Supplement-based nutritional strategies to tackle frailty: A multifactorial, double-blind, randomized placebo-controlled trial.

BACKGROUND: Sarcopenia plays a central role in the development of frailty syndrome. Nutrition and exercise are cornerstone strategies to mitigate the transition to frailty; however, there is a paucity of evidence for which dietary and exercise strategies are effective. OBJECTIVE: This large, multifactorial trial investigated the efficacy of different dietary strategies to enhance the adaptations to resistance training in pre-frail and frail elderly. METHODS: This was a single-site 16-week, double-blind, randomized, placebo-controlled trial conducted at the Clinical Hospital, School of Medicine - University of São Paulo, Sao Paulo, Brazil. Four integrated, sub-investigations were conducted to compare: 1) leucine vs. placebo; 2) whey vs. soy vs. placebo; 3) creatine vs. whey vs. creatine plus whey vs. placebo; 4) women vs. men in response to whey. Sub-investigations 1 to 3 were conducted in women, only. Two-hundred participants (154 women/46 men, mean age 72 ± 6 years) underwent a twice-a-week, resistance training program. The main outcomes were muscle function (assessed by dynamic and isometric strength and functional tests) and lean mass (assessed by DXA). Muscle cross-sectional area, health-related quality of life, bone and fat mass, and biochemical markers were also assessed. RESULTS: We observed that leucine supplementation was ineffective to improve muscle mass and function. Supplementation with whey and soy failed to enhance resistance-training effects. Similarly, supplementation with neither whey nor creatine potentiated the adaptations to resistance training. Finally, no sex-based differences were found in response to whey supplementation. Resistance exercise per se increased muscle mass and function in all sub-investigations. There were no adverse effects. CONCLUSION: Neither protein (whey and soy), leucine, nor creatine supplementation enhanced resistance training-induced adaptations in pre-frail and frail elderly, regardless of sex. These findings do not support the notion that some widely used supplement-based interventions can add to the already potent effects of resistance exercise to counteract frailty-related muscle wasting and dynapenia. CLINICAL TRIAL REGISTRY: NCT01890382; https://clinicaltrials.gov/ct2/show/NCT01890382. DATA SHARING: Data described in the manuscript will be made available upon request pending application.

"I put it in my head that the supplement would help me": Open-placebo improves exercise performance in female cyclists.

This study investigated the effect of open-placebo on cycling time-trial (TT) performance. Twenty-eight trained female cyclists completed a 1-km cycling TT following a control session or an open-placebo intervention. The intervention consisted of an individual presentation, provided by a medic, in which the concept of open-placebo was explained to the participant, before she ingested two red and white capsules containing flour; 15 min later, they performed the TT. In the control session, the participant sat quietly for 20 min. Heart rate and ratings of perceived exertion (RPE) were monitored throughout exercise, while blood lactate was determined pre- and post-exercise. Post-exercise questionnaires were employed to gain insight into the perceived influence of the supplement on performance. Open-placebo improved time-to-completion (P = 0.039, 103.6±5.0 vs. 104.4±5.1 s, -0.7±1.8 s, -0.7±1.7%) and mean power output (P = 0.01, 244.8±34.7 vs. 239.7±33.2, +5.1±9.5 W) during the TT. Individual data analysis showed that 11 individuals improved, 13 remained unchanged and 4 worsened their performance with open-placebo. Heart rate, RPE and blood lactate were not different between sessions (all P>0.05). Positive expectation did not appear necessary to induce performance improvements, suggesting unconscious processes occurred, although a lack of an improvement appeared to be associated with a lack of belief. Open-placebo improved 1-km cycling TT performance in trained female cyclists. Although the intervention was successful for some individuals, individual variation was high, and some athletes did not respond or even performed worse. Thus, open-placebo interventions should be carefully considered by coaches and practitioners, while further studies are warranted.

Does brain creatine content rely on exogenous creatine in healthy youth? A proof-of-principle study.

It has been hypothesized that dietary creatine could influence cognitive performance by increasing brain creatine in developing individuals. This double-blind, randomized, placebo-controlled, proof-of-principle study aimed to investigate the effects of creatine supplementation on cognitive function and brain creatine content in healthy youth. The sample comprised 67 healthy participants aged 10 to 12 years. The participants were given creatine or placebo supplementation for 7 days. At baseline and after the intervention, participants undertook a battery of cognitive tests. In a random subsample of participants, brain creatine content was also assessed in the regions of left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe by proton magnetic resonance spectroscopy (1H-MRS) technique. The scores obtained from verbal learning and executive functions tests did not significantly differ between groups at baseline or after the intervention (all p > 0.05). Creatine content was not significantly different between groups in left dorsolateral prefrontal cortex, left hippocampus, and occipital lobe (all p > 0.05). In conclusion, a 7-day creatine supplementation protocol did not elicit improvements in brain creatine content or cognitive performance in healthy youth, suggesting that this population mainly relies on brain creatine synthesis rather than exogenous creatine intake to maintain brain creatine homeostasis.

Efficacy and safety of creatine supplementation in juvenile dermatomyositis: A randomized, double-blind, placebo-controlled crossover trial.

INTRODUCTION: It has been suggested that creatine supplementation is safe and effective for treating idiopathic inflammatory myopathies, but no pediatric study has been conducted to date. The objective of this study was to examine the efficacy and safety of creatine supplementation in juvenile dermatomyositis (JDM) patients. METHODS: In this study, JDM patients received placebo or creatine supplementation (0.1 g/kg/day) in a randomized, crossover, double-blind design. Subjects were assessed at baseline and after 12 weeks. The primary outcome was muscle function. Secondary outcomes included body composition, aerobic conditioning, health-related quality of life, and muscle phosphocreatine (PCr) content. Safety was assessed by laboratory parameters and kidney function measurements. RESULTS: Creatine supplementation did not affect muscle function, intramuscular PCr content, or any other secondary outcome. Kidney function was not affected, and no side effects were reported. CONCLUSIONS: Twelve weeks of creatine supplementation in JDM patients were well-tolerated and free of adverse effects, but treatment did not affect muscle function, intramuscular PCr, or any other parameter.

Creatine supplementation and resistance training in vulnerable older women: a randomized double-blind placebo-controlled clinical trial.

This study aimed to examine the efficacy of creatine supplementation, associated or not with resistance training, in vulnerable older women. A 24-week, double-blind, randomized, placebo-controlled trial was performed. Sixty subjects were assigned to compose the following groups: placebo (PL), creatine supplementation (CR), placebo with resistance training (PL+RT), and creatine supplementation with resistance training (CR+RT). The subjects were assessed at baseline and after 24weeks. The primary outcome was muscle strength, as assessed by one-repetition maximum (1-RM) tests. Secondary outcomes included appendicular lean mass, bone mass, biochemical bone markers, and physical function tests. The changes in 1-RM leg press were significantly greater in the CR+RT group (+19.9%) than in the PL (+2.4%) and the CR groups (+3.7%), but not than in the PL+RT group (+15%) (p=0.002, p=0.002, and p=0.357, respectively). The CR+RT group showed superior gains in 1-RM bench press (+10%) when compared with all the other groups (p≤0.05). The CR+RT group (+1.31%) showed greater appendicular lean mass accrual than the PL (-1.2%), the CR (+0.3%), and the PL+RT groups (-0.2%) (p≤0.05). The CR and the PL+RT groups experienced comparable gains in appendicular lean mass (p=0.62), but superior to those seen in the PL group. Changes in fat mass, bone mass and serum bone markers did not significantly differ between the groups (p>0.05). In conclusion, creatine supplementation combined with resistance training improved appendicular lean mass and muscle function, but not bone mass, in older vulnerable women. Clinicaltrials.gov: NCT01472393.

Creatine supplementation associated or not with strength training upon emotional and cognitive measures in older women: a randomized double-blind study.

PURPOSE: To assess the effects of creatine supplementation, associated or not with strength training, upon emotional and cognitive measures in older woman. METHODS: This is a 24-week, parallel-group, double-blind, randomized, placebo-controlled trial. The individuals were randomly allocated into one of the following groups (n=14 each): 1) placebo, 2) creatine supplementation, 3) placebo associated with strength training or 4) creatine supplementation associated with strength training. According to their allocation, the participants were given creatine (4 x 5 g/d for 5 days followed by 5 g/d) or placebo (dextrose at the same dosage) and were strength trained or not. Cognitive function, assessed by a comprehensive battery of tests involving memory, selective attention, and inhibitory control, and emotional measures, assessed by the Geriatric Depression Scale, were evaluated at baseline, after 12 and 24 weeks of the intervention. Muscle strength and food intake were evaluated at baseline and after 24 weeks. RESULTS: After the 24-week intervention, both training groups (ingesting creatine supplementation and placebo) had significant reductions on the Geriatric Depression Scale scores when compared with the non-trained placebo group (p = 0.001 and p = 0.01, respectively) and the non-trained creatine group (p < 0.001 for both comparison). However, no significant differences were observed between the non-trained placebo and creatine (p = 0.60) groups, or between the trained placebo and creatine groups (p = 0.83). Both trained groups, irrespective of creatine supplementation, had better muscle strength performance than the non-trained groups. Neither strength training nor creatine supplementation altered any parameter of cognitive performance. Food intake remained unchanged. CONCLUSION: Creatine supplementation did not promote any significant change in cognitive function and emotional parameters in apparently healthy older individuals. In addition, strength training per se improved emotional state and muscle strength, but not cognition, with no additive effects of creatine supplementation. TRIAL REGISTRATION: Clinicaltrials.gov NCT01164020.

Creatine supplementation in fibromyalgia: a randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To investigate the efficacy and safety of creatine supplementation in fibromyalgia patients. METHODS: A 16-week, randomized, double-blind, placebo-controlled, parallel-group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double-blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through (31) P magnetic resonance spectroscopy. RESULTS: After the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus -2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus -0.5% and -7.2% for placebo, respectively; P = 0.02 and P = 0.002, respectively). Isometric strength was greater in the creatine group than in the placebo group (+6.4% versus -3.2%; P = 0.007). However, no general changes were observed in aerobic conditioning, pain, cognitive function, quality of sleep, and quality of life. Food intake remained unaltered and no side effects were reported. CONCLUSION: Creatine supplementation increased intramuscular phosphorylcreatine content and improved lower- and upper-body muscle function, with minor changes in other fibromyalgia features. These findings introduce creatine supplementation as a useful dietary intervention to improve muscle function in fibromyalgia patients.

Creatine in type 2 diabetes: a randomized, double-blind, placebo-controlled trial.

UNLABELLED: Creatine supplementation improves glucose tolerance in healthy subjects. PURPOSES: The aim was to investigate whether creatine supplementation has a beneficial effect on glycemic control of type 2 diabetic patients undergoing exercise training. METHODS: A 12-wk randomized, double-blind, placebo-controlled trial was performed. The patients were allocated to receive either creatine (CR) (5 g·d) or placebo (PL) and were enrolled in an exercise training program. The primary outcome was glycosylated hemoglobin (HbA1c). Secondary outcomes included the area under the curve of glucose, insulin, and C-peptide and insulin sensitivity indexes. Physical capacity, lipid profile, and GLUT-4 protein expression and translocation were also assessed. RESULTS: Twenty-five subjects were analyzed (CR: n=13; PL: n=12). HbA1c was significantly reduced in the creatine group when compared with the placebo group (CR: PRE=7.4 ± 0.7, POST=6.4 ± 0.4; PL: PRE=7.5 ± 0.6, POST=7.6 ± 0.7; P=0.004; difference=-1.1%, 95% confidence interval=-1.9% to -0.4%). The delta area under the curve of glucose concentration was significantly lower in the CR group than in the PL group (CR=-7790 ± 4600, PL=2008 ± 7614; P=0.05). The CR group also presented decreased glycemia at times 0, 30, and 60 min during a meal tolerance test and increased GLUT-4 translocation. Insulin and C-peptide concentrations, surrogates of insulin sensitivity, physical capacity, lipid profile, and adverse effects were comparable between the groups. CONCLUSIONS: Creatine supplementation combined with an exercise program improves glycemic control in type 2 diabetic patients. The underlying mechanism seems to be related to an increase in GLUT-4 recruitment to the sarcolemma.