The role of dietary protein intake in the prevention of sarcopenia of aging

Higher protein intake may benefit in patients with prolonged mechanical ventilation

Background

Patients with prolonged mechanical ventilation (PMV) is usually associated with muscle wasting and diaphragm weakness, resulting in high medical costs and mortality. Adequate energy and protein intake were beneficial in sarcopenia patients. We aimed to investigate the impact of protein intake in weaning parameters in patients with PMV.

Materials and methods

We enrolled patients with PMV (mechanical ventilation ≥6 h/day for ≥21 days) from a respiratory care center (RCC) of a tertiary medical center from December 2020 to October 2022, and classified them into weaning success and weaning failure groups. The patients' characteristics, nutrition records, weaning parameters and outcomes were analyzed.

Results

A total of 289 patients were included (mean age 73.5 years). Of the 289 patients, 149 were weaned successfully and 140 were not. The average protein intake was higher in the weaning success group than in the weaning failure group (1.22 ± 0.320 versus 0.99 ± 0.332 g/kg/day, p < 0.001). No significant differences were noted in the average calorie intake and whey protein intake between the two groups. RSBI <90 breaths/min/L (OR = 2.38, p = 0.045), serum albumin at 4th week ≥3 g/dL (OR = 2.89, p = 0.027), daily protein intake ≥1.01 g/kg/day (OR = 8.10, p < 0.001), PaO2/FiO2 (PF) ratio ≥ 300 (OR = 2.56, p = 0.027) were independent predictors for weaning from ventilator. Weak positive correlations were found between average protein intake with PF ratio (r = 0.1576, p = 0.0227) and PaO2 (r = 0.13359, p = 0.0497).

Conclusion

Daily protein intake had positively correlated with PF ratio and had independently benefit for weaning in patients with PMV.

Leucine Intake and Sarcopenia Indicators of an Elderly Group from the Metropolitan Region, Santiago de Chile, Who Participated in the Program for Complementary Food in Older People (PACAM)

BACKGROUND AND OBJECTIVE

The global aging population has led to increased noncommunicable diseases, often linked to poor diet and declining muscle strength and mass. This study assessed leucine intake and sarcopenia indicators among 181 adults aged 60-80 in Santiago, Chile, participating in the Program for Complementary Food in Older People (PACAM), with 80% being women.

METHODS

Sarcopenia was evaluated through muscle strength and mass using the EWGSOP2 criteria for its identification.

RESULTS

78.45% of participants did not meet the recommended leucine intake of 3 g per day and sarcopenia was identified in 17.13% of them. The skeletal muscle index was 48.07%, and hand grip strength was 26.52%, with men showing significantly higher grip strength (48.60% vs. 28.80%, p = 0.00). Inadequate leucine intake was more common in those aged 60-75 (85.9%) than those over 75 (p = 0.03). No significant differences in BMI, grip strength, or muscle mass were found between those with adequate and inadequate leucine intake, and PACAM food consumption did not significantly affect these parameters. A sub-analysis showed significant differences in grip strength among powdered dairy drink consumers (35.20% vs. 17.80%, p = 0.01).

CONCLUSIONS

Chilean elderly participating in PACAM present a high prevalence of sarcopenia and leucine deficiency among with no notable benefits from PACAM foods intake. Despite the limitations of the local body composition assessment method, this research addresses a critical public health issue in Chile. Future studies should evaluate physical performance and focus on leucine supplementation to clarify its effects on sarcopenia.

Biological basis and treatment of frailty and sarcopenia

In an ageing society, the importance of maintaining healthy life expectancy has been emphasized. As a result of age-related decline in functional reserve, frailty is a state of increased vulnerability and susceptibility to adverse health outcomes with a serious impact on healthy life expectancy. The decline in skeletal muscle mass and function, also known as sarcopenia, is key in the development of physical frailty. Both frailty and sarcopenia are highly prevalent in patients not only with advanced age but also in patients with illnesses that exacerbate their progression like heart failure (HF), cancer, or dementia, with the prevalence of frailty and sarcopenia in HF patients reaching up to 50-75% and 19.5-47.3%, respectively, resulting in 1.5-3 times higher 1-year mortality. The biological mechanisms of frailty and sarcopenia are multifactorial, complex, and not yet fully elucidated, ranging from DNA damage, proteostasis impairment, and epigenetic changes to mitochondrial dysfunction, cellular senescence, and environmental factors, many of which are further linked to cardiac disease. Currently, there is no gold standard for the treatment of frailty and sarcopenia, however, growing evidence supports that a combination of exercise training and nutritional supplement improves skeletal muscle function and frailty, with a variety of other therapies being devised based on the underlying pathophysiology. In this review, we address the involvement of frailty and sarcopenia in cardiac disease and describe the latest insights into their biological mechanisms as well as the potential for intervention through exercise, diet, and specific therapies.

Protein Intake and Physical Activity Levels as Determinants of Sarcopenia Risk in Community-Dwelling Older Adults

Community screening for sarcopenia is complex, with barriers including access to specialized equipment and trained staff to conduct body composition, strength and function assessment. In the current study, self-reported dietary protein intake and physical activity (PA) in adults ≥65 years was assessed relative to sarcopenia risk, as determined by body composition, strength and physical function assessments, consistent with the European Working Group on Sarcopenia in Older People (EWGSOP) definition. Of those screened (n = 632), 92 participants (77% female) were assessed as being at high risk of developing sarcopenia on the basis of dietary protein intake ≤1 g∙kg-1∙day-1 [0.9 (0.7-0.9) g∙kg-1∙day-1] and moderate intensity physical activity <150 min.week-1. A further 31 participants (65% female) were defined as being at low risk, with both protein intake [1.2 (1.1-1.5) g∙kg-1∙day-1] and PA greater than the cut-off values. High-risk participants had reduced % lean mass [53.5 (7.8)% versus 54.8 (6.1)%, p < 0.001] and impaired strength and physical function. Notably, high-risk females exhibited greater deficits in lean mass and strength, with minimal differences between groups for males. In community-dwelling older adults, self-reported low protein intake and low weekly PA is associated with heightened risk for sarcopenia, particularly in older women. Future research should determine whether early intervention in older adults with low protein intake and PA attenuates functional decline.

Factors Associated with Frailty in Older Adults in Community and Nursing Home Settings: A Systematic Review with a Meta-Analysis

Background: Frailty is a globally recognized issue. However, there is a lack of evidence exploring factors associated with frailty among older residents in community and nursing-home settings. Methods: To explore the prevalence and factors associated with frailty among older adults in community and nursing-home settings, we conducted a systematic search following the PRISMA guidelines across Web of Science, MEDLINE, EMBASE, PubMed, and Cochrane databases up until January 2024, selecting 38 studies which encompassed 150,642 participants. Results: Our findings showed higher frailty prevalence in nursing homes compared to communities. Frailty was significantly associated with sociodemographic (living alone, poor self-reported health), physiological (poor sleep, low activity of daily living), behavioral (physical inactivity) and disease (chronic conditions, depression) factors in both community and nursing-home settings. Conclusions: There are numerous factors associated with frailty in older adults in nursing-home and community settings. These factors underscore the significance of promptly identifying high-risk individuals and devising appropriate interventions to mitigate frailty among them.

Improving sarcopenia in older adults: a systematic review and meta-analysis of randomized controlled trials of whey protein supplementation with or without resistance training

OBJECTIVES

The aim of the study was to comprehensively analyze the effects of whey protein (WP)-enriched supplement intake with or without resistance training (RT) in older patients, either from the community or hospital, who were diagnosed with sarcopenia according to the EWGSOP or AWGS criteria.

METHODS

This meta-analysis study was registered in PROSPERO (CRD42023407885). We searched the PubMed, Embase, Web of Science, and Cochrane Library databases for RCTs up to June 1, 2023. Standardized mean differences (SMD) with 95% confidence intervals (CI) were used to estimate the pooled results.

RESULTS

Ten RCT studies, including 1154 participants, were included and analyzed. The primary outcomes were the changes in muscle mass, strength, and physical performance. In WP group versus (vs.) Isocaloric placebo (PLA)/Routine consultation (RC) group, WP significantly increased the appendicular skeletal muscle mass index (SMD: 0.47, 95%CI: 0.23, 0.71), appendicular skeletal muscle mass (SMD: 0.28, 95%CI: 0.11, 0.45) and gait speed (SMD: 1.13, 95%CI: 0.82, 1.44) in older patients with sarcopenia. In WP with RT group vs. PLA/ RC group, there was significant increase in handgrip strength (SMD: 0.67, 95%CI: 0.29, 1.04). In addition, in the secondary outcomes, WP significantly reduced interleukin-6, significantly increased insulin-like growth factor-1 and albumin, promoted participants' intake of total energy and protein, enhanced activities of daily living scores in patients, and had no significant effect on BMI, weight, or fat mass.

CONCLUSION

This review confirms that WP can improve various aspects of older adult with sarcopenia, thereby enhancing their overall physical condition. More studies should be conducted to validate this result and further explore the effects of WP and RT in patients with sarcopenia.

Utilizing the influence of protein enrichment of meal components as a strategy to possibly prevent undernutrition in the elderly: an in vitro approach

Nutritional strategies are required to limit the prevalence of denutrition in the elderly. With this in mind, fortified meals can provide more protein, but their digestibility must be ensured. Using a dynamic in vitro digester, DIDGI®, programmed with the digestion conditions of the elderly, we evaluated the supplementation of each component of a meal and assessed protein digestibility, amino acid profile, micro-nutrients and vitamins bioaccessibility for a full course meal. Higher protein digestibility was evidenced for the fortified meal, with higher release of essential amino acids. Moreover the large increase of leucine released was comparable to the range advocated for the elderly to favour protein anabolism. This in vitro study underlines the interest of using dish formulations to meet the nutritional needs of seniors, which is why this work will be completed by a clinical study in nursing home.

Consumption of hot protein-containing drink accelerates gastric emptying rate and is associated with higher hunger levels in older adults

Meal temperature is known to affect gastric emptying and appetite. While protein intake is recommended for older age, gastric emptying is delayed with age, resulting in loss of appetite. This study aimed to investigate whether adjusting the temperature of protein-containing drinks could improve gastric emptying and appetite in older individuals. Twenty male and female participants aged 65 years and older underwent three one-day trials in random order. Participants visited the laboratory after a 10-hour fast and consumed 200 mL of protein-containing drink dissolved in 13C-sodium acetate at 4°C, 37°C, or 60°C in a 3-minute period. Then, participants sat in a chair for 90 minutes to measure gastric emptying rate by the 13C-sodium acetate breath test and subjective appetite by a visual analog scale. The results showed that 37°C and 60°C drinks had faster gastric emptying at 5 and 10 min after ingestion than did the 4°C drink (trial-time interaction, p = 0.014). Tmax-calc, an indicator of gastric emptying rate, tended to be faster for the 37°C and 60°C drinks than for the 4°C drink (49.7 ± 17.5 min vs. 44.1 ± 18.5 min vs. 45.3 ± 25.8 min for the 4°C, 37°C, and 60°C, respectively; p = 0.085). There were no significant differences in the change in hunger from baseline among the three different temperature drinks (p > 0.05). Only in the 60°C trial, a shorter gastric emptying time was associated with greater hunger (r=-0.554, p = 0.021). These findings suggest that hot protein-containing drinks may accelerate gastric emptying and contribute to rapid nutrient intake and increased appetite in older adults.

Association between nut consumption and frailty in the elderly: a large sample cross-sectional study

BACKGROUND

Limited literature has addressed the impact of nut consumption in mitigating frailty. This study aimed to investigate the association between nut consumption and frailty among Americans aged above 60 years, employing two 24-h dietary recalls for analysis.

METHODS

The data sets of the National Health and Nutrition Examination Survey (NHANES) (2003-2018) and the Food Patterns Equivalents Database were utilised for a weighted multiple logistic regression model to evaluate the association between nut consumption and frailty in elderly adults. Furthermore, a restricted cubic spline model was employed to investigate the nonlinear relationship between nut intake and frailty. Besides, stratified and interaction analyses were conducted to explore the sensitivity of nut consumption in reducing the risk of frailty in diverse subgroups.

RESULTS

The research study comprised 10,033 individuals aged 60 years or above, of whom 3591 were classified as frailty and 5302 consumed nuts. In the multivariate logistic regression analysis that adjusted for covariates, the weighted multivariate adjusted odds ratios demonstrated that the prevalence of frailty was lower in the nut intake group than in nonconsumers. The stratified analysis indicated that nearly all subgroups who consumed nuts had a significantly lower risk of frailty compared to nonconsumers, and an interaction was observed between nut intake and nonhypertensive populations. The optimal threshold for nut intake to decrease the risk of frailty was identified as 1.02 ounces.

CONCLUSIONS

The study concluded that nut consumption has a constructive impact on averting frailty in elderly adults, particularly in nonhypertensive individuals. Nut intake of ~1.02 ounces per day is advantageous in improving the quality of life in elderly adults.

Relationship between monounsaturated fatty acids and sarcopenia: a systematic review and meta-analysis of observational studies

Accumulating evidence suggests that fatty acids (FAs) play an essential role in regulating skeletal muscle mass and function throughout life. This systematic review and meta-analysis aimed to examine the relationship between dietary or circulatory levels of monounsaturated FAs (MUFAs) and sarcopenia in observational studies. A comprehensive literature search was performed in three databases (PubMed, Scopus, and Web of Science) from inception until August 2022. Of 414 records, a total of 12 observational studies were identified for this review. Ten studies were meta-analysed, comprising a total of 3704 participants. The results revealed that MUFA intake is inversely associated with sarcopenia (standardized mean difference = - 0.28, 95% CI - 0.46 to - 0.11; p < 0.01). Despite the limited number of studies, our results suggest that lower MUFA intake is associated with a higher risk of sarcopenia. However, the available evidence is still insufficient and further investigations are needed to demonstrate this relationship.

Sensorial and Nutritional Properties of a Collagen-Fortified Snack Bar Designed for the Elderly

BACKGROUND

This study aimed to develop a highly consumable collagen-containing bar that contributes to enriching the diets of elderly individuals, in terms of energy and nutrients.

METHOD

For this purpose, five different bar samples (C, P1, P2, D1, D2) containing different amounts of collagen, date puree, and pumpkin puree were developed and subsequently evaluated in terms of their sensory and nutritional properties by a panel of 30 adult trained sensorial analysists.

RESULTS

The bars with the highest flavor score were those with high levels of collagen and pumpkin puree (P2) and date puree (D2). For the analyses of multiple criteria among multiple samples, the TOPSIS technique showed that among the snack bar samples with different contents, the most liked sample was the one with a high level of collagen and date puree (D2). One serving of the developed bars contains approximately 300-400 kcal of energy and 6.8-8.8 g of protein. Considering age-related decreased appetite, as well as chewing and swallowing problems in elderly individuals, regular consumption of nutrient-rich small meals or snacks with enhanced sensory characteristics could contribute to improving nutritional and functional status.

Food consumption is associated with frailty in edentulous older adults: evidence from the ELSI-Brazil study

This cross-sectional study aimed to evaluate the association between food consumption (meat, fish, and fruits and vegetables), anthropometric indicators (body mass index, waist circumference, and waist-to-height ratio), and frailty; and to verify whether these associations vary with edentulism. We used data from 8,629 participants of the Brazilian Longitudinal Study of Aging (ELSI-Brazil) (2015-16). Frailty was defined by unintentional weight loss, weakness, slow walking speed, exhaustion, and low physical activity. Statistical analyses included multinomial logistic regression. Of the participants, 9% were frail and 54% pre-frail. Non-regular meat consumption was positively associated with pre-frailty and frailty. Non-regular fish consumption, and underweight were associated only with frailty. Models with interactions reveled a marginal interaction between meat consumption and edentulism (p-value = 0.051). After stratification, non-regular meat consumption remained associated with frailty only in edentulous individuals (OR = 1.97; 95%CI 1.27-3.04). Our results highlight the importance of nutritional assessment, oral health, and public health-promoting policies to avoid, delay and/or reverse frailty in older adults.

A Narrative Review of Non-Pharmacological Strategies for Managing Sarcopenia in Older Adults with Cardiovascular and Metabolic Diseases

This narrative review examines the mechanisms underlying the development of cardiovascular disease (CVD) and metabolic diseases (MDs), along with their association with sarcopenia. Furthermore, non-pharmacological interventions to address sarcopenia in patients with these conditions are suggested. The significance of combined training in managing metabolic disease and secondary sarcopenia in type II diabetes mellitus is emphasized. Additionally, the potential benefits of resistance and aerobic training are explored. This review emphasises the role of nutrition in addressing sarcopenia in patients with CVD or MDs, focusing on strategies such as optimising protein intake, promoting plant-based protein sources, incorporating antioxidant-rich foods and omega-3 fatty acids and ensuring sufficient vitamin D levels. Moreover, the potential benefits of targeting gut microbiota through probiotics and prebiotic fibres in sarcopenic individuals are considered. Multidisciplinary approaches that integrate behavioural science are explored to enhance the uptake and sustainability of behaviour-based sarcopenia interventions. Future research should prioritise high-quality randomized controlled trials to refine exercise and nutritional interventions and investigate the incorporation of behavioural science into routine practices. Ultimately, a comprehensive and multifaceted approach is essential to improve health outcomes, well-being and quality of life in older adults with sarcopenia and coexisting cardiovascular and metabolic diseases.

The Impact of Whey Protein Supplementation on Sarcopenia Progression among the Elderly: A Systematic Review and Meta-Analysis

We conducted a systematic literature review and meta-analysis to investigate the role of whey protein supplementation in the functioning of the elderly with sarcopenia. The aim was to investigate the available scientific evidence and determine the best recommendations with respect to whey protein supplementation in sarcopenic patients. Methods: Databases, including CINAHL, Embase PubMed, and Web of Science, were searched from database inception until 31 December 2022 for randomised controlled trials (RCTs) comparing the efficacy of whey protein supplementation in the elderly with sarcopenia. Data on study design, risk of bias, patient, illness, and treatment characteristics from each study were independently extracted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The tool "assessing risk of bias" from the Cochrane Handbook was used to evaluate the quality of the included papers. Results: The search identified 629 records; 590 articles were excluded as duplicates or after evaluation at the title or abstract level. Out of 39 full-text articles that were reviewed, 29 were excluded for not fulfilling the inclusion criteria. There is some evidence that whey protein supplementation combined with age-appropriate physical exercise might improve muscle mass and lower limb function in the elderly with sarcopenia. The present meta-analysis demonstrated overall that whey supplementation does not improve any of the tested sarcopenia-linked parameters. However, we found that study duration (weeks) and age significantly affect the handgrip strength rate and the chair and stand test rate, respectively, so consideration should be given to oral supplementation combined with the age of participants and an appropriate physical activity as a form of sarcopenia prevention in the high-risk group.

No impact of combining multi-ingredient supplementation with exercise on body composition and physical performance, in healthy middle-aged and older adults: A systematic review and meta-analysis

BACKGROUND

Protein-based multi-ingredient (MTN) supplements have been suggested as a safe and effective way of enhancing exercise outcomes. However, their effectiveness remains controversial when compared to isocaloric and single-nutrient supplements. This review aims to systematically summarise the current knowledge of multi-ingredient supplementation to optimise body composition and physical performance in middle-aged and older adults.

MATERIAL AND METHODS

A systematic review with meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search of the literature was conducted using PubMed, EBSCOhost, Google Scholar, Web of Science, and SPORTDiscus from June to October 2021. Every publication identified from the outset to October 2021 was considered. The main inclusion criteria comprised randomized controlled trial (RCT) studies conducted in adults (≥45 years old), following resistance- or endurance-based training programmes for a period of 6 weeks or longer, combined with MTN supplementation and a calorie equivalent comparator (COMP) supplement (e.g., carbohydrates). Continuous data on body composition [fat-free mass (FFM) or lean body mass], strength, and functional capacity as markers of physical performance were pooled using a random-effects model.

RESULTS

Initially, 3329 publications were identified. Data from nine RCTs were ultimately included, involving 476 participants. The overall quality of the included studies was high, demonstrating a low risk of bias. Compared to COMP, no significant further benefits of ingesting MTN were identified for FFM (kg) (g = 0.044, 95 % CI -0.14 to 0.22), upper-body strength (kg) (g = 0.046, 95 % CI -0.24 to 0.33), lower-body strength, leg press exercise (kg) (g = 0.025, 95 % CI -0.26 to 0.31), leg extension exercise (kg) (g = 0.106, 95 % CI -0.15 to 0.36) and functional capacity (time in seconds) (g = 0.079, 95 % CI -0.12 to 0.27).

CONCLUSIONS

No additional benefits of ingesting MTN vs. COMP to maximise exercise-induced outcomes on body composition and physical performance in healthy physically active middle-aged and older adults have been identified.

Increased Intake of Omega-3 Polyunsaturated Fatty Acids Is Associated with Reduced Odds of Low Hand Grip Strength in Korean Adults

Nutritional status is thought to be one of the modifiable risk factors for muscle health. This study investigates the association between dietary omega-3 polyunsaturated fatty acids (PUFA) intake and hand grip strength (HGS) in Korean adults. The cross-sectional analysis was performed on 18,278 participants aged ≥19 years enrolled in the Korea National Health and Nutrition Examination Survey from 2016-2019. Omega-3 PUFA consumption was positively linked to the dietary intake of nuts, fish, and shellfish in Korean adults. After adjusting for potential confounders, the results showed that increased omega-3 PUFA intake was associated with a decreased risk of low HGS (odds ratio (OR) for upper quartile (Q4) compared to Q1, men: OR = 1.42 (95% CI: 1.17-1.72), women: OR = 1.61 (1.37-1.89)). This inverse association was reported in people who did no resistance exercise or had an insufficient protein intake. In contrast, this association was not evident in adults who did resistance exercise or had sufficient protein intake. Furthermore, participants with hypertension or type 2 diabetes showed stronger associations between dietary omega-3 PUFA intake and HGS compared with other subgroups. These results suggest that dietary omega-3 PUFA intake positively related with HGS in Korean adults.

Impact of resistance exercise rehabilitation and whey protein supplementation in elderly patients with heart failure with preserved ejection fraction with sarcopenia: a study protocol for a randomised controlled trial

INTRODUCTION

Heart failure with preserved ejection fraction (HFpEF) affects more than half of the patients with heart failure. HFpEF and sarcopenia can interact with each other and contribute to reduced physiological function and increased mortality in elderly patients. Resistance training (RT) or resistance exercise rehabilitation (RER) may have benefits for elderly HFpEF patients with sarcopenia. Whey protein supplementation (WPS) may increase the effects of exercise on strength and muscle mass, in addition to promoting heart function and quality of life (QoL). However, studies are needed to evaluate effects of RER and WPS in patients with HFpEF with sarcopenia.

METHODS AND ANALYSIS

This is a prospective, randomised, controlled clinical trial in which patients with HFpEF with sarcopenia will be randomly allocated to three groups, control, RT and RT+WP. Participants in all groups will receive basic intervention including standard medicine treatment, home-based aerobic exercise and basic nutritional intervention. The RT group will undergo resistance exercise programmes, and the RT+WP group will receive daily WPS apart from resistance exercise. The study variables will be evaluated at baseline and 12 weeks. Primary outcome measure is the change of 6 min walking distance. Secondary outcomes include parameters of muscle status, cardiac function, nutritional status, QoL and major adverse cardiovascular events. The primary efficacy analysis will follow the intention-to-treat principle.

ETHICS AND DISSEMINATION

This study was approved by Ethics Committee of China-Japan Friendship Hospital for Clinical Research (No. 2022-KY-003). The results of this study will be disseminated via peer-reviewed publications and presentations at conferences.

TRIAL REGISTRATION NUMBER

ChiCTR2200061069.

Assessing the Effects of Dietary Protein Supplementation on Sarcopenia in Community-Dwelling Older Adults

Sarcopenia, an age-associated skeletal muscle disorder characterized by muscle loss, is associated with disability in elderly populations. This literature review summarizes the impact of protein intake and supplementation on the indicators of severe sarcopenia-muscle mass, muscle strength, and physical function in community-dwelling older adults. We performed a literature search on PubMed, EMBASE, and MedLine, and included studies that evaluated the effects of protein intake with or without exercise intervention and on sarcopenia in community-dwelling older adults. Information regarding study participants, protein intervention, and sarcopenia-related outcomes were collected. Protein supplementation with or without exercise positively improves muscle mass, and aspects of muscle strength and physical function in sarcopenic and pre-frail older adults, while it elicited inconclusive effects in healthy populations. Greater dietary animal-based and soy-based protein diets can improve muscle mass in older adults. In conclusion, protein supplementation can improve muscle mass and reduce the risk of sarcopenia in sarcopenia and pre-frail older adults, while future studies should continue to investigate the effects of protein supplementation on indicators of sarcopenia in healthy older adults.

Protein intake and physical function in older adults: A systematic review and meta-analysis

BACKGROUND

The present study explored cross-sectional and longitudinal associations between protein intake and physical function in older adults.

METHODS

We conducted a systematic review and meta-analysis of cross-sectional and longitudinal studies that investigated the association between protein intake and measures of physical function in older adults. Cross-sectional, case-control, and longitudinal cohort studies that investigated the association between protein intake and physical function as a primary or secondary outcome in people aged 60 + years were included. Studies published in languages other than English, Italian, Portuguese, or Spanish were excluded. Studies were retrieved from MEDLINE, SCOPUS, EMBASE, CINAHL, AgeLine, and Food Science Source databases through January 31, 2022. A pooled effect size was calculated based on standard mean differences (SMD), MD, log odds ratio (OR) and Z-score..

RESULTS

Twenty-two cross-sectional studies examined a total of 11,332 community-dwellers, hospitalized older adults, and elite senior athletes with a mean age of approximately 75 years. The pooled analysis indicated that a protein intake higher than the recommended dietary allowance (RDA) was significantly associated with higher Short Physical Performance Battery (SPPB) scores (SMD: 0.63, 95% CI: 0.27, 0.99, P-value: 0.0006), faster walking speed, greater lower-limb (SMD: 0.22, 95% CI: 0.04, 0.40, P-value: 0.02) and isometric handgrip strength (Z-score: 0.087, 95% CI: 0.046-0.128, P-value: 0.0001), and better balance (SMD: 0.33, 95% CI: 0.05, 0.62, P-value: 0.02). Nine longitudinal studies investigated 12,424 community-dwelling and native older adults with a mean age of approximately 85 years. A protein intake higher than the current RDA was not associated with lower decline in either isometric handgrip strength (logOR: 0.99, 95% CI: 0.97-1.02, P-value= 0.67) or walking speed (logOR: 0.92, 95% CI: 0.77-1.10, P-value= 0.35).

CONCLUSIONS

A protein intake higher than the RDA is cross-sectionally associated with better physical performance and greater muscle strength in older adults. However, a high consumption of proteins does not seem to prevent physical function decline over time.

Relative protein intake and associations with markers of physical function in those with type 2 diabetes

AIMS

To examine the independent associations between relative protein intake (g kg^-1  day ¹ ) and markers of physical function in those with type 2 diabetes, while also comparing with current guidelines for protein intake.

METHODS

This analysis reports data from the ongoing Chronotype of Patients with Type 2 Diabetes and Effect on Glycaemic Control (CODEC) study. Functional assessments included: Short Physical Performance Battery (SPPB), 60 s sit-to-stand (STS-60), 4-m gait speed, time to rise from a chair (×5) and handgrip strength. Participants also completed a self-reported 4 day diet diary. Regression analyses assessed whether relative protein intake was associated with markers of physical function. Interaction terms assessed whether the associations were modified by sex, age, HbA1c or body mass index (BMI).

RESULTS

413 participants were included (mean ± SD:age = 65.0 ± 7.7 years, 33% female, BMI = 30.6 ± 5.1 kg/m² ). The average total protein intake was 0.88 ± 0.31 g kg^-1  day^-1 . 33% of individuals failed to meet the reference nutrient intake for the United Kingdom (≥0.75 g kg^-1  day^-1 ), and 87% for European recommendations (≥1.2 g kg^-1  day^-1 ). After adjustment, each 0.5 g/kg of protein intake was associated with an 18.9% (95% CI: 2.3, 35.5) higher SPPB score, 22.7% (1.1, 44.3) more repetitions in STS-60, 21.1% (4.5, 37.7) faster gait speed and 33.2% (16.9, 49.5) lower chair rise time. There were no associations with handgrip strength or any interactions.

CONCLUSIONS

Relative protein intake was positively associated with physical function outcomes, even after consideration of total energy intake. As a number of individuals were below the current guidelines, protein intake may be a modifiable factor of importance for people with type 2 diabetes.

A high level theory investigation on the lowest-lying ionization potentials of glycine (NH2CH2COOH)

In this work, an investigation on the ionization potentials (IPs) of the glycine molecule (NH₂CH₂COOH) is presented. IPs ranging up to ∼20 eV were probed for each of the six conformations considered, with the referred threshold being chosen based on both: (i) the observations by recent photoelectron-photoion coincidence (PEPICO) experiments and (ii) the energy range of relevance to the modeling of other photo-induced processes (e.g., photoionization). For computing the IPs, the equation-of-motion ionization potential coupled-cluster with single and double excitations method (EOMIP-CCSD) was employed with large correlation consistent aug-cc-pVXZ and aug-cc-pCVXZ (X = D, T, and Q) basis sets. Extrapolation to the complete basis set limit and consideration of core electron correlation effects were also taken into account. Subsequently, the Feller-Peterson-Dixon (FPD) approach was used for considering all the contributions and to obtain accurate IPs. In addition, coupled-cluster with single and double excitations as well as perturbative triples, CCSD(T), was also used with the aug-cc-pVTZ basis set. When compared to each other, results obtained through the use of these approaches yielded excellent agreement. In general, the outcomes from the present work provide additional information to the insights gathered from the recent PEPICO experiments as well as accurate IPs for all 6 conformations of glycine using an approach based on high levels of theory. Hence, it is expected that other investigations focusing on photo-induced processes originating from NH₂CH₂COOH (for instance, the computational modeling of its photoionization) will be motivated for study in the future.

Loss of Eicosapentaenoic Acid (EPA) after Retort Sterilization of the EPA-BCAA Fortified Complete Nutrition Drink

Retort sterilization is cost-effective for small-scale production of specialized nutrition products. However, the sensory properties and stability of active ingredients after sterilization remain undetermined. This study aimed to investigate the effect of retort on the existence of functional compounds and the sensory satisfaction of a fortified complete nutrition formula with branched-chain amino acids (BCAAs), and fish oil providing eicosapentaenoic acid (EPA). Changes in EPA and BCAA contents after retort were determined by using LC-MS/MS. Nutrient values, osmolality, rheology and sensory acceptance of the processed fortified and control formulas were compared. After retort, the fortified formula had an increase in all types of BCAAs but 30% loss of EPA (p = 0.001). The fortified formula had slightly higher protein and fiber contents, along with increased osmolality. It had higher viscosity and shear stress, but similar IDDSI level at 0. Among flavors tested, the fortified formula with Japanese rice flavor received the highest satisfaction scores with over 80% sensory acceptance. In conclusion, retort sterilization preserved BCAAs of the functional drink, but the addition of 30% fish oil was required to compensate for the EPA loss. The sterilized fortified formula with Japanese rice flavor was sensory acceptable.

Interventions for Body Composition and Upper and Lower Extremity Muscle Strength in Older Adults in Rural Taiwan: A Horizontal Case Study

The purpose of this study was to understand the effects of a physical activity program and high-protein supplementation on body composition and upper and lower extremity muscle strength in male older adults in rural areas. In this study, 60 healthy male older adults (mean age 77.5 ± 4.6 years) from rural areas were recruited and randomly assigned to experimental group A (intervention of the physical activity program and high-protein supplementation), experimental group B (daily routine, with only intervention of high-protein supplementation), or control group C (daily routine). Experimental group A (EGa) carried out a physical activity plan three times a week, with an exercise intensity and calorie consumption of 250 kcal (5METs × ⅔hr × 75) for 3 months and drank a high-protein supplement (1.3 g/kg BW/day) after each exercise; experimental group B (EGb) followed only the intervention of high-protein supplementation. All the participants underwent pre- and post-tests for body composition, waist–hip circumference (WC, HC), handgrip strength (HS), 30 s dominant arm curl, 30 s sit to stand, and 2 min step tests. The results of the study showed that EGa significantly decreased body mass index (BMI), body fat mass (BFM), body fat percentage (BFP), WC, HC, and waist-to-hip ratio (WHR) and increased basal metabolic rate and muscle mass. Although both EGa and EGb used high-protein supplementation, EGa’s added three-month intervention of a physical activity program made it easier for that group to increase muscle mass and muscle strength. The WHR decreased from 1.015 to 0.931, representing a decrease of 8.28%, and an obvious weight loss effect was achieved. Thus, we concluded that the best way to maintain muscle strength in older adults is through physical activity with resistance and protein supplementation, which can reduce muscle loss in older adults.

Nutrition of older adults in the Republic of Kazakhstan

This article discusses a study on the nutrition specifics of older adults living in social service institutions in three major cities of the Republic of Kazakhstan: Nur-Sultan, Almaty, and Shymkent. The direction of the research meets the priorities of the World Health Organization to achieve goals on aging and health. The diets of older adults in the Republic of Kazakhstan were studied, food preferences were identified, and needs for basic nutrients were established. This article presents the results of sociological surveys of older adults who answered questions about nutrition, preferred foods, raw materials, and meat products. Based on the survey results, technologies of herodietic meat products aimed at enriching the diet with proteins were developed, along with practical recommendations for a balanced diet. This area of research is relevant due to the lack of products with a herodietic profile on the Kazakhstan market.

Association between dietary intake of branched-chain amino acids and sarcopenia and its components: a cross-sectional study

There is no previous study that investigated the association between dietary intake of total and individual branched-chain amino acids (BCAAs) and odds of sarcopenia. The present study aimed to examine the association between dietary intake of BCAAs and sarcopenia and its components among Iranian adults. The data for this cross-sectional study was collected in 2011 among 300 older people (150 men and 150 female) with aged ≥ 55 years. We used a Block-format 117-item food frequency questionnaire (FFQ) to evaluate usual dietary intakes. BCAAs intake was calculated by summing up the amount of valine, leucine and isoleucine intake from all food items in the FFQ. The European Sarcopenia Working Group (EWGSOP) definition was used to determine sarcopenia and its components. Mean age of study participants was 66.8 years and 51% were female. Average intake of BCAAs was 12.8 ± 5.1 g/day. Prevalence of sarcopenia and its components was not significantly different across tertile categories of total and individual BCAAs intake. We found no significant association between total BCAAs intake and odds of sarcopenia (OR for comparison of extreme tertiles 0.48, 95% CI 0.19–1.19, P-trend = 0.10) and its components (For muscle mass 0.83, 95% CI 0.39–1.77, P-trend = 0.63; for hand grip strength 0.81, 95% CI 0.37–1.75, P-trend: 0.59; for gait speed 1.22, 95% CI 0.58–2.57, P-trend = 0.56). After adjusting for potential confounders, this non-significant relationship did not alter. In addition, we did not find any significant association between individual BCAAs intake and odds of sarcopenia or its components. We found no significant association between dietary intakes of BCAAs and sarcopenia in crude model (OR 0.60; 95% CI 0.29–1.26). After controlling for several potential confounders, the result remained insignificant (OR 0.48; 95% CI 0.19–1.19). In this cross-sectional study, no significant association was observed between dietary intakes of total and individual BCAAs and odds of sarcopenia and its components.

Impact of Diets on Response to Immune Checkpoint Inhibitors (ICIs) Therapy against Tumors

Immunotherapy has revolutionized the established therapeutics against tumors. As the major immunotherapy approach, immune checkpoint inhibitors (ICIs) achieved remarkable success in the treatment of malignancies. However, the clinical gains are far from universal and durable, because of the primary and secondary resistance of tumors to the therapy, or side effects induced by ICIs. There is an urgent need to find safe combinatorial strategies that enhance the response of ICIs for tumor treatment. Diets have an excellent safety profile and have been shown to play pleiotropic roles in tumor prevention, growth, invasion, and metastasis. Accumulating evidence suggests that dietary regimens bolster not only the tolerability but also the efficacy of tumor immunotherapy. In this review, we discussed the mechanisms by which tumor cells evade immune surveillance, focusing on describing the intrinsic and extrinsic mechanisms of resistance to ICIs. We also summarized the impacts of different diets and/or nutrients on the response to ICIs therapy. Combinatory treatments of ICIs therapy with optimized diet regimens own great potential to enhance the efficacy and durable response of ICIs against tumors, which should be routinely considered in clinical settings.

Sex and genetic background define the metabolic, physiologic, and molecular response to protein restriction

Low-protein diets promote metabolic health in humans and rodents. Despite evidence that sex and genetic background are key factors in the response to diet, most protein intake studies examine only a single strain and sex of mice. Using multiple strains and both sexes of mice, we find that improvements in metabolic health in response to reduced dietary protein strongly depend on sex and strain. While some phenotypes were conserved across strains and sexes, including increased glucose tolerance and energy expenditure, we observed high variability in adiposity, insulin sensitivity, and circulating hormones. Using a multi-omics approach, we identified mega-clusters of differentially expressed hepatic genes, metabolites, and lipids associated with each phenotype, providing molecular insight into the differential response to protein restriction. Our results highlight the importance of sex and genetic background in the response to dietary protein level, and the potential importance of a personalized medicine approach to dietary interventions.

Fasting-Mimicking-Diet does not reduce skeletal muscle function in healthy young adults: a randomized control trial

PURPOSE

The aim of this study was to evaluate the short- and long-term effects of the Fasting-Mimicking-Diet (FMD) intervention on neuromuscular parameters of force production in healthy young men.

METHODS

Twenty-four physically active men completed the study. Participants were randomly assigned to Fasting-Mimicking (FMD) or Normal Diet (ND) and asked to follow three cycles of dietary intervention. Neuromuscular parameters of force production during maximal voluntary isometric contractions (MVCs) with the leg extensors muscles and anthropometrics were measured at baseline (T0), at the end of the first cycle (T1), and 7-10 days after the 3rd cycle of the nutritional intervention (T2). The study was registered on Clinicaltrials.gov (No. NCT04476615).

RESULTS

There was a significant decrease in body mass at T1 for FMD (- 2.6 kg, ∆ from baseline, on average; p < 0.05) but not in ND (- 0.1 kg;). Neuromuscular parameters of force production, muscle volume, and MVC torque did not change or differ between groups across visits. Results were similar even when parameters were normalized by muscle volume.

CONCLUSION

The consumption of FMD in a group of young healthy male subjects showed to be feasible, and it did not affect neuromuscular parameters of force production. The results suggest that FMD could be safely adopted by strength athletes without detrimental effects on force and muscle volume. Further research in clinical population at risk of muscle mass loss, such as elderly and obese subjects with sarcopenia, is warranted.

Ursolic acid improves the indoxyl sulfate-induced impairment of mitochondrial biogenesis in C2C12 cells

BACKGROUND/OBJECTIVES

Patients with chronic kidney disease (CKD) have a high concentration of uremic toxins in their blood and often experience muscle atrophy. Indoxyl sulfate (IS) is a uremic toxin produced by tryptophan metabolism. Although an elevated IS level may induce muscle dysfunction, the effect of IS on physiological concentration has not been elucidated. Additionally, the effects of ursolic acid (UA) on muscle hypertrophy have been reported in healthy models; however, it is unclear whether UA ameliorates muscle dysfunction associated with chronic diseases, such as CKD. Thus, this study aimed to investigate whether UA can improve the IS-induced impairment of mitochondrial biogenesis.

MATERIALS/METHODS

C2C12 cells were incubated with or without IS (0.1 mM) and UA (1 or 2 µM) to elucidate the physiological effect of UA on CKD-related mitochondrial dysfunction and its related mechanisms using real-time reverse transcription-polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay.

RESULTS

IS suppressed the expression of differentiation marker genes without decreasing cell viability. IS decreased the mitochondrial DNA copy number and ATP levels by downregulating the genes pertaining to mitochondrial biogenesis (Ppargc1a, Nrf1, Tfam, Sirt1, and Mef2c), fusion (Mfn1 and Mfn2), oxidative phosphorylation (Cycs and Atp5b), and fatty acid oxidation (Pdk4, Acadm, Cpt1b, and Cd36). Furthermore, IS increased the intracellular mRNA and secretory protein levels of interleukin (IL)-6. Finally, UA ameliorated the IS-induced impairment in C2C12 cells.

CONCLUSIONS

Our results indicated that UA improves the IS-induced impairment of mitochondrial biogenesis by affecting differentiation, ATP levels, and IL-6 secretion in C2C12 cells. Therefore, UA could be a novel therapeutic agent for CKD-induced muscle dysfunction.

Associations between mother-child dyad dietary patterns and child anthropometric measures among 6-year-old children

The goals of this study were to study relationships between maternal and children's dietary patterns (DPs) and to assess how children's DP was associated with child anthropometry. This cross-sectional study included 788 pairs of 6-year-old girls and mothers in health centers in Tehran, Iran. Information on dietary intake was collected with a 168-item food frequency questionnaire. Principal component factor analysis was performed to label different data-driven dietary patterns. Three different binary logistic regression models were used to evaluate the associations between child's DPs and child anthropometry. A positive correlation was found between all maternal patterns and child's Western DP (p < 0.001). Maternal prudent and Western DPs were correlated with child's high-protein DP (p < 0.001). Children's high-protein DP was negatively correlated with maternal high fat DP (p < 0.001). Maternal prudent and high fat DPs were correlated with prudent DP in children (p < 0.001). In adjusted models, a child being in the highest compared to the first quartile of the high-protein DP was associated with decreased odds of underweight and wasting (OR 0.43; 95% CI 0.23-0.80).Conclusion: The present study showed inverse associations between a high-protein DP in children and being underweight and wasted. Also, a positive correlation was found between all maternal DPs and children's Western DPs. This correlation should be taken into account while managing child nutrition by means of educating parents on the influence of their own dietary pattern on their children. Moreover, getting enough protein through a balanced diet should be considered in children. What is Known: • Some research exists on the intake of specific foods in relation to risk of abnormal growth in children. • Less is known about the relationship between mothers' and children's food intake. What is New: • Better adherence to a high-protein dietary pattern was significantly associated with lower risk of being both underweight and wasted. • This study suggests that correlation between mothers' and their children's dietary patterns exists, which should be taken into consideration when managing child nutrition.

Association of Sarcopenia with Osteopenia and Osteoporosis in Community-Dwelling Older Korean Adults: A Cross-Sectional Study

Sarcopenia and bone disorders, such as osteopenia and osteoporosis, are common musculoskeletal disorders in older adults. Therefore, this study aimed to establish the association between sarcopenia and bone disorders such as osteoporosis and osteopenia according to sex. We analyzed 3077 participants from the 2008-2011 Korean National Health and Nutrition Examination Survey aged 65 years or older. After adjusting for all covariates, such as physical examinations, exercise, and nutrient intake (model 4), the odds ratios for the association between sarcopenia and bone disorders were 2.051 (95% confidence interval [CI]: 1.498-2.808) in osteopenia and 2.258 (95% CI: 1.584-3.218) in osteoporosis. However, when sex was analyzed separately, the odds ratio was significantly different in men (osteopenia-2.068, 95% CI: 1.462-2.924; osteoporosis-3.247, 95% CI: 1.953-5.399), but not in women. Therefore, the results of this study show an association between sarcopenia and bone disorders in older Korean adults. Sarcopenia is significantly related to osteopenia and osteoporosis, especially in men, when stratified by sex.

Effect of Dietary Protein Intake on Bone Mineral Density and Fracture Incidence in Older Adults in the Health, Aging, and Body Composition Study

BACKGROUND

Dietary recommendations may underestimate the protein older adults need for optimal bone health. This study sought to determine associations of protein intake with bone mineral density (BMD) and fracture among community-dwelling White and Black older adults.

METHOD

Protein as a percentage of total energy intake (TEI) was assessed with a Food Frequency Questionnaire in 2160 older adults (73.5 ± 2.8 years; 51.5% women; 35.8% Black) in the Health, Aging, and Body Composition prospective cohort. Hip, femoral neck, and whole body BMD was assessed by dual-energy x-ray absorptiometry at baseline and 4 years, and lumbar trabecular, cortical, and integral BMD was assessed by computed tomography at baseline and 5 years. Fragility fractures over 5 years were adjudicated from self-report data collected every 6 months. Associations with tertiles of protein intake were assessed using analysis of covariance for BMD and multivariate Cox regression for fracture, adjusting for confounders.

RESULTS

Participants in the upper protein tertile (≥15% TEI) had 1.8%-6.0% higher mean hip and lumbar spine BMD compared to the lower protein tertile (<13% TEI; p < .05). Protein intake did not affect change in BMD at any site over the follow-up period. Participants in the upper protein tertile had a reduced risk of clinical vertebral fracture over 5 years of follow-up (hazard ratio: 0.36 [95% confidence interval: 0.14, 0.97] vs lower protein tertile, p = .04).

CONCLUSIONS

Older adults with higher protein intake (≥15% TEI) had higher BMD at the hip, whole body, and lumbar spine, and a lower risk of vertebral fracture.

Effects of marine oligomeric polyphenols on body composition and physical ability of elderly individuals with sarcopenia: a pilot study

PURPOSE

We aimed to identify the effects of marine oligomeric polyphenol (MOP) intake in elderly individuals with sarcopenia.

METHODS

Older adults (aged 65 years or older) were recruited based on the diagnostic criterion for sarcopenia and were randomly assigned to the MOP intake group (n=10) or the placebo (PBO) intake group (n=10). To determine the effect of MOP intake received for four weeks, the pre- and post-intake body composition (weight, skeletal muscle mass, and bone density) and senior fitness tests were assessed.

RESULTS

Our results showed there were significant differences in the skeletal muscle mass (p=0.039), bone density (p=0.020), fat-free mass index (p=0.026), and 2.4 m up and go test (p=0.001) between pretest and post-test. There was a significant difference between the pre-test and post-test and an interaction effect for the one-leg stand test (p=0.010 and p=0.049, respectively). However, there were no significant differences in body fat percentage, calf circumference, grip strength, or the chair rise test.

CONCLUSION

Some variables exhibited significant differences in the pre- and post-assessments, and there was an interaction effect for the one-leg stand. However, this was insufficient to prove the effectiveness of MOP intake in improving sarcopenia. Therefore, additional studies are essential to examine the effects of MOP intake and exercise intervention on the body composition and fitness of patients over a longer period.

[Protein intake in community-dwelling postmenopausal women and its relationship with sarcopenia]

OBJECTIVES

the general aging of the population is related to the increase in the prevalence of sarcopenic disease; especially among older women, this pathology is closely related to nutrition and specifically to protein consumption in older adults. The aim of our study was to evaluate the possible relationship between a low protein intake and a higher prevalence of sarcopenic disease, a worse dietary pattern, and lower physical performance in postmenopausal women living in the community.

MATERIAL AND METHODS

the study was carried out in a total of 164 independent women over 65 years of age, recruited from a municipal social center in Valencia (Benimaclet). The presence of sarcopenic pathology was evaluated using the latest algorithm published by EWGSOP2, and the intake of nutrients through a three-day dietary record. Physical performance was evaluated through the iPaq-e questionnaire, as well as the SPPB test and the 4-meter gait speed test.

RESULTS

the total sample comprised 164 women with a mean age of ± 72 years; 26.2 % of the sample had a protein intake lower than recommended by the FAO/WHO; 25.6 % of the women presented some stage of sarcopenia; regarding the prevalence of sarcopenic obesity, 12.2 % of the sample was affected by this disease. Significant relationships were found between protein consumption and the prevalence of sarcopenia (p = 0.021) and sarcopenic obesity (p = 0.043). Significant related differences were found between the majority of macronutrients and micronutrients under study and protein consumption. No relationship was found between protein intake and physical performance.

CONCLUSIONS

protein consumption in most of the women studied (73.8 %) was higher than the daily recommendations established by the FAO/WHO. There was a significant relationship between the prevalence of sarcopenia and sarcopenic obesity, and low protein intake. Higher protein intake was associated with a higher energy intake pattern. No relationship was found between protein intake and physical performance of the participants.

Determining the Influence of Habitual Dietary Protein Intake on Physiological Muscle Parameters in Youth and Older Age

Protein ingestion is a potent stimulator of skeletal muscle protein synthesis (MPS). However, older adults demonstrate resistance to anabolic stimuli. Some evidence has demonstrated that a larger acute protein dose is required in older compared to younger adults to elicit the same synthetic response, suggesting that older adults should be consuming higher habitual dietary protein to optimise muscle mass. However, limited research has explored dietary habits in different age groups or the relationship between habitual dietary intake and mechanistic physiological parameters associated with muscle mass and function. This work investigated the effect of habitual dietary intake in young (n = 10, 25.9 (3.2y)) and older (n = 16, 70.2 (3.2y)) community-dwelling adults (16:10 male: female) on physiological muscle parameters. Dietary intake was assessed using four-day diet diaries. Post-absorptive MPS and MPS responses to feeding (4.25x basal metabolic rate; 16% protein) were determined in muscle biopsies of the m. vastus lateralis via stable isotope tracer ([1, 2^-13C₂]-leucine) infusions with mass-spectrometric analyses. Body composition was measured by dual-energy x-ray absorptiometry. Whole body strength was assessed via 1-repetition maximum assessments. No significant differences in habitual dietary intake (protein, fat, carbohydrate and leucine as g.kgWBLM^-1.day^-1) were observed between age groups. Whole-body lean mass (61.8 ± 9.9 vs. 49.8 ± 11.9 kg, p = 0.01) and knee-extensor strength (87.7 ± 28.3 vs. 56.8 ± 16.4 kg, p = 0.002) were significantly higher in young adults. Habitual protein intake (g.kg^-1.day^-1) was not associated with whole-body lean mass, upper-leg lean mass, whole-body strength, knee-extensor strength, basal MPS or fed-state MPS across both age groups. These findings suggest that differences in muscle mass and strength parameters between youth and older age are not explained by differences in habitual dietary protein intake. Further research with a larger sample size is needed to fully explore these relationships and inform on interventions to mitigate sarcopenia development.

Sarcopenia: Etiology, Nutritional Approaches, and miRNAs

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization.

Jiangnan dietary pattern actively prevents muscle mass loss: Based on a cohort study

BACKGROUND

The proportion of sarcopenia in the elderly is very high, although muscle mass loss before sarcopenia covers a wider population. The present study aimed to analyse the effects of different dietary patterns on muscle mass.

METHODS

In both 2015 and 2018, using multilayer random sampling, the same participants were selected, and the same questionnaires and machines were used.

RESULTS

In total, 502 participants were selected. The >65-year-old group showed maximum muscle mass loss in males and females (-1.53 kg ± 4.42 and -1.14 kg ± 2.6 on average, respectively). The cumulative variance of four dietary patterns reached 52.28%. Logistical regression revealed significant differences between 'Jiangnan Dietary' groups: Q2 vs. Q1 [odds ratio (OR) = 0.356, 95% confidence interval (CI) = 0.202-0.629]; Q3 vs. Q1 (OR = 0.457, 95% CI = 0.262-0.797). Relative influence factors for muscle mass loss were age (>65 vs. <45, OR = 2.027, 95% CI = 1.117-3.680), physical activity (OR = 0.550, 95% CI = 0.315-0.960), income (high vs. low, OR = 0.413, 95% CI = 0.210 -0.810), sex (female vs. male, OR = 0.379, 95% CI = 0.235-0.519).

CONCLUSIONS

After 3 years of follow-up, participants' muscle mass declined significantly. The 'Jiangnan Dietary' pattern prevented muscle mass loss and is recommended to the wider population.

The regulation of healthspan and lifespan by dietary amino acids

As a key macronutrient and source of essential macromolecules, dietary protein plays a significant role in health. For many years, protein-rich diets have been recommended as healthy due to the satiety-inducing and muscle-building effects of protein, as well as the ability of protein calories to displace allegedly unhealthy calories from fats and carbohydrates. However, clinical studies find that consumption of dietary protein is associated with an increased risk of multiple diseases, especially diabetes, while studies in rodents have demonstrated that protein restriction can promote metabolic health and even lifespan. Emerging evidence suggests that the effects of dietary protein on health and longevity are not mediated simply by protein quantity but are instead mediated by protein quality - the specific amino acid composition of the diet. Here, we discuss how dietary protein and specific amino acids including methionine, the branched chain amino acids (leucine, isoleucine, and valine), tryptophan and glycine regulate metabolic health, healthspan, and aging, with attention to the specific molecular mechanisms that may participate in these effects. Finally, we discuss the potential applicability of these findings to promoting healthy aging in humans.

Short-Term Protein Supplementation Does Not Alter Energy Intake, Macronutrient Intake and Appetite in 50-75 Year Old Adults

Ageing is associated with a reduction in muscle mass and strength, termed sarcopenia. Dietary protein is important for the maintenance of muscle mass through the promotion of muscle protein synthesis. However, protein is also reported to be a highly satiating nutrient. This raises concerns that protein intake for musculoskeletal health reasons in older adults may exacerbate age-related decreased appetite and may result in reduced energy and nutrient intake. This study aimed to investigate the effect of short-term protein supplementation and its timing (morning vs. evening), on energy and nutrient intake and appetite measures in middle-older age adults. Twenty-four 50-75 year olds were recruited to a randomised cross-over trial. In phase 1 (pre-supplementation) participants completed a food diary and reported hunger and appetite on three alternate days. During the second and third phases, participants consumed a 20 g whey protein gel (78 mL/368 kJ), for four days, either in the morning (after breakfast) or the evening (before bed), whilst completing the same assessments as phase 1. No differences in dietary intakes of energy, macronutrients and micronutrients were recorded when comparing the pre-supplementation phase to the protein supplementation phases, irrespective of timing (excluding the contribution of the protein supplement itself). Similarly, no differences were observed in self-reported feelings of hunger and appetite. In conclusion, a 20 g/day whey protein supplement given outside of meal-times did not alter habitual dietary intakes, hunger or appetite in this middle-older age adult population in the short-term. This approach may be a useful strategy to increasing habitual protein intake in the middle-older age population.

Energy Intake Is Highly Associated with Handgrip Strength in Community-Dwelling Elderly Adults

BACKGROUND

Handgrip strength (HGS) is used to assess muscle strength, which is an important indicator of health status in older adults.

OBJECTIVE

We evaluated associations of demographic, anthropometric, clinical, and nutritional factors with muscle strength in community-dwelling elderly adults.

METHODS

This population-based cross-sectional study employed the 2014-2015 Israeli Health and Nutrition Survey in the Elderly (n = 1039, age ≥65 y, 46.7% males, 9.9% Arabs). Trained personnel performed face-to-face interviews that focused on health and nutrition status, as well as anthropometric measurements and examinations. HGS was measured in the dominant hand 3 times using a digital grip strength dynamometer; the highest result was reported. Dietary intake data were collected using single-day 24-h recall. Multivariable logistic regressions were used to explore factors associated with low HGS (<27 kg for men and <16 kg for women).

RESULTS

HGS measurements were completed by 704 participants. Following adjustment for several factors, higher prevalence of low HGS was significantly associated with age (OR: 1.14; 95% CI: 1.11, 1.18), whereas decreased prevalence was associated with higher levels of education (OR: 0.55; 95% CI: 0.32, 0.94) and meeting physical activity recommendations (OR: 0.53; 95% CI: 0.31, 0.88); P < 0.05 for all. Incremental increases of 100 kcal/d in energy intake and of 1 cm in midarm circumference were associated with decreased prevalence of low HGS (OR: 0.95; 95% CI: 0.91, 0.99 and OR: 0.91; 95% CI: 0.85, 0.97, respectively; P < 0.01 for both). Associations were not found of low HGS with ethnicity, comorbidity, BMI, smoking, or alcohol consumption or with protein, carbohydrate, or fat intakes.

CONCLUSION

Energy intake, physical activity, midarm circumference, and education are associated with HGS in elderly Israeli adults. Further cohort studies are necessary to assess possible causal relations between these factors and HGS. Modifiable factors should be targeted in planning public health strategies for promoting a healthy aging population.

The influence of the interaction of sous-vide cooking time and papain concentration on tenderness and technological characteristics of meat products

The food industry has been slow in harnessing technological developments to expand opportunities and benefit the community. One such opportunity is in the application of proteolytic enzymes to the development of softer-textured meat products that require reduced mastication force, for those with impaired dentition, and reduced strength including older adults. Proteolytic enzymes haven't been fully explored for their potential in this area. Here a response surface methodology (RSM) was applied to model the interactive effects of sous-vide and papain application on texture, color, and cooking loss of meat. An innovative meat product formulation with a reduced toughness (120 min cooking sous-vide and 0.01 mg papain/100 g) was optimized and the technological performance of the formulation was validated. Bias values of the optimized model were in the range of 0.97 to 1.06, while accuracy factors for shear force values, chewiness, TPA hardness, cooking loss, color parameters ranged from 1.00 and 1.06, both of which metrics indicated the reliability of the resultant models.

Role of plant protein in nutrition, wellness, and health

Plant-based diets, and more specifically plant-based proteins, have been the subject of growing interest from researchers and consumers because of their potential health benefits as well as their positive environmental impact. Of course, plant proteins are found in plant foods, and positive health benefits of plant foods are linked to dietary fiber, vitamins, minerals, and phytochemicals. In epidemiological studies it is not possible to separate out the health benefits of plant foods in general as opposed to plant proteins specifically. Additionally, few vegans, who consume only plant-based proteins, are included in existing prospective cohort studies. Isolated plant proteins (soy, pea) have been used in intervention trials, but often to improve biomarkers linked to disease risk, including serum lipids or blood pressure. This review is an overview of plant proteins, the whole foods they are associated with, and the potential health benefits linked to consumption of protein from plant sources. Plant proteins and their potential for reducing the risk of developing metabolic syndrome, diabetes management, cancer prevention, and weight management are each discussed, as are the various rating systems currently used to determine protein quality from plant sources. Although additional research is needed that focuses specifically on the role that plant protein plays in the prevention and management of these chronic illnesses, rather than the role played by a more general plant-based diet, evidence suggests that plant proteins offer nutritional benefits to those who consume them. Limitations to plant proteins, including lower protein quality, must also be considered in this discussion.

Validation of the Thai version of SARC-F, MSRA-7, and MSRA-5 questionnaires compared to AWGS 2019 and sarcopenia risks in older patients at a medical outpatient clinic

Objectives

To validate the Thai Strength, Assistance with walking, Rise from a chair, Climb stairs and Falls (SARC-F), and 2 Mini Sarcopenia Risk Assessment (MSRA-5, and MSRA-7) questionnaires for sarcopenia screening in older patients in the medical outpatient setting, and to assess the improvements of the diagnostic accuracy by adapting the parameters in the SARC-F, MSRA-7, and MSRA-5 questionnaires. Risk factors for sarcopenia are also investigated.

Methods

Thai SARC-F, MSRA-7, and MSRA-5 questionnaires were translated backwards and forwards. Content validity and test–retest reliability were analyzed. Reliability analysis was used for SARC-F, MSRA-7, and MSRA-5 scores to increase the sensitivity and specificity. The sensitivity, specificity, likelihood ratio, and area under the receiver operating characteristic curves (AUCs) were analyzed.

Results

The prevalence of sarcopenia was 22.7% (65 of 286 patients). The sensitivity of the SARC-F, MSRA-7, and MSRA-5 questionnaires was 21.5%, 72.3%, and 61.5%, respectively. The specificity was 93.7%, 43%, and 67.4%, respectively. The AUCs were 0.58, 0.58, and 0.65, respectively. After weighting and adjusting the scores for the least responded-to items of the MSRA-5, the sensitivity increased to 82.6%, specificity to 43.4%, and AUC to 0.65. Multivariate analysis showed that the associated factors of sarcopenia were age [odds ratio (OR) = 5.92], body mass index < 18.5 [OR = 9.59], and currently working [OR = 0.11].

Conclusions

The modified MSRA-5 improved the sensitivity and diagnostic accuracy for screening for sarcopenia. It is potentially useful for screening for sarcopenia in settings with limited resources for bioelectrical impedance analysis, time, or health personnel.

Prevalence and risk factors of primary sarcopenia in community-dwelling outpatient elderly: a cross-sectional study

No previous study has investigated the prevalence and risk factors for primary sarcopenia in outpatient setting. This study aims to evaluate the prevalence and factors associated with primary sarcopenia in outpatient elderly. Additionally, we compared the severity of sarcopenia based on the 2014 and 2019 Asian Working Group for Sarcopenia (AWGS) criteria. This cross-sectional study was performed in 330 subjects aged over 60 years in an outpatient setting. The muscle strength, muscle performance and muscle mass were assessed using the handheld dynamometer, 6-m gait speed, and bioelectrical impedance analysis, respectively. The prevalence of sarcopenia was 10% as per the 2014 and 2019 AWGS criteria. The development of sarcopenia was positively correlated with the age with an odds ratio (OR) of 6.87 [95% confidence interval (CI) 1.63–28.88] in the middle-old group (70–79 years), and 13.71 (95%CI 3.66–51.41; p = 0.009) in the very old group (≥ 80 years). Prefrailty and low physical activity were significantly associated with sarcopenia with an OR of 4.75 (95%CI 1.90—11.89) in prefrailty, 15.35 (95%CI 1.69–139.47) in the middle activity group, and 17.99 (95%CI 1.95–165.73) in the lowest activity group. In conclusion, primary sarcopenia was found in one-tenth of outpatient elderly. Age, prefrailty, and low activity were independent factors associated with sarcopenia.

Long-term effects of a food pattern on cardiovascular risk factors and age-related changes of muscular and cognitive function

INTRODUCTION

The mean age of the German population increased over the last years, which resulted in a higher prevalence of cardiovascular diseases, type 2 diabetes, cognitive impairment, sarcopenia and bone fractures. Current evidence indicates a preservation of human wellbeing in the elderly by a healthy diet, although the recommended macronutrient composition and quality remains unclear and needs further long-term investigation. In this context we investigate the effect of a specific dietary pattern on age-related disorders in a randomized controlled multi-center trial (RCT).

METHODS

We assess the effect of a specific dietary pattern (NutriAct) with a high proportion of unsaturated fat, plant proteins and fibres (fat 35%-40% of total energy (%E) of which 15%E-20%E monounsaturated fatty acids (MUFA) and 10%E-15%E polyunsaturated fatty acids (PUFA), 15%E-25%E proteins, ≥30 g fibres per day and 35%E-45%E carbohydrates) on age-related impairment of health within a 36-months RCT conducted in the region of Berlin and Potsdam. 502 eligible men (n = 183) and women (n = 319), aged 50 to 80 years, with an increased risk to develop age-related diseases were randomly assigned to either an intervention group focusing on NutriAct dietary pattern or a control group focusing on usual care and dietary recommendations in accordance to the German Nutrition Society (DGE). In the intervention group, 21 nutrition counsellings as well as supplementation of rapeseed oil, oil cake and specific designed foods are used to achieve the intended NutriAct dietary pattern.The primary outcome is a composite endpoint of age-related disorders, including cardiovascular morbidity, decline of cognitive function as well as clinical features of sarcopenia. Secondary outcomes include diet-induced effects on quality of life, depression, frailty, cardiovascular function, bone density, fat distribution pattern, glucose, lipid and energy metabolism, as well as the identification of biomarkers linked with age-related disorders.

DISCUSSION

The findings of this trial will provide clinically relevant information regarding dietary effects on age-related impairment of health and will contribute to the definition of the optimal macronutrient composition in the context of healthy aging in the German population.

Muscle Wasting and Sarcopenia in Heart Failure-The Current State of Science

Sarcopenia is primarily characterized by skeletal muscle disturbances such as loss of muscle mass, quality, strength, and physical performance. It is commonly seen in elderly patients with chronic diseases. The prevalence of sarcopenia in chronic heart failure (HF) patients amounts to up to 20% and may progress into cardiac cachexia. Muscle wasting is a strong predictor of frailty and reduced survival in HF patients. Despite many different techniques and clinical tests, there is still no broadly available gold standard for the diagnosis of sarcopenia. Resistance exercise and nutritional supplementation represent the currently most used strategies against wasting disorders. Ongoing research is investigating skeletal muscle mitochondrial dysfunction as a new possible target for pharmacological compounds. Novel agents such as synthetic ghrelin and selective androgen receptor modulators (SARMs) seem promising in counteracting muscle abnormalities but their effectiveness in HF patients has not been assessed yet. In the last decades, many advances have been accomplished but sarcopenia remains an underdiagnosed pathology and more efforts are needed to find an efficacious therapeutic plan. The purpose of this review is to illustrate the current knowledge in terms of pathogenesis, diagnosis, and treatment of sarcopenia in order to provide a better understanding of wasting disorders occurring in chronic heart failure.

Effectiveness of Protein Supplementation Combined with Resistance Training on Muscle Strength and Physical Performance in Elderly: A Systematic Review and Meta-Analysis

The aim of this study was to evaluate the effectiveness of the combination of resistance training (RT) and protein supplementation (PS), compared to RT alone or combined with a placebo (plS), in the improvement of muscle strength and physical performance. The search strategy in PubMed, Cochrane Library, and Web of Sciences databases found a total of 294 studies. Once inclusion and exclusion criteria were applied, 16 studies were included for the qualitative analysis. A total of 657 healthy elderly (>60 years) participants were analysed. Finally, 15 articles were included in the quantitative analysis with one being excluded due to issues with data availability. Upper-limb, lower-limb, and handgrip strength were the primary outcomes of the meta-analysis. The secondary outcomes, related to physical performance, were Short Physical Performance Battery (SPPB), gait speed, and the five-chair-rise test (5CRT). The main results of the meta-analysis show no statistical differences for upper-limb (SMD: 0.56, 95% CI: -0.09, 1.21, p = 0.09, I2 = 68%), lower-limb (SMD: 0.00, 95% CI: -0.18, 0.18, p = 1.0, I2 = 11%), and handgrip strength (SMD: 0.03, 95% CI: -0.26, 0.32, p = 0.84, I2 = 0%) between the RT + PS and the RT alone (or combined with plS). Moreover, no statistical differences were found relating to physical performance. In view of these results, protein supplementation combined with RT does not provide additional benefits compared to RT alone or with plS in healthy elderly adults.

The Effects of Cow-Milk Protein Supplementation in Elderly Population: Systematic Review and Narrative Synthesis

BACKGROUND

To review currently available evidence on the effect of cow-milk proteins supplementation (CPS) on health in the elderly.

METHODS

Five electronic databases (Pubmed, Web of Science, Embase, Cochrane Library, ClinicalTrials.gov) were searched for studies about CPS among older people. All types of publications were included, with the exception of systematic reviews, meta-analyses, opinion letters, editorials, case reports, conference abstracts and comments. An additional search in Google Scholar and a manual review of the reference lists were performed.

RESULTS

Overall, 103 studies were included. Several studies explored the role of CPS in the preservation or improvement of muscle mass among healthy subjects (40 studies) and pre-frail, frail or sarcopenic patients (14), with evidence of beneficial effects. Other studies assessed the effect of CPS on bones (12), cardiovascular disease (8), inflamm-aging (7), chronic pulmonary disease (4), neurocognitive function (4), and vaccines (2), with weak evidence of positive effects. Seven studies in the field of protein metabolism investigated the role of CPS as an important contributor to nutritional needs. Other investigational areas are considered in the last five studies.

CONCLUSIONS

The beneficial effects of CPS in achieving aged-related nutritional goals, in preserving muscle mass and in recovering after hospitalization may be particularly relevant in the elderly.