Perspective: Promoting Healthy Aging through Nutrition: A Research Centers Collaborative Network Workshop Report.

Within 20 y, the number of adults in the United States over the age of 65 y is expected to more than double and the number over age 85 y is expected to more than triple. The risk for most chronic diseases and disabilities increases with age, so this demographic shift carries significant implications for the individual, health care providers, and population health. Strategies that delay or prevent the onset of age-related diseases are becoming increasingly important. Although considerable progress has been made in understanding the contribution of nutrition to healthy aging, it has become increasingly apparent that much remains to be learned, especially because the aging process is highly variable. Most federal nutrition programs and nutrition research studies define all adults over age 65 y as "older" and do not account for physiological and metabolic changes that occur throughout older adulthood that influence nutritional needs. Moreover, the older adult population is becoming more racially and ethnically diverse, so cultural preferences and other social determinants of health need to be considered. The Research Centers Collaborative Network sponsored a 1.5-d multidisciplinary workshop that included sessions on dietary patterns in health and disease, timing and targeting interventions, and health disparities and the social context of diet and food choice. The agenda and presentations can be found at https://www.rccn-aging.org/nutrition-2023-rccn-workshop. Here we summarize the workshop's themes and discussions and highlight research gaps that if filled will considerably advance our understanding of the role of nutrition in healthy aging.

Matrix Gla protein and the long-term incidence and progression of coronary artery and aortic calcification in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND AND AIMS: Matrix Gla protein (MGP) is an inhibitor of calcification that requires carboxylation by vitamin K for activity. The inactive form of MGP, dephosphorylated-uncarboxylated matrix Gla protein (dp-ucMGP), has been associated with increased calcification. However, it is not known whether there is a longitudinal relationship between dephosphorylated-uncarboxylated matrix Gla protein levels and coronary and aortic calcification in large population cohorts. METHODS: The Multi-Ethnic Study of Atherosclerosis (MESA) followed participants with serial cardiac computed tomography (CT) measures of vascular calcification. Dp-ucMGP was measured at baseline in a subset of participants who completed baseline and follow-up CTs approximately 10 years later and had available plasma specimens (n = 2663). Linear mixed effects models (LMMs) were used to determine the association of dp-ucMGP with the simultaneous incidence and progression of coronary artery, ascending thoracic aortic, or descending thoracic aortic calcification (CAC, ATAC, DTAC)]. RESULTS: For every one standard deviation (SD, 178 pmol/L) increment in dp-ucMGP, CAC increased by 3.44 ([95% CI = 1.68, 5.21], p < 0.001) Agatston units/year (AU/year), ATAC increased by 0.63 ([95% CI = 0.27, 0.98], p = 0.001) AU/year, and DTAC increased by 8.61 ([95% CI = 4.55, 12.67], p < 0.001) AU/year. The association was stronger for DTAC in those ≥65 years and with diabetes. CONCLUSIONS: We found a positive association of the inactive form of matrix Gla protein, dp-ucMGP, and long-term incidence/progression of CAC, ATAC, and DTAC. Future studies should investigate dp-ucMGP as a calcification regulator and MGP as a possible therapeutic target to slow progression of calcification in the vasculature.

Associations of inflammatory and metabolic biomarkers with incident erosive hand osteoarthritis in the osteoarthritis initiative cohort.

OBJECTIVE: Erosive hand osteoarthritis (eHOA) is a subtype of hand osteoarthritis (OA) that develops in finger joints with pre-existing OA and is differentiated by clinical characteristics (hand pain/disability, inflammation, and erosions) that suggest inflammatory or metabolic processes. METHOD: This was a longitudinal nested case-cohort design among Osteoarthritis Initiative participants who had hand radiographs at baseline and 48-months, and biospecimens collected at baseline. We classified incident radiographic eHOA in individuals with ≥1 joint with Kellgren-Lawrence ≥2 and a central erosion present at 48-months but not at baseline. We used a random representative sample (n = 1282) for comparison. We measured serum biomarkers of inflammation, insulin resistance and dysglycemia, and adipokines using immunoassays and enzymatic colorimetric procedures, blinded to case status. RESULTS: Eighty-six participants developed incident radiographic eHOA. In the multivariate analyses adjusted for age, gender, race, smoking, and body mass index, and after adjustment for multiple analyses, incident radiographic eHOA was associated with elevated levels of interleukin-7 (risk ratio (RR) per SD = 1.30 [95% confidence interval (CI) 1.09, 1.55] p trend 0.01). CONCLUSION: This exploratory study suggests an association of elevated interleukin-7, an inflammatory cytokine, with incident eHOA, while other cytokines or biomarkers of metabolic inflammation were not associated. Interleukin-7 may mediate inflammation and tissue damage in susceptible osteoarthritic finger joints and participate in erosive progression.

Effects of long-term high dose aspartame on body mass, bone strength, femoral geometry, and microbiota composition in a young and aged cohort of male and female mice.

Background: Recent reassessment of the safety of aspartame has prompted increased evaluation of its effect on the health of a range of tissues. The gut microbiome is altered by oral aspartame. One prior study suggested that changes in the microbiome caused by aspartame could influence the strength of bone in young skeletally developing mice. Here we ask how aspartame influences bone in mice of different age and sex. Objective: The objective of this study was to determine the effect of aspartame on the bone strength and gut microbiota of young and aged mice. Methods: Male and female C57Bl/6J mice were untreated or treated with a high dose of aspartame in their drinking water from 1 month of age until 4 (young cohort; n = 80) or 22 months (aged cohort; n = 52). Results: In aged males, mice treated with aspartame had greater body mass, whole bone strength, and femoral geometry relative to untreated. Specifically, in aged males, aspartame led to 9% increase in body mass (p < 0.001), 22% increase in whole bone strength (p = 0.006), and 17% increase in section modulus (p < 0.001) relative to untreated mice. Aged males and females receiving aspartame had a different microbiota than untreated mice and a decreased abundance of Odoribacter. No differences in body mass, whole bone strength, or femoral geometry were associated with aspartame dosing in young males or young or aged females. Conclusions: Aspartame treated aged males had greater whole bone strength and the effect appeared to be explained by greater body mass. Aspartame treatment did not alter whole bone strength in young males or young or aged females despite the aspartame having a similar effect on the microbiota of both aged males and females.

Dietary Intakes of Community-Dwelling Adults in the United States across Older Adulthood: National Health and Nutrition Examination Survey 2015-March 2020.

BACKGROUND: Dietary guidance is set on the basis of age and life stage and defines older adults as ≥60 y. Yet, little is known about if and/or how diet quality differs beyond the age of 60. OBJECTIVE: The objective of this study was to compare the dietary intakes of 60-69 (n = 2079), 70-79 (n = 1181), and 80+ y old (n = 644) noninstitutionalized men and women in the United States using the Healthy Eating Index 2015 (HEI) and the What We Eat in America food categories. METHODS: Data were obtained from National Health and Nutrition Examination Survey 2015-2016 and 2017-March 2020. HEI and component scores were calculated using the population ratio method. Population estimates for dietary intake were calculated as the average reported over 2 separate nonconsecutive 24-h dietary recalls. RESULTS: In men and women, the reported energy intake was lower among the 80+ y olds (kcal/d men-80+: 1884 ± 30, 70-79: 2022 ± 33, 60-69: 2142 ± 39; women-80+: 1523 ± 36; 70-79: 1525 ± 33, 60-69: 1650 ± 25; P-trend < 0.001). Total HEI scores did not differ significantly across the 3 age categories, but the 80+ y olds had significantly lower scores for the green vegetables and beans component than the 60-69 y olds [men-mean (95% confidence interval): 2.0 (1.5, 2.5) compared with 3.4 (2.6, 4.1); women-2.3 (1.8, 2.8) compared with 4.4 (3.7, 5.0)]. In women, the percentage of daily calories from protein was significantly lower in the 80+ y olds than in the 60-69 and 70-79 y olds (12.9% ± 0.6%, compared with 17.0% ± 0.9% and 15.6% ± 0.6%, respectively). Protein intake did not differ significantly among the 3 age groups in men. The 80+ y old men and women reported consuming a significantly higher percentage of calories from snacks and sweets compared with the 60-69 y olds (men-80+: 18.1% ± 0.8%, 60-69: 15.4% ± 0.7%; women-80+: 19.6% ± 0.8%, 60-69: 15.5% ± 0.7%). CONCLUSION: The diet of 80+ y olds differed from that of 60-69 y olds in some key components, including energy, snacks and sweets, protein, and green vegetables. Future research is needed to determine if there are health-related consequences to these differences.

Lack of Consensus Between Measurements of Plasma Phylloquinone by Enzyme-Linked Immunosorbent assays and a Well-Validated High-Performance Liquid Chromatographic Method.

Enzyme-linked i2mmunosorbent assays (ELISAs) that measure circulating phylloquinone have become commercially available, but their validity is uncertain. The objective of this study was to compare plasma phylloquinone concentrations measured using two commercially available ELISAs with concentrations measured using a validated high-performance liquid chromatography (HPLC) assay in 108 samples obtained from participants in a depletion (∼10 mcg phylloquinone/d)-supplementation (∼500 mcg phylloquinone/d) study. The geometric mean of plasma phylloquinone measured with ELISA A was 0.70 nmol/L, 37% lower than that measured with HPLC. The mean of the ELISA B measures was 12.4 nmol/L, >700% higher than the HPLC measures. Plasma phylloquinone measured using HPLC was significantly lower during phylloquinone depletion than supplementation (0.4 ± 0.1 compared with 1.2 ± 0.2 nmol/L; P < 0.001). Neither of the two ELISAs detected any significant difference in plasma phylloquinone concentrations between depletion and supplementation (ELISA A, P = 0.76; ELISA B, P = 0.29). These findings reinforce the need to validate plasma phylloquinone assays as they become available. Curr Dev Nutr 2023;x:xx.

Association of Vitamin K Status with Arterial Calcification and Stiffness in Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort.

Background: Arterial calcification and stiffness are common in people with chronic kidney disease (CKD). Higher vitamin K status has been associated with less arterial calcification and stiffness in CKD in cross-sectional studies. Objectives: To determine the association of vitamin K status with coronary artery calcium (CAC) and arterial stiffness [pulse wave velocity (PWV)] at baseline and over 2-4 follow-up years in adults with mild-to-moderate CKD. Methods: Participants (n = 2722) were drawn from the well-characterized Chronic Renal Insufficiency Cohort. Two vitamin K status biomarkers, plasma phylloquinone and plasma dephospho-uncarboxylated matrix gla protein [(dp)ucMGP], were measured at baseline. CAC and PWV were measured at baseline and over 2-4 y of follow-up. Differences across vitamin K status categories in CAC prevalence, incidence, and progression (defined as ≥100 Agatston units/y increase) and PWV at baseline and over follow-up were evaluated using multivariable-adjusted generalized linear models. Results: CAC prevalence, incidence, and progression did not differ across plasma phylloquinone categories. Moreover, CAC prevalence and incidence did not differ according to plasma (dp)ucMGP concentration. Compared with participants with the highest (dp)ucMGP (≥450 pmol/L), those in the middle category (300-449 pmol/L) had a 49% lower rate of CAC progression (incidence rate ratio: 0.51; 95% CI: 0.33, 0.78). However, CAC progression did not differ between those with the lowest (<300 pmol/L) and those with the highest plasma (dp)ucMGP concentration (incidence rate ratio: 0.82; 95% CI: 0.56, 1.19). Neither vitamin K status biomarker was associated with PWV at baseline or longitudinally. Conclusions: Vitamin K status was not consistently associated with CAC or PWV in adults with mild-to-moderate CKD.

Chow diet in mouse aging studies: nothing regular about it.

Chow diet is used in the majority of rodent studies and, although assumed to be standardized for dietary source and nutritional contents, it varies widely across commercial formulations. Similarly, current approaches to study aging in rodents involve a single-diet formulation across the lifespan and overlook age-specific nutritional requirements, which may have long-term effects on aging processes. Together, these nutrition-based disparities represent major gaps in geroscience research, affecting the interpretation and reproducibility of the studies. This perspective aims to raise awareness on the importance of rodent diet formulation and proposes that geroscientists include detailed descriptions of all experimental diets and feeding protocols. Detailed reporting of diets will enhance rigor and reproducibility of aging rodent studies and lead to more translational outcomes in geroscience research.

Inhibit progression of coronary artery calcification with vitamin K in hemodialysis patients (the iPACK-HD study): a randomized, placebo-controlled multi-center, pilot trial.

BACKGROUND: Vitamin K activates matrix Gla protein (MGP), a key inhibitor of vascular calcification. There is a high prevalence of sub-clinical vitamin K deficiency in patients with end-stage kidney disease. METHODS: A parallel randomized placebo-controlled pilot trial was designed to determine whether 10 mg of phylloquinone thrice weekly versus placebo modifies coronary artery calcification progression over 12 months in patients requiring hemodialysis with a coronary artery calcium score (CAC) ≥30 Agatston Units (ClinicalTrials.gov identifier NCT01528800). The primary outcome was feasibility (recruitment rate, compliance with study medication, study completion and adherence overall to study protocol). CAC score was used to assess calcification at baseline and 12 months. Secondary objectives were to explore the impact of phylloquinone on vitamin K-related biomarkers (phylloquinone, dephospho-uncarboxylated MGP and the Gla-osteocalcin to Glu-osteocalcin ratio) and events of clinical interest. RESULTS: A total of 86 patients with a CAC score ≥30 Agatston Units were randomized to either 10 mg of phylloquinone or a matching placebo three times per week. In all, 69 participants (80%) completed the trial. Recruitment rate (4.4 participants/month) and medication compliance (96%) met pre-defined feasibility criteria of ≥4.17 and ≥90%, respectively. Patients randomized to phylloquinone for 12 months had significantly reduced levels of dephospho-uncarboxylated MGP (86% reduction) and increased levels of phylloquinone and Gla-osteocalcin to Glu-osteocalcin ratio compared with placebo. There was no difference in the absolute or relative progression of coronary artery calcification between groups. CONCLUSION: We demonstrated that phylloquinone treatment improves vitamin K status and that a fully powered randomized trial may be feasible.

Brain vitamin D forms, cognitive decline, and neuropathology in community-dwelling older adults.

INTRODUCTION: Vitamin D purportedly protects against cognitive decline and dementia based on observational data using circulating 25-hydroxyvitamin D (25(OH)D). Little is known about vitamin D in the human brain and the association with dementia or neuropathology. METHODS: Decedents of the Rush Memory and Aging Project (n = 290) had vitamin D concentrations measured in four brain regions. Associations with cognitive and neuropathological outcomes were estimated using linear and logistic regression. RESULTS: The main form of vitamin D in all brain regions measured was 25(OH)D3 . Higher brain 25(OH)D3 concentrations were associated with a 25% to 33% lower odds of dementia or mild cognitive impairment (MCI) at the last visit before death (all P ≤ .031). However, brain 25(OH)D concentrations were not associated with any post-mortem neuropathology outcome studied. DISCUSSION: Higher brain 25(OH)D3 concentrations were associated with better cognitive function prior to death. Additional research is needed to clarify the specific mechanisms underlying this potentially protective relationship.

Association of Dietary Intake of Flavonols With Changes in Global Cognition and Several Cognitive Abilities.

BACKGROUND AND OBJECTIVES: Previous research has examined the association between cognition and flavonoids: bioactives found in foods, known to possess anti-inflammatory and antioxidant properties. We extend this research by investigating associations of dietary intakes of total flavonols and constituents (kaempferol, quercetin, myricetin, and isorhamnetin) on the change in cognitive performance in global cognition, episodic memory, semantic memory, visuospatial ability, perceptual speed, and working memory. METHODS: The study was conducted using 961 participants (aged 60-100 years) of the Rush Memory and Aging Project, a prospective cohort of community-dwelling Chicagoans who were followed for an average of 6.9 years. Diet was assessed using a validated semiquantitative food frequency questionnaire. Cognitive performance was assessed annually with a battery of 19 standardized tests. Flavonol intake was analyzed as a continuous variable using linear mixed-effects models. Cognitive domain scores were regressed on baseline calorie-adjusted flavonol variables. RESULTS: Higher dietary intakes of total flavonols and flavonol constituents were associated with a slower rate of decline in global cognition and multiple cognitive domains. In continuous models adjusted for age, sex, education, APOE ɛ4, late-life cognitive activity, physical activity, and smoking, total flavonol intake was associated with slower decline in global cognition ß estimate = 0.004 (95% CI 0.001-0.006), episodic memory ß = 0.004 (95% CI 0.002-0.006), semantic memory ß = 0.003 (95% CI 0.001-0.007), perceptual speed ß = 0.003 (95% CI 0.001-0.004), and working memory ß = 0.003 (95% CI 0.001-0.005) and marginally associated with visuospatial ability ß = 0.001 (95% CI -0.001 to 0.003). Analyses of individual flavonol constituents demonstrated that intakes of kaempferol and quercetin were associated with slower global cognitive decline (ß = 0.01 [95% CI 0.006-0.02] and ß = 0.004 [95% CI 0.0005-0.007]), respectively. Myricetin and isorhamnetin were not associated with global cognition. DISCUSSION: Results suggest that dietary intakes of total flavonols and several flavonol constituents may be associated with slower decline in global cognition and multiple cognitive abilities with older age.

Nutritional Aspects of Healthy Aging.

Proper nutrition and healthy eating are key determinants of healthy aging. In older age, energy requirements decrease, yet micronutrient requirements stay the same or increase, which make older adults susceptible to nutrient deficiencies. Therefore, it is important to encourage older adults to consume nutrient-dense foods. Many older adults do not maintain proper hydration, so adequate water intake should also be encouraged. Most older adults have multiple chronic diseases that may influence their dietary intake and nutritional needs. However, currently, our understanding of how individual chronic diseases and their associated treatments influence dietary requirements is limited.

Vitamin K Status and Cognitive Function in Adults with Chronic Kidney Disease: The Chronic Renal Insufficiency Cohort.

Vitamin K is linked to cognitive function, but studies in individuals with chronic kidney disease (CKD), who are at risk for vitamin K insufficiency and cognitive impairment, are lacking. The cross-sectional association of vitamin K status biomarkers with cognitive performance was evaluated in ≥55-y-old adults with CKD (N = 714, 49% female, 44% black). A composite score of a cognitive performance test battery, calculated by averaging the z scores of the individual tests, was the primary outcome. Vitamin K status was measured using plasma phylloquinone and dephospho-uncarboxylated matrix Gla protein [(dp)ucMGP]. Participants with low plasma (dp)ucMGP, reflecting higher vitamin K status, had better cognitive performance than those in the two higher (dp)ucMGP categories based on the composite outcome (P = 0.03), whereas it did not significantly differ according to plasma phylloquinone categories (P = 0.08). Neither biomarker was significantly associated with performance on individual tests (all P > 0.05). The importance of vitamin K to cognitive performance in adults with CKD remains to be clarified.

Leveraging Observational Cohorts to Study Diet and Nutrition in Older Adults: Opportunities and Obstacles.

By 2060, the number of adults aged ≥65 y is expected to double, and the ≥85 y segment of the population is expected to triple in the United States. US federal nutrition guidance is based on the premise that healthy diets contribute to delaying the onset and progression of many age-related diseases and disability. Yet, little is known about the dietary intakes or nutritional needs across the older adulthood age span. This review aims to identify community-based cohorts that collected information on dietary intake of adults ≥65 y in the United States. Thirty-two cohorts met all inclusion criteria. We summarized information on the cohorts' design, demographics, and diet assessment. We also identified key gaps in the existing databases that, if filled, could enhance their utility to address certain research questions. This review serves as a valuable inventory of cohorts that can be leveraged to answer key questions about the diet and nutritional needs of the oldest old, who represent the fastest growing segment of the population in the United States.

Association of vitamin K with cognitive decline and neuropathology in community-dwelling older persons.

Higher vitamin K intakes have been associated with better cognitive function, suggestive of a vitamin K mechanistic effect or simply reflective of a healthy diet. To test the hypothesis that brain vitamin K is linked to cognitive decline and dementia, vitamin K concentrations were measured in four brain regions, and their associations with cognitive and neuropathological outcomes were estimated in 325 decedents of the Rush Memory and Aging Project. Menaquinone-4 (MK4) was the main vitamin K form in the brain regions evaluated. Higher brain MK4 concentrations were associated with a 17% to 20% lower odds of dementia or mild cognitive impairment (MCI) (P-value < .014), with a 14% to 16% lower odds of Braak stage ≥IV (P-value < 0.045), with lower Alzheimer's disease global pathology scores and fewer neuronal neurofibrillary tangles (P-value < 0.012). These findings provide new and compelling evidence implicating vitamin K in neuropathology underlying cognitive decline and dementia.

Feeding Practice and Delivery Mode Are Determinants of Vitamin K in the Infant Gut: An Exploratory Analysis.

Background: Infants have low stores of vitamin K at birth. Dietary intake of phylloquinone (PK) differs dramatically by infant feeding practice, but the contribution of microbially produced vitamin K (menaquinones) to infant vitamin K status is not well understood. Objectives: The objective of this study was to investigate determinants of infant fecal vitamin K profiles in mother-infant dyads at 6 wk postpartum. Methods: Fecal and breast milk samples were collected from a subsample of breastfeeding (n = 23) or formula-feeding (n = 23) mother and infant dyads, delivered vaginally (n = 26) or by cesarean section (CS) (n = 20) in the Synergistic Theory and Research on Nutrition and Growth (STRONG) Kids 2 cohort. Vitamin K concentrations in breast milk and feces were analyzed by LC/MS and/or HPLC. Fecal bacterial metagenomes were analyzed to derive taxonomy and vitamin K biosynthetic genes. Multivariate linear modeling was used to assess effects of delivery and feeding modes on infant fecal vitamin K. Results: Breast milk contained 1.3 ± 0.2 ng/mL PK, and formula was reported to contain 52 ng/mL PK. Fecal PK was 38-times higher (P < 0.001) in formula-fed than breastfed infants. Infant fecal menaquinones (MKn) MK6, MK7, MK12, and MK13 were higher (P < 0.001) in formula-fed than breastfed infants, whereas MK8 predominated in breastfed and was 5-times higher than formula-fed infants. Total MKn were greater (P < 0.001) in vaginally delivered than CS infants. Relative abundances of 33 bacterial species were affected by feeding mode, 2 by delivery mode, and 4 by both (P < 0.05). Bacterial gene content of 5/12 vitamin K biosynthetic genes were greater (P < 0.05) in breastfed compared with formula-fed infants, and 1 differed by delivery mode. Conclusions: Feeding practice and delivery mode influence bacterial vitamin K production in the infant gut. High concentrations of unmetabolized PK in feces of formula-fed infants suggests formula PK content exceeds the absorptive capacity of the infant gut.