BCAAs: benefits, dosage, contraindications
Scientific name(s)
Branched-chain amino acids
Family or group:
Amino acids
Indications
Scoring methodology
EFSA approval.
Hepatic encephalopathy ✪✪✪✪✪
BCAAs are used in hepatic encephalopathy as an energy source to prevent endogenous protein catabolism and reduce ammonia detoxification in the brain by increasing ammonia metabolism in skeletal muscles. They are recommended for malnourished patients with chronic hepatic encephalopathy who do not tolerate protein supplementation. rnrnDaily intake of BCAAs at 240 mg/kg (up to 25 grams) in 3 divided doses for up to 3 months appears to improve symptoms, liver function tests and nitrogen balance in patients with chronic hepatic encephalopathy. rnrn
Posologie
Oral
240 mg/kg
3 - months
Long-term oral branched-chain amino acid treatment in chronic hepatic encephalopathy. A randomized double-blind casein-controlled trial. The Italian Multicenter Study Group
Overview of randomized clinical trials of oral branched-chain amino acid treatment in chronic hepatic encephalopathy
Enteral and parenteral branched chain amino acid-supplemented nutritional support in patients with encephalopathy due to alcoholic liver disease
Branched-chain amino acids for people with hepatic encephalopathy
Sports performance ✪✪✪✪✪
The effects of BCAA intake on physical performance are highly controversial. In most studies, oral BCAA intake does not improve athletic performance but appears beneficial in reducing exercise-induced fatigue and perceived exertion after prolonged or intense exercise. rnrn
Posologie
Oral
0.17 - 0.3 mg/kg
Effects of branched-chain amino acids supplementation on physiological and psychological performance during an offshore sailing race
Branched-chain amino acids and arginine improve performance in two consecutive days of simulated handball games in male and female athletes: a randomized trial
Nutraceutical effects of branched-chain amino acids on skeletal muscle
Branched-chain amino acid supplementation attenuates muscle soreness, muscle damage and inflammation during an intensive training program
The effects of acute branched-chain amino acid supplementation on recovery from a single bout of hypertrophy exercise in resistance-trained athletes
Branched-chain amino acid supplementation improves cycling performance in untrained cyclists
Branched-chain aminoacid supplementation attenuates a decrease in power-producing ability following acute strength training
Branched-chain amino acids prolong exercise during heat stress in men and women
Influence of ingesting a solution of branched-chain amino acids on perceived exertion during exercise
Cachexia ✪✪✪✪✪
BCAA supplementation in malnourished elderly patients appears to reduce anorexia and improve nutritional indices. BCAAs may compete with tryptophan, a precursor of serotonin, for uptake across the blood-brain barrier. By decreasing serotonin synthesis, BCAAs could increase appetite. rnrnPreliminary clinical research conducted in malnourished elderly and hemodialysis patients shows that taking a combination of BCAAs at a dose of 4 grams three times a day improves appetite and caloric intake and increases plasma albumin levels and anthropometric measurements compared to placebo.rnrn
Posologie
Orally
12 g
Cirrhosis ✪✪✪✪✪
A small clinical study shows that taking BCAAs at a dose of 14.4 grams per day for 12 months does not improve survival or liver function in patients with advanced cirrhosis, but reduces the number of hospitalizations and the prevalence of cachexia and improves quality of life compared with the control group. rnrn
Posologie
Oral
14.4 g
12 months
tardive dyskinesia ✪✪✪✪✪
Clinical research conducted in patients taking antipsychotic medications shows that taking a drink containing 222 mg/kg of BCAAs, three times a day for 3 weeks, reduces tardive dyskinesia symptoms (repetitive involuntary movements usually secondary to neuroleptic use) by 30% to 60% compared with placebo. rnrn
Posologie
Oral
222 mg/kg
Alzheimer's disease ✪✪✪✪✪
Observational research has shown that high blood levels of BCAAs are associated with an 11% to 13% lower risk of Alzheimer's disease, although this association was not significant. rnrn
Posologie
Oral
68 mg/kg
Properties
Metabolic
BCAAs, particularly leucine, act as signaling molecules to stimulate protein synthesis. Indeed, leucine, more than isoleucine and valine, has a regulatory effect on muscle protein metabolism. BCAAs also stimulate protein synthesis in adipose tissue and the liver. In the heart, they appear to have a specific anabolic effect on cardiac protein metabolism. In addition, BCAAs appear to stimulate the release of insulin by pancreatic islet cells, which is necessary for the maximal stimulation of protein synthesis. The sensitivity of BCAAs to stimulate protein synthesis appears to decrease with age.
Usages associés
Musculoskeletal effects
BCAA metabolism occurs largely in muscle. Their oxidation releases substrates usable for energy by skeletal muscles and nitrogen atoms destined for the in situ synthesis of alanine and glutamine. Leucine, more than isoleucine and valine, has a regulatory effect on muscle protein metabolism.
Usages associés
Neurological
An increased intake of BCAAs appears to decrease the synthesis of amine neurotransmitters such as dopamine, norepinephrine, and serotonin. By decreasing serotonin synthesis, BCAAs could increase appetite. BCAAs play a role in the oxidation and synthesis of the excitatory neurotransmitter glutamate. Researchers believe that dietary BCAA intake may be necessary to maintain glutamate reserves in the central nervous system. Finally, BCAAs may reduce plasma phenylalanine by increasing protein synthesis and insulin release, thereby lowering phenylalanine levels in the cerebrospinal fluid. They could thus reduce the symptoms of tardive dyskinesia that are associated with increased phenylalanine.
Usages associés
Safe dosage
Adults aged 18 years and older: 68 mg/kg
The estimated average requirements (EAR) for BCAAs for adults are 68 mg/kg/day (leucine 34 mg/kg, isoleucine 15 mg/kg, valine 19 mg/kg). rnrn
Infant from 1 to 3 months: 98 mg/kg
The estimated average requirements for BCAAs for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9-13 years, 81 mg/kg/day; females 9-13 years, 77 mg/kg/day; males 14-18 years, 77 mg/kg/day; females 14-18 years, 71 mg/kg/day. rnrn
Child from 4 to 8 years: 81 mg/kg
The estimated average requirements for BCAAs for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9-13 years, 81 mg/kg/day; females 9-13 years, 77 mg/kg/day; males 14-18 years, 77 mg/kg/day; females 14-18 years, 71 mg/kg/day. rnrn
Male from 9 to 13 years: 81 mg/kg
The estimated average requirements for BCAAs for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9-13 years, 81 mg/kg/day; females 9-13 years, 77 mg/kg/day; males 14-18 years, 77 mg/kg/day; females 14-18 years, 71 mg/kg/day. rnrn
Female from 9 to 13 years: 77 mg/kg
The estimated average requirements for BCAAs for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9-13 years, 81 mg/kg/day; females 9-13 years, 77 mg/kg/day; males 14-18 years, 77 mg/kg/day; females 14-18 years, 71 mg/kg/day. rnrn
Male from 14 to 18 years: 77 mg/kg
The estimated average requirements for BCAAs for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9-13 years, 81 mg/kg/day; females 9-13 years, 77 mg/kg/day; males 14-18 years, 77 mg/kg/day; females 14-18 years, 71 mg/kg/day. rnrn
Female from 14 to 18 years: 71 mg/kg
The estimated average BCAA requirements for children are: 1-3 years, 98 mg/kg/day; 4-8 years, 81 mg/kg/day; males 9 to 13 years, 81 mg/kg/day; females 9 to 13 years, 77 mg/kg/day; males 14 to 18 years, 77 mg/kg/day; females 14 to 18 years, 71 mg/kg/day.
Precautions
Pregnant woman: avoid
Avoid use due to insufficient reliable information.
Breastfeeding woman: avoid
Avoid use due to insufficient reliable information.
