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The effect of vitamin D plus protein supplementation on sarcopenia: A systematic review and meta-analysis of randomized controlled trials.
Gkekas, NK, Anagnostis, P, Paraschou, V, Stamiris, D, Dellis, S, Kenanidis, E, Potoupnis, M, Tsiridis, E, Goulis, DG
Maturitas. 2021;:56-63
Abstract
PURPOSE The exact effect of vitamin D supplementation, either as monotherapy or in combination with protein, on musculoskeletal health in patients with sarcopenia is currently unknown. This study aimed to determine the effect of vitamin D alone or with protein supplementation on muscle strength, mass, and performance in this population. METHODS A comprehensive search was conducted in Medline, Cochrane Central and Scopus databases, up to March 31st, 2020. Data were expressed as standardized mean difference (SMD) with 95 % confidence intervals (CI). I2 index was employed for heterogeneity. RESULTS The initial search identified 1164 studies, eight of which met the eligibility criteria for qualitative and quantitative analysis, yielding a total of 776 patients. Vitamin D (100-1600 IU/day) plus protein (10-44 g/day) supplementation exhibited a beneficial effect on muscle strength, as demonstrated by an improvement in handgrip strength (SMD 0.38 ± 0.07, 95 % CI 0.18-0.47, p = 0.04; I2 76.2 %) and a decrease in the sit-to-stand time (SMD 0.25 ± 0.09, 95 % CI 0.06-0.43, p = 0.007; I2 0%) compared with placebo. However, the effect on muscle mass, assessed by skeletal muscle index, was marginally non-significant (SMD 0.25 ± 0.13, 95 % CI -0.006-0.51, p = 0.05; I2 0%). No effect on appendicular skeletal muscle mass or muscle performance (assessed by walking speed) was observed with vitamin D plus protein. CONCLUSIONS Vitamin D supplementation, combined with protein, improves muscle strength in patients with sarcopenia, but has no effect on muscle mass or performance.
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Are Dietary Proteins the Key to Successful Body Weight Management? A Systematic Review and Meta-Analysis of Studies Assessing Body Weight Outcomes after Interventions with Increased Dietary Protein.
Hansen, TT, Astrup, A, Sjödin, A
Nutrients. 2021;(9)
Abstract
The primary aim was to systematically review the current evidence investigating if dietary interventions rich in protein lead to improved body weight management in adults with excessive body weight. The secondary aim was to investigate potential modifying effects of phenotyping. A systematic literature search in PubMed, Web of Science, and Cochrane Library identified 375 randomized controlled trials with 43 unique trials meeting the inclusion criteria. The Cochrane collaboration tool was used for a thorough risk of bias assessment. Based on 37 studies evaluating effects of dietary protein on body weight, the participants with increased protein intake (ranging from 18-59 energy percentage [E%]) were found to reduce body weight by 1.6 (1.2; 2.0) kg (mean [95% confidence interval]) compared to controls (isocaloric interventions with energy reduction introduced in certain studies). Individuals with prediabetes were found to benefit more from a diet high in protein compared to individuals with normoglycemia, as did individuals without the obesity risk allele (AA genotype) compared to individuals with the obesity risk alleles (AG and GG genotypes). Thus, diets rich in protein would seem to have a moderate beneficial effect on body weight management.
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Coingestion of Carbohydrate and Protein on Muscle Glycogen Synthesis after Exercise: A Meta-analysis.
Margolis, LM, Allen, JT, Hatch-McChesney, A, Pasiakos, SM
Medicine and science in sports and exercise. 2021;(2):384-393
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INTRODUCTION/PURPOSE Evidence suggests that carbohydrate and protein (CHO-PRO) ingestion after exercise enhances muscle glycogen repletion to a greater extent than carbohydrate (CHO) alone. However, there is no consensus at this point, and results across studies are mixed, which may be attributable to differences in energy content and carbohydrate intake relative to body mass consumed after exercise. The purpose of this study was determine the overall effects of CHO-PRO and the independent effects of energy and relative carbohydrate content of CHO-PRO supplementation on postexercise muscle glycogen synthesis compared with CHO alone. METHODS Meta-analysis was conducted on crossover studies assessing the influence of CHO-PRO compared with CHO alone on postexercise muscle glycogen synthesis. Studies were identified in a systematic review from PubMed and Cochrane Library databases. Data are presented as effect size (95% confidence interval [CI]) using Hedges' g. Subgroup analyses were conducted to evaluate effects of isocaloric and nonisocaloric energy content and dichotomized by median relative carbohydrate (high, ≥0.8 g·kg-1⋅h-1; low, <0.8 g·kg-1⋅h-1) content on glycogen synthesis. RESULTS Twenty studies were included in the analysis. CHO-PRO had no overall effect on glycogen synthesis (0.13, 95% CI = -0.04 to 0.29) compared with CHO. Subgroup analysis found that CHO-PRO had a positive effect (0.26, 95% CI = 0.04-0.49) on glycogen synthesis when the combined intervention provided more energy than CHO. Glycogen synthesis was not significant (-0.05, 95% CI = -0.23 to 0.13) in CHO-PRO compared with CON when matched for energy content. There was no statistical difference of CHO-PRO on glycogen synthesis in high (0.07, 95% CI = -0.11 to 0.22) or low (0.21, 95% CI = -0.08 to 0.50) carbohydrate content compared with CHO. CONCLUSION Glycogen synthesis rates are enhanced when CHO-PRO are coingested after exercise compared with CHO only when the added energy of protein is consumed in addition to, not in place of, carbohydrate.
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Does Protein Supplementation Support Adaptations to Arduous Concurrent Exercise Training? A Systematic Review and Meta-Analysis with Military Based Applications.
Chapman, S, Chung, HC, Rawcliffe, AJ, Izard, R, Smith, L, Roberts, JD
Nutrients. 2021;(5)
Abstract
We evaluated the impact of protein supplementation on adaptations to arduous concurrent training in healthy adults with potential applications to individuals undergoing military training. Peer-reviewed papers published in English meeting the population, intervention, comparison and outcome criteria were included. Database searches were completed in PubMed, Web of science and SPORTDiscus. Study quality was evaluated using the COnsensus based standards for the selection of health status measurement instruments checklist. Of 11 studies included, nine focused on performance, six on body composition and four on muscle recovery. Cohen's d effect sizes showed that protein supplementation improved performance outcomes in response to concurrent training (ES = 0.89, 95% CI = 0.08-1.70). When analysed separately, improvements in muscle strength (SMD = +4.92 kg, 95% CI = -2.70-12.54 kg) were found, but not in aerobic endurance. Gains in fat-free mass (SMD = +0.75 kg, 95% CI = 0.44-1.06 kg) and reductions in fat-mass (SMD = -0.99, 95% CI = -1.43-0.23 kg) were greater with protein supplementation. Most studies did not report protein turnover, nitrogen balance and/or total daily protein intake. Therefore, further research is warranted. However, our findings infer that protein supplementation may support lean-mass accretion and strength gains during arduous concurrent training in physical active populations, including military recruits.
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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.
Mendonça, N, Hengeveld, LM, Visser, M, Presse, N, Canhão, H, Simonsick, EM, Kritchevsky, SB, Newman, AB, Gaudreau, P, Jagger, C
The American journal of clinical nutrition. 2021;(1):29-41
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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.
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The Role of Protein Intake and its Timing on Body Composition and Muscle Function in Healthy Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Wirth, J, Hillesheim, E, Brennan, L
The Journal of nutrition. 2020;(6):1443-1460
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BACKGROUND Increased protein intake has been suggested to improve gains in muscle mass and strength in adults. Furthermore, the timing of protein intake has been discussed as a margin of opportunity for improved prevention measures. OBJECTIVE This systematic review investigated the effect of protein supplementation on body composition and muscle function (strength and synthesis) in healthy adults, with an emphasis on the timing of protein intake. METHODS Randomized controlled trials were identified using PubMed, Web of Science, CINAHL, and Embase, up to March 2019. For meta-analyses, data on lean body mass (LBM), handgrip strength, and leg press strength were pooled by age group (mean age 18-55 or >55 y) and timing of protein intake. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. RESULTS Data from 65 studies with 2907 participants (1514 men and 1380 women, 13 unknown sex) were included in the review. Twenty-six, 8, and 24 studies were used for meta-analysis on LBM, handgrip strength, and leg press strength, respectively. The protein supplementation was effective in improving (mean difference; 95% CI) LBM in adults (0.62 kg; 0.36, 0.88) and older adults (0.46 kg; 0.23, 0.70), but not handgrip strength (older adults: 0.26 kg; -0.51, 1.04) and leg press strength (adults: 5.80 kg; -0.33, 11.93; older adults: 1.97 kg; -2.78, 6.72). Sensitivity analyses removing studies without exercise training had no impact on the outcomes. Data regarding muscle synthesis were scarce and inconclusive. Subgroup analyses showed no beneficial effect of a specific timing of protein intake on LBM, handgrip strength, and leg press strength. CONCLUSION Overall, the results support the positive impact of protein supplementation on LBM of adults and older adults, independently of intake timing. Effects on muscle strength and synthesis are less clear and need further investigation. This systematic review was registered on PROSPERO as CRD42019126742.
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The effect of protein supplements on functional frailty in older persons: A systematic review and meta-analysis.
Oktaviana, J, Zanker, J, Vogrin, S, Duque, G
Archives of gerontology and geriatrics. 2020;:103938
Abstract
BACKGROUND The effect of protein supplementation in attenuating loss of muscle mass, strength and function in community-dwelling older people has been promising, however, its benefits in pre-frail and frail older people remains unclear. OBJECTIVE To determine the effect of protein supplementation on muscle mass, strength and function in frail older people by reviewing and conducting meta-analysis of relevant randomized controlled trials (RCTs). DESIGN This review was registered at PROSPERO (CRD42017079276) and conducted according to Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Using a pre-determined e-search strategy, we searched PubMed, Medline, EMBASE, CINAHL, LILACS, Web of Science, Cochrane and Scopus databases. Inclusion criteria were RCTs that assessed the effect of protein supplementation on muscle mass, strength and function in frail individuals aged ≥65 years. The main outcomes were lean body mass (LBM), handgrip, leg extension, leg press strength, short physical performance battery (SPPB) score, and gait velocity. RESULTS Of the eight studies included in this review, 503 subjects were enrolled and four different protein supplements were assessed. Despite the variation in methodology, studies were homogenous with I-squared <10.0%. The meta-analysis showed no significant effect of protein supplementation on LBM (mean difference 1.17 kg, 95% CI: -1.97-4.3), handgrip (mean difference 0.15, 95% CI: -0.95-1.24), leg extension (mean difference -3.68 kg, 95% CI: -12.72-5.36), leg press (mean standardized difference 0.26 kg, 95% CI: -0.30-0.82), SPPB (mean difference 0.61, 95% CI: -0.02-1.23), or gait velocity (mean difference -0.20 m/s, 95% CI: -0.95-0.55). CONCLUSION Protein supplementation alone does not significantly improve muscle mass, strength or function in pre-frail or frail older people.
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Effect of calorie restriction or protein intake on circulating levels of insulin like growth factor I in humans: A systematic review and meta-analysis.
Kazemi, A, Speakman, JR, Soltani, S, Djafarian, K
Clinical nutrition (Edinburgh, Scotland). 2020;(6):1705-1716
Abstract
Calorie restriction (CR) and reductions in protein intake in rodents result in increased lifespan and reduced levels of IGF-1. However, the changes in IGF-1 in humans in response to CR and elevated protein intake are confused. We conducted a systematic review and meta-analysis to investigate the effect of Calorie restriction (CR) or increase in protein intake on IGF-1 in humans. The systematic review protocols have been developed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. Two separate systematic searches were undertaken: first for the effect of CR and second on the effect of increase in protein intake on IGF-1. PubMed, SCOPUS and ISI Web of Science databases were searched. In the meta-analysis of the calorie restriction studies, twelve studies met the inclusion criteria (8 clinical trials and 4 observational studies). The meta-analysis of both clinical trials and observational studies revealed no significant effect of CR on IGF-1 (clinical trials: standardized mean difference (SMD) = 0.002 ng/ml, 95% CI -0.14 to 0.14 ng/ml, p = 0.98; observational studies (SMD = -1.14 ng/ml, 95% CI -1.9 to -0.38 ng/ml, p = 0.003). In the meta-analysis of protein intake studies (six studies), a significant increase in circulating IGF-1 levels in response to increases in dietary protein was revealed (SMD = 0.4 ng/ml, 95% CI 0.18-0.61 ng/ml, p < 0.001). In conclusion, in humans, CR was not associated with a significant change in circulating IGF-1. However an increase in protein intake was associated with increased levels of circulating IGF-1. PROTOCOLS REGISTRATION NUMBER CRD42017073149 for the protein intake meta-analysis and CRD42016046260 for CR meta-analysis.
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The association between dietary protein intake and esophageal cancer risk: a meta-analysis.
Kong, F, Geng, E, Ning, J, Liu, Z, Wang, A, Zhang, S, Wang, H
Bioscience reports. 2020;(1)
Abstract
Several papers studied dietary protein intake as a potential influence factor for esophageal cancer, but their findings were inconsistent. Thus, this meta-analysis was performed to identify the effect of protein intake on esophageal cancer risk. Potential case-control studies or cohort studies from the databases of Embase, Web of Science and PubMed were searched. The strength of association was quantified by pooling odds ratio (OR) and 95% confidence interval (CI). In total, 11 articles involving 2537 cases and 11432 participants were included in this meta-analysis. As a result, dietary protein intake had non-significant association on esophageal cancer risk overall (pooled OR = 1.11, 95% CI = 0.88-1.40). Meanwhile, we obtained consistent results in the subgroups analyses by study design, protein type, geographic locations and number of cases. Interestingly, dietary protein intake could significantly increase the risk of esophageal squamous cell carcinoma (pooled OR = 1.29, 95% CI = 1.02-1.62), instead of other disease type. To sum up, dietary protein intake had no significant association with esophageal cancer risk in the overall analysis; but, protein intake may be associated with the risk of esophageal squamous cell carcinoma. While some limitations existed in the present paper, more studies with large sample size are warranted to further confirm this result.
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Do multi-ingredient protein supplements augment resistance training-induced gains in skeletal muscle mass and strength? A systematic review and meta-analysis of 35 trials.
O'Bryan, KR, Doering, TM, Morton, RW, Coffey, VG, Phillips, SM, Cox, GR
British journal of sports medicine. 2020;(10):573-581
Abstract
OBJECTIVE To determine the effects of multi-ingredient protein (MIP) supplements on resistance exercise training (RT)-induced gains in muscle mass and strength compared with protein-only (PRO) or placebo supplementation. DATA SOURCES Systematic search of MEDLINE, Embase, CINAHL and SPORTDiscus. ELIGIBILITY CRITERIA Randomised controlled trials with interventions including RT ≥6 weeks in duration and a MIP supplement. DESIGN Random effects meta-analyses were conducted to determine the effect of supplementation on fat-free mass (FFM), fat mass, one-repetition maximum (1RM) upper body and 1RM lower body muscular strength. Subgroup analyses compared the efficacy of MIP supplementation relative to training status and chronological age. RESULTS The most common MIP supplements included protein with creatine (n=17) or vitamin D (n=10). Data from 35 trials with 1387 participants showed significant (p<0.05) increases in FFM (0.80 kg (95% CI 0.44 to 1.15)), 1RM lower body (4.22 kg (95% CI 0.79 to 7.64)) and 1RM upper body (2.56 kg (95% CI 0.79 to 4.33)) where a supplement was compared with all non-MIP supplemented conditions (means (95% CI)). Subgroup analyses indicated a greater effect of MIP supplements compared with all non-MIP supplements on FFM in untrained (0.95 kg (95% CI 0.51 to 1.39), p<0.0001) and older participants (0.77 kg (95% CI 0.11 to 1.43), p=0.02); taking MIP supplements was also associated with gains in 1RM upper body (1.56 kg (95% CI 0.80 to 2.33), p=0.01) in older adults. SUMMARY/CONCLUSIONS When MIP supplements were combined with resistance exercise training, there were greater gains in FFM and strength in healthy adults than in counterparts who were supplemented with non-MIP. MIP supplements were not superior when directly compared with PRO supplements. The magnitude of effect of MIP supplements was greater (in absolute values) in untrained and elderly individuals undertaking RT than it was in trained individuals and in younger people. TRIAL REGISTRATION NUMBER CRD42017081970.