Branched-Chain Amino Acids

What other names is Branched-chain Amino Acids known by?

Acide Isovalérique de Leucine, Acides Aminés à Chaîne Ramifiée, Acides Aminés Ramifiés, Aminoacidos Con Cadenas Laterales Ramificadas, BCAA, BCAAs, Branched Chain Amino Acid Therapy, Branched Chain Amino Acids, Isoleucine, Isoleucine Ethyl Ester HCl, Leucine, Leucine Ethyl Ester HCl, Leucine Isovaleric Acid, Leucine Methyl Ester HCl, L-Isoleucine, L-Leucine, L-Leucine Pyroglutamate, L-Valine, N-Acetyl Leucine, N-Acétyl Leucine, Valine, 2-amino-3-methylvaleric acid, 2-amino-4-methylvaleric acid, 2-amino-3-methylbutanoic acid.

What is Branched-chain Amino Acids?

Branched-chain amino acids are essential nutrients that the body obtains from proteins found in food, especially meat, dairy products, and legumes. They include leucine, isoleucine, and valine. "Branched-chain" refers to the chemical structure of these amino acids. People use branched-chain amino acids for medicine.

Branched-chain amino acids are used to treat amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease), brain conditions due to liver disease (chronic hepatic encephalopathy, latent hepatic encephalopathy), a movement disorder called tardive dyskinesia, a genetic disease called McArdle's disease, a disease called spinocerebellar degeneration, and poor appetite in elderly kidney failure patients and cancer patients. Branched-chain amino acids are also used to help slow muscle wasting in people who are confined to bed.

Some people use branched-chain amino acids to prevent fatigue and improve concentration.

Athletes use branched-chain amino acids to improve exercise performance and reduce protein and muscle breakdown during intense exercise.

Healthcare providers give branched-chain amino acids intravenously (by IV) for sudden brain swelling due to liver disease (acute hepatic encephalopathy) and also when the body has been under extreme stress, for example after serious injury or widespread infection.

Possibly Effective for...

  • Anorexia. Taking branched-chain amino acids by mouth seems to reduce anorexia and improve overall nutrition in older, undernourished people. There is also early evidence that taking branched-chain amino acids by mouth might be helpful for people with anorexia that is associated with cancer or liver disease.
  • Poor brain function related to liver disease. Although there are some conflicting results, most research suggests that taking branched-chain amino acids by mouth can improve liver and brain function in people with poor brain function caused by liver disease.
  • Mania. Consuming a drink containing the branched-chain amino acids leucine, isoleucine, and valine seems to reduce symptoms of mania.
  • Muscle breakdown. Taking branched-chain amino acids by mouth seems to reduce the breakdown of muscles during exercise
  • Movement disorder called tardive dyskinesia. Taking branched-chain amino acids by mouth seems to reduce symptoms of the muscle disorder called tardive dyskinesia.

Likely Ineffective for...

  • Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). Early studies showed promising results, but more recent studies show no benefit of branched chain amino acids in people with ALS. In fact, taking branched-chain amino acids might make lung function worse and increase the risk of death in people with this condition.

Insufficient Evidence to Rate Effectiveness for...

  • Liver disease caused by alcohol. Early research suggests that taking branched-chain amino acids daily along with a controlled diet does not reduce the risk of death in people with liver disease caused by drinking alcohol.
  • Athletic performance. There is inconsistent evidence about the effectiveness of branched-chain amino acids for athletic performance. Many studies suggest that taking branched-chain amino acids does not enhance exercise or athletic performance. However, other research suggests that it might reduce tiredness and muscle soreness associated with exercising.
  • Diabetes. Early research suggests that eating carbohydrates with an amino acid/protein mixture might improve insulin response in people with diabetes. However, it is not known if taking branched-chain amino acids as a supplement will provide the same benefits.
  • Liver cancer. Research suggests that drinking a beverage containing branched-chain amino acids daily for one year does not improve survival after surgical removal of liver cancer.
  • Liver cirrhosis. It is not clear if branched-chain amino acids benefit people with liver cirrhosis, the final phase of long-term liver disease. Early research suggests that branched-chain amino acids provide no benefit. However, there is some research that suggests branched-chain amino acids might improve quality of life in people with liver cirrhosis.
  • Genetic disorder that increases phenylalanine in the blood (Phenylketonuria). Taking branched-chain amino acids for up to 6 months seems to improve attention in children with phenylketonuria.
  • Disease of the spine called spinocerebellar degeneration (SCD). There are conflicting results about the effects of branched-chain amino acids in people with a disease of the spine called SCD. Some early research suggests that taking branched-chain amino acids by mouth might improve some symptoms of SCD. However, other research suggests that branched-chain amino acids do not improve muscle control in people with SCD.
  • Preventing fatigue.
  • Improving concentration.
  • Preventing muscle wasting in people confined to bed.
  • Other conditions.
More evidence is needed to rate the effectiveness of branched-chain amino acids for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).


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