Low protein intake, muscle strength and physical performance in the very old: The Newcastle 85+ Study

Effectiveness of Protein-enriched oral nutritional supplements on muscle function in middle-aged and elderly women: A randomized controlled trial

OBJECTIVES

This study evaluated the effects of protein-enriched oral nutritional supplementation (ONS) consumption for 12 weeks on muscle mass, muscular strength, and function in middle-aged and elderly women.

DESIGN

A single-center, double-blind, randomized controlled trial PARTICIPANTS: This study was conducted with 70 healthy female participants aged 50-80.

INTERVENTION AND MEASUREMENTS

Participants were instructed to incorporate two daily packs of either the test ONS (Nucare Active, Daesang Wellife Corp., Seoul, Republic of Korea; 200 kcal/pack, 23 g carbohydrate, 6 g fat, and 15 g protein including branched chain amino acids or placebo ONS (200 kcal/pack, 33 g carbohydrate, 8 g fat, and 1 g protein) into their routine for 12 weeks while maintaining their regular lifestyle. The primary outcome was lean body mass (LBM), while secondary outcomes included muscular strength, physical performance ability, inflammatory markers, and body fat mass (FM).

RESULTS

Sixty-four participants (33 in the test group, 31 in the placebo group; mean ± SD age, [test] 63.06 ± 5.51 years, [placebo] 63.29 ± 3.28 years, p = 0.839) completed the 12-week protocol. The test group exhibited a higher percentage change in LBM than the placebo group (0.26 % [95%CI: -0.27, 0.78] vs. -0.47 % [95%CI: -0.81, -0.13]; p = 0.020). The placebo group experienced a significant increase in FM (38.15 % [95%CI: 36.62, 39.69] to 38.67 % [95%CI: 37.14, 40.21]; p < 0.01). The difference in the changes in LBM/BMI and FM/BMI between the two groups was also visually distinct. There were no significant differences between the two groups in terms of muscular strength, physical performance ability, or inflammatory markers.

CONCLUSIONS

Protein-enriched ONS helped maintain LBM and prevent FM gain in middle-aged and elderly females. This suggests its potential role in preventing frailty and musculoskeletal disorders associated with female aging.

The Effect of Protein Intake on Bone Disease, Kidney Disease, and Sarcopenia: A Systematic Review

Background

Protein is essential for optimal growth, function, and maintenance of health. Its impact on bone, kidney health, and sarcopenia progression remains debated.

Objectives

This review examines the association between dietary protein intake and the risk of bone disease, kidney disease, and sarcopenia to inform protein dietary reference intake updates.

Methods

We searched Medline, EMBASE, AGRICOLA, and Scopus from January 2000 to May 2024, supplemented by citation searching for relevant reviews and original research. We included randomized and nonrandomized controlled trials, prospective cohort studies, and nested case-control studies examining dietary protein intake without exercise. We assessed the risk of bias (RoB), performed a qualitative synthesis of low to moderate RoB studies, and evaluated the strength of evidence.

Results

Of 82 articles detailing 81 unique studies, only 13 were assessed with low to moderate RoB and synthesized, comprising bone disease [4 randomized controlled trials (RCTs) and 1 prospective cohort study], kidney disease (1 RCT), and sarcopenia (9 RCTs). The overarching evidence was insufficient, largely due to the limited number of low to moderate RoB studies, the diversity of dietary protein interventions, and the broad range of outcomes, which complicated synthesis and comparison. Notably, sparse literature addressed children and adolescents, and only a single study each examined the impact of dietary protein intake on bone disease risk (yielding mixed findings) in these populations and on kidney disease risk (showing no significant effects) in adults. The findings on the impact of protein intake on bone disease in adults and sarcopenia risk were mixed; some studies showed no effect, whereas others indicated benefits.

Conclusions

The evidence since 2000 on associations between dietary protein intake and the risks of bone disease, kidney disease, and sarcopenia is unclear, indicating a need for more rigorous research.This trial was registered at PROSPERO as CRD42023446621.

Postprandial plasma amino acid and appetite responses to a low protein breakfast supplemented with whey or pea protein in middle-to-older aged adults

The addition of low-dose protein to low protein-containing meals in middle-to-older aged adults may promote greater postprandial plasma aminoacidemia and mitigate declines in muscle health but may be dependent on the source and quality of protein consumed. This single-blind randomised study investigated postprandial plasma aminoacidemia and appetite regulatory responses to a typical lower protein-containing (∼0.07 g·kg body mass[BM]-1) mixed breakfast supplemented with ∼0.13 g·kg BM- 1 of whey protein concentrate (MB + WPC) or pea protein isolate (MB + PPI) in middle-to-older aged adults. Venous blood samples were collected whilst fasted and over a 180-min postprandial period to determine plasma amino acid and appetite hormone concentrations. Perceived appetite ratings were measured using Visual Analogue Scales. Plasma total amino acids and essential amino acids increased over time (both P < 0.05) with no between-group differences or overall availability over 180 min (incremental area under the curve (iAUC)). Plasma leucine concentrations increased over time (both P < 0.05) with greater peak concentrations (P = 0.032) and iAUC (P = 0.012) in MB + WPC compared with MB + PPI. Plasma total-ghrelin and total-GLP-1 concentrations and perceived ratings of hunger, fullness, and satiety were transiently altered following MB + WPC and MB + PPI (P < 0.05 for all), with no differences between groups. In middle-to-older aged adults, co-ingesting a small bolus of whey protein alongside a typical lower protein-containing breakfast elicits greater plasma leucinemia than co-ingestion of pea protein, with no differential impact on appetite regulation. Whether the addition of low-dose whey protein to typical meals of middle-to-older aged adults can enhance muscle anabolism without adversely affecting appetite remains to be determined.

Effect of Plant Versus Animal Protein on Muscle Mass, Strength, Physical Performance, and Sarcopenia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Dietary protein is recommended for sarcopenia-a debilitating condition of age-related loss of muscle mass and strength that affects 27% of older adults. The effects of protein on muscle health may depend on protein quality.

OBJECTIVE

The aim was to synthesize randomized controlled trial (RCT) data comparing plant with animal protein for muscle health.

DATA SOURCES

Forty-three eligible RCTs were sourced from Medline, Embase, Scopus, Web of Science, and CENTRAL databases.

DATA EXTRACTION

Four reviewers (R.J.R.-M., S.F.B., N.A.W., D.L.) extracted data from RCTs (study setting, population, intervention characteristics, outcomes, summary statistics) and conducted quality assessment using the Cochrane Risk of Bias 2.0.

DATA ANALYSIS

Standardized mean differences (SMDs) (95% CIs) were combined using a random-effects meta-analysis and forest plots were generated. I2 statistics were calculated to test for statistical heterogeneity.

CONCLUSION

Thirty RCTs (70%) were eligible for meta-analysis and all examined muscle mass outcomes. Compared with animal protein, plant protein resulted in lower muscle mass following the intervention (SMD = -0.20; 95% CI: -0.37, -0.03; P = .02), with stronger effects in younger (<60 years; SMD = -0.20; 95% CI: -0.37, -0.03; P = .02) than in older (≥60 years; SMD = -0.05; 95% CI: -0.32, 0.23; P = .74) adults. There was no pooled effect difference between soy and milk protein for muscle mass (SMD = -0.02; 95% CI: -0.20, 0.16; P = .80) (n = 17 RCTs), yet animal protein improved muscle mass compared with non-soy plant proteins (rice, chia, oat, and potato; SMD = -0.58; 95% CI: -1.06, -0.09; P = .02) (n = 5 RCTs) and plant-based diets (SMD = -0.51; 95% CI: -0.91, -0.11; P = .01) (n = 7 RCTs). No significant difference was found between plant or animal protein for muscle strength (n = 14 RCTs) or physical performance (n = 5 RCTs). No trials examined sarcopenia as an outcome. Animal protein may have a small beneficial effect over non-soy plant protein for muscle mass; however, research into a wider range of plant proteins and diets is needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020188658.

The effects of dietary protein on physical performance and body composition in middle age and older people having type II diabetes mellitus: a randomized pilot study

PURPOSE

Protein supplementation has been proposed as an effective dietary strategy for maintaining or increasing skeletal muscle mass and improving physical performance in middle-aged and older adults. Diabetes mellitus exacerbates muscle mass loss, leading to many older adults with type 2 diabetes mellitus (T2DM) experiencing sarcopenia, and vice versa. Our objective was to assess the impact of increased dietary protein intake on muscle mass, strength, physical performance, and the progression of T2DM in middle-aged and older adults diagnosed with this condition.

METHODS

A 12-week randomized, controlled, parallel pilot study was conducted with 26 patients diagnosed with T2DM and had either low muscle mass, or low muscle strength or poor physical performance (age > 55 years old), aiming to investigate the effects of a protein-rich diet in sarcopenic and metabolic markers. The control group received 0.8-1.0 g/kg/day, while the intervention group received 1.2-1.5 g/kg/day of protein respectively. Body composition, muscle mass/strength and biochemical parameters were measured before and after the intervention period.

RESULTS

Different kinetics of skeletal muscle index (SMI), appendicular lean mass (ALM), hand grip strength (HGS), gait speed (GS) and standing balance (SB) (p < 0.05) were observed between two groups. Specifically, the intervention group showed a significant improvement in HGS (p < 0.001) and physical performance (timed-up-and-go, p < 0.001; GS, p = 0.011; SB, p = 0.022), while the control group had its ALM (p = 0.014), SMI (p = 0.011) and HGS (p = 0.011) significantly reduced. The kinetics of metabolic markers indices was similar for both groups.

CONCLUSION

Current recommendation for protein intake (0.8-1 g/kg/day) is certainly not enough to ameliorate the muscle mass loss in middle age and older adults' individuals with T2DM. In contrast, protein intake of 1.2-1.5 g/kg/day seems to be a more appropriate recommendation to combat upcoming sarcopenia, nonetheless the progression of T2DM was not interrupted.

Association between diet protein score comprising plants to animal protein ratio and body composition in an Iranian population

Obesity is increasingly recognized as a leading cause of death and is associated with various comorbidities. This study evaluates the relationship between protein score, characterized by the plant-to-animal protein ratio (PAR) and total protein per calorie (Pro%), and body composition: fat percentage (FATP), fat mass (FATM), and fat-free mass (FFM). We categorized 4512 individuals (55.2% female) into tertiles based on their protein score and its components. Male participants in the highest and middle protein score tertiles exhibited significantly greater FFM in both adjusted and crude models, and lower FATP and FATM in adjusted model 2. FFM was elevated in the top (P < 0.001) and middle (P = 0.002) Pro% tertiles in males in both adjusted models and only in the top tertile of all models in females (P = 0.003). The analysis of male participants revealed significantly lower FATP and FATM in the highest tertiles of Pro% in adjusted models. Among female participants, only the highest PAR tertile was associated with significantly lower FATM in adjusted model 1 (P = 0.042). Our findings indicate that protein score and its components are associated with favorable body composition differences. Health administrators may leverage these insights to refine dietary guidelines.

Effect of Lactational Low-Protein Diet on Skeletal Muscle during Adulthood and Ageing in Male and Female Mouse Offspring

Sarcopenia is characterised by the loss of skeletal muscle mass and function, which leads to a high risk of increased morbidity and mortality. Maternal malnutrition has been linked to impaired development of skeletal muscle of the offspring; however, there are limited studies that report the long-term effect of a maternal low-protein diet during lactation on the ageing of skeletal muscles. This study aimed to examine how a maternal low-protein diet (LPD) during lactation affects skeletal muscle ageing in the offspring. Pups born from control mothers were lactated by mothers fed with an LPD. Post-weaning, mice were either maintained on an LPD or switched to a control, normal-protein diet (NPD). In males, an LPD mainly affected the size of the myofibres without a major effect on fibre number and led to reduced grip strength in ageing mice (24 months). Female mice from mothers on an LPD had a lower body and muscle weight at weaning but caught up with control mice at 3 months. During ageing, the muscle weight, myofibre number and survival rate of female pups were significantly affected. These findings highlight the effect of an LPD during lactation on skeletal muscle ageing, the lifespan of offspring and the importance of sexual dimorphism in response to dietary challenges.

The Effect of Chronic Dietary Protein Manipulation on Amino Acids' Profile and Position Sense in the Elderly Suffering from Type 2 Diabetes Mellitus

Dietary protein with adequate essential amino acids effectively stimulates protein synthesis and improves muscle mass. Musculoskeletal disorders in lower or upper limbs are not uncommon among patients with type II diabetes mellitus (T2DM). Therefore, this study primarily examines the effects of chronic dietary protein manipulation on amino acids' profile and position sense in the elderly suffering from T2DM. A total of 26 individuals suffering from non-insulin-dependent T2DM (age > 55 years old) participated in a 12 week nutritional intervention. The subjects were randomly assigned and the control group received 0.8-1.0 g protein/kg/day, while the intervention group received 1.2-1.5 g protein/kg/day. Lean body mass, muscle strength, and position sense were assessed at baseline, as well as at the 6th and 12th week of the intervention. Only in the intervention group, the essential amino acids intake met the current nutritional recommendations (p < 0.05), while, by the 12th week, only the intervention group showed significant improvement in the muscle strength of knee (p < 0.05) and shoulder (p < 0.05) extension. On the contrary, in the control group, a significant decline in appendicular lean mass (p < 0.05) was observed by the 12th week. Position sense at the knee joint revealed a tendency for improvement in the intervention group by the 12th week (main effect of time p = 0.072). In the present investigation, it was revealed that the higher protein intake in the intervention group seemed to have positive effects on muscle strength and nearly positive effects on position sense.

Relationship of protein, calcium and vitamin D consumption with body composition and fractures in oldest-old independent people

BACKGROUND & AIM

Some studies state that the protein intake has a protective effect against bone mass loss, while others show that the combination of low calcium intake and high protein consumption increases the risk of fractures. Perhaps this phenomenon is also altered by the consumption of vitamin D after the age 80 years. This study aimed to identify if there is an association of protein, calcium and vitamin D intake with body composition and fractures in community dwelling 80 years or older independent people.

METHODS

This is a cross-sectional observational analytic study. We invited community dwelling 80 years or older independent people, with chronic diseases under control, according to the scientific guidelines. The food intake was obtained through a one-day food record (FR) and Avanutri software (4.1 version) was used to calculate the intake of total calories, calcium, protein, and other food nutrients. The body composition and bone densitometry were evaluated by whole-body Dual Energy X-ray Absorptiometry (DXA). The morphometric vertebral fractures were assessed through conventional X-ray of the vertebral, level T4 to L4, on side face position - semi quantitative technique.

RESULTS

One hundred and fifty-nine 80 years or older independent people, mean age 87.0 ± 3.9 years old were studied. The mean calcium intake was 834.6 ± 374.7 mg/day and vitamin D was 6.1 ± 24.3 μg/day, in both cases they were complemented by supplements to reach the recommendations. The mean protein intake was 72.9 ± 26.8 g/day, we found that 48.4% had low muscle mass; there was a frequency of 45.3% of osteoporosis; and vertebral fractures in 24.7% of them. The estimates of the logistic regression model with the outcome variable obesity and low muscle mass with reference to "low muscle mass" showed that the 80 years or older independent people who have a fracture are more likely to be obese with low muscle mass compared to those with only low muscle mass.

CONCLUSION

In the studied population of 80 years or older independent people, we observed that among all the nutrients studied, only dietary protein per g/kg/day was associated with body composition and bone mineral density, but not with fracture, although the elderly who have fracture are more likely to be obese with low muscle mass compared to those not obese with low muscle mass. More studies about nutrients intakes and its relationship with muscle and bone health in this population is necessary.

Biological ageing and the risk of decreased handgrip strength among community-dwelling older adult Indians: a cross-sectional study

BACKGROUND

Evidence from the literature demonstrates that the risk of decreased handgrip strength is associated with various health issues, particularly in older persons. To make judgments regarding their general health condition that are well-informed for longevity, it is crucial to assess the risk level of decreased handgrip strength among community-dwelling older adult Indians. However, no study has examined the relationship between biological aging and the risk of decreased handgrip strength in Indian men and women aged 60 and older. The goal of the current study was to fill this gap in the literature.

METHODS

In this cross-sectional study, we included 31,464 (15,098 men and 16,366 women) community-dwelling older adult Indians aged 60 years and older using data from the Longitudinal Aging Study in India (LASI). The LASI is the world's most extensive and India's first multidisciplinary, internationally harmonized, longitudinal aging study. It has enrolled 72,250 individuals aged 45 and above across all 28 states and 8 union territories of India. Secondary analysis of biological ageing was performed by stratifying for age groups (60-64, 65-69, 70-74, 75-79, 80-84, and 85 + years) for both genders. The dominant right and nondominant left handgrip strength was assessed using the portable Smedley's Hand Dynamometer. All individuals had a dominant right hand. The adjusted logistic regression analysis assessed the association between biological ageing and the risk of decreased handgrip strength for both genders.

RESULTS

Compared to those between the ages of 60-64, those at age 65 and those aged 85 and above had 1-fold and 12-fold odds of decreasing handgrip strength, respectively. Men 85 years or older had a 12-fold higher chance than women in the same age group of having decreased handgrip strength.

CONCLUSIONS

The results indicate that community-dwelling older adult Indians aged 65 years and older are significantly associated with a higher risk of decreased handgrip strength, especially among older men. The results of this study can help assess and implement handgrip strength measurement in medicine for older Indians as part of regular admission assessment, particularly for older men.

Associations of protein intake, sources and distribution on muscle strength in community-dwelling older adults living in Auckland, New Zealand

Protein intake, sources and distribution impact on muscle protein synthesis and muscle mass in older adults. However, it is less clear whether dietary protein influences muscle strength. Data were obtained from the Researching Eating Activity and Cognitive Health (REACH) study, a cross-sectional study aimed at investigating dietary patterns, cognitive function and metabolic syndrome in older adults aged 65-74 years. Dietary intake was assessed using a 4-d food record and muscle strength using a handgrip strength dynamometer. After adjusting for confounders, in female older adults (n 212), total protein intake (β = 0⋅22, P < 0⋅01); protein from dairy and eggs (β = 0⋅21, P = 0⋅03) and plant food sources (β = 0⋅60, P < 0⋅01); and frequently consuming at least 0⋅4 g/kg BW per meal (β = 0⋅08, P < 0⋅01) were associated with higher BMI-adjusted muscle strength. However, protein from meat and fish intake and the coefficient of variance of protein intake were not related to BMI-muscle strength in female older adults. No statistically significant associations were observed in male participants (n = 113). There may be sex differences when investigating associations between protein intake and muscle strength in older adults. Further research is needed to investigate these sex differences.

Relationship between dietary patterns and physical performance in the very old population: a cross-sectional study from the Kawasaki Aging and Wellbeing Project

OBJECTIVES

As the world's population is ageing, improving the physical performance (PP) of the older population is becoming important. Although diets are fundamental to maintaining and improving PP, few studies have addressed the role of these factors in adults aged ≥ 85 years, and none have been conducted in Asia. This study aimed to determine the dietary patterns (DP) and examine their relationship with PP in this population.

DESIGN

This cross-sectional study (Kawasaki Aging and Wellbeing Project) estimated food consumption using a brief-type self-administered diet history questionnaire. The results were adjusted for energy after aggregating into thirty-three groups, excluding possible over- or underestimation. Principal component analysis was used to identify DP, and outcomes included hand grip strength (HGS), timed up-and-go test, and usual walking speed.

SETTING

This study was set throughout several hospitals in Kawasaki city.

PARTICIPANTS

In total, 1026 community-dwelling older adults (85-89 years) were enrolled.

RESULTS

Data of 1000 participants (median age: 86·9 years, men: 49·9 %) were included in the analysis. Three major DP (DP1: various foods, DP2: red meats and coffee, DP3: bread and processed meats) were identified. The results of multiple regression analysis showed that the trend of DP2 was negatively associated with HGS (B, 95 % CI -0·35, -0·64, -0·06).

CONCLUSIONS

This study suggests a negative association between HGS and DP characterised by red meats and coffee in older adults aged ≥ 85 years in Japan.

Protein intake, physical activity and grip strength in European and North American community-dwelling older adults: a pooled analysis of individual participant data from four longitudinal ageing cohorts

Higher dietary protein, alone or in combination with physical activity (PA), may slow the loss of age-related muscle strength in older adults. We investigated the longitudinal relationship between protein intake and grip strength, and the interaction between protein intake and PA, using four longitudinal ageing cohorts. Individual participant data from 5584 older adults (52 % women; median: 75 years, IQR: 71·6, 79·0) followed for up to 8·5 years (mean: 4·9 years, SD: 2·3) from the Health ABC, NuAge, LASA and Newcastle 85+ cohorts were pooled. Baseline protein intake was assessed with food frequency questionnaires and 24-h recalls and categorized into < 0·8, 0·8-<1·0, 1·0-<1·2 and ≥ 1·2 g/kg adjusted body weight (aBW)/d. The prospective association between protein intake, its interaction with PA, and grip strength (sex- and cohort-specific) was determined using joint models (hierarchical linear mixed effects and a link function for Cox proportional hazards models). Grip strength declined on average by 0·018 SD (95 % CI: -0·026, -0·006) every year. No associations were found between protein intake, measured at baseline, and grip strength, measured prospectively, or rate of decline of grip strength in models adjusted for sociodemographic, anthropometric, lifestyle and health variables (e.g., protein intake ≥ 1·2 v· < 0·8 g/kg aBW/d: β = -0·003, 95 % CI: -0·014, 0·005 SD per year). There also was no evidence of an interaction between protein intake and PA. We failed to find evidence in this study to support the hypothesis that higher protein intake, alone or in combination with higher PA, slowed the rate of grip strength decline in older adults.

Dietary Protein Intake and Physical Function in Māori and Non-Māori Adults of Advanced Age in New Zealand: LiLACS NZ

The population of older adults is growing exponentially. Research shows that current protein intake recommendations are unlikely to meet the ageing requirements and may be linked to reduced physical function. Ensuring optimal function levels is crucial for independence and quality of life in older age. This study aims to quantify the protein intake in those over 90 years of age and determine the association between historical protein intake (2011) and subsequent physical function at ten years follow-up (2021). Eighty-one participants (23 Māori and 54 non-Māori) undertook dietary assessment 24 h multiple-pass recall (MPR) and a standardised health and social questionnaire with physical assessment in 2011 and 2021. Intake24, a virtual 24 h MPR, was utilised to analyse dietary intake. Functional status was measured using the Nottingham Extended Activities of Daily Living Scale (NEADL), and physical performance was the Short Physical Performance Battery (SPPB). Māori men and women consumed less protein (g/day) in 2021 than in 2011 (P = 0.043 in men), but weight-adjusted protein intake in Māori participants over the ten years was not significantly reduced. Both non-Māori men and women consumed significantly less protein (g/day) between 2011 and 2021 (p = 0.006 and p = 0.001, respectively), which was also significant when protein intake was adjusted for weight in non-Māori women (p = 0.01). Weight-adjusted protein intake in 2011 was independently associated with functional status (NEADL score) in 2021 (p =< 0.001). There was no association between past protein intake and SPPB score (p = 0.993). Animal protein was replaced with plant-based protein over time. In conclusion, a reduction in protein intake was seen in all participants. The independent association between past protein intake and future functional status supports recommendations to keep protein intake high in advanced age.

Association of Protein Intake with Handgrip Strength and Its Relation to Strength Exercise in Korean Adults Aged over 60 Years in the KNHANES (2014-18)

Weak handgrip strength (HGS) is associated with many negative health outcomes in older adults. There is evidence that with strength exercise, high protein intake leads to increased HGS. The goal of this study was to examine the relationship between weak HGS in older adults and dietary protein and it's relation to resistance exercise. Data on 8497 Korean adults aged over 60 years from the Korea National Health and Nutrition Examination Survey (2014-18) were analyzed. Dietary protein intake measured by 24-h recall were categorized as three levels: low (<0.8 g/kg body weight (BW)), adequate (≥0.8 g/kg BW and <1.2 g/kg BW), and high (≥1.2 g/kg BW). Complex sample multiple logistic regression analyses were carried out. The prevalence of weak HGS was 18.3 (0.7)% in men and 28.8 (0.9)% in women. In a multiple logistic regression analysis, low protein intake was significantly associated with higher risk of weak HGS in men, as compared with adequate protein intake, but this relationship was not statistically significant in women. The risk of weak HGS was significantly reduced for both men and women who engaged in strength exercise and increased their dietary protein intake. In this study, based on a representative sample of Koreans aged over 60, men with low protein intake had a higher risk of weak HGS than did men with adequate protein intake. Men and women with a higher protein intake who also engaged in strength exercises had a lower risk of weak HGS. Increasing protein intake and engaging in strength exercises may be an effective way to preserve muscle strength in older men and women.

Is It Time to Reconsider the U.S. Recommendations for Dietary Protein and Amino Acid Intake?

Since the U.S. Institute of Medicine's recommendations on protein and amino acid intake in 2005, new information supports the need to re-evaluate these recommendations. New lines of evidence include: (1) re-analysis/re-interpretation of nitrogen balance data; (2) results from indicator amino acid oxidation studies; (3) studies of positive functional outcomes associated with protein intakes higher than recommended; (4) dietary guidance and protein recommendations from some professional nutrition societies; and (5) recognition that the synthesis of certain dispensable amino acids may be insufficient to meet physiological requirements more often than previously understood. The empirical estimates, theoretical calculations and clinical functional outcomes converge on a similar theme, that recommendations for intake of protein and some amino acids may be too low in several populations, including for older adults (≥65 years), pregnant and lactating women, and healthy children older than 3 years. Additional influential factors that should be considered are protein quality that meets operational sufficiency (adequate intake to support healthy functional outcomes), interactions between protein and energy intake, and functional roles of amino acids which could impact the pool of available amino acids for use in protein synthesis. Going forward, the definition of "adequacy" as it pertains to protein and amino acid intake recommendations must take into consideration these critical factors.

Prevalence of possible sarcopenia in community-dwelling older Chinese adults: a cross-sectional study

OBJECTIVES

To determine the prevalence of possible sarcopenia and its association with other conditions in older adults in Bengbu, China.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional study of 1082 community-dwelling Chinese people aged at least 60 years from March to June 2022.

METHODS

Handgrip strength and information regarding associated conditions were collected. Possible sarcopenia was estimated based on handgrip strength with cut-off values (<28 kg in men; <18 kg in women) recommended by the Asia Working Group for Sarcopenia in 2019. Mann-Whitney U tests, χ² tests and binary logistic regression analyses were used to explore relationships between possible sarcopenia and associated conditions.

RESULTS

Possible sarcopenia was more prevalent in men (52.79%, n=246, age 79.43±7.33 years among men with possible sarcopenia) than in women (44.48%, n=274, age 78.90±7.71 years among women with possible sarcopenia). In men, possible sarcopenia positively correlated with high age (OR 2.658, 95% CI 1.758 to 4.019), physical inactivity (OR 2.779, 95% CI 1.646 to 4.691) and diabetes (OR 4.269, 95% CI 2.397 to 7.602), and negatively with hypertension (OR 0.586, 95% CI 0.384 to 0.893). The risk of possible sarcopenia in men decreased by 12.6% for every 1 kg/m² increase of body mass index (OR 0.874, 95% CI 0.817 to 0.935). In women, possible sarcopenia positively correlated with high age (OR 3.821, 95% CI 2.677 to 5.455), physical inactivity (OR 2.185, 95% CI 1.488 to 3.210) and arthritis (OR 2.076, 95% CI 1.411 to 3.056).

CONCLUSION

Possible sarcopenia is prevalent in older adults and the factors affecting possible sarcopenia are different in men and women. Health education about these target factors can be considered as a potential measure to prevent possible sarcopenia.

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.

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.

Physical performance reference values for Japanese oldest old: a SONIC study

Background

The oldest old, defined as those aged 90 or over, is now the fastest-growing population sector. This study aimed to determine reference values for several physical performance measures (PPMs) among 90-year-olds using internationally standardized measurements and to clarify the characteristics of these indices by comparing their results for 90-year-olds with those for older people 70 and 80.

Methods

We used the Septuagenarians, Octogenarians, and Nonagenarians Investigation with Centenarians (SONIC) study data from 2010 to 2018. The study subjects were 70, 80, and 90-year-olds in the target area eligible to participate in the venue. Excluding those certified for long-term care, the final number of eligible persons is 70s cohort 1000 (2010), 80s cohort 973 (2011), and 90s cohort 690. 90s cohort only consisted of three survey waves: 2012, 2015, and 2018. We used hand grip strength and score on the Short Physical Performance Battery (SPPB) for our physical performance measurements. In addition, we statistically analyzed sex and age differences.

Result

The simple mean ± standard deviation (SD) for the 90-year-old respondents were in men, 24.1 ± 5.4 kg in hand grip strength, 0.80 ± 0.22 m/s in usual gait speed, 17.2 ± 6.73 s in 5times chair stand, 5.89 ± 4.42 s in tandem balance, and 8.3 ± 2.2 in SPPB respectively and in women, 14.4 ± 4.0 kg in hand grip strength, 0.72 ± 0.20 m/s in usual gait speed, 17.8 ± 7.89 s in 5times chair stand, 4.72 ± 4.35 s in tandem balance, and 7.5 ± 2.4 in SPPB, respectively. For all PPMs, the age 90 cohort was statistically significantly different from the age 70 and 80 cohorts (all trends P <  0.001). Hand grip strength decreased with a similar gradient with age cohort increase of 10 years for both sexes. In contrast, SPPB lower limb score showed a larger drop between the age 80 and 90 cohorts than between the age 70 and 80 cohorts. We also constructed sex-specific appraisal standards according to quintiles.

Conclusions

Our study yielded inclusive sex-specific reference values and appraisal standards for major physical performance measures not certified as requiring long-term care, community-dwelling, oldest old Japanese. The characteristics of age-related decline in physical performance differed between the upper and lower extremity assessments.

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.

Rivastigmine ameliorates indomethacin experimentally induced gastric mucosal injury via activating α7nAChR with inhibiting oxidative stress and apoptosis

The current study aimed to investigate the potential ameliorative role of Rivastigmine (RIVA), the anti-Alzheimer drug, against the gastric mucosal injury caused by indomethacin (IND). The rats were divided into four groups: group I was given a vehicle as a control, group II was given RIVA (0.3 mg/kg) once daily intraperitoneal (ip) for 2 weeks, group III was given a single IP dose of 30 mg/kg IND, and group IV was given RIVA ip 2 weeks before the administration of IND. The gastric mucosal injury was detected by the estimation of ulcer index, gastric acidity, pepsin, and mucin concentrations. Malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione (GSH), total nitrite/nitrate (NOx), and the expression of tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), nuclear factor kappa B (NF-κB), Hemoxygenase 1 (HO-1), and caspase-3 were all measured in gastric tissue. In addition, histological assessment and proliferating cell nuclear antigen (PCNA) immuno-expression were studied. Gastric mucosal injury induced by IND was indicated by both biochemical and histopathological assessments. RIVA Pretreatment reduced ulcer index, MDA, TNF-α, IL-6, NF-κB, and caspase-3 and increased SOD, GSH, NOx, and HO-1. RIVA improved the suppressed nuclear immunoreaction for PCNA observed with IND. The current findings provide novel evidence that RIVA possesses a prophylactic action against IND-induced gastric mucosal damage in rats. Despite being a cholinergic drug that is associated with increased pepsin and stomach acidity, RIVA protected against IND-induced gastric mucosal injury via activating α7nAChR and inhibiting oxidative stress and apoptosis.

Effects of Health-Related Behaviors and Changes on Successful Aging among Indonesian Older People

Whether changes in health behaviors can improve successful aging has not been well explored. The purpose of this study was to assess the effects of health-related behaviors and changes on successful aging in Indonesian older adults. Data were from the fourth and fifth waves of the Indonesia Family Life Survey (IFLS), the participants were aged 60 years and older and who completed both waves (n = 1289). Successful aging indicators were defined as no chronic diseases, no physical function difficulties, no depressive symptoms, intact cognitive function, with social support, and with social participation. Health-related behaviors focused on smoking, physical activities, and protein intake. A logistic regression analysis was conducted. The overall successful aging rate in 2007 was 23.6%, and it had decreased to 5.6% by 2014. There were gender differences in smoking, physical activities, and behavioral changes, including promoting increased physical activity, no smoking/smoking cessation, and adequate protein intake by older adults. Quitting smoking, performing medium physical activity, and increasing protein intake were protective factors for successful aging, but the effects of behavioral changes differed by gender. Health-related behaviors and changes may impact successful aging among older adults. A healthy lifestyle is suggested to be adopted as early as possible in one's life course.

A review of recent evidence of dietary protein intake and health

The Korea National Health and Nutrition Examination Survey of 2013 to 2017 reported that the average protein consumption of the Korean population is above the current recommended nutrient intake of protein proposed by the Dietary Reference Intakes for Koreans. Some health professionals and the media often advise consuming diets high in protein for promoting metabolic regulation, weight control, and muscle synthesis. However, due to lack of scientific evidence, the validity and safety of high protein consumption are yet to be fully ascertained. The present review assesses recent evidence published in 2014-2020 from human studies, focusing on adequate protein intake and protein sources for the prevention of chronic diseases, particularly metabolic disorders and sarcopenia.

Association between food texture levels consumed and the prevalence of malnutrition and sarcopenia in older patients after stroke

BACKGROUND/OBJECTIVES

Texture-modified diets (TMDs) may affect nutritional status and sarcopenia in patients after stroke. This study aimed to investigate the association of food texture levels consumed by patients after stroke with the prevalence of malnutrition and sarcopenia.

SUBJECTS/METHODS

This was a two-center cross-sectional study. A total of 443 patients aged ≥65 years undergoing post-stroke rehabilitation and with oral intake in rehabilitation wards in Shizuoka prefecture and Okinawa prefecture, Japan, were included in the analysis. Food textures were categorized according to the International Dysphagia Diet Standardization Initiative (IDDSI) framework. Malnutrition was diagnosed according to the Global Leadership Initiative on Malnutrition and sarcopenia was assess by the European Working Group on Sarcopenia in Older People 2 criteria. The Cochran-Armitage trend test was used to examine the prevalence of malnutrition and sarcopenia by consumption of lower food texture levels.

RESULTS

Malnutrition and sarcopenia were diagnosed in 245 (55.3%) and 275 (62.1%) participants, respectively. Consumption of lower food texture levels was associated with a higher prevalence of malnutrition and severe malnutrition (P < 0.001 for both). In addition, consumption of lower food texture levels was associated with a higher prevalence of probable sarcopenia and sarcopenia (P < 0.001 for both). On multivariate analysis, significant associations were observed between IDDSI levels 5 (P < 0.001) and 4 (P = 0.009) and malnutrition, and between IDDSI levels 6 (P = 0.015), 5 (P = 0.033), and 4 (P = 0.015) and sarcopenia.

CONCLUSIONS

In patients with stroke, consumption of lower food texture levels categorized by the IDDSI framework was associated with a higher prevalence of malnutrition and sarcopenia.

Positive Association between High Protein Food Intake Frequency and Physical Performance and Higher-Level Functional Capacity in Daily Life

Nutritional factors, including low protein intake and poor dietary variety, affect age-associated impairment in physical performance resulting in physical frailty. This cross-sectional study investigated the association between intake frequency of major high protein foods and both physical performance and higher-level functional capacity using the food frequency score (FFS) and high protein food frequency score (PFFS) among community-dwelling older adults. The data of 1185 older adults categorized into quartiles based on FFS and PFFS were analyzed. After adjusting for covariates, FFS and PFFS were significantly associated with physical performance [FFS, usual gait speed (p for trend = 0.007); PFFS, usual gait speed (p for trend < 0.001), maximum gait speed (p for trend = 0.002), timed up and go (p for trend = 0.025)], and higher-level functional capacity [FFS (p for trend < 0.001); PFFS (p for trend < 0.001)]. After excluding PFFS data, the participants’ scores were associated with only higher-level functional capacity. Multi-regression analysis with higher-level functional capacity as the covariate showed that FFS and PFFS were significantly correlated with physical performance. Hence, improving food intake frequency, particularly that of high protein foods, and dietary variety may help maintain higher-level functional capacity and physical performance in community-dwelling older adults.

[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.

Nutrients with anabolic/anticatabolic, antioxidant, and anti-inflammatory properties: Targeting the biological mechanisms of aging to support musculoskeletal health

Old age is associated with declines in bone density and muscle mass and function, which predisposes to mobility disability, falls, and fractures. Poor nutritional status, a risk factor for several age-related pathologies, becomes prevalent in old age and contributes to the structural and functional changes of the musculoskeletal system that increases the risk of osteoporosis, sarcopenia, osteosarcopenia, and physical frailty. The biological mechanisms underpinning these pathologies often overlap and include loss of proteostasis, impaired redox functioning, and chronic low-grade inflammation. Thus, provision of nutrients with anabolic/anticatabolic, antioxidant, and anti-inflammatory properties may be an effective strategy to offset these age-related pathologies. We searched PUBMED for pre-clinical and clinical work examining the effects of nutrients with a combined effect on muscle and bone. This review summarizes recent evidence on the mechanisms of action and potential clinical use of nutrients that concomitantly improve muscle and bone health in older persons.

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.

Socioeconomic differences in handgrip strength and its association with measures of intrinsic capacity among older adults in six middle-income countries

Handgrip strength, a measure of muscular strength is a powerful predictor of declines in intrinsic capacity, functional abilities, the onset of morbidity and mortality among older adults. This study documents socioeconomic (SES) differences in handgrip strength among older adults aged 50 years and over in six middle-income countries and investigates the association of handgrip strength with measures of intrinsic capacity-a composite of all the physical and mental capacities of an individual. Secondary data analysis of cross-sectional population-based data from six countries from the WHO's Study on global AGEing and adult health (SAGE) Wave 1 were conducted. Three-level linear hierarchical models examine the association of demographic, socioeconomic status and multimorbidity variables with handgrip strength. Regression-based Relative Index of Inequality (RII) examines socioeconomic inequalities in handgrip strength; and multilevel linear and logistic hierarchical regression models document the association between handgrip strength and five domains of intrinsic capacity: locomotion, psychological, cognitive capacity, vitality and sensory. Wealth quintiles are positively associated with handgrip strength among men across all countries except South Africa while the differences by education were notable for China and India. Work and nutritional status are positively associated with handgrip strength. Our findings provide new evidence of robust association between handgrip strength and other measures of intrinsic capacity and confirms that handgrip strength is a single most important measure of capacity among older persons.

Recovery Focused Nutritional Therapy across the Continuum of Care: Learning from COVID-19

Targeted nutritional therapy should be started early in severe illness and sustained through to recovery if clinical and patient-centred outcomes are to be optimised. The coronavirus disease 2019 (COVID-19) pandemic has shone a light on this need. The literature on nutrition and COVID-19 mainly focuses on the importance of nutrition to preserve life and prevent clinical deterioration during the acute phase of illness. However, there is a lack of information guiding practice across the whole patient journey (e.g., hospital to home) with a focus on targeting recovery (e.g., long COVID). This review paper is of relevance to doctors and other healthcare professionals in acute care and primary care worldwide, since it addresses early, multi-modal individualised nutrition interventions across the continuum of care to improve COVID-19 patient outcomes. It is of relevance to nutrition experts and non-nutrition experts and can be used to promote inter-professional and inter-organisational knowledge transfer on the topic. The primary goal is to prevent complications and support recovery to enable COVID-19 patients to achieve the best possible nutritional, physical, functional and mental health status and to apply the learning to date from the COVID-19 pandemic to other patient groups experiencing acute severe illness.

A poor appetite or ability to eat and its association with physical function amongst community-dwelling older adults: age, gene/environment susceptibility-Reykjavik study

A poor appetite or ability to eat and its association with physical function have not been explored considerably amongst community-dwelling older adults. The current study examined whether having an illness or physical condition affecting one's appetite or ability to eat is associated with body composition, muscle strength, or physical function amongst community-dwelling older adults. This is a secondary analysis of cross-sectional data from the age, gene/environment susceptibility-Reykjavik study (n = 5764). Illnesses or physical conditions affecting one's appetite or ability to eat, activities of daily living, current level of physical activity, and smoking habits were assessed with a questionnaire. Fat mass, fat-free mass, body mass index, knee extension strength, and grip strength were measured, and the 6-m walk test and timed up-and-go test were administered. Individuals who reported illnesses or physical conditions affecting their appetite or ability to eat were considered to have a poor appetite. The associations of appetite or the ability to eat with body composition and physical function were analysed with stepwise linear regression models. A total of 804 (14%) individuals reported having conditions affecting their appetite or ability to eat and had a significantly lower fat-free mass and body mass index, less grip strength, and poorer physical function than did those without any conditions affecting their appetite or ability to eat. Although the factors reported to affect one's appetite or ability to eat are seldom considered severe, their strong associations with physical function suggest that any condition affecting one's appetite or ability to eat requires attention.

Dietary Protein Requirement Threshold and Micronutrients Profile in Healthy Older Women Based on Relative Skeletal Muscle Mass

Although multiple nutrients have shown protective effects with regard to preserving muscle function, the recommended amount of dietary protein and other nutrients profile on older adults for maintenance of high muscle mass is still debatable. The aims of this paper were to: (1) identify dietary differences between older women with low and high relative skeletal muscle mass, and (2) identify the minimal dietary protein intake associated with high relative skeletal muscle mass and test the threshold ability to determine an association with skeletal muscle phenotypes. Older women (n = 281; 70 ± 7 years, 65 ± 14 kg), with both low and high relative skeletal muscle mass groups, completed a food questionnaire. Skeletal muscle mass, fat-free mass (FFM), biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VL_ACSA), handgrip strength (HGS), maximum elbow flexion torque (MVC_EF), maximum knee extension torque (MVC_KE), muscle quality (HGS/Body mass), and fat mass were measured. Older women with low relative skeletal muscle mass had a lower daily intake of protein, iodine, polyunsaturated fatty acid (PUFA), Vit E, manganese, milk, fish, nuts and seeds (p < 0.05) compared to women with high relative skeletal muscle mass. The minimum required dietary protein intake for high relative skeletal muscle mass was 1.17 g/kg body mass/day (g/kg/d) (sensitivity: 0.68; specificity: 0.62). Women consuming ≥1.17 g/kg/d had a lower BMI (B = -3.9, p < 0.001) and fat mass (B = -7.8, p < 0.001), and a higher muscle quality (B = 0.06, p < 0.001). The data indicate that to maintain muscle mass and function, older women should consume ≥1.17 g/kg/d dietary protein, through a varied diet including milk, fish and nuts that also contain polyunsaturated fatty acid (PUFA) and micronutrients such as iodine, Vit E and manganese.

Association of Daily Physical Activity and Sedentary Behaviour with Protein Intake Patterns in Older Adults: A Multi-Study Analysis across Five Countries

Physical activity and protein intake are associated with ageing-related outcomes, including loss of muscle strength and functional decline, so may contribute to strategies to improve healthy ageing. We investigated the cross-sectional associations between physical activity or sedentary behaviour and protein intake patterns in community-dwelling older adults across five countries. Self-reported physical activity and dietary intake data were obtained from two cohort studies (Newcastle 85+ Study, UK; LiLACS, New Zealand Māori and Non-Māori) and three national food consumption surveys (DNFCS, The Netherlands; FINDIET, Finland; INRAN-SCAI, Italy). Associations between physical activity and total protein intake, number of eating occasions providing protein, number of meals with specified protein thresholds, and protein intake distribution over the day (calculated as a coefficient of variance) were assessed by regression and repeated measures ANOVA models adjusting for covariates. Greater physical activity was associated with higher total protein intake and more eating occasions containing protein, although associations were mostly explained by higher energy intake. Comparable associations were observed for sedentary behaviour in older adults in Italy. Evidence for older people with higher physical activity or less sedentary behaviour achieving more meals with specified protein levels was mixed across the five countries. A skewed protein distribution was observed, with most protein consumed at midday and evening meals without significant differences between physical activity or sedentary behaviour levels. Findings from this multi-study analysis indicate there is little evidence that total protein and protein intake patterns, irrespective of energy intake, differ by physical activity or sedentary behaviour levels in older adults.

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.

Effects of 6 Months of Soy-Enriched High Protein Compared to Eucaloric Low Protein Snack Replacement on Appetite, Dietary Intake, and Body Composition in Normal-Weight Obese Women: A Randomized Controlled Trial

(1) Background: The favorable effects of high protein snacks on body composition and appetite status in lean and athletic populations have been illustrated previously. However, the effects of soy-enriched high protein snacks have not been investigated in women with normal-weight obesity (NWO). Consequently, we aimed at comparing the effects of six months of soy-enriched high protein snack replacement on appetite, body composition, and dietary intake in women with NWO. (2) Methods: One hundred seven (107) women with NWO [(age: 24 ± 3 yrs, BMI: 22.7 ± 2.3 kg/m², body fat percentage (BFP): 38 ± 3.2%)] who were assigned to one of two groups; high protein snack (HP, n = 52) containing 50 g soybean or isocaloric low-protein snack (protein: 18.2 g, carbohydrate: 15 g, fat: 10 g, energy: 210 kcal) or isocaloric low protein snack (LP, n = 55) containing 3.5 servings of fruit (protein: <2 g, carbohydrate: ≈50 g, fat: <1 g, energy: ≈210 kcal) as part of their daily meals (as a snack at 10 a.m.), successfully completed the study interventions. Body mass (BM), body mass index (BMI), waist circumference (WC), BFP, skeletal muscle mass, dietary intake, and appetite levels were evaluated prior to and after the six-month intervention. (3) Results: Appetite (HP = -12 mm and LP = -0.6 mm), energy intake (HP = -166.2 kcal/day and LP = 91.3 kcal), carbohydrate intake (HP = -58.4 g/day and LP = 6.4 g/day), WC (HP = -4.3 cm and LP = -0.9 cm), and BFP (HP = -3.7% and LP = -0.9%) were significantly (p < 0.05) reduced, while skeletal muscle mass (HP = 1.2 kg and LP = 0.3 kg) significantly increased in the HP compared to the LP group, respectively. (4) Conclusions: Six months of a soy-enriched high protein snack replacement decreased appetite and improved body composition in women with NWO. Our findings suggest that soy-enriched high protein snacks are an efficacious strategy for body composition improvement.

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.

Age-Related Changes in Shear Wave Elastography Parameters of the Gastrocnemius Muscle in Association with Physical Performance in Healthy Adults

BACKGROUND/AIMS

to investigate new indicators for early recognition of physical performance decline. Shear wave elastrography, a new ultrasound technique, was discussed in this study.

METHODS

Gastrocnemius muscle thickness and muscle stiffness were detected by traditional ultrasound and shear wave elastrography in 108 Chinese aged 20-85 years, and then analyzed with physical performance together.

RESULTS

After 70 years old, the decline rate of muscle stiffness under contractive state was significantly faster than that of muscle thickness, muscle relaxed stiffness, and physical performance indicators. The correlation analysis showed that gastrocnemius contractive stiffness was positively related with handgrip strength, step length, and fast gait speed after adjusted by age and gender. Among physical performance variants, step length had closer relationship with muscle strength than repeated chair stands.

CONCLUSIONS

The detection of gastrocnemius muscle by shear wave elastography reflected the change of lower-limb muscle stiffness with aging. Muscle contractive stiffness and step length measurement supplied novel ways for muscle performance and motor function assessment.

Protein intake is not associated with functional biomarkers of physical frailty: A cross-sectional analysis of community-dwelling older adults with type 2 diabetes mellitus

BACKGROUND AND AIM

Frailty has emerged as a third category of complication in patients with type 2 diabetes mellitus (T2DM). It has been suggested that adequate protein intake is an important dietary strategy for counteracting frailty. Therefore, we explored the association between protein intake and functional biomarkers of frailty in older adults with T2DM.

METHODS AND RESULTS

Frailty was operationalized as the presence of three of the following: exhaustion, low muscle strength, low physical activity, slow gait speed, and weight loss. Functional biomarkers included handgrip strength (HGS), chair stands, the short physical performance battery and gait speed. Eighty-seven older adults (71.2 ± 8.2 years; 66.7% males) were included. A total of n = 6 (~7%) and n = 32 (~37%) participants were identified as frail and pre-frail respectively. No significant difference was observed for protein intake across staging of frailty (pre-frail/frail: 1.3 ± 0.4 g/kg BW; non-frail: 1.4 ± 0.4 g/kg BW; P = 0.320). A significant association was observed for total protein intake and HGS (β = 0.44; 95% CI: 0.23-1.8; P = 0.01). However, this was no longer significant after adjusting for age, gender, physical activity, energy intake and total appendicular lean muscle (β = 0.03; 95% CI: -0.45-0.60; P = 0.78). Nil other associations were observed between total protein intake and functional biomarkers of frailty.

CONCLUSION

Adequate protein intake was not associated with functional biomarkers in older adults with T2DM. Future research should focus on the efficacy of protein on attenuating functional decline in vulnerable older adults with low protein intake.

Impact of dietary protein intake on the incidence of low muscle strength in middle-aged and older adults

BACKGROUND

A reduction in skeletal muscle strength is a prognostic indicator of negative consequences, such as physical disability, frailty, and mortality in older adults. Studies investigating associations between the risk of reduction in skeletal muscle strength and the amount of dietary protein which is a factor influenced muscle health are scarce, particularly in Asian populations. Therefore, we investigated the association between the amount and change in daily protein intake and the prospective risk of developing low skeletal muscle strength in middle-aged and older adults.

METHODS

This study used data from the Korean Genome and Epidemiology Study as an ongoing population-based cohort study of adults aged 40 years and over. The amount of daily protein consumed was assessed using a semi-quantitative food frequency questionnaire. Low skeletal muscle strength was measured with a handgrip strength dynamometer.

RESULTS

In total, 32,458 adults (11,358 males and 21,100 females) were evaluated. The amount of daily dietary protein consumed was not associated with the risk of low muscle strength over the 4-year follow-up period after adjusting for covariates. No associations between low muscle strength events according to the change in the amount of protein consumed from the baseline to the follow-up surveys were identified.

CONCLUSIONS

The amount of and change in dietary protein consumed were not associated with developing low muscle strength in middle-aged and older adults. Further studies with a focus on physical activity-protein intake interactions and specific conditions, such as mobility-limited adults or hospitalized patients, are warranted to clarify the relationship between protein intake status and the incidence of low skeletal muscle strength.

Prospective associations of protein intake parameters with muscle strength and physical performance in community-dwelling older men and women from the Quebec NuAge cohort

BACKGROUND

Dietary protein has been related to muscle function in aging. Beyond total intake, parameters such as protein distribution across meals might also be important.

OBJECTIVES

We aimed to examine prospective associations of different protein intake parameters with muscle strength and physical performance in community-dwelling older men and women.

METHODS

In total, 524 men and 574 women aged 67-84 y at baseline (T1) were followed annually for 3 y (T2, T3, T4). Outcomes included handgrip strength (kPa), knee extensor strength (kg), and physical performance (Timed Up and Go, s) at T4, and their 3-y changes (T4 minus T1). Protein intake parameters were assessed using nine 24-h recalls collected over 3 y (T1, T2, T3) and included daily total intake (g/d), number of protein-providing meals and snacks, and protein distribution across meals (expressed as CV). Associations were examined by multivariable linear regression models including all protein intake parameters simultaneously. Also, the optimal protein dose (g) per meal for the maximum effect size of total daily intake was determined.

RESULTS

Higher daily protein intake was associated with better knee extensor strength and physical performance at T4 in both sexes and less physical performance decline in women. Optimal protein doses per meal were 30-35 g in men and 35-50 g in women for these outcomes. In men, more uneven protein distribution was associated with better physical performance at T4 and less handgrip strength decline. In women, a higher number of protein-providing snacks was associated with better handgrip strength and knee extensor strength at T4 and less handgrip strength decline. In neither sex was number of protein-providing meals associated with outcomes.

CONCLUSIONS

Higher daily protein intake, up to 30-50 g protein/meal, may contribute to better knee extensor strength and physical performance in generally well-functioning older men and women. More aspects of protein intake may contribute to muscle strength and physical performance than solely the daily quantity, notably the protein dose per meal.

Relationship between protein intake and bone architecture or bone mineral density among dynapenic-obese older adults

OBJECTIVE

The current study aimed to assess the relationship between protein intake and bone parameters among dynapenic-obese older adults.

DESIGN

The current study is a secondary analysis with an a posteriori and exploratory design.

SETTING

Subjects were recruited from the community via social communication (flyers and meetings in community centres) in the Great Montreal area.

PARTICIPANTS

Twenty-six subjects were divided a posteriori into two groups according to their usual protein intake: PROT-: < 1 g/kg per d (n 13; women: 53·8 %; 66·5 (sd 3·3) years) and PROT+: > 1·2 g/kg per d (n 13; women: 61·5 %; 67·2 (sd 2·7) years).

RESULTS

Both groups were comparable for age (PROT-: 66·5 (sd 3·3) v. PROT+: 67·2 (sd 2·7) years, P = 0·61) and gender (women: PROT-: n 7; 53·8 % v. PROT+: n 8; 61·5 %, P = 0·69). The PROT- group had a higher marrow area (P = 0·049), a greater bone compressive strength (P = 0·048) and a larger total bone area (P = 0·045) than the PROT+ group. However, no significant difference between the two groups was observed regarding body composition (fat and lean masses) or muscle composition.

CONCLUSIONS

A lower protein intake seems to be associated with bone sizes, which influence bone strength, but do not influence bone density among dynapenic-obese older people.

Protein intake and osteosarcopenic adiposity in Korean adults aged 50 years and older

Intake of plant-based protein and recommended protein intake are associated with a lower risk of osteosarcopenic adiposity (co-occurrence of osteopenia/osteoporosis, sarcopenia, and adiposity) in elderly Korean men.

INTRODUCTION

Osteosarcopenic adiposity (OSA) syndrome is defined as the concurrent presence of osteopenia/osteoporosis, sarcopenia, and adiposity and leads to negative functional and metabolic outcomes in late adulthood. This study aimed to investigate the association between OSA and protein intake in adults aged 50 or older.

METHODS

A population-based, cross-sectional survey was conducted using the Korea National Health and Nutrition Examination Survey 2008-2009 data and included 645 men and 706 women aged 50 or older. Subjects were classified into normal and OSA groups. Protein intake was analyzed using the 24-h recall method.

RESULTS

There was no significant difference in the intake of total protein and animal-based protein between normal and OSA groups. However, in males, the intake of plant-based protein (p = 0.0031) was significantly lower in the OSA group than that in the normal group. Further, the protein intake in the OSA group was 0.96 g/kg/day, which was significantly lower than that in the normal group (1.06 g/kg/day; p = 0.0203). After adjusting for confounding factors, men over 65 years old who consumed less than the recommended nutrient intake (RNI) of 0.91 g/kg/day had 5.82 times higher risk of OSA compared with subjects consuming protein equal to or greater than the RNI amount (95% CI 1.81-18.66).

CONCLUSION

In conclusion, a protein intake of RNI or more is associated with a lower risk of OSA in Korean elderly men.

Association between Changes in Nutrient Intake and Changes in Muscle Strength and Physical Performance in the SarcoPhAge Cohort

Muscle weakness and physical performance impairment are common geriatric conditions that raise morbidity and mortality. They are known to be affected by nutrition, but only a few longitudinal studies exist. This study aims to fill this gap by exploring the association, over 3 years, between variations of nutrient intakes, as well as, on one side, the variations of handgrip strength, as a surrogate of muscle strength, and on the other side, the physical performance, assessed by gait speed. Participants from the SarcoPhAge study, a Belgian cohort of people aged 65 years and older, were asked to complete a self-administered food frequency questionnaire (FFQ) at the second (T2) and the fifth (T5) year of follow-up. Daily macro- and micronutrient intakes were measured and their changes in consumption over the three years of follow-up were then calculated. The association between changes in nutrients consumption and the variations in muscle parameters were investigated through multiple linear regressions. Out of the 534 participants included in the cohort, 238 had complete data at T2 and T5 (median age of 72.0 years (70.0-78.0 years), 60.9% women). In the cross-sectional analysis, calories, omega-3 fatty acids, potassium, and vitamins D, A, and K intakes were positively correlated with muscle strength. In the longitudinal analysis, neither the gait speed nor the muscle strength changes were significantly impacted by the variations. Other longitudinal investigations with longer follow-up are required to improve knowledge about these interrelations.

Prevalence of protein intake below recommended in community-dwelling older adults: a meta-analysis across cohorts from the PROMISS consortium

BACKGROUND

Lower protein intake in older adults is associated with loss of muscle mass and strength. The present study aimed to provide a pooled estimate of the overall prevalence of protein intake below recommended (according to different cut-off values) among community-dwelling older adults, both within the general older population and within specific subgroups.

METHODS

As part of the PRevention Of Malnutrition In Senior Subjects in the EU (PROMISS) project, a meta-analysis was performed using data from four cohorts (from the Netherlands, UK, Canada, and USA) and four national surveys [from the Netherlands, Finland (two), and Italy]. Within those studies, data on protein and energy intake of community-dwelling men and women aged ≥55 years were obtained by either a food frequency questionnaire, 24 h recalls administered on 2 or 3 days, or food diaries administered on 3 days. Protein intake below recommended was based on the recommended dietary allowance of 0.8 g/kg body weight (BW)/d, by using adjusted BW (aBW) instead of actual BW. Cut-off values of 1.0 and 1.2 were applied in additional analyses. Prevalences were also examined for subgroups according to sex, age, body mass index (BMI), education level, appetite, living status, and recent weight loss.

RESULTS

The study sample comprised 8107 older persons. Mean ± standard deviation protein intake ranged from 64.3 ± 22.3 (UK) to 80.6 ± 23.7 g/d [the Netherlands (cohort)] or from 0.94 ± 0.38 (USA) to 1.17z ± 0.30 g/kg aBW/d (Italy) when related to BW. The overall pooled prevalence of protein intake below recommended was 21.5% (95% confidence interval: 14.0-30.1), 46.7% (38.3-55.3), and 70.8% (65.1-76.3) using the 0.8, 1.0, and 1.2 cut-off value, respectively. A higher prevalence was observed among women, individuals with higher BMI, and individuals with poor appetite. The prevalence differed only marginally by age, education level, living status, and recent weight loss.

CONCLUSIONS

In community-dwelling older adults, the prevalence of protein intake below the current recommendation of 0.8 g/kg aBW/d is substantial (14-30%) and increases to 65-76% according to a cut-off value of 1.2 g/kg aBW/d. To what extent the protein intakes are below the requirements of these older people warrants further investigation.

Contribution of protein intake and its interaction with physical activity to transitions between disability states and to death in very old adults: the Newcastle 85+ Study

INTRODUCTION

Growth in the number of very old (≥ 85 years) adults will likely lead to increased prevalence of disability. Our aim was to determine the contribution of protein intake, and the interaction between protein intake and physical activity (PA), to the transition between disability states and to death in the very old using the Newcastle 85+ Study.

METHODS

The analytic sample comprised of 717 older adults aged 85 years at baseline and living in the community. Protein intake was estimated with 2 × 24-h multiple pass recalls (24 h-MPR) at baseline. Disability was measured as difficulty performing 17 activities of daily living (ADL) at baseline, at 18, 36, and 60 months, and defined as having difficulties in one or more ADL. The contribution of protein intake [g/kg adjusted body weight/day (g/kg aBW/d)] to transition probabilities to and from disability, and to death over 5 years was examined by multi-state models adjusted for key health covariates.

RESULTS

Participants were expected to spend 0.8 years (95% CI 0.6-1.0) disability-free and 2.8 years (95% CI 2.6-2.9) with disability between the ages 85 and 90 years. One unit increase in protein intake (g/kg aBW/d) halved the likelihood of incident disability (HR 0.44, 95% CI 0.24-0.83) but not for other transitions. Similar reductions in disability incidence were also found in individuals with protein intake ≥ 0.8 (HR 0.50, 95% CI 0.31-0.80) and ≥ 1 g/kg aBW/d (HR 0.49, 95% CI 0.33-0.73). Participants with high PA and protein intake ≥ 1 g/kg aBW/d were less likely to transition from disability-free to disability than those within the same PA level but with protein intake < 1 g/kg aBW/d (HR 0.45, 95% CI 0.28-0.72).

CONCLUSION

Higher protein intake, especially in combination with higher physical activity, may delay the incidence of disability in very old adults.

Immunosenescence profiles are not associated with muscle strength, physical performance and sarcopenia risk in very old adults: The Newcastle 85+ Study

Decline in immune system function (immunosenescence) has been implicated in several age-related disorders. However, little is known about whether alteration in T-cell senescence, a process underlying immunological ageing, is related to muscle health in very old adults (aged ≥85 years). Utilising data from the Newcastle 85+ Study, we aimed to (a) derive and characterise immunosenescence profiles by clustering 13 baseline immunosenescence-related biomarkers of lymphocyte compartments in 657 participants; (b) explore the association between the profiles and 5-year change in muscle strength (grip strength) and physical performance (Timed Up-and-Go test), and (c) determine whether immunosenescence profiles predict 3-year incident sarcopenia. Two distinct clusters were identified; Cluster 1 ('Senescent-like phenotype', n = 421), and Cluster 2 ('Less senescent-like phenotype', n = 236) in individuals with complete biomarker data. Although Cluster 1 was characterised by T-cell senescence (e.g., higher frequency of CD4 and CD8 senescence-like effector memory cells), and elements of the immune risk profile (lower CD4/CD8 ratio, CMV+), it was not associated with change in muscle function over time, or with prevalent or incident sarcopenia. Future studies will determine whether more in-depth characterisation or change in T-cell phenotypes predict the decline in muscle health in late adulthood.

Dietary Selenium Intakes and Musculoskeletal Function in Very Old Adults: Analysis of the Newcastle 85+ Study

Background: Selenium is a trace element essential for health. Severe selenium deficiencies are associated with poor musculoskeletal (MSK) function. However, the effects of moderate deficiency on MSK function, especially in older adults, is unclear. Objectives: To determine the associations between selenium intake and MSK function in very old adults. Methods: Selenium intake at baseline and, hand-grip strength (HGS) and timed-up-and-go (TUG) at four phases over 5 years, were available in 791 participants in the Newcastle 85+ Study, a community-based, longitudinal cohort of ≥85 year old individuals. We investigated relationships between selenium intake and HGS and TUG in cross-sectional analyses at baseline using multivariate analyses and, prospectively using linear mixed models to explore HGS and TUG changes over 5 years in association with baseline selenium intake. Results: At baseline, 53% of participants had selenium intakes that were classified as low. These individuals had 2.80 kg lower HGS and were 2.30 s slower performing the TUG, cross-sectionally. In multivariate, baseline analyses, selenium intake had no significant impact on HGS or TUG. Selenium intake had no significant effect on MSK function, prospectively. Conclusion: Low selenium intake is common among very old adults and, in cross-sectional analyses, is associated with poorer MSK function.

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.