Protein Intake and Functional Integrity in Aging: The Framingham Heart Study Offspring

The relationship between educational attainment, lifestyle, self-rated health, and depressive symptoms among Chinese adults: a longitudinal survey from 2012 to 2020

Education holds significant implications for individual health. This work aims to examine the relationship between educational attainment, lifestyle, self-rated health, and depressive symptoms among Chinese adults. We used China Family Panel Studies data from 2012 to 2020. Multiple linear regression models were used to explore the relationship between educational attainment and self-rated health and depressive symptoms, where multidimensional lifestyle (sleep time, exercise time, overtime time, leisure time, housework time, and protein intake) was the mediator variable of the above relationship, and the causal step method was used to test the mediating effect. Our findings show that educational attainment is associated with higher levels of self-rated health and lower levels of depressive symptoms. More importantly, educational attainment also indirectly affects individuals' self-rated health and depressive symptoms through lifestyle. These findings reveal health interventions to develop education further and improve its quality.

A look inside the gut as a clue to nutritional status

PURPOSE OF REVIEW

Malabsorption and malnutrition are common gastrointestinal manifestations clinicians face, requiring diagnostic workup for effective diagnosis and management of the underlying cause. This review discusses recent advances in diagnostic approaches to malabsorption and maldigestion of macronutrients - lipids, proteins, and carbohydrates. We highlight underrecognized causes, available testing modalities, and ongoing diagnostic unmet needs.

RECENT FINDINGS

Innovations in the diagnostic landscape are enhancing our understanding of malabsorption syndromes. Stool collection and handling is uncomfortable and commonly avoided. The objective quantification of stool lipids, bile acids, and gut enzymes is therefore underused in the diagnosis and management of common disorders such as exocrine pancreatic insufficiency, bile acid diarrhea, protein-losing enteropathy, and more. We review the recent advancements in spot quantification of stool fat and bile acid content, endoscopic imaging techniques such as endocytoscopy, confocal laser endomicroscopy, and optical coherence tomography and the future place in clinical practice.

SUMMARY

Malabsorption and maldigestion represent significant challenges in clinical nutrition and gastroenterology. Through the integration of advanced diagnostic techniques, clinicians will be better equipped to tailor therapy and monitor treatment response, ultimately improving patient health outcomes. This review underscores the critical role of innovative diagnostic tools in accurately detecting and effectively managing gastrointestinal disorders linked to nutritional status.

Adherence to Mediterranean, Dietary Approaches to Stop Hypertension and Healthy Eating Indices are associated with lower risk of disability among Puerto Rican adults from the longitudinal Boston Puerto Rican Health Study

BACKGROUND

Emerging evidence suggests that poor dietary quality is an important risk factor for disability. However, few studies have compared adherence to dietary patterns with disability and none among Puerto Rican adults.

OBJECTIVES

This study was designed to examine relationships between 3 dietary patterns-including Dietary Approaches to Stop Hypertension (DASH), Mediterranean dietary score (MeDS), and Healthy Eating Index (HEI)-2010-and ∼6-y incidence of activities of daily living (ADL) and instrumental activities of daily living (IADL) disability and to assess potential mediation by handgrip strength.

METHODS

Data are from the Boston Puerto Rican Health Study, a longitudinal cohort of Puerto Rican adults aged 45-75 y (N = 1502). Adherence to dietary pattern variables were derived from food frequency questionnaire (FFQ) data averaged at baseline and ∼2 y. Handgrip strength was assessed at baseline. Cox proportional hazards models were used to assess longitudinal associations between DASH, MeDS, and HEI-2010 and incident ∼6-y ADL (and subscales) and IADL disability. Mediation by handgrip strength was also tested.

RESULTS

Participants with higher adherence DASH had lower risk of ADL, ADL mobility, and ADL manual dexterity disabilities (hazards ratio [HR]: 0.96; 95% confidence interval [CI]: 0.91, 0.98; HR: 0.96; 95% CI: 0.92, 0.99; and HR: 0.95; 95% CI: 0.92, 0.98, respectively). Higher adherence to MeDS was associated with lower risk of ADL and ADL mobility disabilities (HR: 0.89; 95% CI: 0.81, 0.98; HR: 0.90; 95% CI: 0.82, 1.00), and higher adherence to HEI with lower risk of ADL manual dexterity (HR: 0.98; 95% CI: 0.97, 0.99) in fully adjusted models. Only DASH tended to be associated with IADL (HR: 0.97; 95% CI: 0.94, 1.00). Baseline handgrip strength was a mediator between HEI and ADL manual dexterity (23.7% of the indirect effect was explained through handgrip strength).

CONCLUSIONS

Higher adherence to a healthy diet pattern may decrease risk of disability and may be an important prevention strategy for ADL and IADL disability associated with aging.

Nutritional importance of animal-sourced foods in a healthy diet

Animal-sourced foods, such as meats, poultry, eggs, milk, and fish are nutrient-dense foods that are rich sources of protein, essential amino acids, and micronutrients that can be challenging to obtain solely through plant-based foods. Animal-sourced protein foods provide crucial nutrients that support the growth and development in children, maintenance of muscle mass and function in adults, gain in muscle mass and strength in exercising individuals, and mitigation of sarcopenia in the elderly. The 2020-2025 Dietary Guidelines for Americans have identified the important role of animal-sourced foods in the diet at every stage of life. Animal-sourced foods are consumed worldwide and contribute to global food security.

Novel dietary strategies to manage sarcopenia

PURPOSE OF REVIEW

Sarcopenia is a wasting disease, mostly age-related in which muscle strength and mass decline, such as physical performance. With aging, both lower dietary protein intake and anabolic resistance lead to sarcopenia. Moreover, aging and sarcopenia display low-grade inflammation, which also worsen muscle condition. In this review, we focused on these two main targets to study dietary strategies.

RECENT FINDINGS

The better understanding in mechanisms involved in sarcopenia helps building combined dietary approaches including physical activity that would slow the disease progression. New approaches include better understanding in the choice of quality proteins, their amount and schedule and the association with antioxidative nutrients.

SUMMARY

First, anabolic resistance can be countered by increasing significantly protein intake. If increasing amount remains insufficient, the evenly delivery protein schedule provides interesting results on muscle strength. Quality of protein is also to consider for decreasing risk for sarcopenia, because varying sources of proteins appears relevant with increasing plant-based proteins ratio. Although new techniques have been developed, as plant-based proteins display a lower availability, we need to ensure an adapted overall amount of proteins. Finally, specific enrichment with leucine from whey protein remains the dietary combined approach most studied and studies on citrulline provide interesting results. As cofactor at the edge between anabolic and antioxidative properties, vitamin D supplementation is to recommend. Antioxidative dietary strategies include both fibers, vitamins, micronutrients and polyphenols from various sources for positive effects on physical performance. The ω 3 -polyunsaturated fatty acids also display positive modifications on body composition. Gut microbiota modifiers, such as prebiotics, are promising pathways to improve muscle mass and function and body composition in sarcopenic patients. Nutritional interventions could be enhanced by combination with physical activity on sarcopenia. In healthy older adults, promoting change in lifestyle to get near a Mediterranean diet could be one of the best options. In sarcopenia adults in which lifestyle changes appears unprobable, specific enrichement potentialized with physical activity will help in the struggle against sarcopenia. Longitudinal data are lacking, which makes it hard to draw strong conclusions. However, the effects of a physical activity combined with a set of nutrition interventions on sarcopenia seems promising.

Dietary protein intake in midlife in relation to healthy aging - results from the prospective Nurses' Health Study cohort

BACKGROUND

Protein intake plays an important role in maintaining the health status of older adults. However, few epidemiologic studies examined midlife protein intake in relation to healthy aging.

OBJECTIVES

The objective of this study was to evaluate the long-term role of dietary protein intake in healthy aging among female participants in the prospective Nurses' Health Study (NHS) cohort.

METHODS

We included 48,762 NHS participants aged <60 y in 1984. Total protein, animal protein, dairy protein (a subset of animal protein), and plant protein were derived from validated food frequency questionnaires. Healthy aging was defined as being free from 11 major chronic diseases, having good mental health, and not having impairments in either cognitive or physical function, as assessed in the 2014 or 2016 NHS participant questionnaires. We used multivariate logistic regression adjusted for lifestyle, demographics, and health status to estimate the odds ratios (ORs) and 95% confidence intervals for protein intake in relation to healthy aging.

RESULTS

A total of 3721 (7.6%) NHS participants met our healthy aging definition. Protein intake was significantly associated with higher odds of healthy aging. The ORs (95% confidence intervals) per 3%-energy increment with healthy aging were 1.05 (1.01, 1.10) for total protein, 1.07 (1.02, 1.11) for animal protein, 1.14 (1.06, 1.23) for dairy protein, and 1.38 (1.24, 1.54) for plant protein. Plant protein was also associated with higher odds of absence of physical function limitations and good mental status. In substitution analyses, we observed significant positive associations for the isocaloric replacement of animal or dairy protein, carbohydrate, or fat with plant protein (ORs for healthy aging: 1.22-1.58 for 3% energy replacement with plant protein).

CONCLUSIONS

Dietary protein intake, especially plant protein, in midlife, is associated with higher odds of healthy aging and with several domains of positive health status in a large cohort of female nurses.

The Association of Tryptophan and Its Metabolites With Incident Hip Fractures, Mortality, and Prevalent Frailty in Older Adults: The Cardiovascular Health Study

Amino acids are the building blocks of proteins, and sufficient protein intake is important for skeletal health. We utilized stored serum from the Cardiovascular Health Study in 1992-1993 to examine the relationship between levels of the essential amino acid tryptophan (trp) and its oxidized and nonoxidized metabolites to risk for incident hip fractures and mortality over 12 years of follow-up. We included 131 persons who sustained a hip fracture during this time period and 131 without a hip fracture over these same 12 years of follow-up; 58% female and 95% White. Weighted multivariable Cox hazards models were used to estimate the hazard ratios (HR) and 95% confidence intervals (CI) of incident hip fracture associated with a one standard deviation (SD) higher trp or its metabolites exposure. Relative risk regression was used to evaluate the cross-sectional association of trp and its metabolites with frailty. Higher serum levels of trp were significantly associated with lower risk of incident hip fractures (HR = 0.75 per SD of trp (95% CI 0.57-0.99) but were not significantly associated with mortality or frailty status by Freid's frailty index. There were no statistically significant associations between any of the oxidized or nonoxidized products of trp with incident hip fractures (p ≥ 0.64), mortality (p ≥ 0.20), or cross-sectional frailty status (p ≥ 0.13) after multiple testing adjustment. Randomized clinical trials examining whether increasing trp intake is beneficial for osteoporosis are needed. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Dairy Food Intake Is Not Associated With Frailty in Adults From the Framingham Heart Study

BACKGROUND

Nutrients, including protein, calcium, and fat may be associated with risk of frailty, yet specific contributions from whole dairy foods rich in these nutrients remain understudied.

OBJECTIVE

To determine associations between dairy intake (milk, yogurt, cheese, total (milk + yogurt + cheese), low-fat and high-fat dairy, and servings per week) and frailty onset and frailty phenotype components.

DESIGN

Prospective cohort study. All dairy intake exposures (servings per week) were assessed via a food frequency questionnaire.

PARTICIPANTS AND SETTING

Participants (aged 33 to 86 years) from the Framingham Offspring Study who were not frail at baseline (1998-2001) completed a food frequency questionnaire and had 1 or 2 follow-up frailty assessments (2005-2008 and 2011-2014) were included.

MAIN OUTCOME MEASURES

Frailty was defined as the presence of ≥3 Fried frailty phenotype components: unintentional weight-loss, exhaustion, slowness (gait speed), weakness (grip strength), and low physical activity. Individuals with zero to two components were considered nonfrail.

STATISTICAL ANALYSES PERFORMED

Repeated measures logistic regression estimated odds ratios and 95% CIs for frailty onset. Logistic (exhaustion and weight loss) and linear regression (gait speed, grip strength, and physical activity) estimated the association between baseline dairy intake and each frailty component at follow-up, adjusting for baseline values for age, sex, energy intake (residual analysis), current smoking, and multivitamin use. Models were further adjusted for health status in a secondary analysis.

RESULTS

Mean baseline age ± SD was 61 ± 9 years (range = 33 to 87 years), and 54% were women. Of 2,550 nonfrail individuals at baseline, 8.8% (2005-2008) and 13.5% (2011-2014) became frail. Higher yogurt intake was associated with decreased odds of frailty (odds ratio 0.96, 95% CI 0.93 to 0.99; P = 0.02). Each additional serving of yogurt (β ± SE) .004 ± .001; P < 0.01) and low-fat dairy (β ± SE) .001 ± .0006; P = 0.04) was associated with significantly faster follow-up gait speed. Dietary intakes of high-fat dairy were associated with increased odds of frailty (odds ratio 1.02, 95% CI 1.00 to 1.04; P = 0.05), but the P value was of borderline significance. No associations were observed for other dairy foods. After adjusting for health status, the associations of high-fat dairy and yogurt with frailty became nonsignificant, although the magnitudes of the associations did not change. The association between yogurt and gait speed decreased in magnitude after adjusting for health status (β ± SE) .002 ± .001; P = 0.01).

CONCLUSIONS

Dietary intakes of yogurt were modestly associated with reduced frailty onset and dietary intakes of high-fat dairy had a borderline association with increased odds of frailty, but other dairy food intakes showed no association in this study of healthy adults. Some dairy food intakes were modestly associated with follow-up gait speed. However, effect sizes were small, and the clinical importance of these associations remains undetermined.

Implementation of weekday time-restricted eating to improve metabolic health in breast cancer survivors with overweight/obesity

OBJECTIVE

This study aimed to evaluate the implementation of telephone-based delivery of weekday-only time-restricted eating (TRE), its preliminary efficacy for metabolic outcomes, and concurrent lifestyle changes.

METHODS

Twenty-two breast cancer survivors aged 60+ years with overweight/obesity completed an 8-week feasibility study of 12 to 8 p.m. weekday-only ad libitum TRE. The intervention was delivered by one registered dietitian call, twice-daily automated text messages asking about eating start and stop times, and three support phone calls. Magnetic resonance imaging, venipuncture, and 3 days of diet records and accelerometry were performed at baseline and after intervention.

RESULTS

Participants had a mean age of 66 (SD 5) years with BMI of 31.8 (4.8) kg/m² . Intervention implementation was successful, including excellent adherence (98%), participant acceptability, and a low symptom profile and cost ($63/participant). There were no significant changes in individual components of metabolic syndrome, lipid profile, or hemoglobin A_1c , despite clinically relevant changes occurring within individual participants. Magnetic resonance imaging-derived hepatic steatosis and thigh myosteatosis did not change. Dietary intake changes included reduced energy (-22%) and protein (-0.2 g/kg). Physical activity and sleep did not change.

CONCLUSIONS

Eight weeks of telephone-delivered weekday TRE is a feasible, acceptable, low-symptom, and low-cost intervention. Future studies may consider a longer intervention length for more consistent metabolic improvements and counseling to enhance protein intake.

Nutrition Strategies Promoting Healthy Aging: From Improvement of Cardiovascular and Brain Health to Prevention of Age-Associated Diseases

BACKGROUND

An increasing number of studies suggest that diet plays an important role in regulating aging processes and modulates the development of the most important age-related diseases.

OBJECTIVE

The aim of this review is to provide an overview of the relationship between nutrition and critical age-associated diseases.

METHODS

A literature review was conducted to survey recent pre-clinical and clinical findings related to the role of nutritional factors in modulation of fundamental cellular and molecular mechanisms of aging and their role in prevention of the genesis of the diseases of aging.

RESULTS

Studies show that the development of cardiovascular and cerebrovascular diseases, neurodegenerative diseases, cognitive impairment and dementia can be slowed down or prevented by certain diets with anti-aging action. The protective effects of diets, at least in part, may be mediated by their beneficial macro- (protein, fat, carbohydrate) and micronutrient (vitamins, minerals) composition.

CONCLUSIONS

Certain diets, such as the Mediterranean diet, may play a significant role in healthy aging by preventing the onset of certain diseases and by improving the aging process itself. This latter can be strengthened by incorporating fasting elements into the diet. As dietary recommendations change with age, this should be taken into consideration as well, when developing a diet tailored to the needs of elderly individuals. Future and ongoing clinical studies on complex anti-aging dietary interventions translating the results of preclinical investigations are expected to lead to novel nutritional guidelines for older adults in the near future.

Sarcopenia and bone health: new acquisitions for a firm liaison

Osteosarcopenia (OS) is a newly defined condition represented by the simultaneous presence of osteopenia/osteoporosis and sarcopenia, the main age-related diseases. The simultaneous coexistence of the two phenotypes derives from the close connection of the main target tissues involved in their pathogenesis: bone and muscle. These two actors constitute the bone-muscle unit, which communicates through a biochemical and mechanical crosstalk which involves multiple factors. Altered pattern of molecular pathways leads to an impairment of both the functionality of the tissue itself and the communication with the complementary tissue, composing the OS pathogenesis. Recent advances in the genetics field have provided the opportunity to delve deeper into the complex biological and molecular mechanisms underlying OS. Unfortunately, there are still many gaps in our understanding of these pathways, but it has proven essential to apply strategies such as exercise and nutritional intervention to counteract OS. New therapeutic strategies that simultaneously target bone and muscle tissue are limited, but recently new targets for the development of dual-action drug therapies have been identified. This narrative review aims to provide an overview of the latest scientific evidence associated with OS, a complex disorder that will pave the way for future research aimed at understanding the bone-muscle-associated pathogenetic mechanisms.

Association of Plant Protein Intake with Change in Physical Performance in Chinese Community-Dwelling Older Adults

(1) Background: Dietary protein intake might be beneficial in optimizing physical performance, yet whether this is dependent on protein source and sex is unclear. We examined the association between dietary protein intake and change in physical performance among Chinese community-dwelling older adults. (2) Methods: This prospective study included older Chinese adults (≥65 years) in Hong Kong. Total, plant and animal protein intakes at baseline were assessed using a food frequency questionnaire. Physical performance at baseline and 4-year follow-up were assessed by the time to complete a 6-m walking test. Adjusted linear regression examined the association between total, plant and animal protein intakes (g/kg of body weight (BW)) and 4-year change in physical performance. (3) Results: 3133 participants (49.8% males) aged 71.8 ± 4.9 years were included. In males, total, plant and animal protein intakes were not associated with a change in physical performance. In females, higher plant protein intake was associated with less decline in physical performance (β 0.723, SE 0.288, p = 0.012). No associations were observed for total animal protein intakes. (4) Conclusion: In Chinese community-dwelling older adults, total and animal protein intakes were not associated with a 4-year change in physical performance. Higher plant protein intake was associated with less decline in physical performance in females.

Animal foods and mobility limitations in community-dwelling young-old adults: longitudinal analysis of the EpiDoC cohort

Background

Nutrition and particularly protein play a role in optimally stimulating muscle protein synthesis and maintaining function. Animal foods are excellent sources of high-quality protein. Therefore, we aimed to determine the association between the consumption of animal foods and mobility limitations in young-old adults.

Methods

The analytic sample was composed of 2860 community-dwelling adults aged 50 and over from a nationally representative longitudinal cohort of Portuguese adults who were followed up to 2.7 years. An animal food intake score was derived from the frequency of consumption of meat, fish, and dairy products. Mobility limitations were defined as the difficulty standing up from a chair, walking, and climbing stairs. To determine the association between animal food intake and mobility limitations mixed effects logistic models were fitted.

Results

Associations between quartiles of animal food intake and mobility limitations (for example, for walking outdoors Quartile 4 v Q1: OR: 0.29; 95%CI: 0.15, 0.56) in unadjusted models were present, but there was no difference in the rate of change of mobility limitations over time in unadjusted models. These associations were no longer present when models were adjusted for sociodemographic, lifestyle and health variables. For example, participants in Q4 of animal food intake were not more or less likely to have difficulty climbing stairs than those in Q1 (OR: 0.95; 95%CI: 0.65, 1.38) nor have a different rate of change over time (OR: 0.86; 95%CI: 0.54, 1.37).

Conclusions

No convincing evidence was found to support an effect of animal foods intake measured at baseline on self-reported mobility limitations over a short period of time.

Association of Dietary Protein Intake and Grip Strength Among Adults Aged 19+ Years: NHANES 2011–2014 Analysis

Background

Research on the role of protein in the diet has evolved beyond a focus on quantity to include the impact of its quality and distribution across meal times in an effort to optimize dietary protein recommendations.

Objective

To determine the association of dietary protein amount, type, and intake pattern with grip strength in adults.

Design

Data from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 for adults 19 + years (N = 9,214) were used with exclusions for pregnant and lactating women. Intakes of dietary total protein (TP), animal protein (AP, including dairy), plant protein (PP), and leucine (Leu) were determined using day 1 24 h dietary recall data after adjusting for the complex sample design of NHANES. Regression analyses were used to assess the association of dietary protein and leucine intake quartiles, and whether consuming &gt; 20 g of dietary protein at one or more meals was related to grip strength with adjustment for age, gender, and ethnicity.

Results

Mean intake of TP among adults aged 19 + years was 83.6 ± 0.5 g/day, and 2/3rd of this was from animal sources (including dairy). Grip strength increased (p &lt; 0.05) with increasing quartiles of TP, AP, PP, and leucine among all adults 19 + years (β = 1.340.19, 1.27 ± 0.19, 0.76 ± 0.20, and 1.33 ± 0.23, respectively), 19–50 years (β = 1.14 ± 0.27, 1.06 ± 0.25, 0.77 ± 0.30, and 1.18 ± 0.27, respectively), and 51 + years (β = 0.95 ± 0.26, 1.08 ± 0.27, and 1.05 ± 0.27, respectively, for TP, AP, and Leu); however, the increase was more pronounced for AP than PP. Grip strength also increased (p &lt; 0.05) with increasing the number of meal occasions containing &gt; 20 g of dietary protein (β = 1.50 ± 0.20, 1.41 ± 0.25, and 0.91 ± 0.37 for 19+, 19–50, and 51 + years, respectively), and significant increases were detected for two meals compared to zero meals.

Conclusion

Dietary protein quantity, quality, and distribution should be considered collectively when looking to optimize protein intake to support muscle strength and function.

Impact of moderate dietary protein restriction on glucose homeostasis in a model of oestrogen deficiency

The need to consume adequate dietary protein to preserve physical function during ageing is well recognized. However, the effect of protein intakes on glucose metabolism is still intensively debated. During age-related oestrogen withdrawal at the time of the menopause, it is known that glucose homeostasis may be impaired but the influence of dietary protein levels in this context is unknown. The aim of the present study is to elucidate the individual and interactive effects of oestrogen deficiency and suboptimal protein intake on glucose homeostasis in a preclinical model involving ovariectomy (OVX) and a 13-week period of a moderately reduced protein intake in 7-month-old ageing rats. To investigate mechanisms of action acting via the pancreas-liver-muscle axis, fasting circulating levels of insulin, glucagon, IGF-1, FGF21 and glycemia were measured. The hepatic lipid infiltration and the protein expression of GLUT4 in the gastrocnemius were analyzed. The gene expression of some hepatokines, myokines and lipid storage/oxidation related transcription factors were quantified in the liver and the gastrocnemius. We show that, regardless of the oestrogen status, moderate dietary protein restriction increases fasting glycaemia without modifying insulinemia, body weight gain and composition. This fasting hyperglycaemia is associated with oestrogen status-specific metabolic alterations in the muscle and liver. In oestrogen-replete (SHAM) rats, GLUT4 was down-regulated in skeletal muscle while in oestrogen-deficient (OVX) rats, hepatic stress-associated hyperglucagonaemia and high serum FGF21 were observed. These findings highlight the importance of meeting dietary protein needs to avoid disturbances in glucose homeostasis in ageing female rats with or without oestrogen withdrawal.

Supplementation of Protein at Breakfast Rather Than at Dinner and Lunch Is Effective on Skeletal Muscle Mass in Older Adults

Background: The effects of different intake patterns of meal protein on muscle mass have not been clarified. We cross-sectionally and longitudinally examined the effect of different timing of protein intake on sarcopenia-related factors in older adults.

Methods: This cross-sectional study 1 included 219 (male, n = 69, female, n = 150) elderly subjects aged ≥65 years. Subjects who consumed more protein at breakfast than at dinner were grouped into the morning group (MG, n = 76; male, n = 26; female, n = 50), and those who consumed more protein at dinner than at breakfast were grouped into the evening group (EG, n = 143; male, n = 43; female, n = 100). In cross-sectional study 2-1 (female, n = 125), the subjects were classified into four groups according to the number of meals with sufficient protein intake. In cross-sectional studies 2-2 (female, n = 125) and 2-3 (female, n = 27), the subjects were classified into eight groups and three groups according to whether they had consumed sufficient protein at three meals; sarcopenia-related factors were compared. The intervention study was a placebo-controlled, double-blind, randomized controlled trial that included 40 elderly women with low daily breakfast protein intake. The subjects were divided into four groups: morning protein and placebo intake groups and evening protein and placebo intake groups. Each group consumed the test food (containing 10 g milk protein) or placebo in the morning or evening for 12 weeks. Blood indices and physical function were assessed before and after the intervention.

Results: Comparing all subjects, MG showed significantly higher handgrip strength than did EG (P < 0.05). The higher ratio of morning protein intake relative to the total protein intake, the better the muscle mass (r = 0.452, P < 0.05) and handgrip strength (r = 0.383, P < 0.05). The intervention study showed an increase in muscle mass with the intake of milk protein in the morning rather than in the evening (P < 0.05).

Conclusions: Protein intake at breakfast might have relatively stronger effects on skeletal muscle mass than at lunch and dinner.

Prolonged nightly fasting and lower-extremity functioning in community-dwelling older adults

It is unknown if time-restricted feeding confers a protective effect on the physical function of older adults. The aim of this study was to assess prolonged nightly fasting in association with performance-based lower-extremity function (LEF) in a large population of community-dwelling older adults. A cross-sectional study was carried out among 1226 individuals ≥64 years from the Seniors-ENRICA-II (Study on Nutrition and Cardiovascular Risk in Spain) cohort. Habitual diet was assessed through a validated diet history. Fasting time was classified into the following categories: ≤9, 10-11 and ≥12 h/d (prolonged nightly fasting). Performance-based LEF was assessed with the Short Physical Performance Battery (SPPB). After adjusting for potential confounders, a longer fasting period was associated with a higher likelihood of impaired LEF (OR for the second and third categories v. ≤ 9 h/d fasting: 2·27 (95 % CI 1·56, 3·33) and 2·70 (95 % CI 1·80, 4·04), respectively; Ptrend < 0·001). Fasting time showed a significant association with the SPPB subtests balance impairment (OR for highest v. shortest fasting time: 2.48; 95 % CI 1·51, 4·08; Ptrend = 0·001) and difficulty to rise from a chair (OR 1·47; 95 % CI 1·05, 2·06; Ptrend = 0·01). The risk associated with ≥12 h fasting among those with the lowest levels of physical activity was three times higher than among those with ≤9 h fasting with the same low level of physical activity. Prolonged nightly fasting was associated with a higher likelihood of impaired LEF, balance impairment, and difficulty to rise from a chair in older adults, especially among those with low levels of physical activity.

The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial

Purpose

To examine the cost effectiveness of dietary advice to increase protein intake on 6-month change in physical functioning among older adults.

Methods

In this multicenter randomized controlled trial, 276 community-dwelling older adults with a habitual protein intake < 1.0 g/kg adjusted body weight (aBW)/d were randomly assigned to either Intervention 1; advice to increase protein intake to ≥ 1.2 g/kg aBW/d (PROT, n = 96), Intervention 2; similar advice and in addition advice to consume protein (en)rich(ed) foods within half an hour after usual physical activity (PROT + TIMING, n = 89), or continue the habitual diet with no advice (CON, n = 91). Primary outcome was 6-month change in 400-m walk time. Secondary outcomes were 6-month change in physical performance, leg extension strength, grip strength, body composition, self-reported mobility limitations and quality of life. We evaluated cost effectiveness from a societal perspective.

Results

Compared to CON, a positive effect on walk time was observed for PROT;  – 12.4 s (95%CI,  – 21.8 to  – 2.9), and for PROT + TIMING;  – 4.9 s (95%CI,  – 14.5 to 4.7). Leg extension strength significantly increased in PROT (+ 32.6 N (95%CI, 10.6–54.5)) and PROT + TIMING (+ 24.3 N (95%CI, 0.2–48.5)) compared to CON. No significant intervention effects were observed for the other secondary outcomes. From a societal perspective, PROT was cost effective compared to CON.

Conclusion

Dietary advice to increase protein intake to ≥ 1.2 g/kg aBW/d improved 400-m walk time and leg strength among older adults with a lower habitual protein intake. From a societal perspective, PROT was considered cost-effective compared to CON. These findings support the need for re-evaluating the protein RDA of 0.8 g/kg BW/d for older adults.

Trial registration

The trial has been registered at ClinicalTrials.gov (NCT03712306). Date of registration: October 2018. Registry name: The (Cost) Effectiveness of Increasing Protein Intake on Physical Functioning in Older Adults. Trial Identifier: NCT03712306.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02675-0.

Low protein intake, physical activity, and physical function in European and North American community-dwelling older adults: a pooled analysis of four longitudinal aging cohorts

BACKGROUND

Dietary protein may slow the decline in muscle mass and function with aging, making it a sensible candidate to prevent or modulate disability progression. At present, studies providing reliable estimates of the association between protein intake and physical function, and its interaction with physical activity (PA), in community-dwelling older adults are lacking.

OBJECTIVES

We investigated the longitudinal relation between protein intake and physical function, and the interaction with PA.

METHODS

We undertook a pooled analysis of individual participant data from cohorts in the PROMISS (PRevention Of Malnutrition In Senior Subjects in the European Union) consortium (the Health Aging and Body Composition Study, Quebec Longitudinal Study on Nutrition and Successful Aging, Longitudinal Aging Study Amsterdam, and Newcastle 85+) in which 5725 community-dwelling older adults were followed up to 8.5 y. The relation between protein intake and walking speed was determined using joint models (linear mixed-effects and Cox proportional hazards models) and the relation with mobility limitation was investigated using multistate models.

RESULTS

Higher protein intake was modestly protective of decline in walking speed in a dose-dependent manner [e.g., protein intake ≥1.2 compared with 0.8 g/kg adjusted body weight (aBW)/d: β = 0.024, 95% CI: 0.009, 0.032 SD/y], with no clear indication of interaction with PA. Participants with protein intake ≥0.8 g/kg aBW/d had also a lower likelihood of incident mobility limitation, which was observed for each level of PA. This association seemed to be dose-dependent for difficulty walking but not for difficulty climbing stairs. No associations between protein intake and other mobility limitations transitions were observed.

CONCLUSIONS

Higher daily protein intake can reduce physical function decline not only in older adults with protein intake below the current RDA of 0.8 g/kg BW/d, but also in those with a protein intake that is already considered sufficient. This dose-dependent association was observed for each level of PA, suggesting no clear synergistic association between protein intake and PA in relation to physical function.

The Effects of Lifestyle and Diet on Gut Microbiota Composition, Inflammation and Muscle Performance in Our Aging Society

Living longer is associated with an increased risk of chronic diseases, including impairments of the musculoskeletal and immune system as well as metabolic disorders and certain cancers, each of which can negatively affect the relationship between host and microbiota up to the occurrence of dysbiosis. On the other hand, lifestyle factors, including regular physical exercise and a healthy diet, can affect skeletal muscle and immune aging positively at all ages. Accordingly, health benefits could partly depend on the effect of such interventions that influence the biodiversity and functionality of intestinal microbiota. In the present review, we first discuss the physiological effects of aging on the gut microbiota, immune system, and skeletal muscle. Secondly, we describe human epidemiological evidence about the associations between physical activity and fitness and the gut microbiota composition in older adults. The third part highlights the relevance and restorative mechanisms of immune protection through physical activity and specific exercise interventions during aging. Fourth, we present important research findings on the effects of exercise and protein as well as other nutrients on skeletal muscle performance in older adults. Finally, we provide nutritional recommendations to prevent malnutrition and support healthy active aging with a focus on gut microbiota. Key nutrition-related concerns include the need for adequate energy and protein intake for preventing low muscle mass and a higher demand for specific nutrients (e.g., dietary fiber, polyphenols and polyunsaturated fatty acids) that can modify the composition, diversity, and metabolic capacity of the gut microbiota, and may thus provide a practical means of enhancing gut and systemic immune function.

Association between dietary protein intake and change in grip strength over time among adults of advanced age: Life and Living in Advanced Age: A Cohort Study in New Zealand (LiLACS NZ)

OBJECTIVE

To determine the association between dietary protein intake and change in grip strength (GS) over time among Māori and non-Māori of advanced age.

METHODS

Protein intake was estimated from 2×24h multiple pass recall (MPR) in 554 participants, and GS was measured yearly over five years. Anthropometric, physical activity and health data were collected.

RESULTS

The median weight-adjusted protein intake was low (for Māori and non-Māori men 1.05 and 0.98g/kg/day; for Māori and non-Māori women 0.87 and 0.91g/kg/day, respectively). There was a general decrease in GS over five years (mean % change of -2.38 ± 15.32 and -4.49 ± 21.92 for Māori and non-Māori women and -5.47 ± 16.09 and -1.81 ± 13.16 for Māori and non-Māori men yearly). Intake of protein was not related to GS at any of the five-year assessment points nor was it related to change over time.

CONCLUSION

Protein intake was low in this cohort of octogenarians and was not protective against loss of GS over five years.

What do Australian adults eat for breakfast? A latent variable mixture modelling approach for understanding combinations of foods at eating occasions

BACKGROUND

The patterning of food intake at eating occasions is a poorly understood, albeit important, step towards achieving a healthy dietary pattern. However, to capture the many permutations of food combinations at eating occasions, novel analytic approaches are required. We applied a latent variable mixture modelling (LVMM) approach to understand how foods are consumed in relation to each other at breakfast.

METHODS

Dietary intake at breakfast (n = 8145 occasions) was assessed via 24-h recall during the 2011-12 Australian National Nutrition and Physical Activity Survey (n = 3545 men and n = 4127 women, ⩾19 y). LVMM was used to determine breakfast food profiles based on 35 food group variables, reflecting compliance with Australian Dietary Guidelines. F and adjusted-chi2 tests assessed differences in timing of consumption and participant characteristics between the breakfast profiles. Regression models, adjusted for covariates, were used to examine associations between breakfast food profiles and objective adiposity measures (BMI and waist circumference).

RESULTS

Five distinct profiles were found. Three were similar for men and women. These were labelled: "Wholegrain cereals and milks" (men: 16%, women: 17%), "Protein-foods" (men and women: 11%) and "Mixed cereals and milks" (men: 33%, women: 37%). Two "Breads and spreads" profiles were also found that were differentiated by their accompanying beverages (men) or type of grain (women). Profiles were found to vary by timing of consumption, participant characteristics and adiposity indicators. For example, the "Protein-foods" profile occurred more frequently on weekends and after 9 am. Men with a "Bread and spreads (plus tea/coffee)" profile were older (P < 0.001) and had lower income and education levels (P < 0.05), when compared to the other profiles. Women with a "Protein-foods" profile were younger (P < 0.001) and less likely to be married (P < 0.01). Both men and women with a "Wholegrain cereals and milks" profile had the most favourable adiposity estimates (P < 0.05).

CONCLUSIONS

We identified five breakfast food profiles in adults that varied by timing of consumption, participant characteristics and adiposity indicators. LVMM was a useful approach for capturing the complexity of food combinations at breakfast. Future research could collect contextual information about eating occasions to understand the complex factors that influence food choices.

Heterogeneous Long-Term Trajectories of Dependency in Older Adults: The PAQUID Cohort, a Population-Based Study over 22 years

BACKGROUND

A critical step toward successful aging is to identify opportunities for prevention of functional decline. Our aim was to describe the heterogeneity in trajectories of dependency preceding death in elders and to identify factors associated with this heterogeneity.

METHODS

The study relied on 3,238 participants of the prospective population-based PAQUID cohort aged 65+ at baseline in 1988. Dependency was defined from an 11-item scale of basic and instrumental activities of daily living (ADL: bathing, dressing, toileting, continence, eating, and transferring; instrumental activities of daily living (IADL): telephoning, shopping, using transport, handling medication, and managing finances) collected over 22 years. Heterogeneous trajectories were estimated using a longitudinal item response theory model including latent classes.

RESULTS

Five distinct profiles of functional dependency were identified over the two last decades of life: persistently high (12%), moderate (26%), persistently low (40%), and accelerated high dependency (15%), and no dependency (8%). Main factors associated with heterogeneity included age at death, sex, education, initial cognition (Mini-Mental State Examination [MMSE] score and dementia), initial disability, and poly-medication.

CONCLUSIONS

In the two last decades of life, more than 9 elders in 10 were characterized as functional decliners. On average, around half of the elders died with no or mild dependency, while 27% live several years with a high level of limitations and would need assistance in activities of daily living, at least for 2-4 years preceding death. The identified factors associated with these trajectories are important to understand functional heterogeneity in elders and to propose interventions to postpone or prevent "chronic" disability.

Trimethylamine But Not Trimethylamine Oxide Increases With Age in Rat Plasma and Affects Smooth Muscle Cells Viability

It has been suggested that trimethylamine oxide (TMAO), a liver oxygenation product of gut bacteria-produced trimethylamine (TMA), is a marker of cardiovascular risk. However, mechanisms of the increase and biological effects of TMAO are obscure. Furthermore, the potential role of TMAO precursor, that is TMA, has not been investigated. We evaluated the effect of age, a cardiovascular risk factor, on plasma levels of TMA and TMAO, gut bacteria composition, gut-to-blood penetration of TMA, histological and hemodynamic parameters in 3-month-old and 18-month-old, male, Sprague-Dawley and Wistar-Kyoto rats. Cytotoxicity of TMA and TMAO was studied in human vascular smooth muscle cells. Older rats showed significantly different gut bacteria composition, a significantly higher gut-to-blood TMA penetration, and morphological and hemodynamic alterations in intestines. In vitro, TMA at concentration of 500 µmol/L (2-fold higher than in portal blood) decreased human vascular smooth muscle cells viability. In contrast, TMAO at 1,000-fold higher concentration than physiological one had no effect on human vascular smooth muscle cells viability. In conclusion, older rats show higher plasma level of TMA due to a "leaky gut". TMA but not TMAO affects human vascular smooth muscle cells viability. We propose that TMA but not TMAO may be a marker and mediator of cardiovascular risk.

Nutrients to mitigate osteosarcopenia: the role of protein, vitamin D and calcium

PURPOSE OF REVIEW

Osteosarcopenia (the joint loss of bone density and muscle mass and function) is an emerging geriatric syndrome, which associates with poor health outcomes. Several nutrients including protein, vitamin D and calcium interact (directly or through absorption properties) to regulate muscle and bone metabolism. We provided an update on the efficacy of these nutrients on musculoskeletal outcomes in older adults with, or at risk of, osteosarcopenia.

RECENT FINDINGS

Randomized trials show that correcting vitamin D and calcium deficiencies to meet the recommended dietary allowance (RDA) increases bone density and reduces fracture (but not falls) risk. Supplementing above the RDA with protein supports gains in lean mass and lumbar-spine bone density; however, there is inconclusive evidence for muscle strength, physical function or other bone density sites. A likely explanation for this relates to the significant heterogeneity between trials regarding protein dose, type and timing, as well as baseline protein intake. Further high-quality trials are needed in older osteosarcopenic adults to investigate the effects of protein (while correcting vitamin D and calcium deficiencies) on clinically meaningful outcomes such as activities of daily living, falls and fractures.

SUMMARY

An adequate intake of protein (1.2-1.5 g/kg/day), vitamin D (800 IU/day) and calcium (1000-1200 mg/day), is well tolerated and effective at mitigating some aspects of osteosarcopenia such as lean mass, bone density and fracture risk.

Non-Pharmacological Interventions in Osteosarcopenia: A Systematic Review

BACKGROUND

Osteosarcopenia is a geriatric syndrome defined by the concomitant presence of osteopenia/osteoporosis (loss of bone mineral density (BMD)) and sarcopenia (loss of muscle mass and/or function), which increases the risk of falls, fractures, and premature mortality.

OBJECTIVE

To examine the efficacy of non-pharmacological (exercise and/or nutritional) interventions on musculoskeletal measures and outcomes in osteosarcopenic adults by reviewing findings from randomized controlled trials (RCTs).

METHODS

This review was registered at PROSPERO (registration number: CRD42020179292) and conducted in accordance with the PRISMA guidelines. Electronic databases were searched for RCTs assessing the effect of at least one non-pharmacological intervention (any form of exercise and/or supplementation with protein, vitamin D, calcium or creatine) on any musculoskeletal measure/outcome of interest (BMD, bone strength/turnover, muscle mass and strength, physical performance, falls/fractures) in adults with osteosarcopenia as defined by any proposed criteria.

RESULTS

Two RCTs (of n=106 older osteosarcopenic adults (≥65 years)) assessing the effects of progressive resistance training (RT) (via resistance bands or machines; 2-3 times/week; ~60 minutes in duration) were eligible for inclusion. The two RCTs demonstrated moderate quality evidence that RT increases muscle mass, strength, and quality, with changes in strength and quality occurring before muscle mass (12 vs 28 weeks). There was low quality evidence that RT increases lumbar spine BMD and maintains total hip BMD when performed for 12 and 18 months, respectively, and moderate quality evidence that RT has no effect on markers of bone turnover or physical performance. No major adverse effects were recorded in either of the RCTs. There were no eligible RCTs examining the impact of nutritional interventions.

CONCLUSION

Chronic RT is safe and effective at potentiating gains in muscle mass, strength, and quality, and increasing or maintaining BMD in older osteosarcopenic adults. No RCT has examined the effects of protein, vitamin D, calcium, or creatine against a control/placebo in this high-risk population.

Low Protein Diets and Plant-Based Low Protein Diets: Do They Meet Protein Requirements of Patients with Chronic Kidney Disease?

A low protein diet (LPD) has historically been used to delay uremic symptoms and decrease nitrogen (N)-derived catabolic products in patients with chronic kidney disease (CKD). In recent years it has become evident that nutritional intervention is a necessary approach to prevent wasting and reduce CKD complications and disease progression. While a 0.6 g/kg, high biological value protein-based LPD has been used for years, recent observational studies suggest that plant-derived LPDs are a better approach to nutritional treatment of CKD. However, plant proteins are less anabolic than animal proteins and amino acids contained in plant proteins may be in part oxidized; thus, they may not completely be used for protein synthesis. In this review, we evaluate the role of LPDs and plant-based LPDs on maintaining skeletal muscle mass in patients with CKD and examine different nutritional approaches for improving the anabolic properties of plant proteins when used in protein-restricted diets.

Determinants of Vitamin B6 Status in Community-Dwelling Older Adults: A Longitudinal Study Over a Period of 18 Years

BACKGROUND

Cross-sectional studies indicate an age-related decline in vitamin B6 status. Because longitudinal studies are lacking, the present study investigates the long-term association between age and vitamin B6 status in older adults by considering potential confounding factors.

METHODS

The study population consists of 249 women and 111 men aged ≥ 60 years, who had at least three follow-ups between 1996 and 2014 with complete data records on relevant parameters. Vitamin B6 status was assessed by serum pyridoxal 5'-phosphate (PLP) concentrations measured by high-performance liquid chromatography. Linear mixed models were used to analyze the influence of age, sex, body composition, supplements, diet, lifestyle, and serum creatinine on PLP concentrations.

RESULTS

At baseline, 37% of the subjects showed PLP concentrations < 30 nmol/L and more than half failed to meet the recommended dietary intake. Longitudinal analyses revealed that age, use of supplements and protein intake were positive determinants of PLP concentrations, whereas body fat showed a negative impact. No influence of sex, dietary vitamin B6 intake, lifestyle factors or serum creatinine on PLP concentrations was found.

CONCLUSION

The present study provides no evidence that in the course of aging PLP concentrations decline between 60 and 90 years. However, age-related changes in body composition, such as an increased ratio of fat mass to fat-free mass may negatively affect vitamin B6 status.

Sex-and race-specific associations of protein intake with change in muscle mass and physical function in older adults: the Health, Aging, and Body Composition (Health ABC) Study

BACKGROUND

Protein intake recommendations advise ≥0.8 g/kg body weight (BW)/d, whereas experts propose a higher intake for older adults (1.0-1.2 g/kg BW/d). It is unknown whether optimal protein intake differs by sex or race.

OBJECTIVES

We examined the shape of sex- and race-specific associations of dietary protein intake with 3- and 6-y changes in appendicular lean mass (aLM) and gait speed and also 6-y incidence of mobility limitation in community-dwelling older men and women.

METHODS

We used data on men (n = 1163) and women (n = 1237) aged 70-81 y of the Health, Aging, and Body Composition Study. Protein intake was assessed using an FFQ (1998-1999). aLM and gait speed were measured at baseline and at 3 and 6 y. Difficulty walking one-quarter mile or climbing stairs was measured every 6 mo over 6 y. Prospective associations were evaluated with linear and Cox regression models, comparing fit of models with and without spline functions. All analyses were stratified by sex and additionally by race.

RESULTS

Mean ± SD protein intake was 0.94 ± 0.36 g/kg adjusted body weight (aBW)/d in men and 0.95 ± 0.36 g/kg aBW/d in women. There were no strong indications of nonlinear associations. In women, higher protein intake was associated with less aLM loss over 3 y (adjusted B per 0.1 g/kg aBW/d: 39.4; 95% CI: 11.6, 67.2), specifically in black women, but not over 6 y or with gait speed decline. In men, protein intake was not associated with changes in aLM and gait speed. Higher protein intake was associated with a lower risk of mobility limitation in men (adjusted HR per 1.0 g/kg aBW/d: 0.55; 95% CI: 0.34, 0.91) and women (adjusted HR: 0.56; 95% CI: 0.33, 0.94), specifically white women.

CONCLUSIONS

Associations between protein intake and physical outcomes may vary by sex and race. Therefore, it is important to consider sex and race in future studies regarding protein needs in older adults.

Optimizing Adult Protein Intake During Catabolic Health Conditions

The DRIs define a range of acceptable dietary intakes for each nutrient. The range is defined from the minimum intake to avoid risk of inadequacy (i.e., the RDA) up to an upper limit (UL) based on a detectable risk of adverse effects. For most nutrients, the minimum RDA is based on alleviating a clear deficiency condition, whereas higher intakes are often recommended to optimize specific health outcomes. Evidence is accumulating that similar logic should be applied to dietary recommendations for protein. Although the RDA for protein of 0.8 g/kg body weight is adequate to avoid obvious inadequacies, multiple studies provide evidence that many adults may benefit from protein quantity, quality, and distribution beyond guidelines currently defined by the RDA. Further, the dietary requirement for protein is a surrogate for the constituent amino acids and, in particular, the 9 considered to be indispensable. Leucine provides an important example of an essential amino acid where the RDA of 42 mg/kg body weight is significantly less than the 100-110 mg/kg required to optimize metabolic regulation and skeletal muscle protein synthesis. This review will highlight the benefits of higher protein diets to optimize health during aging, inactivity, bed rest, or metabolic dysfunction such as type 2 diabetes.

Dietary Intake, D3Cr Muscle Mass, and Appendicular Lean Mass in a Cohort of Older Men

BACKGROUND

We examined cross-sectional associations between dietary patterns, macronutrient intake, and measures of muscle mass and lean mass in older men.

METHODS

Participants in the Osteoporotic Fractures in Men (MrOS) cohort (n = 903; mean ± SD age 84.2 ± 4 years) completed brief Block food frequency questionnaires (May 2014-May 2016); factor analysis was used to derive dietary patterns. The D3-creatine (D3Cr) dilution method was used to measure muscle mass; dual-energy x-ray absorptiometry (DXA) was used to measure appendicular lean mass (ALM). Generalized linear models were used to report adjusted means of outcomes by dietary pattern. Multiple linear regression models were used to determine associations between macronutrients and D3Cr muscle mass and DXA ALM. Multivariable models were adjusted for age, race, clinic site, education, depression, total energy intake, height, and percent body fat.

RESULTS

Greater adherence to a Western dietary pattern (high factor loadings for red meat, fried foods, and high-fat dairy) was associated with higher D3Cr muscle mass (p-trend = .026). Adherence to the Healthy dietary pattern (high factor loadings for fruit, vegetables, whole grains, and lean meats) was not associated with D3Cr muscle mass or DXA ALM. Total protein (β = 0.09, 95% CI = 0.03, 0.14) and nondairy animal protein (β = 0.16, 95% CI = 0.10, 0.21) were positively associated with D3Cr muscle mass. Nondairy animal protein (β = 0.06, 95% CI = 0.002, 0.11) was positively associated with DXA ALM. Associations with other macronutrients were inconsistent.

CONCLUSIONS

Nondairy animal protein intake (within a Western dietary pattern and alone) was positively associated with D3Cr muscle mass in older men.

Distribution of daily protein intake across meals and lower extremity functioning in community-dwelling Spanish older adults: a prospective cohort study

PURPOSE

Total dietary protein intake has been associated with better physical function in older adults. However, it is unclear whether an even mealtime distribution of protein intake also has an impact on physical functioning. The aim of this study was to examine the prospective association between distribution of daily protein intake across meals and the risk of impaired lower extremity function (ILEF).

METHODS

We used information of 2975 individuals ≥ 60 years from the Seniors-ENRICA cohort. Habitual dietary protein intake was assessed in 2008-2010 with a validated diet history. For each participant, dietary protein intake across meals was determined using the coefficient of variation (CV) of the distribution. Study participants were followed up until 2017 to identify incident ILEF, assessed with the short physical performance battery (SPPB).

RESULTS

Over a median follow-up of 6.3 years, we identified 521 participants with ILEF (SPPB ≤ 6). After adjusting for potential confounders including total protein intake/kg/day, a higher CV (less even distribution) of protein intake did not show an association with the risk of ILEF [hazard ratios (HR) and 95% confidence intervals (CI) for second and third vs. the first tertile: 1.08 (0.87-1.34), and 1.06 (0.85-1.32), respectively; p trend = 0.60]. When assessing each component of the SPPB, a higher CV of protein intake was associated with higher risk of impaired standing balance (HR for tertile 3 vs. tertile 1: 1.26 (1.03-1.54); p trend = 0.02).

CONCLUSION

The mealtime distribution of protein intake was not associated with ILEF. The possibility of a detrimental effect of uneven distribution of protein on standing balance needs to be further investigated.

Low Protein Intake Irrespective of Source is Associated with Higher Mortality Among Older Community-dwelling Men

OBJECTIVES

Our aim was to determine the association between protein intake (overall and by source) and all-cause and cause-specific mortality among older men.

DESIGN

Prospective cohort study.

SETTING

5790 ambulatory community-dwelling older men from multicenter Osteoporotic Fractures in Men (MrOS) study.

MEASUREMENTS

Total energy and protein intake, and protein intake by source (dairy, non-dairy animal, plant) were assessed using a 69-item food frequency questionnaire. We included up to 10-year follow-up with adjudicated cardiovascular, cancer and other mortality outcomes. We used time-to-event analysis with protein exposures, mortality outcome, and adjusted for possible confounders including age, center, education, race, smoking, alcohol use, physical activity, weight, total energy intake (TEI), and comorbidities. Hazard ratios were expressed per each unit=2.9% TEI decrement for all protein intake variables.

RESULTS

The mean (SD) baseline age of 5790 men was 73.6 (5.8) y. There were 1611 deaths and 211 drop-outs prior to 10 years, and 3868 men who were alive at the 10-year follow-up. The mean (SD) total protein intake was 64.7 (25.8) g/d, while the mean (SD) intake expressed as percent of total energy intake (%TEI) was 16.1 (2.9) %TEI. Lower protein intake was associated with an increased risk of death, with unadjusted HR=1.11 (95% CI: 1.06, 1.17) and adjusted HR=1.09 (95% CI: 1.04, 1.14) and the associations for protein intake by source were similar. The adjusted HR for cancer mortality was HR=1.13 (95% CI: 1.03, 1.25) while the association for CVD mortality was HR=1.08 (95% CI: 0.99, 1.18).

CONCLUSIONS

Low protein intake, irrespective of source, was associated with a modest increase in risk of all-cause and cause-specific mortality among older men. Special consideration should be given to level of protein intake among older adults.

Daily Protein Intake and Distribution of Daily Protein Consumed Decreases Odds for Functional Disability in Older Americans

Objective: We sought to determine whether daily protein intake and protein distribution across eating occasions were associated with functional disability in a national sample of older Americans. Methods: Data from 8,070 adults aged ≥60 years from the 2007-2016 waves of the National Health and Nutrition Examination Survey were included. Protein intake and functional capacity was self-reported. A daily protein recommendation of ≥1.0 g/kg/day was utilized. The daily protein recommendation was then spread-out across four meals, whereby a ≥0.25 g/kg/meal threshold was used. Results: Those meeting the daily protein recommendation had 0.78 (95% confidence interval [CI] = [0.65, 0.93]) decreased odds for functional disability. Persons meeting the protein intake threshold per eating occasion for one, two, three, and four occasions had 0.60 (CI = [0.38, 0.95]), 0.48 (CI = [0.30, 0.77]), 0.47 (CI = [0.29, 0.77]), and 0.39 (CI = [0.20, 0.75]) decreased odds for functional disability, respectively. Discussion: Protein consumption seems to be important for preserving function in older Americans.

Oral Health, Disability and Physical Function: Results From Studies of Older People in the United Kingdom and United States of America

OBJECTIVES

Studies examining the associations between oral health and disability have limited oral health measures. We investigated the association of a range of objectively and subjectively assessed oral health markers with disability and physical function in older age.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analyses were based on the British Regional Heart Study (BRHS) comprising men aged 71 to 92 years (n = 2147) from 24 British towns, and the Health, Aging, and Body Composition (HABC) Study comprising men and women aged 71 to 80 years (n = 3075) from the United States. Assessments included oral health (periodontal disease, tooth count, dry mouth, and self-rated oral health), disability, and physical function (grip strength, gait speed, and chair stand test).

RESULTS

In the BRHS, dry mouth, tooth loss, and cumulative oral health problems (≥3 problems) were associated with mobility limitations and problems with activities of daily living and instrumental activities of daily living; these remained significant after adjustment for confounding variables (for ≥3 dry mouth symptoms, odds ratio (OR) 2.68, 95% confidence interval (CI) 1.94-3.69; OR 1.76, 95% CI 1.15-2.69; OR 2.90, 95% CI 2.01, 4.18, respectively). Similar results were observed in the HABC Study. Dry mouth was associated with the slowest gait speed in the BRHS, and the weakest grip strength in the HABC Study (OR 1.75, 95% CI 1.22, 2.50; OR 2.43, 95% CI 1.47-4.01, respectively).

CONCLUSIONS AND IMPLICATIONS

Markers of poor oral health, particularly dry mouth, poor self-rated oral health, and the presence of more than 1 oral health problem, were associated with disability and poor physical function in older populations. Prospective investigations of these associations and underlying pathways are needed.

Sex-related differences in the association between frailty and dietary consumption in Japanese older people: a cross-sectional study

BACKGROUND

Female sex is an important factor predisposing individuals to frailty. Appropriate nutrition is one of the most effective ways to prevent older adults from developing frailty; Sex-related differences have also been detected in the association between nutritional intervention and health-related outcomes. However, few studies have discussed these sex-related differences. The aim of the present study was to investigate the sex-related differences in the association between frailty and dietary consumption.

METHODS

We conducted a cross-sectional study which investigated community-dwelling older adults aged ≥65 years. We surveyed age, sex, body mass index, family arrangement (living alone, living with a partner or living with parent(s) and/or child (ren)), dietary consumption and frailty status. Dietary consumption was surveyed using a food frequency questionnaire that included 13 major food categories (fish, meat, eggs, dairy products, soybean products, vegetables, seaweeds, potatoes, fruits, fats or oils, snacks, salty foods and alcohol). Frailty was defined by the Kihon Checklist score. The Kihon Checklist is composed of 25 simple yes/no questions, and it has been validated as a metric for frailty. A higher score indicates a greater degree of frailty. Multinomial regression analysis was performed to clarify the association between frailty and dietary consumption for each sex.

RESULTS

We analyzed 905 older adults (420 (46.4%) were male). After adjusting for cofounders, a low frequency of meat consumption (less than twice/week) was associated with a high prevalence of frailty in men (odds ratio: 2.76 (95%CI: 1.12-6.77), p = 0.027). In contrast, in women, low frequencies of consumption of fish, meat, vegetables, potatoes and snacks were associated with a higher prevalence of frailty compared with those who consumed foods from those categories daily (odds ratios: fish 2.45 (1.02-5.89), p = 0.045; meat 4.05 (1.67-9.86), p = 0.002; vegetables 5.03 (2.13-11.92), p < 0.001; potatoes 3.84 (1.63-9.05), p = 0.002; snacks 2.16 (1.02-4.56), p = 0.043).

CONCLUSIONS

More food categories were associated with frailty in women than in men. Nutritional intervention to prevent frailty is presumably more effective for women than for men.