Vitamin B and One-Carbon Metabolite Profiles Show Divergent Associations with Cardiometabolic Risk Markers but not Cognitive Function in Older New Zealand Adults: A Secondary Analysis of the REACH Study.

BACKGROUND: Vitamin B inadequacies and elevated homocysteine status have been associated with impaired cognitive and cardiometabolic health with aging. There is, however, a scarcity of research investigating integrated profiles of one-carbon (1C) metabolites in this context, including metabolites of interconnected folate, methionine, choline oxidation, and transsulfuration pathways. OBJECTIVES: The study aimed to examine associations between vitamins B and 1C metabolites with cardiometabolic health and cognitive function in healthy older adults, including the interactive effects of Apolipoprotein E-ε4 status. METHODS: Three hundred and thirteen healthy participants (65-74 y, 65% female) were analyzed. Vitamins B were estimated according to dietary intake (4-d food records) and biochemical status (serum folate and vitamin B12). Fasting plasma 1C metabolites were quantified by liquid chromatography with tandem mass spectrometry. Measures of cardiometabolic health included biochemical (lipid panel, blood glucose) and anthropometric markers. Cognitive function was assessed by the Computerized Mental Performance Assessment System (COMPASS) and Montreal Cognitive Assessment (MoCA). Associations were analyzed using multivariate linear (COMPASS, cardiometabolic health) and Poisson (MoCA) regression modeling. RESULTS: Over 90% of participants met dietary recommendations for riboflavin and vitamins B6 and B12, but only 78% of males and 67% of females achieved adequate folate intakes. Higher serum folate and plasma betaine and glycine concentrations were associated with favorable cardiometabolic markers, whereas higher plasma choline and homocysteine concentrations were associated with greater cardiometabolic risk based on body mass index and serum lipids concentration values (P< 0.05). Vitamins B and homocysteine were not associated with cognitive performance in this cohort, though higher glycine concentrations were associated with better global cognitive performance (P = 0.017), episodic memory (P = 0.016), and spatial memory (P = 0.027) scores. Apolipoprotein E-ε4 status did not modify the relationship between vitamins B or 1C metabolites with cognitive function in linear regression analyses. CONCLUSIONS: Vitamin B and 1C metabolite profiles showed divergent associations with cardiometabolic risk markers and limited associations with cognitive performance in this cohort of healthy older adults.

Plasma nervonic acid levels were negatively associated with attention levels in community-living older adults in New Zealand.

The global population is aging. Preserving function and independence of our aging population is paramount. A key component to maintaining independence is the preservation of cognitive function. Metabolomics can be used to identify biomarkers of cognition before noticeable deterioration. Our study investigated the plasma metabolome of 332 community-living New Zealanders between 65 and 74 years of age, using gas chromatography-mass spectrometry. Six cognitive domains were assessed. Of the 123 metabolites identified using an in-house mass spectral libraries of standards, nervonic acid had a significant, inverse association with the attention domain (P-value = 1.52E- 4; FDR = 0.019), after adjusting for covariates (apolipoprotein E -ε4 genotype, sex, body fat percentage (standardised by sex), age, education, deprivation index, physical activity, metabolic syndrome, polypharmacy, smoking status, and alcohol intake) and multiple testing. Attention is defined as the ability to concentrate on selected aspects of the environment while ignoring other stimuli. This is the first study to identify nervonic acid as a potential biomarker of attention in older adults. Future research should confirm this association in a longitudinal study.

Relative Validity and Reproducibility of a Semi-Quantitative Food Frequency Questionnaire for Determining Nutrient Intake in Older Adults in New Zealand: The REACH Study.

Dietary intake is an important predictor of health and disease outcomes. This cross-sectional study evaluated the relative validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) for assessing energy and nutrient intake in older adults. Dietary data were collected 2018-2019 in Auckland, New Zealand from a convenience sample of community-dwelling adults (65-74 years, n = 294, 37% male) using a 109-item self-administered FFQ at baseline (FFQ1) and four weeks later to assess reproducibility. FFQ1 was compared to a four-day food record to determine relative validity. Agreement between dietary assessment tools was assessed for both raw and energy-adjusted nutrient intakes using paired t-tests, correlation coefficients, weighted kappa statistic, Bland-Altman plots, and linear regression analysis. Energy adjustments moderately improved the relative validity and reproducibility for most nutrients. For energy and energy-adjusted nutrient intakes, the mean correlation coefficients were 0.38 (validity) and 0.65 (reproducibility); the mean weighted kappa statistics were 0.27 (validity) and 0.51 (reproducibility). A significant slope of bias was present in 54% (validity) and 25% (reproducibility) of Bland-Altman plots. The Researching Eating, Activity, and Cognitive Health (REACH) FFQ has acceptable relative validity and good reproducibility for ranking nutrient intakes in older New Zealand adults, but is less suitable for assessing absolute nutrient intakes.

Dietary patterns and cognitive function in older New Zealand adults: the REACH study.

PURPOSE: The global population is ageing. Evidence show dietary patterns may be associated with cognitive status in older adults. This cross-sectional study investigated associations between dietary patterns and cognitive function in older adults in New Zealand. METHODS: The REACH study (Researching Eating, Activity, and Cognitive Health) included 371 participants (65-74 years, 36% male) living independently in Auckland, New Zealand. Valid and reproducible dietary patterns were derived, using principal component analysis, from dietary data collected by a 109-item validated food frequency questionnaire. Six cognitive domains (global cognition, attention and vigilance, executive function, episodic memory, working memory, and spatial memory) were tested using COMPASS (Computerised Mental Performance Assessment System). Associations between dietary patterns and cognitive scores, adjusted for age, sex, education, physical activity, energy, and Apolipoprotein E-ε4 status were analysed using multiple linear regression analysis. RESULTS: Three dietary patterns explained 18% of dietary intake variation-'Mediterranean style' (comprising: salad vegetables, leafy cruciferous vegetables, other vegetables, avocados and olives, alliums, nuts and seeds, white fish and shellfish, oily fish, and berries); 'Western' (comprising: processed meats, sauces and condiments, cakes, biscuits and puddings, meat pies and chips, and processed fish); and 'Prudent' (comprising: dried legumes, soy-based foods, fresh and frozen legumes, whole grains, and carrots). No associations between any cognitive domain and dietary pattern scores were observed. Global cognitive function was associated with being younger and having a university education. CONCLUSION: In this cohort of community-dwelling, older adults in New Zealand, current dietary patterns were not associated with cognitive function.

Associations between dietary patterns and the metabolic syndrome in older adults in New Zealand: the REACH study.

The metabolic syndrome is common in older adults and may be modified by the diet. The aim of this study was to examine associations between a posteriori dietary patterns and the metabolic syndrome in an older New Zealand population. The REACH study (Researching Eating, Activity, and Cognitive Health) included 366 participants (aged 65-74 years, 36 % male) living independently in Auckland, New Zealand. Dietary data were collected using a 109-item FFQ with demonstrated validity and reproducibility for assessing dietary patterns using principal component analysis. The metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel III. Associations between dietary patterns and the metabolic syndrome, adjusted for age, sex, index of multiple deprivation, physical activity, and energy intake were analysed using logistic regression analysis. Three dietary patterns explained 18 % of dietary intake variation - 'Mediterranean style' (salad/leafy cruciferous/other vegetables, avocados/olives, alliums, nuts/seeds, shellfish and white/oily fish, berries), 'prudent' (dried/fresh/frozen legumes, soya-based foods, whole grains and carrots) and 'Western' (processed meat/fish, sauces/condiments, cakes/biscuits/puddings and meat pies/hot chips). No associations were seen between 'Mediterranean style' (OR = 0·75 (95 % CI 0·53, 1·06), P = 0·11) or 'prudent' (OR = 1·17 (95 % CI 0·83, 1·59), P = 0·35) patterns and the metabolic syndrome after co-variate adjustment. The 'Western' pattern was positively associated with the metabolic syndrome (OR = 1·67 (95 % CI 1·08, 2·63), P = 0·02). There was also a small association between an index of multiple deprivation (OR = 1·04 (95 % CI 1·02, 1·06), P < 0·001) and the metabolic syndrome. This cross-sectional study provides further support for a Western dietary pattern being a risk factor for the metabolic syndrome in an older population.

Relative Validity and Reproducibility of a Food Frequency Questionnaire for Assessing Dietary Patterns and Food Group Intake in Older New Zealand Adults: The Researching Eating, Activity, and Cognitive Health Study.

BACKGROUND: Dietary pattern analysis considers the overall dietary intake and combinations of foods eaten. Valid and reproducible tools for determining dietary patterns are necessary to assess diet-disease relationships. OBJECTIVE: This study evaluated the relative validity and reproducibility of the Researching Eating, Activity, and Cognitive Health (REACH) Study food frequency questionnaire (FFQ) specifically designed to identify dietary patterns in older adults. DESIGN: A subset of participants from the REACH study completed two identical 109-item FFQs 1 month apart (FFQ1 and FFQ2) to assess reproducibility and a 4-day food record between FFQ administrations to assess relative validity. Foods from each dietary assessment tool were assigned to 57 food groups. Principal component analysis was applied to the food group consumption reported in each dietary assessment tool to derive dietary patterns. PARTICIPANTS AND SETTING: Dietary data were collected (2018 and 2019) from a subset of the REACH study (n = 294, 37% men) aged 65 to 74 years, living in Auckland, New Zealand. MAIN OUTCOME MEASURES: Daily intakes of 57 food groups and dietary patterns of older adults participating in REACH living in New Zealand. STATISTICAL ANALYSIS: Agreement of dietary pattern loadings were assessed using Tucker's congruence coefficient. Agreement of dietary pattern scores and food group intakes were assessed using Spearman correlation coefficients (acceptable correlation rho = 0.20 to 0.49), weighted kappa statistic (acceptable statistic κw = 0.20 to 0.60), and Bland-Altman analysis, including mean difference, limits of agreement, plots, and slope of bias. RESULTS: Three similar dietary patterns were identified from each dietary assessment tool: Mediterranean style, Western, and prudent. Congruence coefficients between factor loadings ranged from 0.54 to 0.80. Correlations of dietary pattern scores ranged from 0.47 to 0.59 (reproducibility) and 0.33 to 0.43 (validity) (all P values < 0.001); weighted kappa scores from 0.40 to 0.48 (reproducibility) and 0.27 to 0.37 (validity); limits of agreement from ± 1.79 to ± 2.09 (reproducibility) and ± 2.09 to ± 2.27 (validity); a negative slope of bias was seen in the prudent pattern for reproducibility and validity (P < 0.001). CONCLUSIONS: The REACH FFQ generated dietary patterns with acceptable reproducibility and relative validity and therefore can be used to examine associations between dietary patterns and health outcomes in older New Zealand adults.

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

BACKGROUND: Loss of cognitive function is a significant issue as the world's population ages. Preserving cognitive function maintains independence in older adults bringing major societal and financial benefits. Lifestyle factors such as diet are modifiable risk factors, which may help preserve cognitive function. Most nutrition research aimed at preserving cognitive function and metabolic health has focussed on individual nutrients and foods, not allowing for food combinations and interactions. A dietary pattern approach considers the entire diet including its complexity. Previous research investigating dietary patterns and cognitive function has not always considered relevant covariates such as physical activity and the Apolipoprotein E genotype, which are known to have associations with cognitive function. The aim of the REACH (Researching Eating, Activity and Cognitive Health) study is to investigate associations between dietary patterns, cognitive function and metabolic syndrome, accounting for a range of covariates. METHODS: This cross-sectional study design will recruit older, community-living adults (65-74 years) from Auckland, New Zealand. Dietary data will be collected via a 109-item food frequency questionnaire validated using a 4-day food record. Cognitive function will be assessed using the Montreal Cognitive Assessment (paper based) and the Computerised Mental Performance Assessment System (COMPASS) - a testing suite covering six domains. Additional data will include genetic (Apolipoprotein E ε4) and biochemical markers (fasting glucose, HbA1c, lipids profile), anthropometric measurements (weight, height, waist and hip circumference, body composition using dual X-ray absorptiometry), blood pressure, physical activity (International Physical Activity Questionnaire - short form) and health and demographics (questionnaire). Dietary patterns will be derived by principal component analysis. Associations between cognitive function and dietary patterns will be examined using multiple regression analysis. Covariates and interaction factors will include age, education, socio-economic status, physical activity, Apolipoprotein E ε4 genotype, family history of dementia or cognitive impairment, and lifestyle factors. Differences between participants with and without metabolic syndrome will also be examined. DISCUSSION: This study will bring new knowledge regarding associations between dietary patterns and cognitive function and metabolic health in older adults living in New Zealand. This is important for developing nutrition related recommendations to help older adults maintain cognitive function.