single-stranded DNA molecules from serum and dairy products of Eurasian Aurochs (Bos taurus)-derived cattle, obviously persisting as episomes in infected cells, provides the basis for further investigations. Gene expression of these agents in human cells has been demonstrated, and frequent infection of humans is implicated by the detection of antibodies in a high percentage of healthy individuals. Epidemiological observations suggest their relationship to the development multiple sclerosis, to heterophile antibodies, and to N-glycolylneuraminic acid (Neu5Gc) containing cell surface receptors.

An Inflammation-related Nutrient Pattern is Associated with Both Brain and Cognitive Measures in a Multiethnic Elderly Population

Background:

Accumulating evidence suggests that dietary factors are associated with Alz-heimer’s disease, cognition, and brain health in older adults. It is however unclear whether inflammation explains this association.

Objective:

To examine whether an inflammation-related nutrient pattern (INP) was associated with neu-roimaging and cognitive measures of brain health.

Method:

The current cross-sectional study included 330 non-demented elderly (mean age 79 years at MRI scan) participants in a multi-ethnic, community-based cohort study who had information on nutritional in-take (estimated from food frequency questionnaire), circulating C-reactive protein and interleukin-6 (meas-ured by ELISA), MRI scans, and cognition. Diet and blood samples were collected approximately 5.3 years prior to the MRI and cognitive test visit. We used a reduced rank regression model to derive an INP based on 24 nutrients' relationship with CRP and interleukin-6. We examined the association of the INP with brain and cognitive measures using regression models adjusted for age, sex, race/ethnicity, education, caloric intake, APOE genotype, body mass index, and vascular burden, as well as intracranial volume for the brain MRI measures.

Results:

The INP was characterized by low intake (effect loading <-0.15) of calcium, vitamins (D, E, A, B1, B2, B3, B5, B6), folate, Ω-3 poly-unsaturated fatty acids, and high intake (>0.15) of cholesterol. As designed, this INP was positively correlated with CRP (Pearson’s r=0.25 p=0.005) and interleukin-6 (r=0.30, p<0.0001). Each unit increase in INP was associated with 36.8 cm3 (p=0.023) smaller total brain volume and 0.21 (p=0.038) lower visuospatial z-score. Mediation analysis showed that TGMV (b=0.002, p=0.003) was associated with visuospatial cognitive function, and there was a significant mediation effect by TGMV (indirect effect: -0.049, 95% CI: -0.1121 ~ -0.0131) for the association between INP and visuospatial cognitive score.

Conclusions:

Among older adults, a diet with high inflammatory potential is associated with less favora-ble brain and cognitive health.

Study protocol: associations between dietary patterns, cognitive function and metabolic syndrome in older adults - a cross-sectional study

BACKGROUND

Loss of cognitive function is a significant issue as the world's population ages. Preserving cognitive function maintains independence in older adults bringing major societal and financial benefits. Lifestyle factors such as diet are modifiable risk factors, which may help preserve cognitive function. Most nutrition research aimed at preserving cognitive function and metabolic health has focussed on individual nutrients and foods, not allowing for food combinations and interactions. A dietary pattern approach considers the entire diet including its complexity. Previous research investigating dietary patterns and cognitive function has not always considered relevant covariates such as physical activity and the Apolipoprotein E genotype, which are known to have associations with cognitive function. The aim of the REACH (Researching Eating, Activity and Cognitive Health) study is to investigate associations between dietary patterns, cognitive function and metabolic syndrome, accounting for a range of covariates.

METHODS

This cross-sectional study design will recruit older, community-living adults (65-74 years) from Auckland, New Zealand. Dietary data will be collected via a 109-item food frequency questionnaire validated using a 4-day food record. Cognitive function will be assessed using the Montreal Cognitive Assessment (paper based) and the Computerised Mental Performance Assessment System (COMPASS) - a testing suite covering six domains. Additional data will include genetic (Apolipoprotein E ε4) and biochemical markers (fasting glucose, HbA1c, lipids profile), anthropometric measurements (weight, height, waist and hip circumference, body composition using dual X-ray absorptiometry), blood pressure, physical activity (International Physical Activity Questionnaire - short form) and health and demographics (questionnaire). Dietary patterns will be derived by principal component analysis. Associations between cognitive function and dietary patterns will be examined using multiple regression analysis. Covariates and interaction factors will include age, education, socio-economic status, physical activity, Apolipoprotein E ε4 genotype, family history of dementia or cognitive impairment, and lifestyle factors. Differences between participants with and without metabolic syndrome will also be examined.

DISCUSSION

This study will bring new knowledge regarding associations between dietary patterns and cognitive function and metabolic health in older adults living in New Zealand. This is important for developing nutrition related recommendations to help older adults maintain cognitive function.

The sociodemographic characteristics and dietary and blood plasma fatty acid profiles of elderly Saudi women with Alzheimer disease

Background

Alzheimer’s disease (AD) is a progressive neurodegenerative disease, and due to various physiological and psychological factors the patients are at risk of nutritional insufficiencies. The purpose of this study was to assess the dietary fatty acid intake and its effect on plasma fatty acids in elderly Saudi women and to compare the differences in their food and plasma fatty acid profile on the basis of their residence.

Methods

A total of 76 elderly women (50–100 years) were recruited through a random sampling method. A structured proforma was designed to gather information related to their age, income, dietary habits, and presence of any disease and awareness of AD. A 24-h dietary recall method for 3 days and food frequency questionnaire, concentrating on fish consumption and consumption of foods rich in ω-3 fatty acids, which was planned by dietitians, was used for dietary assessment. The gathered data were then analyzed using food processor software. The blood samples were collected to determine plasma fatty acids.

Results

The mean age of women diagnosed with AD was more than 75 years, and the prevalence of illiteracy was higher among AD subjects. As compared to the AD group, the concentration of LA and total ω-6 was significantly (p ≤ 0.05) higher in the control group from both recruitment sites [National Guard Health Affairs, King Abdulaziz Medical City, Riyadh (NGH) and Social Welfare Homes for the Elderly (SWH)]. Similarly, the concentrations of EPA, DHA, and ω-3 were also slightly higher in the control group at both sites, but the difference between the control and AD subjects was only significant (p ≤ 0.05) in subjects from NGH. We found no significant difference in the ω-6/ ω-3 ratio between groups. Also, no significant difference was found in the mean level of the plasma fatty acid when comparing the control and AD groups. The concentration of DHA in controls only and AA, EPA and ω-6 in both control and AD were significant (although weakly) correlated with their respective dietary intakes. No correlations were found between the intake of 18 C precursors (LA and ALA) and plasma levels of their long chain derivatives (AA, EPA, and DHA). Education, income, overall health status and the concentration of various fatty acids from food was higher and better in subjects from SWH than NGH. The lower plasma level indicates lower impaired systemic availability of several nutrients.

Conclusion

We found that dietary intervention might play a role in the prevention of AD.

Attitudes of Students from the High Medical College of Professional Studies and Nurses Towards People Suffering from Dementia

Dementia is characterized by a progressive decrease in cognitive functions, and the term includes different etiologies. Cognitive decline includes loss of memory and deterioration in executive functions, such as planning and organizing skills, sufficient to influence social activities. The aim of this study was to examine and compare the attitudes (knowledge, emotions and behaviour) of students at the High Medical College of Professional Studies and nurses towards people suffering from dementia. The study was designed as a qualitative study with the use of a questionnaire. The Dementia Attitudes Scale (DAS) was used in our study. A total of 283 respondents answered the survey: 56.25% were students, and 43.75% were nurses. The internal consistency of the DAS was found to be good with a Cronbach’s α of 0.792. In the overall score for attitudes, a significant difference was found between students (100.47±10.91) and nurses (95.51±16.10). The students had a better score regarding questions describing their behaviour towards these individuals (p<0.001) and emotions for these patients (p<0.001). For knowledge, there was no difference between the two groups of subjects (p=0.901). Regarding the overall score, attitudes of students and nurses towards people with dementia were positive. This research suggested that the training of senior team members who then had dementia expertise was a key component in developing attitudes and improving care practices and outcomes for these patients. Continuous education of all medical staff who have contact with people who suffer from dementia is important.

Nutrients in Alzheimer’s Disease: The Interaction of Diet, Drugs and Disease

In recent decades, clinical trials in Alzheimer’s disease (AD) have failed at an unprecedented rate. The etiology of AD has since come under renewed scrutiny, both to elucidate the underlying pathologies and to identify novel therapeutic strategies. Here, diet has emerged as a potential causative/protective agent. A variety of nutrients, including lipids, minerals, vitamins, antioxidants and sugars as well as broader dietary patterns and microbiotal interactions have demonstrated associations with AD. Although clinical trials have yet to definitively implicate any singular dietary element as therapeutic or causative, it is apparent that dietary preferences, likely in complex synergies, may influence the risk, onset and course of AD. This review catalogs the impact of major dietary elements on AD. It further examines an unexplored reciprocal association where AD may modulate diet, as well as how potential therapeutics may complicate these interactions. In doing so, we observe diet may have profound effects on the outcome of a clinical trial, either as a confounder of a drug/disease interaction or as a generally disruptive covariate. We therefore conclude that future clinical trials in AD should endeavor to control for diet, either in study design or subsequent analyses.

The Association Between Eating Green Vegetables Every Day And Mild Cognitive Impairment: A Community-Based Cross-Sectional Study In Shanghai

BACKGROUND

Emerging evidence has suggested that green vegetables may prevent cognitive decline.

METHODS

We examined the cross-sectional association between green vegetables intake and mild cognitive impairment (MCI) using data from 525 participants aged 55 years and above from the China Longitudinal Aging Study (CLAS) in Shanghai.

RESULTS

Compared with participants who did not eat green vegetables every day, those who had consumed green vegetables every day had a significantly lower risk of mild cognitive impairment (MCI) (OR = 0.218, 95% CI, 0.116-0.411, p < 0.001), and this association was independent of age, education, having hobbies, surfing the Internet, sleep time per night (youth), long-term residency and consumption of specific red food, such as meat, bread, bean curd, and ginger.

CONCLUSION

In summary, using community-based data in Shanghai, we found out that subjects who eat green vegetables every day have significantly lower odds of MCI than those who do not eat every day. Based on current evidence, we propose that eating green vegetables every day might be a potential preventive measure to slow cognitive decline and neurodegeneration in the elderly.

Comparative studies of DHA-enriched phosphatidylcholine and recombination of DHA-ethyl ester with egg phosphatidylcholine on ameliorating memory and cognitive deficiency in SAMP8 mice

DHA-PLs (DHA-PC) could not be substituted by recombination of commercial fish oil with DHA-free PC in alleviating age-related memory loss and cognitive deficiency in SAMP8 mice.

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Healthy Dietary Changes in Midlife Are Associated with Reduced Dementia Risk Later in Life

Diet is an important modifiable lifestyle factor related to dementia risk. Yet, the role of midlife dietary changes is unclear. The goal is to investigate whether midlife healthy dietary changes are associated with late-life dementia risk. Data were collected within the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) population-based cohort study (n = 2000) (mean baseline age = 56 years). Participants returned for two late-life re-examinations (mean age = 70 and 78 years). Self-reported midlife diet was measured in a sub-sample (n = 341) (mean total follow-up = 16.8 years). Changes in specific dietary components (fats, vegetables, sugar, salt) were measured in midlife. Dementia diagnoses were ascertained with detailed examinations. Analyses adjusted for potential confounders. Total midlife healthy dietary changes (improving quality of fats, increasing vegetables, decreasing sugar and salt) were associated with a reduced risk of dementia (fully adjusted odds ratio (OR) 0.41, 95% confidence interval (CI) = 0.20⁻0.85). In contrast, when each factor was assessed individually, associations were not significant. This study is the first to show that beneficial midlife dietary changes are associated with a reduced dementia risk later in life. The results highlight the importance of targeting dietary patterns, where various food items may have synergistic effects.

Comparison of the effects of selenomethionine and selenium-enriched yeast in the triple-transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a complex, multifactorial neurodegenerative disease that exhibits multiple pathogeneses and heterogeneity. Selenium (Se) is an essential trace element for human and animal nutrition. It has been shown that supplementation with two organic forms of Se, Se-enriched yeast (Se-yeast) and selenomethionine (Se-Met), could improve cognitive impairment, reverse synaptic deficits and mitigate tau pathology in triple-transgenic (3× Tg) AD mice. Se-yeast is well known for its high Se-Met content, which may mediate its anti-AD effects. In addition, a large amount of the physiological and biochemical mechanisms of these two Se drugs in the amelioration AD pathology remains unknown. In this study, the content of Se-yeast aside from Se was analyzed, and the effects of Se-Met and Se-yeast on 3× Tg-AD mice were investigated and compared. The results showed that both Se-Met and Se-yeast not only significantly increased the Se levels, enhanced the antioxidant capacity and improved the cognitive decline in the model, but also decreased the Aβ and tau pathologies in the brain tissue of the AD mice. Moreover, the ability of Se-Met to increase the Se levels in different tissues of the AD mice was more significant than that of Se-yeast. However, the positive effect of Se-yeast on improving the cognitive ability of the AD mice was better than that of Se-Met, likely due to the various elements, vitamins and other nutrients in Se-yeast. Collectively, these results suggest that Se-yeast has potential as a clinical health product or drug for AD but that Se-Met, as a pure organic Se compound, is more suitable for studying the therapeutic mechanism of Se because of its comprehensive effects on AD.

Association between diets and mild cognitive impairment in adults aged 50 years or older

BACKGROUND/OBJECTIVE

As aging progresses, the number of patients with cognitive impairment also increases. Cognitive function is not generally correlated with diet, and there is debate over that association. Thus, the present study aimed to investigate the association between dietary intake and cognitive function among adults aged 50 years or older.

SUBJECTS/METHODS

Between July 2017 and March 2018, 324 adults aged over 50 years from Gwangju Sun-Han hospital participated in a dietary survey. The frequency of food intake and related information were collected using a semi-quantitative food frequency questionnaire (SQ-FFQ) and determining the mini-mental state examination (MMSE) level for 276 participants. The association between dietary intake and cognitive function was assessed by performing logistic regression analysis.

RESULTS

Depending on the MMSE score, the participants' age, education level, inhabitation status, medications, alcohol consumption, sleep duration, physical activity, and short geriatric depression scale score were significantly different (P < 0.05). Moreover, those participant characteristics were associated with either decreased or increased odds ratios (OR) for the risk of mild cognitive impairment (MCI). Based on analysis of the participants' intake of 112 detailed food items, which were categorized into 20 food types, intakes of cooked white rice (< 2 times/day compared with ≥ 3 times/day) (P < 0.05), properly cooked rice with other grains and legumes (P < 0.001), fruits (P < 0.05), milk (low fat and normal) (P = 0.044), liquid-type yogurt (P = 0.019), and curd-type yogurt (P = 0.015) were found to significantly decrease the OR for the risk of MCI.

CONCLUSIONS

Associations were significant between the risk of MCI and the intake of certain food types. Specifically, a moderate intake of cooked white rice and an adequate intake of whole grains, fruits, milk, and dairy products were associated with reduced risks of MCI among adults aged over 50 years.

Nutrition and prevention of cognitive impairment

Nutrition is an important lifestyle factor that can modify the risk of future cognitive impairment and dementia. Some, but not conclusive, evidence (mostly from observational studies and infrequently from clinical trials) exists of a protective association between certain nutrients (eg, folate, flavonoids, vitamin D, and certain lipids) or food groups (eg, seafood, vegetables, and fruits, and potentially moderate alcohol and caffeine consumption) and cognitive outcomes in older people. For some nutrients and food groups, protection might be greater in individuals with either deficiencies in certain nutrients or a genetic predisposition to cognitive impairment. Identification of potentially different associations between such subgroups should be a priority for future research. At present, evidence of an association between nutrition and cognitive outcomes is somehow stronger for healthy dietary patterns, such as the Mediterranean-type diet, than for individual nutrients and food groups, possibly because of the cumulative beneficial effects of the many ingredients in these diets. Multidomain interventions (including a nutrition component) might also hold some promise for the prevention of cognitive impairment and dementia, but their effectiveness is still uncertain. Use of advanced technologies for nutrition assessment (eg, metabolomics and innovative methods of dietary intake assessment) and recently identified biomarkers of nutrition and neurobiological outcomes will be important to achieve this goal.

Neuro-nutrients as anti-alzheimer's disease agents: A critical review

Alzheimer's disease (AD) is characterized by a massive neuronal death causing memory loss, cognitive impairment and behavioral alteration that ultimately lead to dementia and death. AD is a multi-factorial pathology controlled by molecular events such as oxidative stress, protein aggregation, mitochondrial dysfunction and neuro inflammation. Nowadays, there is no efficient disease-modifying treatment for AD and epidemiological studies have suggested that diet and nutrition have a significant impact on the development of this disorder. Indeed, some nutrients can protect all kind of cells, including neurons. As prevention is better than cure, life style improvement, with a special emphasis on diet, should seriously be considered as an anti-AD track and intake of nutrients promoting neuronal health is the need of the hour. Diets rich in unsaturated fatty acids, polyphenols and vitamins have been shown to protect against AD, whereas saturated fatty acids-containing diets deprived of polyphenols promote the development of the disease. Thus, Mediterranean diets, mainly composed of fruits, vegetables and omega-3 fatty acids, stand as valuable, mild and preventive anti-AD agents. This review focuses on our current knowledge in the field and how one can fight this devastating neurodegenerative disorder through the simple proper modification of our life style.

Harnessing the Power of Microbiome Assessment Tools as Part of Neuroprotective Nutrition and Lifestyle Medicine Interventions

An extensive body of evidence documents the importance of the gut microbiome both in health and in a variety of human diseases. Cell and animal studies describing this relationship abound, whilst clinical studies exploring the associations between changes in gut microbiota and the corresponding metabolites with neurodegeneration in the human brain have only begun to emerge more recently. Further, the findings of such studies are often difficult to translate into simple clinical applications that result in measurable health outcomes. The purpose of this paper is to appraise the literature on a select set of faecal biomarkers from a clinician’s perspective. This practical review aims to examine key physiological processes that influence both gastrointestinal, as well as brain health, and to discuss how tools such as the characterisation of commensal bacteria, the identification of potential opportunistic, pathogenic and parasitic organisms and the quantification of gut microbiome biomarkers and metabolites can help inform clinical decisions of nutrition and lifestyle medicine practitioners.

Association between cognitive function and supplementation with omega-3 PUFAs and other nutrients in ≥ 75 years old patients: A randomized multicenter study

A few studies have assessed the association between omega-3 polyunsaturated fatty acids (n-3 PUFA) and cognitive impairment (CI) in very old adults. The aim of this study was to evaluate the effect of a multinutrient supplementation rich in n-3 PUFA on the cognitive function in an institutionalized ≥75-year-old population without CI or with mild cognitive impairment (MCI). A multicenter placebo-controlled double-blind randomized trial was conducted between 2012 and 2013. Cognitive function was assessed at baseline and after one year using 4 neuropsychological tests. Nutritional status was assessed using Mini Nutritional Assessment (MNA). Interaction between Mini-Mental State Examination (MMSE) score and nutritional status were analyzed using linear regression models. A total of 99 participants were randomized to receive placebo or pills rich in n-3 PUFA. After 1-year follow-up, both groups decreased their MMSE score (-1.18, SD:0. 53 and -0.82, SD:0. 63, p = 0.67 for the control and the intervention group respectively). The memory subscale of the MMSE showed an improvement (+0.26, SD:0.18) in the intervention group against a worsening in the control group (-0.11, SD: 0.14; p = 0.09 for differences between groups). Patients at intervention group with normal nutritional status (MNA ≥24) showed an improvement in the MMSE (+1.03, p = 0.025 for differences between 1-y and baseline measurements) against a worsening in the group with malnutrition (MNA<24) (-0.4, p = 0.886 for differences between 1-y and baseline; p of interaction p = 0.05). Supplementation with n-3 PUFA did not show an improvement in the global cognitive function in institutionalized elderly people without CI or with MCI. They only suggest an apparent improvement in memory loss if previously they were well nourished.

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.

7T Brain MRS in HIV Infection: Correlation with Cognitive Impairment and Performance on Neuropsychological Tests

BACKGROUND AND PURPOSE

Validated neuroimaging markers of HIV-associated neurocognitive disorder in patients on antiretroviral therapy are urgently needed for clinical trials. The purpose of this study was to explore the relationship between cognitive impairment and brain metabolism in older subjects with HIV infection. It was hypothesized that MR spectroscopy measurements related to neuronal health and function (particularly N-acetylaspartate and glutamate) would be lower in HIV-positive subjects with worse cognitive performance.

MATERIALS AND METHODS

Forty-five HIV-positive patients (mean age, 58.9 ± 5.3 years; 33 men) underwent detailed neuropsychological testing and brain MR spectroscopy at 7T. Twenty-four subjects were classified as having asymptomatic cognitive impairment, and 21 were classified as having symptomatic cognitive impairment. Single-voxel proton MR spectra were acquired from 5 brain regions and quantified using LCModel software. Brain metabolites and neuropsychological test results were compared using nonparametric statistics and Pearson correlation coefficients.

RESULTS

Differences in brain metabolites were found between symptomatic and asymptomatic subjects, with the main findings being lower measures of N-acetylaspartate in the frontal white matter, posterior cingulate cortex, and precuneus. In the precuneus, glutamate was also lower in the symptomatic group. In the frontal white matter, precuneus, and posterior cingulate cortex, NAA and glutamate measurements showed significant positive correlation with better performance on neuropsychological tests.

CONCLUSIONS

Compared with asymptomatic subjects, symptomatic HIV-positive subjects had lower levels of NAA and glutamate, most notably in the frontal white matter, which also correlated with performance on neuropsychological tests. High-field MR spectroscopy offers insight into the pathophysiology associated with cognitive impairment in HIV and may be useful as a quantitative outcome measure in future treatment trials.

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

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

Oleocanthal-rich extra-virgin olive oil enhances donepezil effect by reducing amyloid-β load and related toxicity in a mouse model of Alzheimer's disease

Previous evidence suggested that extra-virgin olive oil (EVOO) is linked to attenuating amyloid-β (Aβ) pathology and improving cognitive function in Alzheimer's disease (AD) mouse models. In addition, we recently reported the beneficial effect of oleocanthal, a phenolic compound in EVOO, against AD pathology. Currently, medications available to target AD pathology are limited. Donepezil is an acetylcholine esterase inhibitor approved for use for all AD stages. Donepezil has been reported to have limited Aβ-targeting mechanisms beside its acetylcholine esterase inhibition. The aim of this study was to investigate the consumption of EVOO rich with oleocanthal (hereafter EVOO) as a medical food on enhancing the effect of donepezil on attenuating Aβ load and related toxicity in 5xFAD mouse model of AD. Our results showed that EVOO consumption in combination with donepezil significantly reduced Aβ load and related pathological changes. Reduced Aβ load could be explained, at least in part, by enhancing Aβ clearance pathways including blood-brain barrier (BBB) clearance and enzymatic degradation, and shifting amyloid precursor protein processing toward the nonamyloidogenic pathway. Furthermore, EVOO combination with donepezil up-regulated synaptic proteins, enhanced BBB tightness and reduced neuroinflammation associated with Aβ pathology. In conclusion, EVOO consumption as a medical food combined with donepezil offers an effective therapeutic approach by enhancing the noncholinergic mechanisms of donepezil and by providing additional mechanisms to attenuate Aβ-related pathology in AD patients.

Dietary patterns: a literature review of the methodological characteristics of the main step of the multivariate analyzes

OBJECTIVE

To describe the solutions adopted in the multiple steps of the use of multivariate techniques to obtain a dietary pattern (DP) concerning: the objective of the studies, the selection of the method for measuring food intake, the criteria for grouping the foods, the number of food groups used, the number of DP obtained, and the nomenclature criteria.

METHODS

The articles were selected from MEDLINE and Lilacs scientific databases using the following keywords: "dietary patterns" versus "factor analysis"; "principal components analysis"; "cluster analysis" and "reduced regression rank." The initial search resulted in 1,752 articles. After inclusion and exclusion criteria, 189 publications were selected.

RESULTS

The following aspects were relevant among the studies: the prevalence of the principal component analysis (PCA); the prevalence of the use of 4 to 5 DPs in the studies of association with health outcomes; the use of 30 or more food groups from the food frequency questionnaire (FFQ); the prevalence of studies that associated DPs with health outcomes and socioeconomic factors; and the heterogeneity of criteria used throughout the analytical stages of the multivariate techniques.

CONCLUSION

The heterogeneity between the publications concentrates on the criteria for food grouping, the nomenclature, and the number of dietary patterns calculated, which varied depending on the number of food groups present in these analyses. To understand, apply, and explore in full, the multivariate techniques has become necessary in order to improve the reliability of the results and, consequently, to improve the relationships with health outcomes and socioeconomic factors.

The Role of Dietary and Lifestyle Factors in Maintaining Cognitive Health

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

Dietary pattern, inflammation and cognitive decline: The Whitehall II prospective cohort study

BACKGROUND & AIMS

Low-grade inflammation appears to play an etiological role in cognitive decline. However the association between an inflammatory dietary pattern and cognitive decline has not been investigated. We aimed to investigate dietary patterns associated with inflammation and whether such diet is associated with cognitive decline.

METHODS

We analyzed 5083 participants (28.7% women) from the Whitehall II cohort study. Diet and serum interleukin-6 (IL-6) were assessed in 1991-1993 and 1997-1999. We used reduced rank regression methods to determine a dietary pattern associated with elevated IL-6. Cognitive tests were performed in 1997-1999 and repeated in 2002-2004 and 2007-2009. The association between dietary pattern and cognitive decline between ages 45 and 79 was assessed using linear mixed models.

RESULTS

We identified an inflammatory dietary pattern characterized by higher intake of red meat, processed meat, peas and legumes, and fried food, and lower intake of whole grains which correlated with elevated IL-6 both in 1991-1993 and 1997-1999. A greater decline in reasoning was seen in participants in the highest tertile of adherence to the inflammatory dietary pattern (-0.37 SD; 95% confidence interval [CI] -0.40, -0.34) compared to those in the lowest tertile (-0.31; 95% CI -0.34, -0.28) after adjustment for age, sex, ethnicity, occupational status, education, and total energy intake (p for interaction across tertiles = 0.01). This association remained significant after multivariable adjustment. Similarly for global cognition, the inflammatory dietary pattern was associated with faster cognitive decline after multivariable adjustment (p for interaction across tertiles = 0.04). Associations were stronger in younger participants (<56 years), reducing the possibility of reverse causation.

CONCLUSIONS

Our study found that a dietary pattern characterized as higher intake of red and processed meat, peas, legumes and fried food, and lower intake of whole grains was associated with higher inflammatory markers and accelerated cognitive decline at older ages. This supports the case for further research.

The protective role of plant biophenols in mechanisms of Alzheimer's disease

Self-assembly of amyloid beta peptide (Aβ) into the neurotoxic oligomers followed by fibrillar aggregates is a defining characteristic of Alzheimer's disease (AD). Several lines of proposed hypotheses have suggested the mechanism of AD pathology, though the exact pathophysiological mechanism is not yet elucidated. The poor understanding of AD and multitude of adverse responses reported from the current synthetic drugs are the leading cause of failure in the drug development to treat or halt the progression of AD and mandate the search for safer and more efficient alternatives. A number of natural compounds have shown the ability to prevent the formation of the toxic oligomers and disrupt the aggregates, thus attracted much attention. Referable to the abundancy and multitude of pharmacological activities of the plant active constituents, biophenols that distinguish them from the other phytochemicals as a natural weapon against the neurodegenerative disorders. This review provides a critical assessment of the current literature on in vitro and in vivo mechanistic activities of biophenols associated with the prevention and treatment of AD. We have contended the need for more comprehensive approaches to evaluate the anti-AD activity of biophenols at various pathologic levels and to assess the current evidences. Consequently, we highlighted the various problems and challenges confronting the AD research, and offer recommendations for future research.

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

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

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

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

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

2016 Alzheimer's disease facts and figures

This report describes the public health impact of Alzheimer's disease, including incidence and prevalence, mortality rates, costs of care, and the overall impact on caregivers and society. It also examines in detail the financial impact of Alzheimer's on families, including annual costs to families and the difficult decisions families must often make to pay those costs. An estimated 5.4 million Americans have Alzheimer's disease. By mid-century, the number of people living with Alzheimer's disease in the United States is projected to grow to 13.8 million, fueled in large part by the aging baby boom generation. Today, someone in the country develops Alzheimer's disease every 66 seconds. By 2050, one new case of Alzheimer's is expected to develop every 33 seconds, resulting in nearly 1 million new cases per year. In 2013, official death certificates recorded 84,767 deaths from Alzheimer's disease, making it the sixth leading cause of death in the United States and the fifth leading cause of death in Americans age ≥ 65 years. Between 2000 and 2013, deaths resulting from stroke, heart disease, and prostate cancer decreased 23%, 14%, and 11%, respectively, whereas deaths from Alzheimer's disease increased 71%. The actual number of deaths to which Alzheimer's disease contributes is likely much larger than the number of deaths from Alzheimer's disease recorded on death certificates. In 2016, an estimated 700,000 Americans age ≥ 65 years will die with Alzheimer's disease, and many of them will die because of the complications caused by Alzheimer's disease. In 2015, more than 15 million family members and other unpaid caregivers provided an estimated 18.1 billion hours of care to people with Alzheimer's and other dementias, a contribution valued at more than $221 billion. Average per-person Medicare payments for services to beneficiaries age ≥ 65 years with Alzheimer's disease and other dementias are more than two and a half times as great as payments for all beneficiaries without these conditions, and Medicaid payments are 19 times as great. Total payments in 2016 for health care, long-term care and hospice services for people age ≥ 65 years with dementia are estimated to be $236 billion. The costs of Alzheimer's care may place a substantial financial burden on families, who often have to take money out of their retirement savings, cut back on buying food, and reduce their own trips to the doctor. In addition, many family members incorrectly believe that Medicare pays for nursing home care and other types of long-term care. Such findings highlight the need for solutions to prevent dementia-related costs from jeopardizing the health and financial security of the families of people with Alzheimer's and other dementias.

The Calculator of Anti-Alzheimer's Diet. Macronutrients

The opinions about optimal proportions of macronutrients in a healthy diet have changed significantly over the last century. At the same time nutritional sciences failed to provide strong evidence backing up any of the variety of views on macronutrient proportions. Herein we present an idea how these proportions can be calculated to find an optimal balance of macronutrients with respect to prevention of Alzheimer’s Disease (AD) and dementia. These calculations are based on our published observation that per capita personal income (PCPI) in the USA correlates with age-adjusted death rates for AD (AADR). We have previously reported that PCPI through the period 1925–2005 correlated with AADR in 2005 in a remarkable, statistically significant oscillatory manner, as shown by changes in the correlation coefficient R (R_original). A question thus arises what caused the oscillatory behavior of R_original? What historical events in the life of 2005 AD victims had shaped their future with AD? Looking for the answers we found that, considering changes in the per capita availability of macronutrients in the USA in the period 1929–2005, we can mathematically explain the variability of R_original for each quarter of a human life. On the basis of multiple regression of R_original with regard to the availability of three macronutrients: carbohydrates, total fat, and protein, with or without alcohol, we propose seven equations (referred to as “the calculator” throughout the text) which allow calculating optimal changes in the proportions of macronutrients to reduce the risk of AD for each age group: youth, early middle age, late middle age and late age. The results obtained with the use of “the calculator” are grouped in a table (Table 4) of macronutrient proportions optimal for reducing the risk of AD in each age group through minimizing Rpredicted−i.e., minimizing the strength of correlation between PCPI and future AADR.