Stimulate Muscle Protein Synthesis Research Articles

E-PROOF: E-intervention for protein intake and resistance training to optimize function: A study protocol.

Accounting for more than 60% of cancer survivors, older (≥65 years) cancer survivors have a 2- to 5-fold risk of physical function impairment, compared to cancer-free peers. One strategy to improve physical function is dietary and resistance training interventions, which improve muscle strength and mass by stimulating muscle protein synthesis. The E-PROOF (E-intervention for Protein Intake and Resistance Training to Optimize Function) study will examine the feasibility, acceptability, and preliminary efficacy of a 12-week randomized controlled trial of an online, tailored nutritional and resistance training education and counseling intervention to improve physical function and associated health outcomes (muscle strength, health-related quality of life (HRQoL), self-efficacy, and weight management). In this study, 70 older cancer survivors will be randomized to one of two groups: experimental (receiving remote behavioral counseling and evidence-based education and resources), and control (general survivorship education). We will examine the intervention effects on physical function, muscle strength, HRQoL, self-efficacy, weight, and waist circumference during a 12-week period between the experimental and control groups. Three months following the end of the intervention, we will conduct a follow-up assessment to measure physical function, muscle strength, and HRQoL. This study is the first synchronous, online protein-focused diet and resistance training intervention among older cancer survivors. This novel study advances science by promoting independent health behaviors among older cancer survivors to improve health outcomes, and provide foundational knowledge to further address this growing problem on a wider scale through online platforms.

Muscle Protein Synthesis in Response to Plant-Based Protein Isolates With and Without Added Leucine Versus Whey Protein in Young Men and Women

BackgroundPlant-based protein supplements often contain lower amounts of leucine and other essential amino acids (EAAs), potentially making them less effective in stimulating muscle protein synthesis (MPS) than animal-based proteins. Combining plant proteins could improve the EAA profile and more effectively support MPS. ObjectivesThe aim of this study was to determine the effect of a novel plant-based blend protein (PBP), PBP with added leucine (PBP + Leu) to levels equivalent to whey protein isolate (WHEY) on aminoacidemia and MPS responses in young men and women. We hypothesized that PBP + Leu would stimulate MPS equivalent to WHEY, and both would be greater than PBP. MethodsWe employed a randomized, double-blind, crossover study consisting of 3 separate study visits to compare PBP, PBP + Leu, and WHEY. To measure MPS response to ingestion of the supplements, a primed continuous infusion of L-[ring13C6] phenylalanine was administered for 8 h at each study visit. Skeletal muscle tissue and blood samples were collected to measure aminoacidemia and MPS. ResultsAll protein supplements increased mixed MPS above postabsorptive levels (P < 0.001). However, MPS increase following ingestion of PBP was less than that following ingestion of PBP + Leu (P = 0.002) and WHEY (P = 0.046). There were no differences in MPS between PBP + Leu and WHEY (P = 0.052). ConclusionsConsumption of PBP isolate with added leucine stimulated MPS to a similar extent as whey protein in young men and women. PBPs containing higher leucine content promote anabolism to a similar extent as animal-based proteins.This study was registered at clinicaltrials.gov as NCT05139160.

Stimulation of muscle protein synthesis with low-dose amino acid composition in older individuals.

Essential amino acid (EAA)-based compositions have been shown to be effective stimulators of muscle protein synthesis, but the lower limit of effective dosage is not clear. We have used stable isotope tracer methodology to quantify the response of muscle protein fractional synthetic rate (FSR) to a dose of 3.6 g of a high-leucine composition of EAAs plus arginine in older subjects. Muscle protein FSR increased 0.058%/hour over 3 h following consumption. When account was taken of the total muscle mass, this increase in muscle protein FSR represented approximately 80% of ingested EAAs. We conclude that a low dose of an EAA-based composition can effectively stimulate muscle protein synthesis.

P070 The influence of Crohn’s disease-derived blood plasma upon anabolic signaling responses to leucine stimulation in skeletal muscle cells in vitro

Abstract Background Many Crohn’s Disease (CD) patients have low muscle mass and function (sarcopenia), yet the precise drivers of this pathophysiology are unclear. Positive muscle protein balance is driven by essential amino acids (EAA) that stimulate muscle protein synthesis (MPS), with the EAA leucine (L) playing a key role. However, if circulating factors in CD impact muscle anabolic responses to feeding remain unclear. Our aims were to use plasma from healthy human volunteers (HV) and active CD patients to investigate the impact on anabolic signaling and responses to feeding. Methods HV were 32 ± 4 y with a BMI 24 ± 1 and CD 26 ± 3 y with a BMI 23 ± 1 disease duration 5 ± 1 y faecal calprotectin 720 ± 12 ug/g. C2C12 myotubes were treated with 4 conditions of media conditioned with 5% plasma from HV or CD, in addition to being treated ± 5mM L for 4 hrs. Protein content was quantified via nanodrop and muscle anabolic signaling measured via immunoblotting for p-mTORC1 (Ser2448), p-4E-BP1 (Thr37/46) and p-P70S6K1 (Thr389). Results Immunoblotting revealed no difference in mTORC1 phosphorylation between HV and CD (HV:18.9 ± 2.7 AU, CD: 19.9 ± 3.2 AU), with no change in response to L treatment (HV:18.0 ± 2.4 AU, CD: 16.6 ± 2.3 AU). There was no difference in P70S6K1 phosphorylation between HV and CD (HV: 33.7 ± 3.2 AU, CD: 28.0 ± 4.7 AU) with both groups showing significant increases in phosphorylation with L treatment (HV: 56.4 ± 4.2 AU (P&amp;lt;0.05), CD: 54.5 ± 9.2 AU (P&amp;lt;0.001)). There was no difference in 4EBP1 phosphorylation between HV and CD (HV: 49.8 ± 6.4 AU, CD: 64.6 ± 7.5 AU) with only HV showing a significant increase in phosphorylation with L (HV: 105.5 ± 8.7 AU (P&amp;lt;0.0001), CD: 47.8 ± 5.3 AU). There was difference in total protein concentration between HV and CD, or with L treatment. Conclusion We found CD derived blood plasma did not impact the leucine stimulated increase in P70S6K1 phosphorylation but did result in blunted phosphorylation of 4EBP1. These disparities in anabolic signaling indicate that systemic factors in CD may impact muscle anabolic responses to feeding. Yet, the relationship between anabolic markers and rates of MPS remains complex.

Management of disease-related malnutrition: a real-world experience with a novel concentrated high-protein energy-dense oral nutritional supplement

ABSTRACT Objective Despite the availability of a wide range of oral nutritional supplements (ONS) offerings, individuals with malnutrition are still struggling to meet their nutritional targets. A new concentrated and high-protein energy-dense ONS (≥2.1 kcal/mL;32 g protein/200 mL) with high-quality protein (60% whey protein) has emerged as a pivotal formula to reach the patient’s energy-protein requirements, enhance compliance, and maximize stimulation of muscle protein synthesis, key factors driving better nutritional, functional, and clinical outcomes. The purpose of this article is to provide our clinical experience using this new nutritionally concentrated ONS as a therapeutic strategy for patients with DRM. Methods Three clinical cases have been examined using new assessment procedures and a new form of nutritional therapy, and their impact on the nutritional and functional outcomes in patients with moderate-to-severe DRM. Results A tailored individualized nutritional interventions improved anthropometric, biochemical, and functional outcomes (Case 1,2, and 3) assessed using hand grip strength, bioimpedance and muscle ultrasound, and as well as good gastrointestinal tolerance (Case 1) and compliance to the ONS in patients with DRM (Case 1,2,3). Conclusion The use of this novel high-protein energy-dense formula with high-quality protein source (≥2.1 kcal/mL; 32 g protein/200 mL; 60% whey protein) overcome common practical challenges in the medical nutrition therapy of patients with DRM, either because these patients require a highly concentrated formulation to meet nutritional requirements due to loss of appetite, lack of interest in food, and high caloric-protein needs due to disease, and a large quantity and quality of protein to optimize muscle recovery due to sarcopenia, common in patients with moderate-severe malnutrition.

ROLE OF THE METHYLTRANSFERASE METTL21C IN DRIVING MUSCLE ATROPHY WITH AGING AND HIV INFECTION

Abstract Osteoporosis and sarcopenia are both frequently observed in older people living with HIV. We developed an animal model to investigate the cellular and molecular mechanisms underlying accelerated muscle aging in the setting of HIV infection. Wild-type C57BL/6 mice received bone marrow from Tg26 HIV-1 transgenic mice at 8 weeks of age and tissues were collected 8 weeks later. Tg26 mice express 7 of 9 HIV proteins but lack gag and pol so are non-infectious. RNA was isolated from the tibialis anterior and microarray was performed using the Clariom S Mouse array that contains more than 22,100 well-annotated genes and 150,300 transcripts. Differential expressions were calculated using ANOVA and filtered with a p-value cutoff of 0.05. Results show that the methyltransferase Mettl21c, a methyltransferase previously shown to stimulate muscle protein synthesis and suppress muscle degradation, is one of the most highly downregulated (more than two-fold) genes in muscle from mice receiving Tg26 bone marrow. We then analyzed GEO data sets to identify changes in muscle Mettl21c expression in various disease settings. These data sets reveal that Mettl21c is consistently downregulated in skeletal muscle with inflammatory conditions such as cancer cachexia and sepsis. In addition, GWAS studies have previously shown Mettl21c deficiency in patients with sarcopenia and osteoporosis. Our data suggest that HIV proteins may produce epigenetic modifications in skeletal muscle leading to muscle loss, and that therapies restoring expression of methyltransferases such as Mettl21c might improve muscle health in patients living with HIV.

Long-chain n-3 PUFA ingestion for the stimulation of muscle protein synthesis in healthy older adults.

This review aims to critically evaluate the efficacy of long-chain ո-3 PUFA ingestion in modulating muscle protein synthesis (MPS), with application to maintaining skeletal muscle mass, strength and function into later life. Ageing is associated with a gradual decline in muscle mass, specifically atrophy of type II fibres, that is exacerbated by periods of (in)voluntary muscle disuse. At the metabolic level, in otherwise healthy older adults, muscle atrophy is underpinned by anabolic resistance which describes the impaired MPS response to non-pharmacological anabolic stimuli, namely, physical activity/exercise and amino acid provision. Accumulating evidence implicates a mechanistic role for n-3 PUFA in upregulating MPS under stimulated conditions (post-prandial state or following exercise) via incorporation of EPA and DHA into the skeletal muscle phospholipid membrane. In some instances, these changes in MPS with chronic ո-3 PUFA ingestion have translated into clinically relevant improvements in muscle mass, strength and function; an observation evidently more prevalent in healthy older women than men. This apparent sexual dimorphism in the adaptive response of skeletal muscle metabolism to EPA and DHA ingestion may be related to a greater propensity for females to incorporate ո-3 PUFA into human tissue and/or the larger dose of ingested ո-3 PUFA when expressed relative to body mass or lean body mass. Future experimental studies are warranted to characterise the optimal dosing and duration of ո-3 PUFA ingestion to prescribe tailored recommendations regarding n-3 PUFA nutrition for healthy musculoskeletal ageing into later life.

A single bout of prior resistance exercise attenuates muscle atrophy and declines in myofibrillar protein synthesis during bed-rest in older men.

Impairments in myofibrillar protein synthesis (MyoPS) during bed rest accelerate skeletal muscle loss in older adults, increasing the risk of adverse secondary health outcomes. We investigated the effect of prior resistance exercise (RE) on MyoPS and muscle morphology during a disuse event in 10 healthy older men (65-80years). Participants completed a single bout of unilateral leg RE the evening prior to 5days of in-patient bed-rest. Quadriceps cross-sectional area (CSA) was determined prior to and following bed-rest. Serial muscle biopsies and dual stable isotope tracers were used to determine rates of integrated MyoPS (iMyoPS) over a 7day habitual 'free-living' phase and the bed-rest phase, and rates of acute postabsorptive and postprandial MyoPS (aMyoPS) at the end of bed rest. Quadriceps CSA at 40%, 60% and 80% of muscle length significantly decreased in exercised (EX) and non-exercised control (CTL) legs with bed-rest. The decline in quadriceps CSA at 40% and 60% of muscle length was attenuated in EX compared with CTL. During bed-rest, iMyoPS rates decreased from habitual values in CTL, but not EX, and were significantly different between legs. Postprandial aMyoPS rates increased above postabsorptive values in EX only. The change in iMyoPS over bed-rest correlated with the change in quadriceps CSA in CTL, but not EX. A single bout of RE attenuated the decline in iMyoPS rates and quadriceps atrophy with 5days of bed-rest in older men. Further work is required to understand the functional and clinical implications of prior RE in older patient populations. KEY POINTS: Age-related skeletal muscle deterioration, linked to numerous adverse health outcomes, is driven by impairments in muscle protein synthesis that are accelerated during periods of disuse. Resistance exercise can stimulate muscle protein synthesis over several days of recovery and therefore could counteract impairments in this process that occur in the early phase of disuse. In the present study, we demonstrate that the decline in myofibrillar protein synthesis and muscle atrophy over 5days of bed-rest in older men was attenuated by a single bout of unilateral resistance exercise performed the evening prior to bed-rest. These findings suggest that concise resistance exercise intervention holds the potential to support muscle mass retention in older individuals during short-term disuse, with implications for delaying sarcopenia progression in ageing populations.

Protein intake, distribution, and sources in community-dwelling older adults living in Auckland, New Zealand

BACKGROUND: To maximally stimulate muscle protein synthesis (MPS), older adults should consume≥1.2 g/kg body weight (BW) of high-quality protein, evenly distributed across the day ( 0.4 g/kg BW per meal). OBJECTIVES: To investigate protein intake, distribution, and sources in community-dwelling older adults. METHODS: Data (including a 4-day food record) were obtained from the Researching Eating, Activity, and Cognitive Health (REACH) study, a cross-sectional study in adults aged 65 to 74 years. RESULTS: Participants (n = 327, 65.4% female) had a median daily protein intake of 1.16 g/kg BW (males) and 1.09 g/kg BW (females). Over half of participants consumed less than 1.2 g protein/kg BW/day (62% females, 57% males). Protein intake was unevenly distributed throughout the day (CV = 0.48 for males and females) and was inadequate for reaching 0.4 g/kg BW/meal at breakfast and at the mid-day meal (males only). The main sources of protein at breakfast were milk (28%), breakfast cereals (22%), and bread (12%); at the mid-day meal, bread (18%), cheese (10%) and milk (9%); and at the evening meal, meat provided over half the protein (56%). CONCLUSIONS: Protein intake for a high proportion of older adults was less than 1.2 g/kg BW/day, and unevenly distributed through the day. Protein was obtained mainly from cereals and dairy products at breakfast and the mid-day meal, and meat sources at the evening meal.

International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance.

Position Statement: The International Society of Sports Nutrition (ISSN) presents this position based on a critical examination of literature surrounding the effects of essential amino acid (EAA) supplementation on skeletal muscle maintenance and performance. This position stand is intended to provide a scientific foundation to athletes, dietitians, trainers, and other practitioners as to the benefits of supplemental EAA in both healthy and resistant (aging/clinical) populations. EAAs are crucial components of protein intake in humans, as the body cannot synthesize them. The daily recommended intake (DRI) for protein was established to prevent deficiencies due to inadequate EAA consumption. The following conclusions represent the official position of the Society: 1. Initial studies on EAAs' effects on skeletal muscle highlight their primary role in stimulating muscle protein synthesis (MPS) and turnover. Protein turnover is critical for replacing degraded or damaged muscle proteins, laying the metabolic foundation for enhanced functional performance. Consequently, research has shifted to examine the effects of EAA supplementation - with and without the benefits of exercise - on skeletal muscle maintenance and performance. 2. Supplementation with free-form EAAs leads to a quick rise in peripheral EAA concentrations, which in turn stimulates MPS. 3. The safe upper limit of EAA intake (amount), without inborn metabolic disease, can easily accommodate additional supplementation. 4. At rest, stimulation of MPS occurs at relatively small dosages (1.5-3.0 g) and seems to plateau at around 15-18 g. 5. The MPS stimulation by EAAs does not require non-essential amino acids. 6. Free-form EAA ingestion stimulates MPS more than an equivalent amount of intact protein. 7. Repeated EAA-induced MPS stimulation throughout the day does not diminish the anabolic effect of meal intake. 8. Although direct comparisons of various formulas have yet to be investigated, aging requires a greater proportion of leucine to overcome the reduced muscle sensitivity known as "anabolic resistance." 9. Without exercise, EAA supplementation can enhance functional outcomes in anabolic-resistant populations. 10. EAA requirements rise in the face of caloric deficits. During caloric deficit, it's essential to meet whole-body EAA requirements to preserve anabolic sensitivity in skeletal muscle.

Analisa Pengaruh Pemberian Informasi Tentang Persiapan Operasi Sectio Ceasarea Dengan Pendekatan Komunikasi Terapeutik Terhadap Tingkat Kecemasan Pasien Pre-Operasi

Introduction: Stunting is one of the most common child health problems in the world. Eggs contain essential amino acids that stimulate muscle protein synthesis. The Pakuhaji Community Health Center, Tangerang Banten Regency, obtained quite high data on stunting under five in 2021 there were 162. The Community Health Center is trying to provide animal food in the form of giving One Egg One Day (Saluri), the program has only been implemented this month in October 2022. Methods: Quasy experiment with a one-group pretest-posttest design method. The sample was 39 toddlers who experienced stunting in October 2022 using a purposive sampling technique. Intervention giving one item a day for 3 months. Bivariate analysis using the Wilcoxon test. Results: The results of the univariate study of stunting toddlers' height before the administration of saluri averaged = 74,81 cm after the administration of salivation averaged = 79,00 cm. Bivariate research results with p = 0,000. Discussion: Giving saluri (one egg per day) is effective for height in stunting toddlers. It is hoped that stunted toddler mothers can take good care of their toddlers and pay attention to their intake of foods that contain high animal protein, one of which is by giving one egg a day routinely and obediently in order to increase bone growth and toddler brain development so that stunting can be overcome.

Efektivitas Pemberian Saluri (Satu Telur Satu Hari) Terhadap Tinggi Badan Pada Balita Stunting Di Puskesmas Pakuhaji Kabupaten Tangerang Banten Tahun 2022

Introduction: Stunting is one of the most common child health problems in the world. Eggs contain essential amino acids that stimulate muscle protein synthesis. The Pakuhaji Community Health Center, Tangerang Banten Regency, obtained quite high data on stunting toddlers, namely in 2021 there were 162. The Health Center is trying to provide animal food in the form of giving One Egg One Day (Saluri) in October 2022. Methods: Quasy experiment with the one-group pretest-posttest design method. The sample was 39 toddlers who experienced stunting in October 2022 using a purposive sampling technique. Intervention giving one item a day for 3 months. Bivariate analysis using the Wilcoxon test. Results: The results of the univariate study of stunting toddlers' height before the administration of saluri averaged = 74,81 cm after the administration of saluri averaged = 79,00 cm. Bivariate research results with p = 0,000. Discussion: Giving saluri (one egg a day) is effective for height in stunting toddlers. It is hoped that stunted toddler mothers can take good care of their toddlers and pay attention to their intake of foods that contain high animal protein, one of which is by giving one egg a day routinely and obediently in order to increase bone growth and toddler brain development so that stunting can be overcome.

Does the blunted stimulation of skeletal muscle protein synthesis by aging in response to mechanical load result from impaired ribosome biogenesis?

Age-related loss of skeletal muscle mass leads to a reduction of strength. It is likely due to an inadequate stimulation of muscle protein synthesis (MPS) in response to anabolic stimuli, such as mechanical load. Ribosome biogenesis is a major determinant of translational capacity and is essential for the control of muscle mass. This mini-review aims to put forth the hypothesis that ribosome biogenesis is impaired by aging in response to mechanical load, which could contribute to the age-related anabolic resistance and progressive muscle atrophy. Recent animal studies indicate that aging impedes muscle hypertrophic response to mechanical overload. This is associated with an impaired transcription of ribosomal DNA (rDNA) by RNA polymerase I (Pol I), a limited increase in total RNA concentration, a blunted activation of AKT/mTOR pathway, and an increased phosphorylation of AMPK. In contrast, an age-mediated impairment of ribosome biogenesis is unlikely in response to electrical stimulations. In human, the hypertrophic response to resistance exercise training is diminished with age. This is accompanied by a deficit in long-term MPS and an absence of increased total RNA concentration. The results addressing the acute response to resistance exercise suggest an impaired Pol I-mediated rDNA transcription and attenuated activation/expression of several upstream regulators of ribosome biogenesis in muscles from aged individuals. Altogether, emerging evidence indicates that impaired ribosome biogenesis could partly explain age-related anabolic resistance to mechanical load, which may ultimately contribute to progressive muscle atrophy. Future research should develop more advanced molecular tools to provide in-depth analysis of muscle ribosome biogenesis.

Increasing Muscle Mass in Elders through Diet and Exercise: A Literature Review of Recent RCTs.

This study aimed to review the current evidence on the independent and combined effects of diet and exercise and their impact on skeletal muscle mass in the elderly population. Skeletal muscle makes up approximately 40% of total body weight and is essential for performing daily activities. The combination of exercise and diet is known to be a potent anabolic stimulus through stimulation of muscle protein synthesis from amino acids. Aging is strongly associated with a generalized deterioration of physiological function, including a progressive reduction in skeletal muscle mass and strength, which in turn leads to a gradual functional impairment and an increased rate of disability resulting in falls, frailty, or even death. The term sarcopenia, which is an age-related syndrome, is primarily used to describe the gradual and generalized loss of skeletal muscle mass (mainly in type II muscle fibers) and function. Multimodal training is emerging as a popular training method that combines a wide range of physical dimensions. On the other hand, nutrition and especially protein intake provide amino acids, which are essential for muscle protein synthesis. According to ESPEN, protein intake in older people should be at least 1 g/kgbw/day. Essential amino acids, such as leucine, arginine, cysteine, and glutamine, are of particular importance for the regulation of muscle protein synthesis. For instance, a leucine intake of 3 g administered alongside each main meal has been suggested to prevent muscle loss in the elderly. In addition, studies have shown that vitamin D and other micronutrients can have a protective role and may modulate muscle growth; nevertheless, further research is needed to validate these claims. Resistance-based exercise combined with a higher intake of dietary protein, amino acids, and/or vitamin D are currently recognized as the most effective interventions to promote skeletal muscle growth. However, the results are quite controversial and contradictory, which could be explained by the high heterogeneity among studies. It is therefore necessary to further assess the impact of each individual exercise and nutritional approach, particularly protein and amino acids, on human muscle turnover so that more efficient strategies can be implemented for the augmentation of muscle mass in the elderly.

Protein quality and the food matrix: defining optimal versus maximal meal-based protein intakes for stimulating muscle protein synthesis.

This paper examines the opinion that we should aim to optimize, rather than maximize, protein intakes to avoid over-emphasizing muscle-centric protein requirements. An optimal eating approach strives to minimize amino acid oxidative waste and more efficiently stimulate postprandial muscle protein accretion. To do this, practitioners should acknowledge higher quality protein foods as better in delivering target amounts of amino acids into circulation, and the food matrix (e.g., nutrient-nutrient interactions) can be leveraged to potentiate essential amino acid incorporation into skeletal muscle protein.

Soy Food Consumption Is Inversely Associated with Handgrip Strength: Results from the TCLSIH Cohort Study.

Background: Soy foods contain high levels of soy protein or isoflavones, which can stimulate muscle protein synthesis and increase antioxidant capacity, and thus ameliorate muscle strength decline. However, data from epidemiological studies investigating the association of habitual soy food consumption with muscle strength decline among general Chinese adults are limited. Methods: This study included 29,525 participants (mean age: 41.6 years; 16,933 (53.8%) males). Soy food consumption was evaluated using a validated 100-item food frequency questionnaire. Handgrip strength (HGS) was assessed with a hand dynamometer. Analysis of covariance were performed to assess the multivariable-adjusted least square means (LSM) and 95% confidence interval (CI) for HGS. Results: The multiple adjusted LSM (95% CI) of HGS across soy food consumption were 35.5 (34.2, 37.1) kg for <1 time per week, 36.1 (34.6, 37.6) kg for 1 time per week, 36.3 (34.8, 37.8) kg for 2−3 times per week, and 36.6 (35.1, 38.0) kg for ≥4 times per week (p for trend < 0.001). Compared to participants with soy food consumption less than one time per week, the multiple adjusted odds ratio (95% CI) of low HGS was 0.638 (0.485, 0.836) when the weekly consumption was ≥ 4 times (p for trend < 0.01). Conclusions: Higher habitual soy food consumption was positively associated with HGS in general Chinese adults. Consumption of soy foods may have beneficial effects on muscle health.

Peripheral Amino Acid Appearance Is Lower Following Plant Protein Fibre Products, Compared to Whey Protein and Fibre Ingestion, in Healthy Older Adults despite Optimised Amino Acid Profile

Plant-based proteins are generally characterised by lower Indispensable Amino Acid (IAA) content, digestibility, and anabolic properties, compared to animal-based proteins. However, they are environmentally friendlier, and wider consumption is advocated. Older adults have higher dietary protein needs to prevent sarcopenia, a disease marked by an accelerated loss of muscle mass and function. Given the lower environmental footprint of plant-based proteins and the importance of optimising dietary protein quality among older adults, this paper aims to assess the net peripheral Amino Acid (AA) appearance after ingestion of three different plant protein and fibre (PPF) products, compared to whey protein with added fibre (WPF), in healthy older adults. In a randomised, single-blind, crossover design, nine healthy men and women aged ≥65 years consumed four test meals balanced in AA according to the FAO reference protein for humans, matched for leucine, to optimally stimulate muscle protein synthesis in older adults. A fasted blood sample was drawn at each visit before consuming the test meal, followed by postprandial arterialise blood sampling every 30 min for 3 h. The test meal was composed of a soup containing either WPF or PPF 1-3. The PPF blends comprised pea proteins with varying additional rice, pumpkin, soy, oat, and/or almond protein. PPF product ingestion resulted in a lower maximal increase of postprandial leucine concentration and the sum of branched-chain AA (BCAA) and IAA concentrations, compared to WPF, with no effect on their incremental area under the curve. Plasma methionine and cysteine, and to a lesser extent threonine, appearance were limited after consuming the PPF products, but not WPF. Despite equal leucine doses, the WPF induced greater postprandial insulin concentrations than the PPF products. In conclusion, the postprandial appearance of AA is highly dependent on the protein source in older adults, despite providing equivalent IAA levels and dietary fibre. Coupled with lower insulin concentrations, this could imply less anabolic potential. Further investigation is required to understand the applicability of plant-based proteins in healthy older adults.

Resistance exercise enhances long-term mTORC1 sensitivity to leucine

ObjectiveExercise enhances the sensitivity of mammalian target of rapamycin complex 1 (mTORC1) to amino acids, in particular leucine. How long this enhanced sensitivity lasts, and which mechanisms control enhanced leucine-mediated mTORC1 activation following exercise is currently unknown. MethodsC57BL/6J mice were exercised for one night in a resistance-braked running wheel after a 12-day acclimatization period. Mice were gavaged with a submaximal dose of l-leucine or saline acutely or 48 h after exercise cessation, following 3 h food withdrawal. Muscles were excised 30 min after leucine administration. To study the contribution of mTORC1, we repeated those experiments but blocked mTORC1 activation using rapamycin immediately before the overnight running bout and one hour before the first dose of leucine. mTORC1 signaling, muscle protein synthesis and amino acid sensing machinery were assessed using immunoblot and qPCR. Leucine uptake was measured using L-[14C(U)]-leucine tracer labeling. ResultsWhen compared to sedentary conditions, leucine supplementation more potently activated mTORC1 and protein synthesis in acutely exercised muscle. This effect was observed in m. soleus but not in m. tibialis anterior nor m. plantaris. The synergistic effect in m. soleus was long-lasting as key downstream markers of mTORC1 as well as protein synthesis remained higher when leucine was administered 48 h after exercise. We found that exercise enhanced the expression of amino acid transporters and promoted uptake of leucine into the muscle, leading to higher free intramuscular leucine levels. This coincided with increased expression of activating transcription factor 4 (ATF4), a main transcriptional regulator of amino acid uptake and metabolism, and downstream activation of amino acid genes as well as leucyl-tRNA synthetase (LARS), a putative leucine sensor. Finally, blocking mTORC1 using rapamycin did not reduce expression and activation of ATF4, suggesting that the latter does not act downstream of mTORC1. Rather, we found a robust increase in eukaryotic initiation factor 2α (eIF2α) phosphorylation, suggesting that the integrated stress response pathway, rather than exercise-induced mTORC1 activation, drives long-term ATF4 expression in skeletal muscle after exercise. ConclusionsThe enhanced sensitivity of mTORC1 to leucine is maintained at least 48 h after exercise. This shows that the anabolic window of opportunity for protein ingestion is not restricted to the first hours immediately following exercise. Increased mTORC1 sensitivity to leucine coincided with enhanced leucine influx into muscle and higher expression of genes involved in leucine sensing and amino acid metabolism. Also, exercise induced an increase in ATF4 protein expression. Altogether, these data suggest that muscular contractions switch on a coordinated program to enhance amino acid uptake as well as intramuscular sensing of key amino acids involved in mTORC1 activation and the stimulation of muscle protein synthesis.

The effect of fermented wheat protein hydrolysate on the exercise performance in mice

Backgrouds. Fermented wheat protein hydrolysate (FWPH) is obtained by lightly hydrolysing wheat protein and then fermented using lactic acid bacteria (LAB). Protein supplementation could stimulate muscle protein synthesis and alleviate fatigue. The objectives of this study were to assess the effects of fermented wheat protein hydrolysate (FWPH) on the capacity of exercise and intestinal flora composition in mice. The results showed that FWPH can improve the ability of anti-fatigue by decresing creatine kinase activity, blood urea nitrogen, and lactic acid levels and increasing liver and muscle glycogen. The consequence of by prolonged exhausted swimming time, enhanced the histology of muscle tissue and increased the MyoG (50.01%) and MYOD1 (32.12%) expression indicated that the administration of FWPH were conducive to exercise performance. And the FWPH could cause significant changes on the phylum Actinobacteria and Proteobacteria and genus Faecalibaculum and Turicibacter in the intestinal flora, compared with casein (NC), whey potein (WP). Our research indicated that the supplementation of FWPH could aid in overcoming physical fatigue, improving the capacity of exercise and alter the intestinal flora composition.

Branched-Chain Amino Acids and Mitochondrial Biogenesis: An Overview and Mechanistic Summary.

Branched-chain amino acids (BCAA) are essential in the diet and promote several vital cell responses which may have benefits for health and athletic performance, as well as disease prevention. While BCAA are well-known for their ability to stimulate muscle protein synthesis, their effects on cell energetics are also becoming well-documented, but these receive less attention. In this review, much of the current evidence demonstrating BCAA ability (as individual amino acids or as part of dietary mixtures) to alter regulators of cellular energetics with an emphasis on mitochondrial biogenesis and related signaling is highlighted. Several studies have shown, both in vitro and in vivo, that BCAA (either individual or as a mixture) may promote signaling associated with increased mitochondrial biogenesis including the upregulation of master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), as well as numerous downstream targets and related function. However, sparse data in humans and the difficulty of controlling variables associated with feeding studies leave the physiological relevance of these findings unclear. Future well-controlled diet studies will be needed to assess if BCAA consumption is associated with increased mitochondrial biogenesis and improved metabolic outcomes in healthy and/or diseased human populations.