Branched Chain Amino Acids (BCAA) Uses, Benefits, Dosages & Side Effects

The three proteinaceous Branched Chain Amino Acids (BCAAs) are valine, leucine and isoleucine. There is also one nonproteinaceous BCAA called 2-aminoisobutyric acid.

For those with low intake of dietary protein, BCAA supplementation promotes protein synthesis in muscle tissue, and can lead to muscular growth with consistent usage.

Some of the most common uses for BCAAs include improving athletic performance, reducing fatigue and preventing muscle breakdown during periods of intense physical activity. [1]

Not a lot of research has been focused on valine in the past. However, leucine is generally associated with increased synthesis of muscle proteins, and isoleucine is important for cellular uptake of glucose. [1]

According to research, most people have no need for a BCAA supplement, as long as they are getting at least between 1 and 1.5 grams of protein per kilogram of bodyweight per day. [1]

BCAAs

Amino Acids

Muscle Growth

Body-Building

Workout

How It Works:

• Supports muscle protein synthesis
• Prevents breakdown of lean muscle tissue
• Supports workout performance

Dosage:

Between 25-65 mg/kg bodyweight per day

Safety:

Rated Likely Safe

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What are BCAAs?

Branched chain amino acids are essential aminos; meaning they have to come from the diet, or by taking a supplement.

There are 9 essential amino acids in total. What makes BCAAs different than other essential aminos?

According to an article published by the American Society of Plant Physiologists, a BCAA is “an amino acid having aliphatic side-chains with a branch (a central carbon atom bound to three or more carbon atoms)”. [2]

According to Bodybuilding.com, BCAAs are different from other amino acids in that they are mainly metabolized inside skeletal muscle tissue. They are converted to usable forms much less frequently than other aminos.

BCAA are important for the function of skeletal muscle cells, and supplementing with a quality BCAA supplement might help to enhance performance in athletic events.

Bodybuilders and other strength-training athletes commonly use a BCAA supplement to optimize their performance and improve power output for weight lifting.

How do Branched Chain Amino Acids Work Inside the Body?

BCAAs might have additional purposes in the body other than protein synthesis. BCAAs are also thought to: [3]

• Activate mTOR (mechanistic target of rapamycin), increasing leptin production in adipocytes;
• Serve as a precursor for the synthesis other non-essential amino acids, especially glutamine and alanine;
• Stimulate insulin secretion and activation in the PI3K pathway;
• Act as substrates for energy production;

BCAAs are important for various physiologic and metabolic pathways in humans, particularly those concerning protein synthesis, protein turnover, cell signaling and glucose metabolism. [1]

Routine use of a quality BCAA supplement can prevent the decline in serum BCAA that commonly occurs during intense exercise. When serum BCAAs are low, an amino acid called tryptophan increases in the brain.

Tryptophan is the amino concentrated in turkey meat; commonly known to induce mild sedative effects. That is because it is a precursor to a neurotransmitter called serotonin.

Low serum BCAAs stimulate a tryptophan influx to the brain, and subsequently cause upregulated serotonin production. Increased serotonin production can promote a relaxed state and may cause fatigue.

By inhibiting low serum BCAAs, supplementation may also help to limit fatigue. However, more research is needed to understand the specific mechanisms of action here.

BCAAs and Weight Loss

Fatty acid oxidation refers to a set of catabolic processes that help cellular mitochondria to produce energy, and anabolic processes that create ketone bodies, hormones, phospholipids and triglycerides. [4]

BCAAs might increase the oxidation of fatty acids in the body, possibly helping to improve certain factors related to obesity. [4]

This supplement is not commonly used for weight loss, but may have benefits for body re-composition, which refers to increasing lean muscle mass and reducing body fat.

Some evidence suggests that low levels of BCAAs could affect appetite, and possibly increase the risk of anorexia nervosa. In elderly patients with anorexia, BCAA supplementation seems to reduce symptoms and improve general nutrition. [5]

BCAAs and Immune Function

BCAAs may affect immunity as these amino acids are broken down by certain enzymes expressed in immune cells.

Specifically, decarboxylase and dehydrogenase enzymes are degraded by immune system cells to facilitate growth and replication of special white blood cells called lymphocytes. [3]

These same enzymes are also required for certain activities of cells called cytotoxic T lymphocytes. These T cells are known for their capacities to kill cancer cells. [3]

BCAAs and Protein Synthesis

Insulin secretion is required in protein synthesis. The Natural Medicines Comprehensive Database (NMCD) states that several studies have suggested that BCAAs stimulate insulin release from pancreatic islet cells. [5]

Although most BCAAs are metabolized in skeletal muscles during protein synthesis, they also facilitate protein production in the liver and adipose tissue, but not inside the kidneys. [5]

NMCD states that nearly all skeletal muscle protein synthesis is facilitated by leucine, not isoleucine or valine. [5]

Oral administration of branched chain amino acids before working out increases levels of serum ammonia while exercising. This seems to slow down muscle breakdown, and inhibit glycogen degradation while exercising. [5]

BCAAs and Brain Function

Branched chain amino acids share a transport protein into the brain with non-BCAA aminos: tyrosine, tryptophan and phenylalanine. Researchers believe that once BCAAS enter the brain, they may help to synthesize neurotransmitters, protein and energy there. [4]

BCAAs are able to cross the BBB (blood brain barrier). Inside the brain, BCAAs play roles in glutamate synthesis and metabolism. Scientists think that BCAAs may be needed to sustain adequate levels of glutamate in the CNS (central nervous system). [5]

Higher levels of BCAAs in the body seem to downregulate production of amine brain chemicals including dopamine, serotonin and noradrenaline (norepinephrine). [5]

Some evidence suggests that routine supplementation with BCAAs can improve symptoms associated with mania. This might be due to decreased central dopaminergic overactivity. [5]

In a brain disorder caused by liver damage called hepatic encephalopathy, BCAAs are used as sources of cellular energy.

By increasing ammonia metabolism in skeletal muscle cells, these molecules may help to prevent the breakdown (catabolism) of proteins, and decrease the amount of ammonia that gets produced in the brain. [5]

Branched chain amino acids might decrease clearance of phenylalanine, which can subsequently increase serum phenylalanine levels.

Because phenylalanine is a precursor of tyrosine, and tyrosine is a precursor of dopamine, BCAA might helps with dopamine-related disorders like tardive dyskinesia. [5]

Branched Chain Amino Acids Health Benefits

There are various uses for BCAA supplementation, but most of them need more research to be validated clinically. According to NMCD, people use BCAA supplements for:

• ALS (amyotrophic lateral sclerosis, Lou Gehrig’s disease);
• A genetic metabolic disorder called McArdle’s disease;
• Latent portosystemic encephalopathy;
• Improving focus and concentration:
• Chronic hepatic encephalopathy;
• Enhancing athletic performance;
• Preventing muscular fatigue;

NMCD states that BCAAs are also used for tardive dyskinesia, anorexia in cancer patients, spinocerebellar degeneration and muscle wasting (cachexia) during extended periods of bed rest. [5]

BCAAs are also used intravenously in health conditions brought on high levels of metabolic stress; normally due to severe sepsis or trauma. [5]

NMCD states that branched chain amino acids are Possibly Effective in five conditions. They are:

• Hepatic encephalopathy;
• Muscle breakdown;
• Tardive dyskinesia;
• Anorexia;
• Mania;

Some of the other conditions BCAAs are being studied in include diabetes mellitus, liver cirrhosis, liver cancer, PKU (phenylketonuria) and alcoholic hepatitis. [5]

The FDA has not approved the use of BCAA supplements as a treatment for any medical condition.

Branched Chain Amino Acids Deficiency

There has not been a lot of research into the potential symptoms of a BCAA deficiency symptoms.

In general, valine deficiency seems to cause neurological defects inside the brain, and leucine deficiency is associated with muscle tremors. [6]

Some other possible signs of amino acid deficiency include fatigue, poor production of antibodies, weakened immunity, imbalanced cellular pH, dizziness, water retention and infertility. [6]

As stated, BCAA deficiency is not normally a concern in those with adequate intake of protein-rich dietary sources.

However, there may be supplemental benefits of consuming more BCAAs than the level required to prevent deficiency.

Branched Chain Amino Acids Foods

According to an article from SFGate, women should aim to get a minimum of 46 grams of protein each day, while men should aim for 56 grams. This should provide the necessary amounts of BCAAs your body requires. [7]

BCAAs are found in all protein-rich foods. Some of the best sources for branched chain amino acids include lean cuts of beef, bison, lamb, poultry, fish and goat – and organic beans, legumes and eggs.

Raw organic milk, cheese, yogurt and other dairy products also contain good amounts of these nutrients. [7]

Branched Chain Amino Acids Dosage

According to NMCD, BCAAs have been used orally to treat latent or chronic hepatic encephalopathy in 240 mg/kg doses, up to a maximum dosage of 25 grams daily. [5]

To treat mania, a BCAA beverage with a 3:3:4 ratio of valine, isoleucine and leucine was used each morning over 7 days. [5]

To treat tardive dyskinesia, a BCAA beverage has been used 3 times daily for 3 weeks at a 222 mg/kg dosage level. [5]

For treating anorexia and for improving nutritional status in malnourished, elderly patients on hemodialysis, 4-gram doses of BCAA granules have been used 3 times daily. [5]

Always follow the dosing instructions on dietary supplements you may take – unless you are otherwise instructed by your physician.

Whatever your intended purpose for using a BCAA supplement, you should discuss the best dose for you with a doctor who understands your current health and health history.

Branched Chain Amino Acids Side Effects

Research has shown that BCAAs can raise levels of ammonia in plasma samples. This can cause decreased motor coordination and muscular fatigue. [5]

NMCD states that 60-gram doses daily for up to 60 days have increased plasma ammonia, but not to toxic levels. Long-term or high-dose use should only be taken with medical supervision and regular tests for liver function. [5]

NMCD recommends that BCAAs should be used with caution, especially before or during activities that require advanced motor coordination. [5]

NMCD states that in one case, branched chain amino acids may have contributed to hepatic encephalopathy in a chronic alcoholic. Encephalopathy was resolved when BCAAs were stopped, and then reoccurred when supplementation was resumed. [5]

In one study that used this supplement to treat Lou Gehrig’s disease, mortality rates increased generally. [5]

You should discuss all possible side effects of branched chain amino acid supplements with a qualified healthcare professional before beginning to use one.

Branched Chain Amino Acid Drug Interactions

According to NMCD, there are no known interactions possible between BCAAs and herbs or other supplements.

However, these amino acids may interact with certain prescription medications. Seek medical advice and use caution if using a BCAA dietary supplement along with: [5]

• Antidiabetes drugs like insulin, DiaBeta, Glucotrol, Orinase and Diabinese;
• Corticosteroids like dexamethasone, methylprednisolone, and prednisone;
• Diazoxide (Hyperstat, Proglycem);
• Thyroid hormone;
• Levodopa;

BCAAs are not known to interact with laboratory tests, but might have effects in certain health conditions. Do not use this product without your physician’s approval if you have Lou Gehrig’s disease (ALS), branched-chain keto aciduria, or idiopathic hypoglycemia. [5]

Do not use BCAAs without consulting a doctor if you are a chronic alcoholic. This supplement has been associated with hepatic encephalopathy (a spectrum of neuropsychiatric abnormalities) in cases of chronic alcoholism. [5]

NMCD recommends that all people using BCAA supplements discontinue use at least 2 weeks prior to undergoing surgery. This supplement might alter blood glucose levels by stimulating insulin release, which could lead to complications during the surgery.

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