Research
Essential Amino Acids (EAAs)
39 peer-reviewed studies curated from PubMed and Semantic Scholar.
Studies
Sorted by quality and recency
Combined resistance exercise and essential amino acid intake enhance follistatin/myostatin ratio and muscle fitness in older women: a randomized controlled trial.
A 12-week randomized controlled trial with 96 healthy women aged ≥65 years assessed the combined effect of resistance exercise and essential amino acid supplementation. The RE + EAA group showed significant increases in muscle mass, muscle fitness, and follistatin/myostatin ratio, along with reductions in inflammatory markers, compared to control and other groups.
Pre-Operative Resistance Training and Amino Acid Supplementation in Frail Patients With Gastrointestinal Cancer: A Randomized Clinical Trial.
This randomized controlled trial investigated the impact of preoperative resistance training and amino acid supplementation on postoperative outcomes in frail older patients with gastrointestinal cancer. The intervention group showed superior maintenance of knee extension strength and lower rates of decreased activities of daily living or death 1 year postoperatively, although there were no significant differences in postoperative complications.
Combined intravenous bolus amino acid supplementation and mobilization on early muscle loss in critically ill adults: A randomized controlled trial.
RCT evaluating the effect of intravenous amino acid supplementation and mobilization on early muscle loss in critically ill patients. The intervention did not reduce muscle loss or improve muscle quality, strength, or physical capability compared to standard care.
Differential plasma protein expression after ingestion of essential amino acid-based dietary supplement verses whey protein in low physical functioning older adults.
RCT comparing essential amino acids (EAAs) to whey protein in older adults with low physical function. EAAs showed superior plasma protein expression changes, potentially improving muscle strength and physical function.
Late evening snack and oral amino acid capsules improved respiratory quotient and Fischer ratio in patients with alcoholic liver cirrhosis.
RCT involving 91 patients with alcoholic liver cirrhosis, divided into groups receiving a late evening snack (LES) with or without oral amino acid (OAA) capsules. The LES and OAA group showed significant improvements in respiratory quotient, carbohydrate oxidation rate, and Fischer ratio compared to LES alone and control groups.
Essential Amino Acid and Tea Catechin Supplementation after Resistance Exercise Improves Skeletal Muscle Mass in Older Adults with Sarcopenia: An Open-Label, Pilot, Randomized Controlled Trial.
Open-label, pilot RCT among older adults with sarcopenia evaluating the effect of EAA and TCC supplementation after resistance exercise on skeletal muscle mass. The RE + EAA + TCC group showed a significantly higher increase in skeletal muscle mass compared to the RE group alone.
Daily Consumption of a Specially Formulated Essential Amino Acid-Based Dietary Supplement Improves Physical Performance in Older Adults With Low Physical Functioning.
RCT comparing essential amino acids (EAA) supplementation to whey protein and a control group in older adults with low physical functioning. EAA supplementation significantly improved walking distance, grip strength, leg strength, and reduced body weight, fat mass, and plasma low-density lipoprotein concentration. No adverse responses were observed.
Anabolic response to essential amino acid plus whey protein composition is greater than whey protein alone in young healthy adults.
RCT comparing the anabolic response of a proprietary composition containing essential amino acids and whey protein to a whey protein-based supplement in young healthy adults. The EAA/protein composition showed a greater anabolic response, with increased whole-body protein synthesis and reduced protein breakdown, especially at higher doses.
Elevated miR-194-5p Expression during Short-Term Energy Deficit Attenuates Postexercise Muscle Protein Synthesis by Inhibiting Anabolic Signaling.
This study examined the effects of consuming EAA-enriched whey or carbohydrate on skeletal muscle miRNA after exercise in energy balance and deficit. miR-194-5p expression increased during energy deficit, inversely associated with muscle protein synthesis, suggesting postexercise anabolic resistance.
Effects of an amino acid mixture on alcohol metabolism and alcohol-related symptoms in healthy adults.
RCT investigating the effects of Amino Liver (an amino acid mixture) on alcohol metabolism and alcohol-related symptoms in healthy adults. AL intake was associated with a more rapid reduction in blood alcohol and acetaldehyde concentrations and lower severity of alcohol-related symptoms, particularly fatigue and cognitive difficulty, compared to placebo.
Effects of a Hypocaloric Diet Plus Resistance Training with and Without Amino Acids in Older Participants with Dynapenic Obesity: A Randomized Clinical Trial.
RCT comparing a hypocaloric diet plus resistance training with and without essential amino acids (EAAs) in 48 older adults with dynapenic obesity. Both groups improved body composition and physical function, but EAA supplementation did not provide additional benefits.
Pre-workout multi-ingredients or carbohydrate alone promote similar resistance training outcomes in middle-aged adults: a double-blind, randomized controlled trial.
This double-blind, randomized controlled trial compared the effects of a pre-workout supplement containing caffeinated ingredients and plant-based protein enriched with amino acids versus carbohydrates alone on body composition and physical performance in middle-aged adults. Both groups showed improvements in fat mass reduction, fat-free mass increase, and muscle thickness, with no significant differences between groups except for waist circumference reduction in the pre-workout group.
Dileucine-supplemented essential amino acids support whole-body anabolism after resistance exercise and serum-stimulated cell-based anabolism.
This randomized, double-blind, crossover study investigated the effects of dileucine-supplemented essential amino acids (DIEAA) on whole-body anabolism after resistance exercise in 12 healthy adults. The study found that both DIEAA and BCAA supported greater whole-body anabolism compared to collagen hydrolysate, with a potential anabolic effect of DIEAA in stimulating muscle protein synthesis.
Effects of Resistance Exercise and Essential Amino Acid Intake on Muscle Quality, Myokine, and Inflammation Factors in Young Adult Males.
RCT with 34 young adult males assigned to placebo, resistance exercise, EAA supplementation, or RE + EAA groups. Lean body mass increased only in the RE + EAA group. Muscle quality, myokines, and inflammation factors improved in RE, EAA, and RE + EAA groups, highlighting the benefits of resistance exercise and amino acid intake.
Replacement of the massive amino acid losses induced by hemodialysis: A new treatment option proposal for a largely underestimated issue.
A three-month randomized double-blind study on 30 hemodialysis patients over 70 years old tested a novel amino acid formula to replace losses during dialysis. The treatment group showed significant improvements in protein intake, IgG, C3 serum levels, and anemia markers, suggesting the formula should be standard for HD patients.
Nutritional Management in Stricturing Crohn's Disease: A Pilot Study.
Pilot RCT investigating the efficacy of 12 months of dietary intervention with essential amino acids and sodium butyrate supplementation in stricturing Crohn's disease patients. The study found significant improvements in muscle mass and skeletal muscle index, with fewer surgeries required in the supplemented group compared to controls.
Clinical evaluation of sodium hypochlorite/amino acids and cross-linked hyaluronic acid adjunctive to non-surgical periodontal treatment: a randomized controlled clinical trial
RCT comparing mechanical subgingival debridement alone versus with adjunctive sodium hypochlorite/amino acid and cross-linked hyaluronic acid gels in 48 patients with periodontitis. The test group showed significantly better outcomes in probing depth reduction, clinical attachment level gain, and bleeding on probing reduction compared to control.
Essential Amino Acid Ingestion Facilitates Leucine Retention and Attenuates Myofibrillar Protein Breakdown following Bodyweight Resistance Exercise in Young Adults in a Home-Based Setting.
This double-blind, placebo-controlled, crossover study tested the effects of essential amino acids (EAA+) and branched-chain amino acids (BCAAs) on leucine retention and myofibrillar protein breakdown following home-based resistance exercise in 12 recreationally active adults. EAA+ and BCAA ingestion resulted in greater leucine retention compared to a carbohydrate placebo, with EAA+ more effectively attenuating myofibrillar protein breakdown.
Effect of Aerobic Exercise Training and Essential Amino Acid Supplementation for 24 Weeks on Physical Function, Body Composition, and Muscle Metabolism in Healthy, Independent Older Adults: A Randomized Clinical Trial.
RCT of 50 older adults examining the effects of essential amino acid supplementation and aerobic exercise on muscle function and metabolism over 24 weeks. EAA supplementation combined with aerobic exercise increased muscle strength and protein synthesis, but did not significantly change lean body mass.
Despite Inflammation, Supplemented Essential Amino Acids May Improve Circulating Levels of Albumin and Haemoglobin in Patients after Hip Fractures.
RCT of 112 elderly patients with hip fractures comparing essential amino acids (EAAs) supplementation to placebo over two months. EAAs improved circulating albumin levels significantly and reduced anaemia prevalence, though the latter was not statistically significant.
Supplementation of essential amino acids may reduce the occurrence of infections in rehabilitation patients with brain injury.
RCT of 125 rehabilitation patients with brain injury comparing 8 g/day oral essential amino acids to placebo for 2 months. The EAA group had a 23.2% lower infection rate compared to the placebo group, suggesting EAAs may reduce nosocomial infections.
Effect of oral supplementation of free amino acids in type 2 diabetic patients-- a pilot clinical trial.
A double-blind pilot clinical trial on 77 type 2 diabetic patients examined the effect of oral amino acid supplementation. Group B, receiving essential amino acids, showed a significant decrease in post-prandial plasma glucose compared to groups C and D after 45 days. No significant changes were observed in other parameters.
Randomized double-blind trial of oral essential amino acids for dialysis-associated hypoalbuminemia.
RCT of 52 dialysis patients comparing 3.6 g of essential amino acids (EAAs) to placebo three times daily for three months. EAAs significantly improved serum albumin concentration in hemodialysis patients but not in peritoneal dialysis patients. Improvements were also seen in grip strength and SF-12 mental health score.
Effects of essential amino acid supplementation and rehabilitation on functioning in hip fracture patients: a pilot randomized controlled trial.
Pilot RCT evaluating the impact of a 2-month rehabilitative protocol with or without essential amino acid supplementation on functioning in hip fracture patients. The study involved 32 patients, with group A receiving amino acid supplementation. Significant improvements were observed in sarcopenic patients in group A across all primary outcomes, while group B showed improvement only in ILOA.
Human Muscle Protein Synthetic Responses during Weight-Bearing and Non-Weight-Bearing Exercise: A Comparative Study of Exercise Modes and Recovery Nutrition.
RCT comparing muscle protein synthesis and whole-body protein turnover during weight-bearing (LC) and non-weight-bearing (CE) exercise with and without essential amino acid (EAA) supplementation. EAA enhanced muscle protein synthesis and net protein balance during and after exercise, with LC showing greater muscle protein synthesis than CE.
High anabolic potential of essential amino acid mixtures in advanced nonsmall cell lung cancer.
RCT in 13 patients with advanced NSCLC and 11 healthy subjects comparing protein synthesis and net protein anabolism after intake of 14 g of EAA with high leucine levels versus a balanced amino acid mixture. EAA/leucine intake resulted in higher protein synthesis and net protein anabolism, independent of cancer presence.
Dietary essential amino acids are highly anabolic in pediatric patients with cystic fibrosis.
RCT in 15 pediatric CF patients comparing ingestion of 6.7 g essential amino acids (EAA) versus a mixture of total amino acids as present in whey. EAA intake resulted in higher protein synthesis and net anabolism, with lower Arginine turnover. The study suggests CF patients are highly responsive to EAA intake.
Liver and muscle glycogen repletion using 13C magnetic resonance spectroscopy following ingestion of maltodextrin, galactose, protein and amino acids.
The study evaluated the effect of including protein and amino acids in a maltodextrin and galactose recovery drink on post-exercise liver and muscle glycogen repletion in seven trained male cyclists. Despite higher postprandial insulin concentrations with the protein and amino acids formulation, there were no significant differences in liver or muscle glycogen concentrations compared to the maltodextrin and galactose formulation alone.
Effects of supplementation with essential amino acids on intrahepatic lipid concentrations during fructose overfeeding in humans.
RCT with 9 healthy male volunteers using a crossover design to study the effect of essential amino acid supplementation on hepatic fat content during high-fructose feeding. Essential amino acids decreased intrahepatocellular lipid content but did not affect VLDL-triglyceride concentrations or VLDL-[(13)C]palmitate production.
Mammalian target of rapamycin complex 1 activation is required for the stimulation of human skeletal muscle protein synthesis by essential amino acids.
RCT examining the role of mTORC1 activation in muscle protein synthesis following ingestion of 10 g of essential amino acids (EAA) in 8 young individuals. EAA ingestion increased muscle protein synthesis by ~60% in the control trial, but this effect was blocked by rapamycin, indicating mTORC1's role in muscle protein synthesis.
Effects of a combined essential amino acids/carbohydrate supplementation on muscle mass, architecture and maximal strength following heavy-load training.
RCT evaluating the effects of essential amino acid supplementation on muscle mass, architecture, and strength in young males during a 12-week heavy-load training program. EAA supplementation resulted in greater changes in muscle architecture and hypertrophy, particularly in subjects with lower nitrogen balance and initial strength.
Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass, and strength.
RCT of 19 untrained males examining the effects of 10 weeks of resistance training combined with 20 g protein (14 g whey and casein protein, 6 g free amino acids) supplementation versus dextrose placebo. The protein supplement led to greater increases in total body mass, fat-free mass, thigh mass, muscle strength, and markers of muscle protein synthesis and anabolism.
Amino acid supplementation alters bone metabolism during simulated weightlessness.
RCT examining the effects of an amino acid/carbohydrate supplement on bone resorption during bed rest in 13 subjects. The amino acid-supplemented group showed increased bone resorption and urinary calcium excretion, with decreased bone mineral content compared to the control group.
Hypercortisolemia alters muscle protein anabolism following ingestion of essential amino acids.
RCT investigating the effect of essential amino acids (EAA) on muscle protein metabolism during hypercortisolemia induced by hydrocortisone infusion. EAA ingestion improved muscle protein anabolism despite hypercortisolemia, suggesting potential benefits in minimizing muscle loss following injury.
An oral essential amino acid-carbohydrate supplement enhances muscle protein anabolism after resistance exercise.
This study investigated the effects of an essential amino acid-carbohydrate drink on muscle protein anabolism after resistance exercise. Six subjects consumed either the treatment drink or a placebo. The amino acid-carbohydrate drink significantly increased muscle protein synthesis when ingested 1 or 3 hours after exercise, compared to placebo.
Acute amino acids supplementation enhances pituitary responsiveness in athletes.
This study investigated the effect of an amino acid mixture on pituitary responsiveness in athletes using a double-blinded protocol. The amino acid mixture enhanced the ACTH, LH, and FSH response to CRH + GnRH stimulation compared to placebo.
Supplemented low-protein diets--are they superior in chronic renal failure?
RCT of 22 patients with chronic renal failure comparing a conventional low-protein diet to a very-low-protein diet supplemented with essential amino acids over 9 months. No significant differences were found between the groups in terms of protein-energy status, renal function, or biochemical parameters of renal osteodystrophy.
Effect of parenteral amino acid supplementation in alcoholic hepatitis.
A controlled randomized study in 15 patients with alcoholic hepatitis examined the effect of parenteral amino acid-glucose solution on various parameters. The treated group showed more improvement in nitrogen balance and a greater resolution of fatty infiltration compared to the control group. However, amino acid therapy did not significantly improve other nutritional or biochemical markers compared to the control.
A controlled study of supplementation with essential amino acids and alpha-keto acids in the conservative management of patients with chronic renal failure.
This study compared the effect of supplementation with essential amino acids and alpha-keto acids versus placebo in 15 ambulatory patients with chronic renal failure. The study found that alpha-keto acids diminished serum phosphate concentration, but no other significant beneficial effects were demonstrated during supplementation with either essential amino acids or alpha-keto acids.