BCAA as a nutritional supplement has flooded the market for the past few years. Above all, it is considered as a multi-millionaire business as it is believed that intake of BCAA instigates the muscle protein synthesis thus, induces an anabolic response.
Diet rich in protein with a well-balanced amino acid profile is critical for the growth of lean muscle mass. Both protein and individual amino acid components that form proteins are essential for development and maintenance of the body. Therefore, both essential amino acids supplements and BCAA supplements are streaming in the market. As our body is unable to synthesise BCAA’s because of the lack of several enzymes, it becomes mandatory to consume it from outside sources.
Branched-chain amino acids are available in the supplement market by the name of BCAA. Leucine, isoleucine and valine are among the nine dietary essential amino acids for a human lifecycle. BCAA makes upto 35-40% of the dietary essential amino acids of body proteins and 14% of total amino acids found in skeletal muscles (Ferrando et al, (1995). The principal goal of consuming BCAA supplements is to augment the anabolic state by initiating the protein synthesis in muscles. Not only BCAA but the availability of all indispensable amino acids is required for the significant stimulation of muscle protein synthesis (Volpi et al, 2003). Hence, BCAA supplements are popular among the bodybuilding fraternity but people with regular or moderate physical activity are also taking this supplement. So, through this article we will try to learn about the importance of BCAA.
Unlike other essential amino acids, BCAA is directly metabolised in the skeletal muscles. Several studies showed that ingestion of BCAA to people in catabolic states (like postoperative, severe burns, sepsis, etc.) ameliorated nitrogen balance, increases amino acid concentration in the plasma, improves protein synthesis while minimising the skeletal muscle catabolism (Echenique et al,1984).
Promote Protein Synthesis
The three BCAAs either together or leucine alone has the ability to initiate protein synthesis (Tischler et al, 1982) and reduce the rate of protein breakdown (Nair & Short, 2005). Hence, BCAAs play a cardinal role in the modulation of protein synthesis and turnover. It also maintains the glutamate-glutamine level in the body (Nahid & Mahmood, 2014).
Alleviate Mental Fatigue
Brestensky et al. (2015) stated that raised BCAA concentration in the blood inhibits fatigue by blocking the tryptophan entrance into the brain. The same is proven by several works dealing with the effect of BCAA on fatigue. Bloomstrand et al. (1997) studies showed that the ingestion of BCAA mixture reduces the exertion and mental fatigue.
Accelerate Muscle Growth
Among BCAA’s, leucine stimulates the protein synthesis rate while minimising the protein degradation rate in resting state as well as during recovery phase post endurance exercises. The anabolic effect of BCAA may be mediated via changes in a signalling pathway which controls protein synthesis (Blomstrand et al, 2006).
In contrast to other amino acids, BCAAs are catabolised by extrahepatic tissues such as muscle, adipose tissues, kidney and brain. The first step includes a transamination reaction where BCAAs transfer their amino group to alpha-ketoglutarate to form glutamate and branched chain Keto acids. Then, glutamine synthetase carries out the conversion of glutamate to glutamine.
Glutamine performs various functions like protein synthesis in muscles, maintain the acid-base balance in the kidney, production of glutathione, etc. (Rouse et al, 1995; Hammarqvist et al, 1989; Schuldt et al, 1999)
Reduce Muscle Soreness
Howatson et al (2012) indicated in their study that administration of BCAA prior and during damaging resistance exercise decreases the muscle damage while accelerating the muscle recovery in resistance-trained males.
Additionally, results of a study conducted by Coombes & McNaughton, 2000 revealed that BCAA supplementation reduces the serum concentration of creatine kinase and Lactate dehydrogenase (Intramuscular enzymes) during prolonged exercise. Therefore, BCAA supplementation may reduce the muscle damage related to endurance exercise.
Enhance Weight Loss
The conclusion of the study conducted by Yan-chuan et al (2015) manifested that dietary BCAA in a higher ratio is inversely related to the prevalence of obesity, postprandial glucose and inflammation status in young northern Chinese adults. Several studies showed that BCAAs administration may help prevent weight gain and increase weight loss. But additional research is required to conclude whether BCAA supplement provides any additional benefits over a high protein diet.
Nutrition plays an important role in the activation of immunity, also BCAAs are directly associated in the lymphocyte proliferation or maturation of dendritic cells (Tajiri & Shimizu, 2013). Data from Bassit et al (2000) indicated that BCAA supplementation inverses the decreased level of serum glutamine concentration, after a prolonged intense exercise like Olympic triathlon. Reduction in serum glutamine concentration is associated with an increased prevalence in symptoms of infection. Therefore, athletes who are supplemented with BCAA have a lower occurrence of infections.
The three Branched-chain amino acids (leucine, isoleucine and valine) are essential amino acids which stimulate the protein synthesis and decrease the protein degradation. Among the three, particularly leucine has a more anabolic effect. Apart from this, BCAAs supplementation can be a nutritional strategy to treat various problems like liver diseases. Footprints of several studies showed that BCAA can prevent the muscle wastage or loss and its administration accelerates the muscle growth. Additionally, it also plays a role in enhancing immunity, prevent weight gain and reduce muscle soreness. Last but not the least, it reduces the mental fatigue and maintains the glutamate-glutamine pool in the body. Besides this, more research is needed to narrow down the gap between knowledge about BCAA metabolism and the associated regulation of these amino acids. Hence, BCAA supplementation is found to be beneficial for athletes, bodybuilders and even for individuals with low physical activity level in enhancing their health.
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