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Effect of gut microbiome modulation on muscle function and cognition: the PROMOTe randomised controlled trial.
Ni Lochlainn, M, Bowyer, RCE, Moll, JM, García, MP, Wadge, S, Baleanu, AF, Nessa, A, Sheedy, A, Akdag, G, Hart, D, et al
Nature communications. 2024;15(1):1859
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Humans lose skeletal muscle with advancing age, and this can progress to sarcopenia. Dietary protein is crucial for maintaining skeletal muscle health; however, several factors can lead to reduced protein intake in older age. The aim of this study was to test whether the addition of gut microbiome modulation could augment established muscle function improvements from combined protein (branched chain amino acids [BCAA]) and resistance exercise. This study was based on the PROMOTe (effect of PRebiotic and prOtein on Muscle in Older Twins) trial which was a randomised controlled trial in which twin pairs (n= 72) were randomised, one twin to each study arm. Results showed that prebiotics improved cognition but did not impact muscle strength and function, compared with placebo. Furthermore, gut microbiome modulation via prebiotic supplementation in the context of ageing-muscle research is feasible and well tolerated, with clear responses noted in the gut microbiota composition and function. Authors concluded that cheap and readily available gut microbiome interventions hold promise for improving cognitive frailty in our ageing population.
Abstract
Studies suggest that inducing gut microbiota changes may alter both muscle physiology and cognitive behaviour. Gut microbiota may play a role in both anabolic resistance of older muscle, and cognition. In this placebo controlled double blinded randomised controlled trial of 36 twin pairs (72 individuals), aged ≥60, each twin pair are block randomised to receive either placebo or prebiotic daily for 12 weeks. Resistance exercise and branched chain amino acid (BCAA) supplementation is prescribed to all participants. Outcomes are physical function and cognition. The trial is carried out remotely using video visits, online questionnaires and cognitive testing, and posting of equipment and biological samples. The prebiotic supplement is well tolerated and results in a changed gut microbiome [e.g., increased relative Bifidobacterium abundance]. There is no significant difference between prebiotic and placebo for the primary outcome of chair rise time (β = 0.579; 95% CI -1.080-2.239 p = 0.494). The prebiotic improves cognition (factor score versus placebo (β = -0.482; 95% CI,-0.813, -0.141; p = 0.014)). Our results demonstrate that cheap and readily available gut microbiome interventions may improve cognition in our ageing population. We illustrate the feasibility of remotely delivered trials for older people, which could reduce under-representation of older people in clinical trials. ClinicalTrials.gov registration: NCT04309292.
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Vegan Diets and Health - NED Infobite
BANT's scientific NED InfoBites are designed to provide key elements of the latest research using plain language. They provide quick overviews on particular health issues and nutrition topics for a speedy introduction to the science. Visually attractive and easily shareable with clients and social media followers.
2024
Abstract
With the interest in vegan diets growing from both a health and environmental point of view, it is worth a look at what the science says in this area. This NED Infobite includes a selection of scientific articles looking at the vitamin and mineral status of vegan diets and where deficiencies may occur. It also includes information on the impact of plant-based and vegetarian diets on inflammatory markers and blood pressure.
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Effects of whey and soy protein supplementation on inflammatory cytokines in older adults: a systematic review and meta-analysis.
Prokopidis, K, Mazidi, M, Sankaranarayanan, R, Tajik, B, McArdle, A, Isanejad, M
The British journal of nutrition. 2023;129(5):759-770
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Reduced muscle mass and reduction in physical activity may lead to sarcopenia in older people. Age-related sarcopenia is associated with increased systemic low-grade inflammation and obesity. Protein supplementation is found to be beneficial in reducing circulating pro-inflammatory cytokines in old people. Previous research has shown that supplementation with isolated whey and soy protein reduces the levels of inflammatory cytokines in older adults. However, there is limited research on intact whey and soy protein supplementation in reducing age-related inflammation. This systematic review and meta-analysis investigated the effect of intact whey and soy protein on serum inflammatory markers such as C-reactive protein (CRP), Interleukin-6 (IL6) and TNF-α in older adults. The results of this meta-analysis show a significant reduction in circulating IL-6 and TNF-α levels after the supplementation with whey and soy protein. The addition of soy isoflavones resulted in a further decline in serum CRP levels. Subgroup analysis showed that the whey protein supplementation significantly improved sarcopenia and pre-frailty. Healthcare professionals can use the result of this systematic review and meta-analysis to understand the anti-inflammatory properties of intact whey and soy protein and soy isoflavones. However, further robust studies are required to assess the anti-inflammatory properties of whey and soy protein due to the high heterogeneity of included studies in this review.
Abstract
BACKGROUND AND AIMS Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers. METHODS We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603). RESULTS Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): -0·79, 95 % CI: -1·15, -0·42, I2 = 96 %] and TNF-α levels following soy protein supplementation (MD: -0·16, 95 % CI: -0·26, -0·05, I2 = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: -0·20, 95 % CI: -0·31, -0·08, I2 = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: -0·98, 95 % CI: -1·56, -0·39, I2 = 0 %). These findings may be dependent on participant characteristics and treatment duration. CONCLUSIONS These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.
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Individualized Hospital to Home, Exercise-Nutrition Self-Managed Intervention for Pre-Frail and Frail Hospitalized Older Adults: The INDEPENDENCE Randomized Controlled Pilot Trial.
Han, CY, Sharma, Y, Yaxley, A, Baldwin, C, Woodman, R, Miller, M
Clinical interventions in aging. 2023;18:809-825
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As the global population ages, the incidence of frailty is expected to increase. Frailty has been associated with higher dependency and an increased risk of death. Research has shown that exercise and nutrition have been shown to be effective at treating and preventing frailty, however this is open to criticism as most of the research has been performed in healthy older adults, and not those who are at risk or suffering from frailty. This pilot randomised control trial aimed to determine the effectiveness of an individualised exercise and nutrition programme on frailty and its complications in 32 individuals with pre frailty and frailty. The nutrition programme focused on ensuring diet quality and that individuals were receiving 100% of their energy requirements, adequate protein, and at an ideal body weight. The exercise programme focused on resistance exercise at least 3 times per week. The results showed that an individualised diet and exercise programme improved the degree of pre-frailty and frailty after 3 and 6 months. Brain function and mood were also improved in individuals on the diet and exercise programme. Interestingly there was an indication that the number of well-nourished individuals was slightly higher in these individuals, however this was not significantly greater than those who were not undergoing the diet and exercise regime. It was concluded that adherence to a self-managed nutrition and exercise programme can slow and even reverse frailty and pre-frailty. This study could be used by healthcare professionals to recommend an individualised diet and exercise programme that focuses on ensuring 100% of daily energy requirements are met, adequate protein levels and resistance exercise to older adults with pre-frailty and frailty.
Abstract
PURPOSE Pre-frailty and frailty in older adults are associated with poor health outcomes and increase health-care costs, and further worsening during hospitalization. This study aimed to examine the effect of an individualized hospital to home, exercise-nutrition self-managed intervention for pre-frail and frail hospitalized older adults. PATIENTS AND METHODS Older adults admitted to an acute medical unit of a tertiary hospital in South Australia who were pre-frail or frail were recruited from September 2020 to June 2021, randomized to either control or intervention group and followed up at 3 and 6 months. The outcome variables were program adherence, frailty status by the Edmonton Frail Scale (EFS) score, lower extremity physical function, handgrip strength, nutritional status, cognition, mood, health-related quality of life, risk of functional decline, unplanned readmissions. RESULTS Participants were 79.2 ±6.6 years old, 63% female, mostly frail (67%), with EFS of 8.6±1.9. Adherence to the inpatient and home visits/telehealth intervention were high (91±13% and 92±21%, respectively). Intention-to-treat analysis using linear regression models showed that participants in the intervention group had significantly greater reduction in EFS at 3 (-3.0; 95% CI: -4.8 to -3.0) and 6 months (-2.5; 95% CI: -3.8 to -1.0, P<0.001 for both) compared to the control group; particularly the functional performance component. There were also improvements in overall Short Physical Performance Battery score at 3 (4.0; 95% CI: 1.3 to 6.6) and 6 months (3.9; 95% CI: 1.0 to 6.9, P<0.05 for both), mini-mental state examination (2.6; 95% 0.3-4.8, P=0.029) at 3 months and handgrip strength (3.7; 95% CI: 0.2-7.1, P=0.039) and Geriatric Depression Scale, at 6 months (-2.2; 95% CI: -4.1 to -0.30, P=0.026) in the intervention group as compared to control. CONCLUSION This study provided evidence of acceptability to a patient self-managed exercise-nutrition program that may benefit and alleviate pre-frailty and frailty in hospitalised older adults.
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Reducing hip and non-vertebral fractures in institutionalised older adults by restoring inadequate intakes of protein and calcium is cost-saving.
Baek, Y, Iuliano, S, Robbins, J, Poon, S, Seeman, E, Ademi, Z
Age and ageing. 2023;52(6)
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Older adults in aged care account for 30% of the population burden of hip fractures. Inadequate intakes of protein and calcium are common in older adults living in aged care homes. The aims of this study were to determine cost-effectiveness of this dietary intervention, and the threshold at which nutritional intervention was cost-effective, from the Australian healthcare perspective. This study was a 2-year cluster-randomised controlled trial which was conducted in 60 residential aged care homes. Aged care homes prepared all foods on-site and were randomised in a 1:1 ratio to nutritional intervention (calcium and protein enriched menu) or control (regular menu). Results showed that reducing fracture risk in older adults in residential aged care homes by restoring calcium and protein intakes to recommended levels using high-calcium and high-protein foods is cost-saving. Authors concluded that averting hip and other non-vertebral fractures in older adults living in aged care homes by restoring nutritional inadequacy of protein and calcium is cost-saving and supports the wide-spread implementation of this type of nutritional intervention in similar settings.
Abstract
BACKGROUND older adults in aged care account for 30% of the population burden of hip fractures. Nutritional interventions to correct under nutrition reduce these debilitating fractures, perhaps partly by reducing falls and slowing deterioration in bone morphology. OBJECTIVE to determine whether a nutritional approach to fracture risk reduction in aged care homes is cost-effective. DESIGN cost-effectiveness was estimated based on results from a prospective 2-year cluster-randomised controlled trial and secondary data. Intervention residents consumed a total of 3.5 daily servings of milk, yoghurt and/or cheese, resulting in 1,142 mg of calcium and 69 g of protein compared with the daily intakes of 700 mg of calcium and 58 g of protein consumed by the control group. SETTING fifty-six aged care homes. PARTICIPANTS residents for 27 intervention (n = 3,313) and 29 control (n = 3,911) homes. METHODS ambulance, hospital, rehabilitation and residential care costs incurred by fracture were estimated. The incremental cost-effectiveness ratios per fracture averted within a 2-year time horizon were estimated from the Australian healthcare perspective applying a 5% discount rate on costs after the first year. RESULTS intervention providing high-protein and high-calcium foods reduced fractures at a daily cost of AU$0.66 per resident. The base-case results showed that the intervention was cost-saving per fracture averted, with robust results in a variety of sensitivity and scenario analyses. Scaling the benefits of intervention equates to a saving of AU$66,780,000 annually in Australia and remained cost-saving up to a daily food expenditure of AU$1.07 per resident. CONCLUSIONS averting hip and other non-vertebral fractures in aged care residents by restoring nutritional inadequacy of protein and calcium is cost-saving.
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Effects of a low-protein nutritional formula with dietary counseling in older adults with chronic kidney disease stages 3-5: a randomized controlled trial.
Yang, WC, Hsieh, HM, Chen, JP, Liu, LC, Chen, CH
BMC nephrology. 2023;24(1):372
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Chronic kidney disease (CKD) is a prevalent clinical issue often observed in older adults. Nutritional management has become essential for older adults with CKD. Recent nutritional guidelines have suggested that a low-protein diet (LPD) can be prescribed. The aim of this study was to compare the effects of a regular LPD alone or a 6% LPF combined with a regular LPD prescription on nutrition status, physical performance, and clinical parameter changes in older adults with CKD stages 3–5. This study was a single-centre, two-armed, open-label, parallel, randomised controlled clinical trial. Participants were allocated at a 1:1 ratio - (1) the control group, patients received a regular LPD prescription; (2) the intervention group, patients received a regular LPD prescription with 6% LPF. Results showed that an LPD plus a 6% LPF provided no changes in energy and protein intake while increasing fatty acid and specific micronutrient intake during the 3-month follow-up period. Furthermore, blood urea nitrogen (clinical parameter) was significantly reduced in the intervention group over three months. Authors concluded that an LPD prescription with a 6% LPF can delay physical performance deterioration and increase micronutrient intake in three months compared to LPD education alone in older adults with CKD stages 3–5.
Abstract
BACKGROUND Although combining a low-protein diet (LPD) with oral nutritional supplements increases treatment adherence and nutritional status in patients with chronic kidney disease (CKD), the effect of this combination approach in older adults remains unclear. This study examined the impact of a 6% low-protein formula (6% LPF) with diet counseling in older adults with stage 3-5 CKD. METHODS In this three-month randomized controlled study, 66 patients (eGFR < 60 mL/min/1.73 m2, non-dialysis, over 65 years of age) were randomly assigned to an intervention group (LPD plus a 6% LPF) or control group (LPD alone). The 6% LPF comprised 400 kcal, 6 g of protein, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and various micronutrients. All data were collected at baseline and after three months, including physical performance based on hand grip strength (HGS) and gait speed, nutritional status using Mini Nutritional Assessment-Short Form (MNA-SF) scores, body composition through bioelectrical impedance analysis, and dietary intake from 24-h dietary records. RESULTS This study incorporated 47 participants (median age, 73; median eGFR, 36 ml/min/1.73 m2; intervention group: 24; control group: 23). The intervention group exhibited significant differences in HGS and gait speed, and micronutrient analysis revealed significantly higher monounsaturated fatty acids (MUFA), EPA, DHA, calcium, iron, zinc, copper, thiamine, riboflavin, niacin, B6, B12, and folic acid intake than the control group. MNA-SF scores, macronutrient intake, and body composition did not differ significantly between the two groups. CONCLUSIONS Compared to LPD counseling alone, an LPD prescription with 6% LPF in older adults with CKD stages 3-5 helped relieve physical deterioration and increased micronutrient intake after three months. TRIAL REGISTRATION ClinicalTrials.gov NCT05318014 (retrospectively registered on 08/04/2022).
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Effects of dietary supplements on athletic performance in elite soccer players: a systematic review.
Abreu, R, Oliveira, CB, Costa, JA, Brito, J, Teixeira, VH
Journal of the International Society of Sports Nutrition. 2023;20(1):2236060
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Dietary supplements are used by elite soccer players to improve performance and recovery. However, it is unclear as to whether the research can back up the reasons for their use. This systematic review of 18 randomised control trials aimed to determine any effects of dietary supplements on elite, adult soccer players. The results showed that studies on the use of supplementation in soccer players has been completed using caffeine, caffeinated energy drinks, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, yohimbine, Resurgex Plus, and sodium and potassium bicarbonate with potassium, magnesium, and calcium citrate. It was concluded that the use of creatine, protein, and caffeine may be of benefit to the performance of elite soccer players. The use of yohimbine was strongly discouraged due to unclear safety data. There was a lack of evidence for the use of any of the other supplements and it was concluded that more studies need to be completed. This study could be used by healthcare professionals to understand that certain supplements may enhance athletic performance in elite soccer players, but more research is encouraged.
Abstract
Dietary supplements are widely used among athletes, and soccer players are no exception. Nevertheless, evidence supporting the use of dietary supplements aiming to enhance performance in soccer is somewhat contradictory, scarce, or even nonexistent. Thus, the present study aimed to systematically review and synthesize the effects of dietary supplements on athletic performance (e.g. distance covered, sprinting, jump performance) in elite soccer players. Studies enrolling highly trained, elite, and world-class soccer players using dietary supplements were searched in MEDLINE/PubMed, Web of Science, Scopus, and EBSCO databases in June 2022. In total, 1043 studies were identified, and 18 met the eligibility criteria. The studies evaluated the impacts on athletic performance of several dietary supplements, including caffeine, creatine, protein, beverages with carbohydrates and electrolytes, tart cherry juice, nitrate-rich beetroot juice, sodium bicarbonate with minerals, yohimbine, and a proprietary nutraceutical blend. Caffeine supplementation in doses between 3 and 6 mg/kg of body mass may improve jump height and sprint ability, particularly in female players, but individual response to caffeine must be considered. Creatine may improve sprint, agility, and in female players, jump performance. Protein supplementation can improve sprint and jump performance between matches, especially if protein ingested from food is not up to recommendations. Beverages containing carbohydrates and electrolytes can be used as part of the strategies to achieve carbohydrate intake during training and match-days but used alone do not benefit athletic performance. Tart cherry juice might be useful for maintaining athletic performance after matches that produce higher force loss and exercise-induced muscle damage, although polyphenols from the diet might attenuate the effects of tart cherry supplementation. Nitrate-rich beetroot concentrate can attenuate performance decrease in the days following matches. Further investigation with sodium bicarbonate alone is necessary, as supplementation protocols with elite players included other substances. Finally, the available data does not support yohimbine supplementation or the use of Resurgex Plus® to improve athletic performance in elite soccer players. Still, more well-designed research with elite soccer players is needed to improve support and advice regarding the use of dietary supplements for athletic performance enhancement.
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The Influence of Whey Protein on Muscle Strength, Glycemic Control and Functional Tasks in Older Adults with Type 2 Diabetes Mellitus in a Resistance Exercise Program: Randomized and Triple Blind Clinical Trial.
Soares, ALS, Machado-Lima, A, Brech, GC, Greve, JMD, Dos Santos, JR, Inojossa, TR, Rogero, MM, Salles, JEN, Santarem-Sobrinho, JM, Davis, CL, et al
International journal of environmental research and public health. 2023;20(10)
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Type 2 Diabetes Mellitus (T2DM) is a common metabolic disease and the prevalence of T2DM is increasing among older adults. Resistance training is known to be an effective therapeutic strategy as it can positively influence the mechanisms of T2DM pathophysiology. Previous research suggests that whey protein supplementation can positively influence the different mechanisms of T2DM pathophysiology and improve muscle mass and glycaemic control. This triple-blinded, randomised controlled parallel-arm trial included twenty-eight male older adults to assess the effect of whey protein supplementation combined with resistance training for twelve weeks on glycaemic control, functional tasks, muscle strength, and body composition. The control group was supplemented with maltodextrin. All participants followed resistance training and were given nutritional guidance. Twelve weeks of resistance training improved muscle strength significantly. However, 20g whey protein supplementation did not improve performance in functional tasks, glycaemic control, or body composition in the test group of older adults with T2DM. Whey protein supplementation showed no significant synergetic effects when combined with resistance training in the test group. Due to the heterogeneity of the present study, further robust studies are warranted to investigate the effects of whey protein supplementation and resistance training. However, healthcare professionals can use the results of this study to understand the effect of resistance training alone and the safety profile of whey protein supplementation in older adults with T2DM.
Abstract
OBJECTIVES To evaluate the effect of whey protein (WP) supplementation associated with resistance training (RT) on glycemic control, functional tasks, muscle strength, and body composition in older adults living with type 2 diabetes mellitus (T2DM). Secondly, to evaluate the safety of the protocol for renal function. METHODS The population comprised twenty-six older men living with T2DM (68.5 ± 11.5 years old). The participants were randomly assigned to the Protein Group (PG) and the Control Group (CG). The handgrip test and evolution of exercise loads, according to the Omni Resistance Exercise Scale, evaluated muscle strength. Functional tasks were assessed by force platform in three different protocols: Sit-to-Stand, Step/Quick Turn, and Step Up/Over. Body composition was evaluated by bioimpedance and glycemic control and renal function were assessed by biochemical analyses. Both groups performed RT for 12 weeks, twice a week, prioritizing large muscle groups. Protein supplementation was 20 g of whey protein isolate and the CG was supplemented with an isocaloric drink, containing 20 g of maltodextrin. RESULTS There was a significant difference in muscle strength, according to the evolution of the exercise loads, but it was not confirmed in the handgrip test. However, there was no significant difference between the groups, regarding performance in functional tasks, glycemic control, or body composition. Renal function showed no alteration. CONCLUSION The intake of 20 g of WP in older male adults living with T2DM did not increase the effect of RT on muscle strength, functional tasks, and glycemic control. The intervention was proven safe regarding renal function.
Sponsored Case Study
9.
Specialized Pro-Resolving Mediators (SPMs) Case Study
Metagenics Institute is a trusted, peer-to-peer, evidence-based educational resource for nutrition and personalized medicine. At Metagenics Institute, we translate credible research with scientific integrity into innovative and actionable clinical decision-making. Metagenics Institute supports a diverse practitioner base to optimize patient outcomes by shifting existing paradigms in healthcare. Our mission is to transform healthcare by inspiring and educating practitioners, and their patients, about personalized lifestyle medicine.
2023
Abstract
This paper is entitled, “Supplementation with Specialized Pro-Resolving Mediators Reduces Inflammatory Biomarkers and Improves Reported Clinical Symptomology in Subjects with Chronic Inflammatory Conditions: Results from a Multi-Center Open-Case Series” Highlights: Inflammation has 2 phases: initiation and resolution. Many chronic health issues are linked to unresolved inflammation Specialized pro-resolving mediators (SPMs) are endogenous molecules essential for resolution of inflammation but may not be produced in required levels in certain condition Multi-center case study assessed effects of a proprietary SPM supplement (LM-O3) on inflammatory biomarkers in 34 men and women (21-75 y/o) with conditions indicating raised inflammatory tone Results showed a 43% reduction in high-sensitivity C-reactive protein (hs-CRP) at 4 weeks with concurrent reduction in prostaglandin E2 (PGE2) At 8 weeks, hs-CRP remained reduced, and PGE2 was reduced to within normal range Functional measurements including reported measures of pain as well as quality of life indicated continued improvement at 4 and 8 weeks Adverse events were minimal and managed without incident.
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Pre-sleep Protein Ingestion Increases Mitochondrial Protein Synthesis Rates During Overnight Recovery from Endurance Exercise: A Randomized Controlled Trial.
Trommelen, J, van Lieshout, GAA, Pabla, P, Nyakayiru, J, Hendriks, FK, Senden, JM, Goessens, JPB, van Kranenburg, JMX, Gijsen, AP, Verdijk, LB, et al
Sports medicine (Auckland, N.Z.). 2023;53(7):1445-1455
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Protein intake prior to overnight sleep has been shown to stimulate muscle protein synthesis overnight and increase muscle mass. This randomised, placebo-controlled, double-blind study of 36 healthy young men compared the effects of pre-sleep casein and whey protein, following a bout of endurance training in the evening. Outcome measures were overnight protein synthesis rates in microfibrils (the contractile organelle of muscle cells) and mitochondria (the energy producing organelle). Ingestion of whey protein resulted in a statistically significantly higher rates of both microfibrillar and mitochondrial protein synthesis compared to placebo. Results for casein were intermediate and not significantly different from either placebo or whey. Both casein and whey protein intake led to a significant increase in circulating total and essential amino acids overnight, compared to placebo, with the whey protein leading to a quicker and casein to a slower but more sustained increase, although the overall increase (area under the curve) did not differ between the two protein groups. There were no differences in sleep, hunger or energy intake at breakfast between groups. The authors conclude that pre-sleep protein intake following endurance exercise increases both microfibrillar and mitochondrial protein synthesis overnight, with casein not being superior to whey.
Abstract
BACKGROUND Casein protein ingestion prior to sleep has been shown to increase myofibrillar protein synthesis rates during overnight sleep. It remains to be assessed whether pre-sleep protein ingestion can also increase mitochondrial protein synthesis rates. Though it has been suggested that casein protein may be preferred as a pre-sleep protein source, no study has compared the impact of pre-sleep whey versus casein ingestion on overnight muscle protein synthesis rates. OBJECTIVE We aimed to assess the impact of casein and whey protein ingestion prior to sleep on mitochondrial and myofibrillar protein synthesis rates during overnight recovery from a bout of endurance-type exercise. METHODS Thirty-six healthy young men performed a single bout of endurance-type exercise in the evening (19:45 h). Thirty minutes prior to sleep (23:30 h), participants ingested 45 g of casein protein, 45 g of whey protein, or a non-caloric placebo. Continuous intravenous L-[ring-13C6]-phenylalanine infusions were applied, with blood and muscle tissue samples being collected to assess overnight mitochondrial and myofibrillar protein synthesis rates. RESULTS Pooled protein ingestion resulted in greater mitochondrial (0.087 ± 0.020 vs 0.067 ± 0.016%·h-1, p = 0.005) and myofibrillar (0.060 ± 0.014 vs 0.047 ± 0.011%·h-1, p = 0.012) protein synthesis rates when compared with placebo. Casein and whey protein ingestion did not differ in their capacity to stimulate mitochondrial (0.082 ± 0.019 vs 0.092 ± 0.020%·h-1, p = 0.690) and myofibrillar (0.056 ± 0.009 vs 0.064 ± 0.018%·h-1, p = 0.440) protein synthesis rates. CONCLUSIONS Protein ingestion prior to sleep increases both mitochondrial and myofibrillar protein synthesis rates during overnight recovery from exercise. The overnight muscle protein synthetic response to whey and casein protein does not differ. CLINICAL TRIAL REGISTRATION NTR7251 .