The Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) Diet for the Aging Brain: A Systematic Review

The Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet seems a promising approach to preserve brain function during aging. Previous systematic reviews have demonstrated benefits of the MIND diet for cognition and dementia, though an update is needed. Additionally, other outcomes relevant to brain aging have not been summarized. Therefore, this systematic review aims to give an up-to-date and complete overview on human studies that examined the MIND diet in relation to brain aging outcomes in adults aged ≥40 y. Ovid Medline, Web of Science core collection, and Scopus were searched up to July 25, 2023. Study quality was assessed using the Newcastle-Ottawa Scale and the Cochrane Risk-of-Bias tool. We included 40 articles, of which 32 were unique cohorts. Higher MIND diet adherence was protective of dementia in 7 of 10 cohorts. Additionally, positive associations were demonstrated in 3 of 4 cohorts for global cognition and 4 of 6 cohorts for episodic memory. The protective effects of the MIND diet on cognitive decline are less apparent, with only 2 of 7 longitudinal cohorts demonstrating positive associations for global decline and 1 of 6 for episodic memory decline. For other brain outcomes (domain-specific cognition, cognitive impairments, Parkinson's disease, brain volume, and pathology), results were mixed or only few studies had been performed. Many of the cohorts demonstrating protective associations were of North American origin, raising the question if the most favorable diet for healthy brain aging is population-dependent. In conclusion, this systematic review provides observational evidence for protective associations between the MIND diet and global cognition and dementia risk, but evidence for other brain outcomes remains mixed and/or limited. The MIND diet may be the preferred diet for healthy brain aging in North American populations, though evidence for other populations seems less conclusive. This review was registered at PROSPERO as CRD42022254625.

The association between adherence to a plant-based diet and cognitive ageing

PURPOSE

While the benefits of adopting a more plant-based diet for sustainability and animal welfare are clear, its long-term health impacts, including the impact on cognitive ageing, are limited studied. Therefore, we investigated the associations between plant-based diet adherence and cognitive ageing.

METHODS

Data from a previous intervention study involving community-dwelling adults aged ≥ 65 years were analysed at baseline (n = 658) and after 2-year follow-up (n = 314). Global and domain-specific cognitive functioning were assessed at both timepoints. Overall, healthful and unhealthful plant-based dietary indices were calculated from a 190-item food frequency questionnaire. Multivariate-adjusted linear regression models were applied to test for associations.

RESULTS

After full-adjustment, higher overall adherence to a plant-based diet was not associated with global cognitive function (difference in Z-score, tertile 1 versus 3 [95% CI]: 0.04 [- 0.05, 0.13] p = 0.40) or cognitive change (- 0.04 [- 0.11, 0.04], p = 0.35). Similarly, healthful and unhealthful plant-based diet indices were not associated with cognitive functioning (respectively p = 0.48; p = 0.87) or change (respectively p = 0.21, p = 0.33). Interestingly, we observed fish consumption to influence the association between plant-based diet adherence and cognitive functioning (p-interaction = 0.01), with only individuals with a fish consumption of ≥ 0.93 portion/week benefitting from better overall plant-based diet adherence (β per 10-point increment [95% CI]: 0.12 [0.03, 0.21] p = 0.01).

CONCLUSION

We did not demonstrate associations of a more plant-based diet with cognitive ageing. However, possibly such association exists in a subpopulation with higher fish intake. This would be in line with earlier observations that diets rich in plant foods and fish, such as the Mediterranean diet, may be beneficial for cognitive ageing.

TRIAL REGISTRATION

Registered at clinicaltrials.gov (NCT00696514) on June 12, 2008.

The Association of Vitamin D Status with Mild Cognitive Impairment and Dementia Subtypes: A Cross-Sectional Analysis in Dutch Geriatric Outpatients

BACKGROUND

Vitamin D deficiency is associated with all-cause dementia and Alzheimer's disease (AD). At the same time, this knowledge is limited specifically for vascular dementia (VaD), while data regarding other subtypes of dementia are even more limited.

OBJECTIVE

To investigate the association of 25-hydroxy vitamin D (25(OH)D) status with dementia subtypes in an outpatient geriatric population.

METHODS

In a cross-sectional design, we analyzed data from 1,758 patients of an outpatient memory clinic in The Netherlands. Cognitive disorders were diagnosed by a multidisciplinary team according to international clinical standards. At each first-visit 25(OH)D levels were measured. Data were analyzed using ANCOVA in four models with age, gender, BMI, education, alcohol, smoking, season, polypharmacy, calcium, eGFR, and glucose as co-variates. 25(OH)D was treated as a continuous square rooted (sqr) variable.

RESULTS

In the fully adjusted model, reduced 25(OH)D serum levels (sqr) were found in AD (estimated mean 7.77±0.11 CI95% 7.55-7.99): and in VaD (estimated mean 7.60±0.16 CI95% 7.28-7.92) patients compared to no-dementia (ND) patients (estimated mean 8.27±0.09 CI95% 8.10-8.45) (ND-AD: p = 0.006, CI95% 0.08-0.92.; ND-VaD p = 0.004 CI95% 0.13-1.22). We did not find differences in 25(OH)D levels of mild cognitive impairment (MCI) or other dementia patients compared to ND patients, nor differences in comparing dementia subtypes.

CONCLUSION

We observed significantly lower 25(OH)D serum levels in both AD and VaD patients compared to no-dementia patients, but no significant differences between MCI and Lewy body and mixed dementia subtypes in this cross-sectional study of a geriatric outpatient clinic population.

PLIS: A metabolomic response monitor to a lifestyle intervention study in older adults

The response to lifestyle intervention studies is often heterogeneous, especially in older adults. Subtle responses that may represent a health gain for individuals are not always detected by classical health variables, stressing the need for novel biomarkers that detect intermediate changes in metabolic, inflammatory, and immunity-related health. Here, our aim was to develop and validate a molecular multivariate biomarker maximally sensitive to the individual effect of a lifestyle intervention; the Personalized Lifestyle Intervention Status (PLIS). We used ¹ H-NMR fasting blood metabolite measurements from before and after the 13-week combined physical and nutritional Growing Old TOgether (GOTO) lifestyle intervention study in combination with a fivefold cross-validation and a bootstrapping method to train a separate PLIS score for men and women. The PLIS scores consisted of 14 and four metabolites for females and males, respectively. Performance of the PLIS score in tracking health gain was illustrated by association of the sex-specific PLIS scores with several classical metabolic health markers, such as BMI, trunk fat%, fasting HDL cholesterol, and fasting insulin, the primary outcome of the GOTO study. We also showed that the baseline PLIS score indicated which participants respond positively to the intervention. Finally, we explored PLIS in an independent physical activity lifestyle intervention study, showing similar, albeit remarkably weaker, associations of PLIS with classical metabolic health markers. To conclude, we found that the sex-specific PLIS score was able to track the individual short-term metabolic health gain of the GOTO lifestyle intervention study. The methodology used to train the PLIS score potentially provides a useful instrument to track personal responses and predict the participant's health benefit in lifestyle interventions similar to the GOTO study.

Dietary supplements for aggressive behaviour in people with intellectual disabilities: A randomised controlled crossover trial

BACKGROUND

Aggressive incidents are common in people with intellectual disabilities. Therefore, we aimed to assess whether supplementation of multivitamins, minerals, and omega-3 fatty acids (FA) reduces aggressive incidents.

METHODS

We conducted a randomised, triple blind, placebo controlled, single crossover intervention trial. People with intellectual disabilities or borderline intellectual functioning, between 12 and 40 years of age, and showing aggressive behaviour were included. Participants received either a daily dose of dietary supplements, or placebo. Primary outcome was the number of aggressive incidents, measured using the Modified Overt Aggression Scale (MOAS).

RESULTS

there were 113 participants (placebo, n = 56), of whom 24 (placebo, n = 10) participated in the crossover phase of the trial. All 137 trajectories were included in the analyses. There was no significant difference in mean number of aggressive incidents per day between those assigned to supplements and those who received placebo (rate ratio = 0.93: 95% Confidence Interval [CI] = 0.59-1.45).

CONCLUSION

In this pragmatic trial, we did not find significant differences in the outcomes between the supplement and placebo arms. The COVID-19 pandemic started midway through our trial, this may have affected the results.

Effects of multivitamin, mineral and n-3 polyunsaturated fatty acid supplementation on aggression among long-stay psychiatric in-patients: randomised clinical trial

BACKGROUND

Aggression and violent incidents are a major concern in psychiatric in-patient care. Nutritional supplementation has been found to reduce aggressive incidents and rule violations in forensic populations and children with behavioural problems.

AIMS

To assess whether multivitamin, mineral and n-3 polyunsaturated fatty acid supplementation would reduce the number of aggressive incidents among long-stay psychiatric in-patients.

METHOD

The trial was a pragmatic, multicentre, randomised, double-blind placebo-controlled study. Data were collected from 25 July 2016 to 29 October 2019, at eight local sites for mental healthcare in The Netherlands and Belgium. Participants were randomised (1:1) to receive 6-month treatment with either three supplements containing multivitamins, minerals and n-3 polyunsaturated fatty acid, or placebo. The primary outcome was the number of aggressive incidents, determined by the Staff Observation Aggression Scale - Revised (SOAS-R). Secondary outcomes were patient quality of life, affective symptoms and adverse events.

RESULTS

In total, 176 participants were randomised (supplements, n = 87; placebo, n = 89). Participants were on average 49.3 years old (s.d. 14.5) and 64.2% were male. Most patients had a psychotic disorder (60.8%). The primary outcome of SOAS-R incidents was similar in supplement (1.03 incidents per month, 95% CI 0.74-1.37) and placebo groups (0.90 incidents per month, 95% CI 0.65-1.19), with a rate ratio of 1.08 (95% CI 0.67-1.74, P = 0.75). Differential effects were not found in sensitivity analyses on the SOAS-R or on secondary outcomes.

CONCLUSIONS

Six months of nutritional supplementation did not reduce aggressive incidents among long-stay psychiatric in-patients.

Personalized nutrition for dementia prevention

The role of nutrition has been investigated for decades under the assumption of one-size-fits-all. Yet there is heterogeneity in metabolic and neurobiological responses to diet. Thus a more personalized approach may better fit biological reality and have increased efficacy to prevent dementia. Personalized nutrition builds on the food exposome, defined as the history of diet-related exposures over the lifetime, and on its interactions with the genome and other biological characteristics (eg, metabolism, the microbiome) to shape health. We review current advances of personalized nutrition in dementia research. We discuss key questions, success milestones, and future roadmap from observational epidemiology to clinical studies through basic science. A personalized nutrition approach based on the best prescription for the most appropriate target population in the most relevant time-window has the potential to strengthen dementia-prevention efforts.

Positive effects of folic acid supplementation on cognitive aging are dependent on ω-3 fatty acid status: a post hoc analysis of the FACIT trial

BACKGROUND

Although epidemiological studies suggest a protective role of B vitamins and omega-3 (ω-3) fatty acids in cognitive decline, findings from intervention studies are conflicting. Mechanistic studies suggest that the ω-3 (n-3) fatty acid status can modulate the effects of B vitamins on cognitive decline.

OBJECTIVES

We investigated the interaction between baseline ω-3 fatty acid statuses and folic acid treatment on cognitive decline in a placebo-controlled trial [FACIT (Folic Acid and Carotid Intima-media Thickness)].

METHODS

This post hoc analysis included 791 older adults aged 50-70 y with plasma total homocysteine ≥13 µmol/L and ≤26 µmol/L and serum vitamin B12 ≥200 pmol/L. Participants received 800 µg folic acid or placebo daily for 3 y. Global cognitive functioning and domain-specific functioning (episodic memory, information processing speed, executive functioning) were assessed at baseline and after 3 y. The effect of the folic acid supplementation was analyzed according to tertiles of baseline ω-3 fatty acid concentrations using linear multiple regression.

RESULTS

The mean ± SD age of the study population was 60.2 ± 5.6 y, and the mean ± SD Mini-Mental State Examination score was 28.6 ± 1.5. The treatment effect of folic acid was significantly larger in participants in the low compared to high ω-3 fatty acid tertile for global cognition (difference in z-score: mean ± SE = 0.16 ± 0.059; P < 0.01). Regarding domain-specific functioning, similar results were observed for information processing speed (mean ± SE = 0.167 ± 0.068; P = 0.01). There were no overall interactions between folic acid treatment and ω-3 fatty acid tertiles for episodic memory (P = 0.14) and executive functioning (P = 0.21).

CONCLUSIONS

This post hoc analysis revealed that the efficacy of folic acid treatment on cognitive functioning is dependent on the ω-3 fatty acid status. Individuals with a lower ω-3 fatty acid status at baseline benefited from folic acid treatment, while individuals with a higher ω-3 fatty acid status did not. The results potentially explain the inconsistency in outcomes of B-vitamin supplementation trials and emphasize the importance of a personalized approach. This trial was registered at clinicaltrials.gov as NCT00110604.

LDL cholesterol and uridine levels in blood are potential nutritional biomarkers for clinical progression in Alzheimer's disease: The NUDAD project

INTRODUCTION

We examined associations between nutritional biomarkers and clinical progression in individuals with subjective cognitive decline (SCD), mild cognitive impairment (MCI), and Alzheimer's disease (AD)-type dementia.

METHODS

We included 528 individuals (64 ± 8 years, 46% F, follow-up 2.1 ± 0.87 years) with SCD (n = 204), MCI (n = 130), and AD (n = 194). Baseline levels of cholesterol, triglycerides, glucose, homocysteine, folate, vitamin A, B12, E and uridine were measured in blood and S-adenosylmethionine and S-adenosylhomocysteine in cerebrospinal fluid. We determined associations between nutritional biomarkers and clinical progression using Cox proportional hazard models.

RESULTS

Twenty-two (11%) patients with SCD, 45 (35%) patients with MCI, and 100 (52%) patients with AD showed clinical progression. In SCD, higher levels of low-density lipoprotein (LDL) cholesterol were associated with progression (hazard ratio [HR] [95% confidence interval (CI)] 1.88 [1.04 to 3.41]). In AD, lower uridine levels were associated with progression (0.79 [0.63 to 0.99]).

DISCUSSION

Our findings suggest that LDL cholesterol and uridine play a-stage-dependent-role in the clinical progression of AD.

Nutritional Status Is Associated With Clinical Progression in Alzheimer's Disease: The NUDAD Project

OBJECTIVE

In cognitively normal adults, nutritional parameters are related to cognitive decline and incidence of dementia. Studies on the role of nutrition in predementia stages subjective cognitive decline and mild cognitive impairment, and mild stages of Alzheimer's disease (AD) dementia in a clinical setting are lacking. In the absence of a curative treatment, this evidence is important for targeting nutritional factors to potentially prevent or delay further cognitive decline. Our aim is to investigate associations of nutritional parameters with clinical progression in patients ranging from those who are cognitively normal to those who have AD dementia.

DESIGN

Longitudinal.

SETTING AND PARTICIPANTS

Memory clinic, 551 patients (219 with subjective cognitive decline, 135 with mild cognitive impairment, and 197 with AD dementia), mean age 64 ± 8 years.

MEASUREMENTS

We assessed body mass index, fat-free mass, Mini-Nutritional Assessment, and dietary intake with the Dutch Healthy Diet food frequency questionnaire and the 238-item healthy life in an urban setting (HELIUS) food frequency questionnaire at baseline. Cox proportional hazard models were used to evaluate associations of nutritional parameters with clinical progression. Additional analyses were restricted to patients who were amyloid positive.

RESULTS

We observed clinical progression in 170 patients (31%) over 2.2 ± 0.9 years. Poorer Mini-Nutritional Assessment score [hazard ratio (95% confidence interval) 1.39 (1.18-1.64)], lower body mass index [1.15 (0.96-1.38)], lower fat-free mass [1.40 (0.93-2.10)], and a less healthy dietary pattern [1.22 (1.01-1.48)] were associated with a higher risk of clinical progression. Similar effect sizes were found in patients who were amyloid positive.

CONCLUSIONS AND IMPLICATIONS

Poorer nutritional status and a less healthy dietary pattern are associated with a higher risk of clinical progression. This study provides support for investigating whether improving nutritional status can alter the clinical trajectory of AD.

Fingerfoods: a feasibility study to enhance fruit and vegetable consumption in Dutch patients with dementia in a nursing home

BACKGROUND

Eating problems are highly prevalent in older patients with dementia and as a consequence, these patients are at greater risk of becoming malnourished. Fingerfoods, snacks that can be picked with thumb and forefinger, could be used to counteract malnutrition in patients with dementia. The aim of this feasibility study was to evaluate whether providing fruit and vegetable rich fingerfoods in the form of recognizable and familiar snacks on top of the normal intake was feasible for both patients with dementia and caregivers as a means to increase patients' nutritional status.

METHODS

Institutionalised patients with dementia (N = 15, 93% female, mean age = 85 years) were included in this feasibility study in the Netherlands. The residents received their regular diet supplemented with fingerfoods, comprising quiches and cakes rich in fruit or vegetables, for 6 weeks. Daily fingerfood consumption together with compensation behaviour at dinner of residents was administered with a checklist and food diaries at the start and end of the intervention as dose delivered. Furthermore, caregivers were asked to fill out a feedback form at the end of the intervention to measure fidelity and appreciation of the intervention.

RESULTS

Patients consumed on average 1.4 pieces (70 g) of fingerfoods daily, containing 41 g of fruit and/or vegetables. Fruit and vegetable consumption increased during the provision of the fingerfoods and the residents seemed not to compensate this intake during the rest of the day. The intervention was generally positively received by the majority of caregivers, depending on the type of fingerfood and state of the resident.

CONCLUSION

This feasibility study showed that providing recognizable fruit and vegetable rich fingerfoods to patients with dementia seems feasible for both patients and caregivers and could provide a pragmatic approach to enhance fruit and vegetable consumption and total food intake in institutionalized elderly. In an up-scaled study, effects of fingerfoods on nutritional status and quality of life should be investigated.

Impact of prolonged sitting and physical activity breaks on cognitive performance, perceivable benefits, and cardiometabolic health in overweight/obese adults: The role of meal composition

BACKGROUND & AIMS

Physical activity (PA) breaks may effectively attenuate the detrimental impact of prolonged sitting on acute cognitive performance, perceivable benefits (e.g. mood), vascular function, and metabolic health. To date, the impact of meal composition on the effects of sedentary behavior and/or PA breaks on health has been scarcely studied. Therefore, our aim was to investigate whether meal composition alters how sedentary behavior and PA breaks affect these acute health outcomes.

METHODS

A total of 24 overweight and obese, sedentary adults completed four conditions in randomized order in a cross-over design: [a] high-protein, low-fat breakfast (HPLF) + 4hrs uninterrupted sitting (SIT), [b] HPLF + 4hrs interrupted sitting (ACT; 5-min cycling every 30 min), [c] Western breakfast (WEST; higher in fats/simple sugars, lower in protein/fiber) + SIT, [d] WEST + ACT. WEST and HPLF were isocaloric. Linear mixed models were used to examine changes in cognitive performance (Test of Attentional Performance), perceivable benefits (Likert-scales, Profile of Mood States questionnaire), vascular health (carotid artery reactivity, blood pressure), and metabolic health (post-breakfast glucose, insulin, lipids).

RESULTS

Independent of meal composition, we did not observe any effect of PA breaks on cognitive performance, vascular health and post-breakfast lipid responses. PA breaks delayed post-breakfast mood and vigor decrements, as well as increases in fatigue and sleepiness (all p < 0.05), but effects were independent of meal composition (p > 0.05). WEST resulted in higher post-breakfast glucose levels compared to HPLF (p < 0.05), while PA breaks did not impact this response (p > 0.05). PA breaks reduced post-breakfast insulin (p < 0.05), which did not differ between meals (p > 0.05).

CONCLUSIONS

The acute impact of PA breaks and/or prolonged sitting on cognitive performance, perceivable benefits, and vascular and metabolic health was not altered by the composition of a single meal in overweight/obese, sedentary adults. Possibly, breaking up prolonged sitting, rather than meal composition, is a more potent strategy to impact acute health outcomes, such as perceivable benefits and insulin levels.

Nutritional status and structural brain changes in Alzheimer's disease: The NUDAD project

INTRODUCTION

Weight loss is associated with higher mortality and progression of cognitive decline, but its associations with magnetic resonance imaging (MRI) changes related to Alzheimer's disease (AD) are unknown.

METHODS

We included 412 patients from the NUDAD project, comprising 129 with AD dementia, 107 with mild cognitive impairment (MCI), and 176 controls. Associations between nutritional status and MRI measures were analyzed using linear regression, adjusted for age, sex, education, cognitive functioning, and cardiovascular risk factors.

RESULTS

Lower body mass index (BMI), fat mass (FM), and fat free mass index were associated with higher medial temporal atrophy (MTA) scores. Lower BMI, FM, and waist circumference were associated with more microbleeds. Stratification by diagnosis showed that the observed associations with microbleeds were only significant in MCI.

DISCUSSION

Lower indicators of nutritional status were associated with more MTA and microbleeds, with largest effect sizes in MCI.

Mapping the multicausality of Alzheimer's disease through group model building

Alzheimer’s disease (AD) is a complex, multicausal disorder involving several spatiotemporal scales and scientific domains. While many studies focus on specific parts of this system, the complexity of AD is rarely studied as a whole. In this work, we apply systems thinking to map out known causal mechanisms and risk factors ranging from intracellular to psychosocial scales in sporadic AD. We report on the first systemic causal loop diagram (CLD) for AD, which is the result of an interdisciplinary group model building (GMB) process. The GMB was based on the input of experts from multiple domains and all proposed mechanisms were supported by scientific literature. The CLD elucidates interaction and feedback mechanisms that contribute to cognitive decline from midlife onward as described by the experts. As an immediate outcome, we observed several non-trivial reinforcing feedback loops involving factors at multiple spatial scales, which are rarely considered within the same theoretical framework. We also observed high centrality for modifiable risk factors such as social relationships and physical activity, which suggests they may be promising leverage points for interventions. This illustrates how a CLD from an interdisciplinary GMB process may lead to novel insights into complex disorders. Furthermore, the CLD is the first step in the development of a computational model for simulating the effects of risk factors on AD.

Lifestyle-Intervention-Induced Reduction of Abdominal Fat Is Reflected by a Decreased Circulating Glycerol Level and an Increased HDL Diameter

Scope

Abdominal obesity is one of the main modifiable risk factors of age‐related cardiometabolic disease. Cardiometabolic disease risk and its associated high abdominal fat mass, cholesterol, and glucose concentrations can be reduced by a healthier lifestyle. Hence, the aim is to understand the relation between lifestyle‐induced changes in body composition, and specifically abdominal fat, and accompanying changes in circulating metabolic biomarkers.

Methods and results

Data from the Growing Old Together (GOTO) study was used, which is a single arm lifestyle intervention in which 164 older adults (mean age 63 years, BMI 23–35 kg/m²) changed their lifestyle during 13 weeks by 12.5% caloric restriction plus 12.5% increase in energy expenditure. It is shown here that levels of circulating metabolic biomarkers, even after adjustment for body mass index, specifically associate with abdominal fat mass. The applied lifestyle intervention mainly reduces abdominal fat mass (−2.6%, SD = 3.0) and this reduction, when adjusted for general weight loss, is highly associated with decreased circulating glycerol concentrations and increased HDL diameter.

Conclusion

The lifestyle‐induced reduction of abdominal fat mass is particularly associated, independent of body mass index or general weight loss, with decreased circulating glycerol concentrations and increased HDL diameter.

Alcohol Consumption, Drinking Patterns, and Cognitive Performance in Young Adults: A Cross-Sectional and Longitudinal Analysis

Long-term alcohol abuse is associated with poorer cognitive performance. However, the associations between light and moderate drinking and cognitive performance are less clear. We assessed this association via cross-sectional and longitudinal analyses in a sample of 702 Dutch students. At baseline, alcohol consumption was assessed using questionnaires and ecological momentary assessment (EMA) across four weeks (‘Wave 1’). Subsequently, cognitive performance, including memory, planning, and reasoning, was assessed at home using six standard cognition tests presented through an online platform. A year later, 436 students completed the four weeks of EMA and online cognitive testing (‘Wave 2’). In both waves, there was no association between alcohol consumption and cognitive performance. Further, alcohol consumption during Wave 1 was not related to cognitive performance at Wave 2. In addition, EMA-data-based drinking patterns, which varied widely between persons but were relatively consistent over time within persons, were also not associated with cognitive performance. Post-hoc analyses of cognitive performance revealed higher within-person variance scores (from Wave 1 to Wave 2) than between-person variance scores (both Wave 1 and Wave 2). In conclusion, no association was observed between alcohol consumption and cognitive performance in a large Dutch student sample. However, the online cognitive tests performed at home may not have been sensitive enough to pick up differences in cognitive performance associated with alcohol consumption.

Effects of glucose and sucrose on mood: a systematic review of interventional studies

Context

Glucose is the main energy source for the brain, and as such, manipulation of glucose supply may affect brain function. It has been suggested that a change in blood glucose may influence mood.

Objective

The aim of this review was to investigate the potential effects of glucose and sucrose, compared with placebo, on mood.

Data Sources

The electronic databases PubMed and Scopus were searched. Reference lists of selected articles were checked manually.

Data Extraction

Randomized controlled trials or crossover trials comparing the effects of glucose or sucrose on mood that were published up to May 2017 were eligible. Potentially eligible articles were selected independently by 2 reviewers.

Results

In total, 19 studies were found. Thirteen studies investigated the effects of glucose consumption compared with placebo on mood. Seven of these 13 studies found no effect of glucose on mood. The other 6 studies found small and partial effects that may also be due to other factors like palatability and expectation. Seven of the 19 studies investigated the effects of sucrose ingestion versus placebo on mood. None of these studies found a positive effect on mood, and 1 study observed an adverse effect. One of the studies investigated the effects of both glucose and sucrose.

Conclusions

The results from this review show limited effects of glucose ingestion on mood and no effect of sucrose on mood.

Quality of Dietary Fat Intake and Body Weight and Obesity in a Mediterranean Population: Secondary Analyses within the PREDIMED Trial

A moderately high-fat Mediterranean diet does not promote weight gain. This study aimed to investigate the association between dietary intake of specific types of fat and obesity and body weight. A prospective cohort study was performed using data of 6942 participants in the PREDIMED trial, with yearly repeated validated food-frequency questionnaires, and anthropometric outcomes (median follow-up: 4.8 years). The effects of replacing dietary fat subtypes for one another, proteins or carbohydrates were estimated using generalized estimating equations substitution models. Replacement of 5% energy from saturated fatty acids (SFA) with monounsaturated fatty acids (MUFA) or polyunsaturated fatty acids (PUFA) resulted in weight changes of -0.38 kg (95% Confidece Iinterval (CI): -0.69, -0.07), and -0.51 kg (95% CI: -0.81, -0.20), respectively. Replacing proteins with MUFA or PUFA decreased the odds of becoming obese. Estimates for the daily substitution of one portion of red meat with white meat, oily fish or white fish showed weight changes up to -0.87 kg. Increasing the intake of unsaturated fatty acids at the expense of SFA, proteins, and carbohydrates showed beneficial effects on body weight and obesity. It may therefore be desirable to encourage high-quality fat diets like the Mediterranean diet instead of restricting total fat intake.

Changes in Dietary Intake and Adherence to the NU-AGE Diet Following a One-Year Dietary Intervention among European Older Adults-Results of the NU-AGE Randomized Trial

BACKGROUND

The Mediterranean Diet has been proposed as an effective strategy to reduce inflammaging, a chronic low grade inflammatory status, and thus, to slow down the aging process. We evaluated whether a Mediterranean-like dietary pattern specifically targeting dietary recommendations of people aged over 65 years (NU-AGE diet) could be effective to shift dietary intake of older adults towards a healthful diet.

METHODS

Adults aged 65⁻80 years across five EU-centers were randomly assigned to a NU-AGE diet group or control group. The diet group followed one year of NU-AGE dietary intervention specifying consumption of 15 food groups plus the use of a vitamin D supplement. Participants in the diet group received counselling and individually tailored dietary advice, food products and a vitamin D supplement. Dietary intake was assessed by means of seven-day food records at baseline and one-year follow-up. A continuous NU-AGE index (0⁻160 points) was developed to assess NU-AGE diet adherence.

RESULTS

In total 1296 participants were randomized and 1141 participants completed the intervention (571 intervention, 570 control). After one year, the diet group improved mean intake of 13 out of 16 NU-AGE dietary components (p < 0.05), with a significant increase in total NU-AGE index (difference in mean change = 21.3 ± 15.9 points, p < 0.01).

CONCLUSIONS

The NU-AGE dietary intervention, based on dietary recommendations for older adults, consisting of individual dietary counselling, free healthy foods and a vitamin D supplement, may be a feasible strategy to improve dietary intake in an aging European population.

High Adiposity Is Associated With Higher Nocturnal and Diurnal Glycaemia, but Not With Glycemic Variability in Older Individuals Without Diabetes

BACKGROUND

It is well known that adiposity is a risk factor for insulin resistance and type 2 diabetes mellitus. In the present study, we aimed to investigate the associations of measures of adiposity with indices of glycemia and of glycemic variability over a 72-h period in non-diabetic older adults.

METHODS

This cross-sectional study was conducted in non-diabetic individuals from the Active and Healthy Aging Study (N = 228), Switchbox (N = 116), and the Growing Old Together Study (N = 94). Body mass index (BMI) and waist circumference were measured, and indices of glycemia and glycemic variability were derived from continuous glucose monitoring (CGM) using the Mini-Med^® CGM system. Associations between adiposity and CGM were studied separately for the three cohorts, and derived estimates were subsequently meta-analyzed.

RESULTS

After meta-analyzing the results from the separate cohorts, individuals with a higher BMI had higher levels of glycemia. Individuals with BMI between 30 and 35 kg/m² had 0.28 mmol/L [95% confidence interval (CI): 0.12-0.44] higher 72 h-mean glucose concentration, 0.26 mmol/L (0.10-0.42) higher diurnal glucose (6:00 a.m. to 0:00 a.m.), and 0.39 mmol/L (0.19; 0.59) higher nocturnal glucose (3:00 a.m. to 6:00 a.m.) than participants with a normal weight (BMI 18.5-25 kg/m²). However, no associations were observed between higher BMI and glycemic variability. Results for glycemia and glycemic variability were similarly observed for a high waist circumference.

CONCLUSION

High adiposity associates with constant higher mean glucose levels over the day in non-diabetic older adults.

Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging

The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults (aged 60–75 years) received a single administration of 100, 150, or 200 mg/kg body weight of tyrosine. For comparison, 17 young adults (aged 18–35 years) received a dose of 150 mg/kg body weight of tyrosine. Tyrosine plasma concentrations were determined before and 90, 120, 150, 180, 210, and 240 min after tyrosine intake. Working memory was assessed using the N-back task at 90 min after tyrosine administration. Older adults showed a dose-dependent increase in plasma tyrosine concentrations (p < 0.001), and the plasma response was higher than for young adults with the same dose (p < 0.001). Load-dependent working memory performance decreased with higher doses of tyrosine (p = 0.048), especially in older adults with greater dose-dependent plasma tyrosine responses (p = 0.035). Our results show an age-related increase in plasma tyrosine response, which was associated with a dose-dependent decline in cognitive functioning in older adults.

Nutrition for the ageing brain: Towards evidence for an optimal diet

As people age they become increasingly susceptible to chronic and extremely debilitating brain diseases. The precise cause of the neuronal degeneration underlying these disorders, and indeed normal brain ageing remains however elusive. Considering the limits of existing preventive methods, there is a desire to develop effective and safe strategies. Growing preclinical and clinical research in healthy individuals or at the early stage of cognitive decline has demonstrated the beneficial impact of nutrition on cognitive functions. The present review is the most recent in a series produced by the Nutrition and Mental Performance Task Force under the auspice of the International Life Sciences Institute Europe (ILSI Europe). The latest scientific advances specific to how dietary nutrients and non-nutrient may affect cognitive ageing are presented. Furthermore, several key points related to mechanisms contributing to brain ageing, pathological conditions affecting brain function, and brain biomarkers are also discussed. Overall, findings are inconsistent and fragmented and more research is warranted to determine the underlying mechanisms and to establish dose-response relationships for optimal brain maintenance in different population subgroups. Such approaches are likely to provide the necessary evidence to develop research portfolios that will inform about new dietary recommendations on how to prevent cognitive decline.

Association of Adherence to a Healthy Diet with Cognitive Decline in European and American Older Adults: A Meta-Analysis within the CHANCES Consortium

AIM

To examine the association between a healthy diet, assessed by the Healthy Diet Indicator (HDI), and cognitive decline in older adults.

METHODS

Data from 21,837 participants aged ≥55 years from 3 cohorts (Survey in Europe on Nutrition and the Elderly, a Concerted Action [SENECA], Rotterdam Study [RS], Nurses' Health Study [NHS]) were analyzed. HDI scores were based on intakes of saturated fatty acids, polyunsaturated fatty acids, mono- and disaccharides, protein, cholesterol, fruits and vegetables, and fiber. The Telephone Interview for Cognitive Status in NHS and Mini-Mental State Examination in RS and SENECA were used to assess cognitive function from multiple repeated measures. Using multivariable-adjusted, mixed linear regression, mean differences in annual rates of cognitive decline by HDI quintiles were estimated.

RESULTS

Multivariable-adjusted differences in rates in the highest versus the lowest HDI quintile were 0.01 (95% CI -0.01, 0.02) in NHS, 0.00 (95% CI -0.02, 0.01) in RS, and 0.00 (95% CI -0.05, 0.05) in SENECA with a pooled estimate of 0.00 (95% CI -0.01, 0.01), I2 = 0%.

CONCLUSIONS

A higher HDI score was not related to reduced rates of cognitive decline in European and American older adults.

The Dietary Approaches to Stop Hypertension Diet, Cognitive Function, and Cognitive Decline in American Older Women

OBJECTIVES

To examine the association between long-term adherence to the Dietary Approaches to Stop Hypertension (DASH) diet with cognitive function and decline in older American women.

DESIGN

Prospective cohort study.

SETTING

The Nurses' Health Study, a cohort of registered nurses residing in 11 US states.

PARTICIPANTS

A total of 16,144 women from the Nurses' Health Study, aged ≥70 years, who underwent cognitive testing a total of 4 times by telephone from 1995 to 2001 (baseline), with multiple dietary assessments between 1984 and the first cognitive examination. DASH adherence for each individual was based on scoring of intakes of 9 nutrient or food components.

MEASUREMENTS

Long-term DASH adherence was calculated as the average DASH adherence score from up to 5 repeated measures of diet. Primary outcomes were cognitive function calculated as the average scores of the 4 repeated measures, as well as cognitive change of the Telephone Interview for Cognitive Status score and composite scores of global cognition and verbal memory.

RESULTS

Greater adherence to long-term DASH score was associated with better average cognitive function, irrespective of apolipoprotein E ε4 allele status [multivariable-adjusted differences in mean z-scores between extreme DASH quintiles = 0.04 (95% confidence interval, CI 0.01-0.07), P trend = .009 for global cognition; 0.04 (95% CI 0.01-0.07), P trend = .002 for verbal memory and 0.16 (95% CI 0.03-0.29), and P trend = .03 for Telephone Interview for Cognitive Status, P interaction >0.24]. These differences were equivalent to being 1 year younger in age. Adherence to the DASH score was not associated with change in cognitive function over 6 years.

CONCLUSIONS

Our findings in the largest cohort on dietary patterns and cognitive function to date indicate that long-term adherence to the DASH diet is important to maintain cognitive function at older ages.

Folate and Vitamin B12-Related Biomarkers in Relation to Brain Volumes

AIM

We investigated cross-sectional associations between circulating homocysteine, folate, biomarkers of vitamin B₁₂ status and brain volumes. We furthermore compared brain volumes of participants who received daily folic acid and vitamin B₁₂ supplementation with participants who did not.

METHODS

Participants of the B-PROOF study (n = 2919) were assigned to 400 µg folic acid and 500 µg vitamin B₁₂, or a placebo. After two years of intervention, T₁-weighted magnetic resonance imaging (MRI) scans were made in a random subsample (n = 218) to obtain grey and white matter volume, and total brain volume (TBV). Plasma homocysteine, serum folate, vitamin B₁₂, holotranscobalamin, and methylmalonic acid concentrations were measured.

RESULTS

Multiple linear regression analyses showed inverse associations between plasma homocysteine with TBV (β = -0.91, 95% CI -1.85-0.03; p = 0.06) and between serum folate and TBV (β = -0.20, 95% CI -0.38, -0.02; p = 0.03). No significant associations were observed for serum vitamin B₁₂ and holotranscobalamin. Fully adjusted ANCOVA models showed that the group that received B-vitamins had a lower TBV (adjusted mean 1064, 95% CI 1058-1069 mL) than the non-supplemented group (1072, 95% CI 1067-1078 mL, p = 0.03).

CONCLUSIONS

Results were contradictory, with higher Hcy levels associated with lower TBV, but also with higher folate levels associated with lower TBV. In addition, the lack of a baseline measurement withholds us from giving recommendations on whether folic acid and vitamin B₁₂ supplementation will be beneficial above and beyond normal dietary intake for brain health.

The effect of standardized food intake on the association between BMI and 1H-NMR metabolites

Multiple studies have shown that levels of ¹H-NMR metabolites are associated with disease and risk factors of disease such as BMI. While most previous investigations have been performed in fasting samples, meta-analysis often includes both cohorts with fasting and non-fasting blood samples. In the present study comprising 153 participants (mean age 63 years; mean BMI 27 kg/m²) we analyzed the effect of a standardized liquid meal (SLM) on metabolite levels and how the SLM influenced the association between metabolites and BMI. We observed that many metabolites, including glycolysis related metabolites, multiple amino acids, LDL diameter, VLDL and HDL lipid concentration changed within 35 minutes after a standardized liquid meal (SLM), similarly for all individuals. Remarkable, however, is that the correlations of metabolite levels with BMI remained highly similar before and after the SLM. Hence, as exemplified with the disease risk factor BMI, our results suggest that the applicability of ¹H-NMR metabolites as disease biomarkers depends on the standardization of the fasting status rather than on the fasting status itself. Future studies are required to investigate the dependency of metabolite biomarkers for other disease risk factors on the fasting status.

Metabolic effects of a 13-weeks lifestyle intervention in older adults: The Growing Old Together Study

For people in their 40s and 50s, lifestyle programs have been shown to improve metabolic health. For older adults, however, it is not clear whether these programs are equally healthy. In the Growing Old Together study, we applied a 13-weeks lifestyle program, with a target of 12.5% caloric restriction and 12.5% increase in energy expenditure through an increase in physical activity, in 164 older adults (mean age=63.2 years; BMI=23-35 kg/m²). Mean weight loss was 4.2% (SE=2.8%) of baseline weight, which is comparable to a previous study in younger adults. Fasting insulin levels, however, showed a much smaller decrease (0.30 mU/L (SE=3.21)) and a more heterogeneous response (range=2.0-29.6 mU/L). Many other parameters of metabolic health, such as blood pressure, and thyroid, glucose and lipid metabolism improved significantly. Many ¹H-NMR metabolites changed in a direction previously associated with a low risk of type 2 diabetes and cardiovascular disease and partially independently of weight loss. In conclusion, 25% reduction in energy balance for 13 weeks induced a metabolic health benefit in older adults, monitored by traditional and novel metabolic markers.

Cortical phase changes measured using 7-T MRI in subjects with subjective cognitive impairment, and their association with cognitive function

Studies have suggested that, in subjects with subjective cognitive impairment (SCI), Alzheimer's disease (AD)-like changes may occur in the brain. Recently, an in vivo study has indicated the potential of ultra-high-field MRI to visualize amyloid-beta (Aβ)-associated changes in the cortex in patients with AD, manifested by a phase shift on T2 *-weighted MRI scans. The main aim of this study was to investigate whether cortical phase shifts on T2 *-weighted images at 7 T in subjects with SCI can be detected, possibly implicating the deposition of Aβ plaques and associated iron. Cognitive tests and T2 *-weighted scans using a 7-T MRI system were performed in 28 patients with AD, 18 subjects with SCI and 27 healthy controls (HCs). Cortical phase shifts were measured. Univariate general linear modeling and linear regression analysis were used to assess the association between diagnosis and cortical phase shift, and between cortical phase shift and the different neuropsychological tests, adjusted for age and gender. The phase shift (mean, 1.19; range, 1.00-1.35) of the entire cortex in AD was higher than in both SCI (mean, 0.85; range, 0.73-0.99; p < 0.001) and HC (mean, 0.94; range, 0.79-1.10; p < 0.001). No AD-like changes, e.g. increased cortical phase shifts, were found in subjects with SCI compared with HCs. In SCI, a significant association was found between memory function (Wechsler Memory Scale, WMS) and cortical phase shift (β = -0.544, p = 0.007). The major finding of this study is that, in subjects with SCI, an increased cortical phase shift measured at high field is associated with a poorer memory performance, although, as a group, subjects with SCI do not show an increased phase shift compared with HCs. This increased cortical phase shift related to memory performance may contribute to the understanding of SCI as it is still unclear whether SCI is a sign of pre-clinical AD. Copyright © 2014 John Wiley & Sons, Ltd.

APOE ε4 and the associations of seafood and long-chain omega-3 fatty acids with cognitive decline

OBJECTIVE

To examine the association between consumption of seafood and long-chain n-3 fatty acids with change in 5 cognitive domains over an average of 4.9 years.

METHODS

From an ongoing longitudinal, community-based epidemiologic study of aging and dementia (the Rush Memory and Aging Project), we included 915 participants (age 81.4 ± 7.2 years, 25% men) who had completed at least one follow-up cognitive assessment and dietary data. Diet was assessed by semiquantitative food frequency questionnaire. Scores for global cognitive function and 5 cognitive domains (episodic, semantic, and working memory, perceptual speed, and visuospatial ability) were assessed using 19 cognitive tests. Mixed models adjusted for multiple risk factors of cognitive change were used to assess the associations.

RESULTS

Consumption of seafood was associated with slower decline in semantic memory (β = 0.024; p = 0.03) and perceptual speed (β = 0.020; p = 0.05) in separate models adjusted for age, sex, education, participation in cognitive activities, physical activity, alcohol consumption, smoking, and total energy intake. In secondary analyses, APOE ε4 carriers demonstrated slower rates of decline in global cognition and in multiple cognitive domains with weekly seafood consumption and with moderate to high long-chain n-3 fatty acid intake from food. These associations were not present in APOE ε4 noncarriers. Higher intake levels of α-linolenic acid were associated with slower global cognitive decline, but also only in APOE ε4 carriers.

CONCLUSIONS

These results suggest protective relations of one meal per week of seafood and long-chain n-3 fatty acids against decline in multiple cognitive domains. The role of APOE ε4 in this association needs further study.

Apolipoprotein E genotype status affects habitual human blood mononuclear cell gene expression and its response to fish oil intervention

SCOPE

People who carry the apolipoprotein E4 (APOE4) single nucleotide polymorphism have an increased risk of cardiovascular disease (CVD). Fish-oil supplementation may help in the prevention of CVD, though interindividual differences in the response to n-3 PUFAs have been observed. We aimed to assess the impact of APOE genotype on peripheral blood mononuclear cell whole genome gene expression at baseline and following a fish-oil intervention.

METHODS AND RESULTS

Participants received 6 months of fish-oil supplementation containing 1800 mg of eicosapentaenoic acid and docosahexaenoic acid per day. APOE genotype and peripheral blood mononuclear cell whole genome gene expression before and after supplementation were measured. We characterized the differences in gene expression profiles in carriers of APOE4 (N = 8) compared to noncarriers (N = 15). At baseline, 1320 genes were differentially expressed and the fish-oil supplementation differentially regulated 866 genes between APOE4 carriers and noncarriers. Gene set enrichment analysis showed that carriers had a higher gene expression of cholesterol biosynthesis and IFN signaling pathways. Fish-oil supplementation reduced expression of IFN-related genes in carriers only.

CONCLUSION

The increased expression of IFN signaling and cholesterol biosynthesis pathways might explain part of the association between APOE4 and CVD. Fish-oil supplementation may particularly benefit APOE4 carriers by decreasing expression of IFN-related genes.

Association of Seafood Consumption, Brain Mercury Level, and APOE ε4 Status With Brain Neuropathology in Older Adults

IMPORTANCE

Seafood consumption is promoted for its many health benefits even though its contamination by mercury, a known neurotoxin, is a growing concern.

OBJECTIVE

To determine whether seafood consumption is correlated with increased brain mercury levels and also whether seafood consumption or brain mercury levels are correlated with brain neuropathologies.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analyses of deceased participants in the Memory and Aging Project clinical neuropathological cohort study, 2004-2013. Participants resided in Chicago retirement communities and subsidized housing. The study included 286 autopsied brains of 554 deceased participants (51.6%). The mean (SD) age at death was 89.9 (6.1) years, 67% (193) were women, and the mean (SD) educational attainment was 14.6 (2.7) years.

EXPOSURES

Seafood intake was first measured by a food frequency questionnaire at a mean of 4.5 years before death.

MAIN OUTCOMES AND MEASURES

Dementia-related pathologies assessed were Alzheimer disease, Lewy bodies, and the number of macroinfarcts and microinfarcts. Dietary consumption of seafood and n-3 fatty acids was annually assessed by a food frequency questionnaire in the years before death. Tissue concentrations of mercury and selenium were measured using instrumental neutron activation analyses.

RESULTS

Among the 286 autopsied brains of 544 participants, brain mercury levels were positively correlated with the number of seafood meals consumed per week (ρ = 0.16; P = .02). In models adjusted for age, sex, education, and total energy intake, seafood consumption (≥ 1 meal[s]/week) was significantly correlated with less Alzheimer disease pathology including lower density of neuritic plaques (β = -0.69 score units [95% CI, -1.34 to -0.04]), less severe and widespread neurofibrillary tangles (β = -0.77 score units [95% CI, -1.52 to -0.02]), and lower neuropathologically defined Alzheimer disease (β = -0.53 score units [95% CI, -0.96 to -0.10]) but only among apolipoprotein E (APOE ε4) carriers. Higher intake levels of α-linolenic acid (18:3 n-3) were correlated with lower odds of cerebral macroinfarctions (odds ratio for tertiles 3 vs 1, 0.51 [95% CI, 0.27 to 0.94]). Fish oil supplementation had no statistically significant correlation with any neuropathologic marker. Higher brain concentrations of mercury were not significantly correlated with increased levels of brain neuropathology.

CONCLUSIONS AND RELEVANCE

In cross-sectional analyses, moderate seafood consumption was correlated with lesser Alzheimer disease neuropathology. Although seafood consumption was also correlated with higher brain levels of mercury, these levels were not correlated with brain neuropathology.

Effects of glucose load on cognitive functions in elderly people

Glucose is the main fuel for the brain, and manipulation of the glucose supply may consequently affect brain function. The present review was conducted to provide an overview of studies that investigated the acute effects of glucose load on memory and other cognitive functions in elderly people. The effects of sucrose on cognition and suggested mechanisms were also explored. A total of twenty studies met the inclusion criteria. In the majority of studies, episodic memory was investigated and a beneficial role for glucose in that specific cognitive domain was suggested. Other cognitive domains, i.e., working memory, semantic memory, visual memory, information-processing speed, attention, executive function, and visual/spatial function, have been studied less frequently and evidence for a beneficial effect of glucose was equivocal. Mechanisms are suggested to be mainly related to the human body's need for glucose as a metabolic substrate for physiological mechanisms in both central and peripheral processes.

Higher Serum 25-Hydroxyvitamin D and Lower Plasma Glucose Are Associated with Larger Gray Matter Volume but Not with White Matter or Total Brain Volume in Dutch Community-Dwelling Older Adults

BACKGROUND

Previous studies have shown beneficial associations between 25-hydroxyvitamin D [25(OH)D] status and cognitive performance, but results are inconclusive. Studies on 25(OH)D status and brain volumetric measures may provide more insight in the potential role of vitamin D in cognitive performance.

OBJECTIVES

The aims of this study were to cross-sectionally investigate the association between vitamin D status and brain tissue volumes in 217 Dutch community-dwelling older adults aged ≥65 y and to examine whether surrogate markers of glucose homeostasis act as modifiers in these associations.

METHODS

Serum 25(OH)D, plasma glucose, and plasma insulin were analyzed, serving as exposure measures. Estimates of total brain volume, gray matter volume, and white matter volume were obtained using MRI, serving as outcome measures. Associations of serum 25(OH)D, plasma glucose, and plasma insulin concentrations with brain tissue volumes were evaluated using multiple linear regression analyses. Potential effect modification by glucose homeostasis in the association between 25(OH)D and brain volumetric measures was examined by stratification and testing for interaction.

RESULTS

After full adjustment, higher serum 25(OH)D concentrations and lower plasma glucose concentrations were associated with larger gray matter volume, [β ± SE: 0.20 ± 0.08 mL (P = 0.02) and -3.26 ± 1.59 mL (P = 0.04), respectively]. There were no associations between serum 25(OH)D and plasma insulin concentrations with total brain volume and white matter volume. Furthermore, there was no evidence for a mediation or modification effect of plasma glucose on the associations between serum 25(OH)D and brain tissue volumes.

CONCLUSION

Higher serum 25(OH)D and lower plasma glucose are associated with larger gray matter volume, but not white matter or total brain volume, in a population of Dutch adults aged ≥65 y. This trial was registered at clinicaltrials.gov as NCT00696514.

Dietary patterns, cognitive decline, and dementia: a systematic review

Nutrition is an important modifiable risk factor that plays a role in the strategy to prevent or delay the onset of dementia. Research on nutritional effects has until now mainly focused on the role of individual nutrients and bioactive components. However, the evidence for combined effects, such as multinutrient approaches, or a healthy dietary pattern, such as the Mediterranean diet, is growing. These approaches incorporate the complexity of the diet and possible interaction and synergy between nutrients. Over the past few years, dietary patterns have increasingly been investigated to better understand the link between diet, cognitive decline, and dementia. In this systematic review we provide an overview of the literature on human studies up to May 2014 that examined the role of dietary patterns (derived both a priori as well as a posteriori) in relation to cognitive decline or dementia. The results suggest that better adherence to a Mediterranean diet is associated with less cognitive decline, dementia, or Alzheimer disease, as shown by 4 of 6 cross-sectional studies, 6 of 12 longitudinal studies, 1 trial, and 3 meta-analyses. Other healthy dietary patterns, derived both a priori (e.g., Healthy Diet Indicator, Healthy Eating Index, and Program National Nutrition Santé guideline score) and a posteriori (e.g., factor analysis, cluster analysis, and reduced rank regression), were shown to be associated with reduced cognitive decline and/or a reduced risk of dementia as shown by all 6 cross-sectional studies and 6 of 8 longitudinal studies. More conclusive evidence is needed to reach more targeted and detailed guidelines to prevent or postpone cognitive decline.

Results of 2-year vitamin B treatment on cognitive performance: secondary data from an RCT

OBJECTIVE

We investigated the effects of 2-year folic acid and vitamin B12 supplementation on cognitive performance in elderly people with elevated homocysteine (Hcy) levels.

METHODS

This multicenter, double-blind, randomized, placebo-controlled trial included 2,919 elderly participants (65 years and older) with Hcy levels between 12 and 50 µmol/L. Participants received daily either a tablet with 400 µg folic acid and 500 µg vitamin B12 (B-vitamin group) or a placebo tablet. Both tablets contained 15 µg vitamin D3. Data were available for global cognitive functioning assessed by Mini-Mental State Examination (n = 2,556), episodic memory (n = 2,467), attention and working memory (n = 759), information processing speed (n = 731), and executive function (n = 721).

RESULTS

Mean age was 74.1 (SD 6.5) years. Hcy concentrations decreased 5.0 (95% confidence interval -5.3 to -4.7) µmol/L in the B-vitamin group and 1.3 (-1.6 to -0.9) µmol/L in the placebo group. Cognitive domain scores did not differ over time between the 2 groups, as determined by analysis of covariance. Mini-Mental State Examination score decreased with 0.1 (-0.2 to 0.0) in the B-vitamin group and 0.3 (-0.4 to -0.2) in the placebo group (p = 0.05), as determined by an independent t test.

CONCLUSIONS

Two-year folic acid and vitamin B12 supplementation did not beneficially affect performance on 4 cognitive domains in elderly people with elevated Hcy levels. It may slightly slow the rate of decline of global cognition, but the reported small difference may be attributable to chance.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that 2-year supplementation with folic acid and vitamin B12 in hyperhomocysteinemic elderly people does not affect cognitive performance.

Effect of resistance-type exercise training with or without protein supplementation on cognitive functioning in frail and pre-frail elderly: secondary analysis of a randomized, double-blind, placebo-controlled trial

Physical activity has been proposed as one of the most effective strategies to prevent cognitive decline. Protein supplementation may exert an additive effect. The effect of resistance-type exercise training with or without protein supplementation on cognitive functioning in frail and pre-frail elderly people was assessed in a secondary analysis. Two 24-week, double-blind, randomized, placebo-controlled intervention studies were carried out in parallel. Subjects performed a resistance-type exercise program of two sessions per week (n=62) or no exercise program (n=65). In both studies, subjects were randomly allocated to either a protein (2×15 g daily) or a placebo drink. Cognitive functioning was assessed with a neuropsychological test battery focusing on the cognitive domains episodic memory, attention and working memory, information processing speed, and executive functioning. In frail and pre-frail elderly, resistance-type exercise training in combination with protein supplementation improved information processing speed (changes in domain score 0.08±0.51 versus -0.23±0.19 in the non-exercise group, p=0.04). Exercise training without protein supplementation was beneficial for attention and working memory (changes in domain scores 0.35±0.70 versus -0.12±0.69 in the non-exercise group, p=0.02). There were no significant differences among the intervention groups on the other cognitive tests or domain scores.

Serum 25-hydroxyvitamin D is associated with cognitive executive function in Dutch prefrail and frail elderly: a cross-sectional study exploring the associations of 25-hydroxyvitamin D with glucose metabolism, cognitive performance and depression

OBJECTIVES

The primary objective was to explore the possible association of serum 25-hydroxyvitamin D (25[OH]D) and vitamin D intake with markers of glucose metabolism, depression, and cognitive performance. In addition, we examined to what extent the associations between vitamin D and cognitive performance were modified or mediated by fasting plasma glucose (FPG) levels.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study using data of 127 frail or prefrail Dutch elderly, aged 65 years or older. Frailty was defined according to the criteria of Fried and colleagues. A participant was classified prefrail when 1 to 2 criteria were met; frailty was classified as the presence of 3 or more criteria.

MEASUREMENTS

Associations of 25(OH)D and vitamin D intake with markers of glucose metabolism and domain-specific cognitive performance were examined by multivariable regression analyses. The possible association of vitamin D with depression and global cognitive performance was explored by Poisson regression.

RESULTS

No associations were observed for 25(OH)D with FPG, fasting plasma insulin (FPI), Homeostasis Model Assessment-estimated Insulin Resistance (HOMA-IR), or depression. In contrast, serum 25(OH)D was positively associated with executive functioning (β 0.007, P = .01) and tended to be associated with information-processing speed (β 0.006, P = .06). FPG did not modify or mediate these associations. Vitamin D intake was not associated with cognitive performance, glucose metabolism, or depression.

CONCLUSION

This cross-sectional study suggests an association of serum 25(OH)D with domain-specific cognitive performance, in particular executive functioning and possibly information-processing speed, but not with FPG, FPI, HOMA-IR, or depression. Whether these associations are causal is yet to be demonstrated.

Probiotics Lactobacillus reuteri DSM 17938 and Lactobacillus casei CRL 431 modestly increase growth, but not iron and zinc status, among Indonesian children aged 1-6 years

Probiotics and milk calcium may increase resistance to intestinal infection, but their effect on growth and iron and zinc status of Indonesian children is uncertain. We investigated the hypotheses that cow milk with added probiotics would improve growth and iron and zinc status of Indonesian children, whereas milk calcium alone would improve growth but reduce iron and zinc status. A 6-mo randomized trial was conducted in low-socioeconomic urban communities of Jakarta. Healthy children (n = 494) were randomly assigned to receive low-lactose milk with a low calcium content of ∼50 mg/d (LC; n = 124), a regular calcium content of ∼440 mg/d (RC group; n = 126), regular calcium with 5 × 10(8) CFU/d Lactobacillus casei CRL 431 (casei; n = 120), or regular calcium with 5 × 10(8) CFU/d Lactobacillus reuteri DSM 17938 (reuteri; n = 124). Growth, anemia, and iron and zinc status were assessed before and after the intervention. Compared with the RC group, the reuteri group had significantly greater weight gain [0.22 (95% CI: 0.02, 0.42) kg], weight-for-age Z-score (WAZ) changes [0.09 (95% CI: 0.01, 0.17)], and monthly weight [0.03 (95% CI: 0.002, 0.05) kg/mo] and height [0.03 (95% CI: 0.01, 0.05) cm/mo] velocities. Casei significantly increased monthly weight velocity [0.03 (95% CI: 0.001, 0.05) kg/mo], but not height. However, the changes in underweight, stunting, anemia prevalence, and iron and zinc status were similar between groups. In conclusion, L. reuteri DSM 17938 modestly improved growth by increasing weight gain, WAZ changes, and weight and height velocity, whereas L. casei CRL 431 modestly improved weight velocity. Independent from probiotics supplementation, regular milk calcium did not affect growth or iron and zinc status.

Protein supplementation improves physical performance in frail elderly people: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

Protein supplementation has been proposed as an effective dietary strategy to increase skeletal muscle mass and improve physical performance in frail elderly people. Our objective was to assess the impact of 24 weeks of dietary protein supplementation on muscle mass, strength, and physical performance in frail elderly people.

DESIGN/SETTING/PARTICIPANTS

A total of 65 frail elderly subjects were included and randomly allocated to either daily protein or placebo supplementation (15 g protein at breakfast and lunch).

MEASUREMENTS

Skeletal muscle mass (DXA), muscle fiber size (muscle biopsy), strength (1-RM), and physical performance (SPPB) were assessed at baseline, and after 12 and 24 weeks of dietary intervention.

RESULTS

Skeletal muscle mass did not change in the protein- (from 45.8 ± 1.7 to 45.8 ± 1.7 kg) or placebo-supplemented group (from 46.7 ± 1.7 to 46.6 ± 1.7 kg) following 24 weeks of intervention (P > .05). In accordance, type I and II muscle fiber size did not change over time (P > .05). Muscle strength increased significantly in both groups (P < .01), with leg extension strength tending to increase to a greater extent in the protein (57 ± 5 to 68 ± 5 kg) compared with the placebo group (57 ± 5 to 63 ± 5 kg) (treatment × time interaction effect: P = .059). Physical performance improved significantly from 8.9 ± 0.6 to 10.0 ± 0.6 points in the protein group and did not change in the placebo group (from 7.8 ± 0.6 to 7.9 ± 0.6 points) (treatment × time interaction effect: P = .02).

CONCLUSION

Dietary protein supplementation improves physical performance, but does not increase skeletal muscle mass in frail elderly people.

Protein supplementation increases muscle mass gain during prolonged resistance-type exercise training in frail elderly people: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

Protein supplementation has been proposed as an effective dietary strategy to augment the skeletal muscle adaptive response to prolonged resistance-type exercise training in elderly people. Our objective was to assess the impact of protein supplementation on muscle mass, strength, and physical performance during prolonged resistance-type exercise training in frail elderly men and women.

DESIGN/SETTING/PARTICIPANTS

A randomized, double-blind, placebo-controlled trial with 2 arms in parallel among 62 frail elderly subjects (78 ± 1 year). These elderly subjects participated in a progressive resistance-type exercise training program (2 sessions per week for 24 weeks) during which they were supplemented twice daily with either protein (2 * 15 g) or a placebo.

MEASUREMENTS

Lean body mass (DXA), strength (1-RM), and physical performance (SPPB) were assessed at baseline, and after 12 and 24 weeks of intervention.

RESULTS

Lean body mass increased from 47.2 kg (95% CI, 43.5-50.9) to 48.5 kg (95% CI, 44.8-52.1) in the protein group and did not change in the placebo group (from 45.7 kg, 95% CI, 42.1-49.2 to 45.4 kg, 95% CI, 41.8-48.9) following the intervention (P value for treatment × time interaction = .006). Strength and physical performance improved significantly in both groups (P = .000) with no interaction effect of dietary protein supplementation.

CONCLUSIONS

Prolonged resistance-type exercise training represents an effective strategy to improve strength and physical performance in frail elderly people. Dietary protein supplementation is required to allow muscle mass gain during exercise training in frail elderly people.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01110369.