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

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.

Association between dietary patterns and sarcopenia among community-dwelling older adults in five provinces of China: a cross-sectional study

Background

Sarcopenia is prevalent in older adults and not only severely affects their health, but also brings a greater economic burden on the patient's family as well as society. High-quality diet is one of influencing factors of sarcopenia, particularly important for muscle mass and function. This study aims to examine the dietary patterns of community-dwelling older adults in a typical region of China and explore the relationship between these dietary patterns and sarcopenia.

Methods

We used data of the Nutrition and Health Follow-up Study of the Chinese Population in 2021. Food frequency questionnaires were used to obtain food items intake frequency during the last year. Appendicular skeletal muscle mass (ASM), muscle strength and physical performance were assessed according to the Asian Sarcopenia Working Group (AWGS2019) criteria. Exploratory factor analysis was used to identify dietary patterns. Logistic regression models were used to examine the association between dietary patterns and sarcopenia.

Results

A total of 1,967 participants over the age of 65 were included in the study, and the prevalence of sarcopenia was 17.0%. According to the factor loadings of all of the 18 food groups, three dietary patterns were identified. These dietary patterns include the diversified dietary pattern, which is mainly characterized by the intake of soybeans, fungi and algae, animal meat, fruits, and legumes; the traditional dietary pattern, which is mainly defined by the consumption of rice, pork, poultry, vegetables, and aquatic products; and the wheat-based dietary pattern, which is mainly characterized by the intake of wheat, tubers, and other cereals. The diversified dietary pattern (OR = 0.54, p < 0.05) and the traditional dietary pattern (OR = 0.51, p < 0.05) were linked to a lower risk of developing sarcopenia, whereas the wheat-based dietary pattern (OR = 3.54, p < 0.05) was associated with a higher risk of sarcopenia. All three dietary patterns exhibited significantly correlated with muscle mass, grip strength, and physical performance (p < 0.05).

Conclusion

Dietary patterns are associated with sarcopenia in community-dwelling older adults in China. Adopting a healthy and sensible balanced diet and avoiding a single dietary preference may reduce the risk of sarcopenia in older adults.

Nutrition in the prevention and treatment of skeletal muscle ageing and sarcopenia: a single nutrient, a whole food and a whole diet approach

Loss of skeletal muscle strength and mass (sarcopenia) is common in older adults and associated with an increased risk of disability, frailty and premature death. Finding cost-effective prevention and treatment strategies for sarcopenia for the growing ageing population is therefore of great public health interest. Although nutrition is considered an important factor in the aetiology of sarcopenia, its potential for sarcopenia prevention and/or treatment is still being evaluated. Nutrition research for sarcopenia utilises three main approaches to understand muscle-nutrition relationships, evaluating: single nutrients, whole foods and whole diet effects - both alone or combined with exercise. Applying these approaches, we summarise recent evidence from qualitative and quantitative syntheses of findings from observational and intervention studies of healthy older adults, and those with sarcopenia. We consider protein supplements, whole foods (fruits and vegetables) and the Mediterranean diet as exemplars. There is some evidence of beneficial effects of protein supplementation ≥ 0·8 g/kg body weight/d on muscle mass when combined with exercise training in intervention studies of healthy and sarcopenic older adults. In contrast, evidence for effects on muscle function (strength and physical performance) is inconclusive. There is reasonably consistent epidemiological evidence suggesting benefits of higher fruits and vegetables consumption for better physical performance. Similarly, higher adherence to the Mediterranean diet is associated with beneficial effects on muscle function in observational studies. However, intervention studies are lacking. This review discusses how current evidence may inform the development of preventive and intervention strategies for optimal muscle ageing and nutritional public policy aimed at combatting sarcopenia.

The role of nutrition in the prevention of sarcopenia

Sarcopenia is a common skeletal muscle disorder characterized by a loss of muscle mass and impaired muscle function that is associated with poor health outcomes. Although nutrition is considered an important factor in the etiology of sarcopenia, the preventive potential of diet, specifically the extent to which differences in habitual patterns of diet and/or nutrient intakes impact risk of its development, is poorly understood. This narrative review considered research evidence on dietary patterns and nutrient intakes in mid- (<60 y) and young-older (60-70 y) adulthood to evaluate how they relate to age-related changes in muscle mass and function. A key finding was that current evidence on adult diet and sarcopenia risk in older age is limited and fragmented, with different outcomes reported across studies (for example, lean mass, strength) and few reporting links to incident diagnosed sarcopenia. As these outcomes are not interchangeable, it challenges collation of the evidence, leaving many gaps in understanding. There is also limited information about adult (<70 y) diet and few longitudinal studies with repeated dietary assessments to enable definition of cumulative exposures across adulthood. However, despite these limitations, findings from studies of dietary patterns already provide reasonably consistent messages about the benefits of diets of higher quality in earlier adulthood for later physical performance, although whole-diet intervention trials are urgently needed to understand their potential. In comparison, there is little evidence of benefits of higher intakes of individual nutrients in earlier adulthood for later muscle mass and function. Although these gaps need to be addressed in future research, there may already be sufficient data to promote messages about diet quality more widely - that healthier diets of higher quality across adulthood, with known benefits for a range of health outcomes, are also linked to the effective preservation of muscle mass and function.

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.

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.

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.

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.

The Relevance of Diet, Physical Activity, Exercise, and Persuasive Technology in the Prevention and Treatment of Sarcopenic Obesity in Older Adults

The aging population faces two conditions that threaten healthy aging: high fat mass (obesity) and low muscle mass and function (sarcopenia). The combination of both-referred to as sarcopenic obesity-synergistically increases the risk of adverse health outcomes. The two conditions often co-occur because they reinforce each other and share common etiologies, including poor nutrition and inactivity. All aging people are at risk of gaining weight and losing muscle mass and could benefit from improvements in physical activity, exercise and dietary intake. one specific window of opportunity is during the transient time of retirement, as older adults already need to restructure their daily activities. It is key to change lifestyle behavior in a sustainable manner, providing scientifically proven, personalized, and acceptable principles that can be integrated in daily life. Health technologies (e.g., applications) can provide promising tools to deliver personalized and appealing lifestyle interventions to a large group of people while keeping health care costs low. Several studies show that health technologies have a strong positive effect on physical activity, exercise and dietary intake. Specifically, health technology is increasingly applied to older people, although strong evidence for long term effects in changing lifestyle behavior is generally lacking. Concluding, technology could play an important role in the highly warranted prevention of sarcopenic obesity in older adults. Although health technology seems to be a promising tool to stimulate changes in physical activity, exercise and dietary intake, studies on long lasting effects and specifically targeted on older people around the time of retirement are warranted.