Branched-chain amino acids or BCAA are three of the nine essential amino acids: leucine, isoleucine and valine. They are so called for the presence of branching in their chemical structure.
What are branched-chain amino acids?
Branched-chain amino acids are part of the nine essential amino acids, and specifically they are: leucine, isoleucine and valine. They must be necessarily introduced in the body with foods, because they can’t be produced by our cells. Their chemical structure is characterized by the presence of branching. Branched-chain amino acids are especially localized in muscular tissues, and in particular they represent a third of the total proteins in muscles.
Once absorbed by the small intestine, these amino acids are metabolized only into muscular tissue, and not into the liver. The enzymes of Branched-chain alpha-keto acid dehydrogenase complex start the degradation of these amino acids under fasting conditions and during physical exercise. In fact Branched-chain amino acids are used not only to obtain proteins, but also to get energy for the body.
Branched-chain amino acids benefits
Branched-chain amino acids are largely used by athletes to enhance sports performance, but also in medicine to treat many diseases. The benefits of Branched-chain amino acids include:
- Accelerate protein synthesis into muscular tissue
- Allow gluconeogenesis
- Provide energy
- Reduce the risk of obesity
- Help to lose weight
- Reduce the sense of fatigue and muscle soreness
- Reduce reaction time for mental activities
- Stimulate of the concentration and storage
- Enhance neurotransmitters production, as serotonin, to relieve depression
- Protect the liver
- Improve insulin sensitivity
Branched-chain amino acids and foods
Branched-chain amino acids are found in foods rich of proteins, as legumes, meat, cheese and dairy products. In particular leucine is present mostly into eggs, meat, fish, legumes, nuts and peanuts. Foods rich of isoleucine are: lamb, chicken, pork, salami, tuna, eggs, cheese, dairy products, nuts, legumes. Valine is found in particular in all the types of meat, salmon, tuna, trout, nuts, spinach, eggs, cheese, dairy products, potatoes, carrots, tomatoes, cherries.
Branched-chain amino acids include:
Leucine is found especially in meat, fish, eggs, but also in legumes and cereals. It is particularly important during exercise because it helps to reduce the sense of fatigue and recovery time mostly in endurance athletes, and it counteracts the production of lactic acid. Bodybuilders instead use it primarily to increase muscle volume. It is also used for other scope, for example to enhance the beauty of the skin, with a natural anti-age effect.
Isoleucine stimulate protein synthesis and it reduces recovery time after the exercise. It is particularly important under fasting conditions, when the body perceives glycemia reduction, so it stimulate gluconeogenesis using also isoleucine and it enhance the production of ketogenic bodies. It is also used by the body to stimulate hemoglobin synthesis.
Valine is found primarily in form of supplements of L-valina, a particular form of this amino acid. In particular it is used not only by athletes, but also to treat many conditions. In fact valine allows a more stable control of muscular functions, so it is very helpful in patients with muscular diseases, as muscular dystrophy. It is also able to strengthen the nervous system, so it’s used in particular in people who suffer from nervous disorders, as dyskinesia. Valine moreover can improve digestive conditions. Athletes use this amino acid to reduce fat mass, and increase muscles volume.
Branched-chain amino acids in sports
Exercise causes an increase in serotonin levels, which are believed to cause fatigue. But BCAAs are believed to reduce serotonin levels, and thus cancel out the fatigue and actually enhance exercise performance. There have been many studies that promote this exact ability: In 1998, subjects ingested either BCAA or a placebo before taking an endurance cycle ride in the heat.
Branched-chain amino acids side effects
Supplements of branched-chain amino acids must be used following the usage and dosage advices. In the case of leucine, an abuse of this amino acid can lead to different side effects, as hypoglycemia, kidney or liver failure which can cause an accumulation of ammonia in the body, allergic reactions, and pellagra, a disturb that occurs when there is a deficiency of vitamin B3.
An excess of isoleucine can reduce the levels of tyrosine, an important precursor of many hormones and neurotransmitters; therefore isoleucine can lead to depression. Valine is considered generally safe for the body, but specific groups of people must not use valine, to prevent dangerous side effects, as alcoholics, subjects with hypoglycemia or Lou Gehring disease.