BCAAs may sound like a collegiate sporting organization but are, in fact, branched-chain amino acids. BCAAs are a group of three essential amino acids: leucine, isoleucine and valine. They are essential, meaning they can't be produced by your body and must be obtained from food. The human body requires 20 amino acids in order to regulate functions such as immunity, muscle building, hormones, etc and nine of these are considered essential. BCAA products have been marketed as supplements that build muscle, decrease muscle fatigue and alleviate muscle soreness. While this sounds like an advantageous product for athletes, do they really deliver as marketed?
A multi-million dollar industry of nutritional supplements has developed around the concept that a dietary supplement of BCAAs alone can provide an anabolic response in humans driven by muscle protein synthesis. Some claims even go so far as to promise a 30% greater muscle synthesis when compared to a traditional protein supplement, such as a whey protein concentrate drink. This may be an over-estimate of the effectiveness of BCAAs considering that other essential amino acids are involved in the muscle building process. In fact, a few studies have found that infusing cells with BCAAs, only, actually decreases the potential for muscle synthesis.[1]
Other studies have found that BCAAs have functions beyond protein synthesis and can help regulate control of protein metabolism. This not only pertains to the production, or synthesis, or proteins but also the rate in which proteins are destroyed by the body, or catabolism.[2] In these cases BCAAs were given along with other essential amino acids. Several studies conducted on collegiate athletes from 2003 through 2017 also suggest that BCAAs can increase lean muscle mass, decrease body fat and assist in recovery after strenuous workouts.[3] However, since BCAAs were given in conjunction with typical protein supplements it is unclear if BCAAs alone are responsible for providing recovery benefits or if the BCAAs work in conjunction with other amino acids to promote muscle synthesis and recovery.
BCAAs may have benefits beyond muscle synthesis. Medical studies have found that patients with end-stage liver disease benefitted from increased amounts of BCAAs. When the normal diet was supplemented with additional BCAAs the rates of cirrhosis related complications decreased and probability of survival increased.[4] Additional studies are currently determining if adding a BCAA supplement to the normal diet can help people with heart disease, diabetes and kidney disease.
While the science on BCAAs is unclear if these triplets are directly responsible for muscle synthesis or if they work in conjunction with other amino acids, they are essential for many functions of the human body and are an important to obtain through a healthy diet.
[1] “Branched-chain amino acids and muscle protein synthesis; myth or reality.” Journal of Sports Nutrition. Wolfe. R.R. 2017
[2] Chapter 8: Branched-Chain Amino Acids. Nutrition and Traumatic Brain Injury: Improving Acute and Subacute Health Outcomes in Military Personnel. 2011
[3] Health Benefits of BCAAs. Medical News Today. A. Stinson. 2019
[4] “Effects of branched-chain amino acids (BCAAs) on the progression of advanced liver disease.” Medicine (Baltimore). 2017 Jun; 96(24): e6580