Consideration of nutrient levels in studies of cognitive decline

Towards consistency in dietary pattern scoring: standardising scoring workflows for healthy dietary patterns using 24-h recall and two variations of a food frequency questionnair

Healthy dietary patterns such as the Mediterranean diet (MeDi), Dietary Approaches to Stop Hypertension (DASH) and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) have been evaluated for their potential association with health outcomes. However, the lack of standardisation in scoring methodologies can hinder reproducibility and meaningful cross-study comparisons. Here we provide a reproducible workflow for generating the MeDi, DASH and MIND dietary pattern scores from frequently used dietary assessment tools including the 24-h recall tool and two variations of FFQ. Subjective aspects of the scoring process are highlighted and have led to a recommended reporting checklist. This checklist enables standardised reporting with sufficient detail to enhance the reproducibility and comparability of their outcomes. In addition to these aims, valuable insights in the strengths and limitations of each assessment tool for scoring the MeDi, DASH and MIND diet can be utilised by researchers and clinicians to determine which dietary assessment tool best meets their needs.

Cognitive functions of patients treated with chemotherapy: A comparative study

OBJECTIVES

Chemobrain is a well-established clinical syndrome that has become an increasing concern because of the growing number of long-term cancer survivors. It refers to the post-chemotherapy related cognitive dysfunction. The aim of this study was to objectively assess the impact of cancer treatment on the cognition of cancer patients.

METHODS

This was a convenience sample comparative study conducted at the Hematology and Oncology Department of Hôtel Dieu de France University Hospital in Beirut, Lebanon. It included cancer patients (G1) aged under 65 years who had already been treated for cancer compared to two control groups. The first control group (G2) consisted of treatment-naïve cancer patients aged under 65, and the second group (G3) was recruited from a pool of healthy controls aged between 40 and 65 years. All participants were asked to complete the part B of the trail making test (TMT) and the digital symbolic substitution test (DSST).

RESULTS

In the bivariate analysis, patients in G1 had significantly higher scores than patients in G2 (P=0.017) and G3 (P<0.001) on the TMT-B. However, patients in G1 only had lower scores on DSST when compared with G3 (P=0.017). In the logistic regression taking different groups two-by-two as the dependent variable, the only significant difference was found in the comparison between G2 and G3 with higher TMT-B scores more in favor of belonging to G2 (OR=0.946; P=0.003).

CONCLUSIONS

Our results suggest that, after controlling for anxiety and depression symptoms, patients treated with chemotherapy have significantly poorer outcomes on the DSST and TMT-B than treatment-naïve cancer patients and healthy controls. However, when taking confounding factors into account, the difference only persisted between patients undergoing chemotherapy and healthy controls. These findings are in favor of a multifactor cognitive impairment in patients with cancer partially related to chemotherapeutic treatment.

Plasma folate levels in relation to cognitive impairment: a community-based cohort of older adults in China

PURPOSE

Lower plasma level of folate has been associated with an increased risk of age-related cognitive impairment. However, studies that examined this relation have yielded mixed results. We aimed to examine the prospective association of plasma folate level with risk of cognitive impairment in a community-based prospective cohort of older adults in China.

METHODS

This study included 615 participants (mean age: 76.3 years) without baseline cognitive impairment from the Rugao Longevity and Ageing Study (RuLAS). We used logistic regression to examine the prospective association between baseline plasma folate and risk of cognitive impairment in the next two years. Fasting blood samples were collected and assayed for plasma folate level at baseline. Cognitive impairment was defined as Hasegawa Dementia Scale (HDS) score ≤ 21.5 points.

RESULTS

During two years' follow-up, 20.7% of the participants developed cognitive impairment. After controlled for age, gender, and plasma homocysteine, a higher level of plasma folate was associated with lower odds of cognitive impairment. The corresponding odds ratio (OR) with 95% confidence interval was 0.41 (0.19-0.89) comparing participants at extreme quintiles of plasma folate (median level 17.2 vs. 6.3 nmol/L). The associations were similar after further adjustment for major demographic and lifestyle factors (OR = 0.42, 0.18-0.98). Moreover, the inverse association was particularly stronger among males (OR = 0.12, 0.03-0.52) but was non-significant among females.

CONCLUSION

Our findings support a potential beneficial role of higher plasma folate levels in cognitive function in older Chinese adults, particularly among males. Future studies with larger sample size and longer follow-up are warranted to confirm these findings and to identify the optimal plasma folate level for cognitive function.

Health economic benefits from optimized meal services to older adults-a literature-based synthesis

Malnutrition among older adults causes health problems and economic costs. Prevention of malnutrition through meal service can reduce such costs. This study estimates potential health economic benefits to be generated through meal service to home-dwelling older adults. The study contains three components: (1) systems analysis describing the relationship between meal service, nutritional status, health risk, and health-related costs, focusing on older adults, (2) a series of literature reviews to quantify the identified elements in each stage-subject combination: (i) meal service impact on nutrition status of older adults, (ii) associations between nutrition status and health risks, (iii) health care resource needs associated with these health risks, and (3) a model synthesis of literature findings to estimate the expected economic benefit of improved health status derived from meal service enrollment, using Denmark as an example. Expected economic benefits in terms of saved direct and indirect health care costs and improved quality-of-life was estimated at an amount of €307 per year per individual enrolled, of which direct health care cost savings constituted €75, while value of improved quality-of-life and reduced mortality constituted the rest. The average health economic benefit from enrolling older adults into meal service is likely to decrease with the number of subscribers. Findings like these are important to take into consideration, when making policy decisions regarding size of the meal service capacity, although it should be noted that the presented estimates are based on a number of assumptions of which some are subject to uncertainty.

Vitamin E Intake Is Associated with Lower Brain Volume in Haptoglobin 1-1 Elderly with Type 2 Diabetes

BACKGROUNDS

The efficacy of vitamin E in prevention of diabetes-related complications differs by Haptoglobin (Hp) genotype.

OBJECTIVE

To examine the role of Hp genotype in the relationship of vitamin E intake with brain volume in cognitively normal elderly patients with type 2 diabetes.

METHODS

Brain volumes for the superior, middle, and inferior frontal gyri and for the middle temporal gyrus were generated from structural T1 MRI in 181 study participants (Hp 1-1: n = 24, Hp 2-1: n = 77, Hp 2-2: n = 80). Daily vitamin E intake was assessed using the Food Frequency Questionnaire. Analyses of covariance, controlling for demographic and cardiovascular variables was used to evaluate whether the association of daily vitamin E intake with brain volume was modified by Hp genotype.

RESULTS

Average age was 70.8 (SD = 4.2) with 40% females, and mean Mini-Mental State Examination score of 28.17 (SD = 1.90). A significant interaction was found between vitamin E intake and Hp genotype in inferior frontal gyrus' volume; p = 0.0108. For every 1 microgram increase in vitamin E intake, the volume of the inferior frontal gyrus decreased by 0.955% for Hp 1-1 (p = 0.0348), increased by 0.429% for Hp 2-1 (p = 0.0457), and by 0.077% for Hp 2-2 (p = 0.6318). There were no significant interactions between vitamin E intake and Hp genotype for the middle (p = 0.6011) and superior (p = 0.2025) frontal gyri or for the middle temporal gyrus (p = 0.503).

CONCLUSIONS

The effect of dietary vitamin E on the brain may differ by Hp genotype. Studies examining the impact of vitamin E on brain-related outcomes should consider Hp genotype.

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.

[n-3 fatty acids and the maintenance of neuronal functions]

The functions of n-3 fatty acids are known to be diverse, and they play roles in cardiovascular and neuronal systems and in lipid metabolism. Docosahexaenoic acid (DHA), which is the most abundant n-3 fatty acid in the brain, is essential for the maintenance of brain functions throughout the human lifespan. Epidemiological studies have demonstrated that reduced n-3 fatty acid intake is closely associated with the onset of mental and neurological diseases such as brain developmental disorders, depression, and Alzheimer's disease. DHA is primarily involved in neurogenesis, synapse formation, neuronal differentiation, neurite outgrowth, maintenance of membrane fluidity, anti-inflammatory action, and antioxidant action. Its mechanism of action include: 1) the effects on ion channels and membrane bound receptors/enzymes achieved by changing membrane fluidity, as a cell membrane constituent, and 2) free DHA molecules, derived from the cell membrane that directly or metabolically, by conversion to protectin D1 and other molecules, indirectly regulates the gene expression and the activity of intracellular proteins. Although future studies are required, the supplementation of n-3 fatty acids such as DHA may suppress the deterioration of brain functions, delay the onset and progression of various mental/neurological diseases, and further improve the outcome of the neuronal diseases.

Meat Intake and the Dose of Vitamin B3 - Nicotinamide: Cause of the Causes of Disease Transitions, Health Divides, and Health Futures?

Meat and vitamin B3 - nicotinamide - intake was high during hunter-gatherer times. Intake then fell and variances increased during and after the Neolithic agricultural revolution. Health, height, and IQ deteriorated. Low dietary doses are buffered by 'welcoming' gut symbionts and tuberculosis that can supply nicotinamide, but this co-evolved homeostatic metagenomic strategy risks dysbioses and impaired resistance to pathogens. Vitamin B3 deficiency may now be common among the poor billions on a low-meat diet. Disease transitions to non-communicable inflammatory disorders (but longer lives) may be driven by positive 'meat transitions'. High doses of nicotinamide lead to reduced regulatory T cells and immune intolerance. Loss of no longer needed symbiotic 'old friends' compounds immunological over-reactivity to cause allergic and auto-immune diseases. Inhibition of nicotinamide adenine dinucleotide consumers and loss of methyl groups or production of toxins may cause cancers, metabolic toxicity, or neurodegeneration. An optimal dosage of vitamin B3 could lead to better health, but such a preventive approach needs more equitable meat distribution. Some people may require personalised doses depending on genetic make-up or, temporarily, when under stress.

The Walnuts and Healthy Aging Study (WAHA): Protocol for a Nutritional Intervention Trial with Walnuts on Brain Aging

Introduction: An unwanted consequence of population aging is the growing number of elderly at risk of neurodegenerative disorders, including dementia and macular degeneration. As nutritional and behavioral changes can delay disease progression, we designed the Walnuts and Healthy Aging (WAHA) study, a two-center, randomized, 2-year clinical trial conducted in free-living, cognitively healthy elderly men and women. Our interest in exploring the role of walnuts in maintaining cognitive and retinal health is based on extensive evidence supporting their cardio-protective and vascular health effects, which are linked to bioactive components, such as n-3 fatty acids and polyphenols. Methods: The primary aim of WAHA is to examine the effects of ingesting walnuts daily for 2 years on cognitive function and retinal health, assessed with a battery of neuropsychological tests and optical coherence tomography, respectively. All participants followed their habitual diet, adding walnuts at 15% of energy (≈30-60 g/day) (walnut group) or abstaining from walnuts (control group). Secondary outcomes include changes in adiposity, blood pressure, and serum and urinary biomarkers in all participants and brain magnetic resonance imaging in a subset. Results: From May 2012 to May 2014, 708 participants (mean age 69 years, 68% women) were randomized. The study ended in May 2016 with a 90% retention rate. Discussion: The results of WAHA might provide high-level evidence of the benefit of regular walnut consumption in delaying the onset of age-related cognitive impairment and retinal pathology. The findings should translate into public health policy and sound recommendations to the general population (ClinicalTrials.gov identifier NCT01634841).

Nutritional strategies to optimise cognitive function in the aging brain

Old age is the greatest risk factor for most neurodegenerative diseases. During recent decades there have been major advances in understanding the biology of aging, and the development of nutritional interventions that delay aging including calorie restriction (CR) and intermittent fasting (IF), and chemicals that influence pathways linking nutrition and aging processes. CR influences brain aging in many animal models and recent findings suggest that dietary interventions can influence brain health and dementia in older humans. The role of individual macronutrients in brain aging also has been studied, with conflicting results about the effects of dietary protein and carbohydrates. A new approach known as the Geometric Framework (GF) has been used to unravel the complex interactions between macronutrients (protein, fat, and carbohydrate) and total energy on outcomes such as aging. These studies have shown that low-protein, high-carbohydrate (LPHC) diets are optimal for lifespan in ad libitum fed animals, while total calories have minimal effect once macronutrients are taken into account. One of the primary purposes of this review is to explore the notion that macronutrients may have a more translational potential than CR and IF in humans, and therefore there is a pressing need to use GF to study the impact of diet on brain aging. Furthermore, given the growing recognition of the role of aging biology in dementia, such studies might provide a new approach for dietary interventions for optimizing brain health and preventing dementia in older people.

Advances in clinical determinants and neurological manifestations of B vitamin deficiency in adults

B vitamin deficiency is a leading cause of neurological impairment and disability throughout the world. Multiple B vitamin deficiencies often coexist, and thus an understanding of the complex relationships between the different biochemical pathways regulated in the brain by these vitamins may facilitate prompter diagnosis and improved treatment. Particular populations at risk for multiple B vitamin deficiencies include the elderly, people with alcoholism, patients with heart failure, patients with recent obesity surgery, and vegetarians/vegans. Recently, new clinical settings that predispose individuals to B vitamin deficiency have been highlighted. Moreover, other data indicate a possible pathogenetic role of subclinical chronic B vitamin deficiency in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. In light of these findings, this review examines the clinical manifestations of B vitamin deficiency and the effect of B vitamin deficiency on the adult nervous system. The interrelationships of multiple B vitamin deficiencies are emphasized, along with the clinical phenotypes related to B vitamin deficiencies. Recent advances in the clinical determinants and diagnostic clues of B vitamin deficiency, as well as the suggested therapies for B vitamin disorders, are described.

Effectiveness of interventions to directly support food and drink intake in people with dementia: systematic review and meta-analysis

BACKGROUND

Eating and drinking difficulties are recognised sources of ill health in people with dementia. In the EDWINA (Eating and Drinking Well IN dementiA) systematic review we aimed to assess effectiveness of interventions to directly improve, maintain or facilitate oral food and drink intake, nutrition and hydration status, in people with cognitive impairment or dementia (across all settings, levels of care and support, types and degrees of dementia). Interventions included oral nutrition supplementation, food modification, dysphagia management, eating assistance and supporting the social element of eating and drinking.

METHODS

We comprehensively searched 13 databases for relevant intervention studies. The review was conducted with service user input in accordance with Cochrane Collaboration's guidelines. We duplicated assessment of inclusion, data extraction, and validity assessment, tabulating data, carrying out random effects meta-analysis and narrative synthesis.

RESULTS

Forty-three controlled interventions were included, disappointingly none were judged at low risk of bias. Oral nutritional supplementation studies suggested small positive short term but unclear long term effects on nutritional status. Food modification or dysphagia management studies were smaller and of low quality, providing little evidence of an improved nutritional status. Eating assistance studies provided inconsistent evidence, but studies with a strong social element around eating/drinking, although small and of low quality provided consistent suggestion of improvements in aspects of quality of life. There were few data to address stakeholders' questions.

CONCLUSIONS

We found no definitive evidence on effectiveness, or lack of effectiveness, of specific interventions but studies were small and short term. People with cognitive impairment and their carers have to tackle eating problems despite this lack of evidence, so promising interventions are listed. The need remains for high quality trials tailored for people with cognitive impairment assessing robust outcomes.

SYSTEMATIC REVIEW REGISTRATION

The systematic review protocol was registered (CRD42014007611) and is published, with the full MEDLINE search strategy, on Prospero.

The Mediterranean Lifestyle as a Non-Pharmacological and Natural Antioxidant for Healthy Aging

Oxidative stress has been suggested to affect age-associated physiological dysfunction. Therefore, it is speculated that antioxidant supplements could have a potential role in preventing age-related diseases and death. Among different dietary habits, the highly antioxidant Mediterranean dietary pattern, which includes high vegetable and fruit intake, consumption of legumes, cereals, and fish, low intake of meat and dairy derivatives, moderate red wine consumption, and use of extra-virgin olive oil, is characterized by other aspects than food, such as conviviality, sensory stimulation, socialization, biodiversity, and seasonality that can reinforce the Mediterranean diet’s (MeD) beneficial effects on wellbeing, quality of life, and healthy aging. The present review aims to discuss available data on the relationship between oxidative stress and aging, biomarkers of oxidative stress status, protective effects of the MeD, and the adoption of the Mediterranean lifestyle as a non-pharmacological and natural tool to cope with oxidative stress damage for a longer life span, and—even more important—healthy aging beyond the biological, psychological, and social challenges that old age entails.

MIND diet slows cognitive decline with aging

INTRODUCTION

The Mediterranean and dash diets have been shown to slow cognitive decline; however, neither diet is specific to the nutrition literature on dementia prevention.

METHODS

We devised the Mediterranean-Dietary Approach to Systolic Hypertension (DASH) diet intervention for neurodegenerative delay (MIND) diet score that specifically captures dietary components shown to be neuroprotective and related it to change in cognition over an average 4.7 years among 960 participants of the Memory and Aging Project.

RESULTS

In adjusted mixed models, the MIND score was positively associated with slower decline in global cognitive score (β = 0.0092; P < .0001) and with each of five cognitive domains. The difference in decline rates for being in the top tertile of MIND diet scores versus the lowest was equivalent to being 7.5 years younger in age.

DISCUSSION

The study findings suggest that the MIND diet substantially slows cognitive decline with age. Replication of these findings in a dietary intervention trial would be required to verify its relevance to brain health.

MIND diet associated with reduced incidence of Alzheimer's disease

INTRODUCTION

In a previous study, higher concordance to the MIND diet, a hybrid Mediterranean-Dietary Approaches to Stop Hypertension diet, was associated with slower cognitive decline. In this study we related these three dietary patterns to incident Alzheimer's disease (AD).

METHODS

We investigated the diet-AD relations in a prospective study of 923 participants, ages 58 to 98 years, followed on average 4.5 years. Diet was assessed by a semiquantitative food frequency questionnaire.

RESULTS

In adjusted proportional hazards models, the second (hazards ratio or HR = 0.65, 95% confidence interval or CI 0.44, 0.98) and highest tertiles (HR = 0.47, 95% CI 0.26, 0.76) of MIND diet scores had lower rates of AD versus tertile 1, whereas only the third tertiles of the DASH (HR = 0.61, 95% CI 0.38, 0.97) and Mediterranean (HR = 0.46, 95% CI 0.26, 0.79) diets were associated with lower AD rates.

DISCUSSION

High adherence to all three diets may reduce AD risk. Moderate adherence to the MIND diet may also decrease AD risk.

MIND diet associated with reduced incidence of Alzheimer's disease

INTRODUCTION

In a previous study, higher concordance to the MIND diet, a hybrid Mediterranean-Dietary Approaches to Stop Hypertension diet, was associated with slower cognitive decline. In this study we related these three dietary patterns to incident Alzheimer's disease (AD).

METHODS

We investigated the diet-AD relations in a prospective study of 923 participants, ages 58 to 98 years, followed on average 4.5 years. Diet was assessed by a semiquantitative food frequency questionnaire.

RESULTS

In adjusted proportional hazards models, the second (hazards ratio or HR = 0.65, 95% confidence interval or CI 0.44, 0.98) and highest tertiles (HR = 0.47, 95% CI 0.26, 0.76) of MIND diet scores had lower rates of AD versus tertile 1, whereas only the third tertiles of the DASH (HR = 0.61, 95% CI 0.38, 0.97) and Mediterranean (HR = 0.46, 95% CI 0.26, 0.79) diets were associated with lower AD rates.

DISCUSSION

High adherence to all three diets may reduce AD risk. Moderate adherence to the MIND diet may also decrease AD risk.