The ABCs of BCAAs: Why are They Important?

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Not to be confused with car insurance, BCAAs have claimed a solid position of repute among sports nutrition supplements. Available in both encapsulated and powdered form, BCAAs are surrounded with controversy and even a little bit of mystery as ongoing research continues. The following “ABCs of BCAAs” aims to provide some insight and clarity around this fiercely popular and widely used athletic supplement.

But first, Fundamentals:

What are BCAAs?

20 different amino acids combine endlessly into the thousands of diverse proteins that compose the structure of the human body. Think of it in LEGO terms: If proteins are a LEGO masterpiece, then amino acids are the individual LEGOs. The human body is incapable of manufacturing nine of these amino acids, qualifying them for the designation of essential, meaning that they MUST be consumed in the diet. Of the nine essential amino acids, three have a unique carbon atom configuration and are known as the branched-chain amino acids. Consisting of more than one-third of all protein found in human muscle: leucine, isoleucine, and valine are the trio of what is commonly known as BCAAs. Supplemental BCAAs offer this unique trio isolated from the full amino acid profile that is found in whole food sources such as eggs, dairy, and meat. Due to the conflicts found within the scientific literature, unanimity remains elusive in regards to the safety involved with the use of supplemental BCAAs, particularly at higher and/or longer than recommended doses. Can the performance of three-star players deliver superior results or detrimental dangers, apart from the complete protein team?

A is for Action

BCAAs have a unique metabolic action that causes them to stand out from the other amino acids. Leucine, isoleucine, and valine bypass break down in the liver and are primarily metabolized within the muscle itself. Entering the bloodstream rapidly, BCAAs are then absorbed at an accelerated rate by active muscle tissues. This particular action is at the base of both the benefits and considerations of BCAA supplementation.

B is for Benefits

Since BCAAs enter the bloodstream rapidly and are readily absorbed by the active muscle tissues, they provide an immediate fast-burning fuel source for working muscle. The claims of BCAA's ability to inhibit fatigue enhance both aerobic capacity and anaerobic performance find scientific legitimacy. Of the BCAAs, leucine takes the spotlight for instigating muscle growth, maintaining lean body mass during caloric restriction, as well as reducing muscle breakdown during long/intense exercise. Leucine acts much like the foreman of a muscle construction crew but does require the efforts of every amino acid squad member to sustain continued growth. An intake of supplemental BCAAs spares the body from dipping into and consuming its amino acid reserves in extremely catabolic conditions, resulting in the preservation of muscle mass and a reduction of muscle damage. With less sustained damage, muscles recover faster with less soreness following intense physical exertion. Researchers have found that supplemental BCAAs can also be used by immune cells within the gut as ammunition for more effective immune system regeneration following the natural damage induce by intense or endurance training.

C is for Considerations

The proven benefits of BCAA supplementation must be balanced by its considerations. The mTORC1 cellular growth pathway initiated by BCAAs can cause growth and proliferation of both muscles as well as cancer cells, with leucine showing to be carcinogenic in some animal studies. Research shows that the same unique metabolic action of BCAA supplementation that results in rapidly fuelled muscle can also lead to impairment of the function of insulin. With tissues no longer responding properly to insulin, the bloodstream remains flooded with sugar, leading to insulin insensitivity and resistance which is linked to the development of obesity, type 2 diabetes, and metabolic syndrome.

Furthermore, because tryptophan and BCAAs compete against each other for transportation into the brain, elevated serum levels of BCAAs can dislocate tryptophan out of position in the brain.

As one of the only precursors to serotonin, a deficit of tryptophan results in decreased mood, disturbed sleep, and appetite deregulation severe enough to lead to a shortened lifespan.

The unequivocal conclusion of BCAA supplementation is that it is pro-growth. When dosed accordingly, BCAAs have the potential to aid with muscle growth, recovery, and immunity. However, with long-term or high doses, they also carry negative growth risks, including cancer proliferation, insulin resistance, and depression.