For a long time, branched-chain amino acids (BCAA) have been regarded as a magical supplement that inhibits muscle breakdown, increases muscle synthesis, and relieves sports fatigue. However, with the increase in related research in recent years, its mythical status has been frequently questioned.
BCAA, or branched-chain amino acids, include isoleucine, leucine, and valine. These three amino acids are called essential amino acids, which refer to amino acids that the human body needs but cannot synthesize on its own and can only obtain through external intake.
Unlike common fitness supplements such as taurine and creatine, BCAA can also be obtained from a more daily diet. People often think that BCAA is magical or even mysterious. In fact, in daily life, when people consume protein-rich foods such as meat, eggs, and milk, they must also consume these three essential amino acids, but they are not as efficient and concentrated as directly consuming purified BCAA powder.
After briefly understanding the composition and sources of BCAA, let's continue to explore its functions and mechanisms of action.
Since the American Medical Association first announced the recommended daily intake of BCAA in 2002, BCAA has become a big name in the nutrition world, and scientific research on it has gradually increased.
Superpower 1: Promote muscle synthesis
The uniqueness of BCAA is that it independently stimulates muscle protein synthesis through the insulin pathway and can produce many intermediates that are important for cellular metabolism. Therefore, BCAA can skip liver metabolism and be quickly absorbed by skeletal muscle, among which leucine promotes muscle protein synthesis by activating the mTOR signaling system center. This function is the earliest confirmed by research among the three main functions of BCAA, and it has received the most close attention from the academic community among the three functions.
Scholars have found through research that adding BCAA in moderation to the diet can reduce food intake and reduce weight gain, that is, it can help lose weight. However, a long-term high-BCAA diet can lead to obesity. The mechanism is insulin resistance caused by activation of the downstream of the mTOR pathway.
Superpower 2: Fighting muscle breakdown
Relevant studies have shown that when BCAA is taken at rest, the rate of protein degradation decreases and the rate of synthesis increases; when BCAA is taken during aerobic exercise, the net rate of protein degradation decreases.
This is easy to understand. When the exercise time is long and the exercise intensity is high, the proportion of protein energy supply will also increase. Especially in endurance exercise, the branched-chain amino acids in muscle protein will increase oxidation. Preventive supplementation of BCAA can reduce some decomposition.
Superpower 3: Relieve exercise fatigue
Relevant studies have shown that if the concentration of BCAA in the blood is reduced, it will accelerate the production of brain neurotransmitters serotonin or 5-hydroxytryptophan), which will cause premature exercise fatigue and feel "tired, sleepy, and want to sleep." Tryptophan is a precursor of serotonin. When the BCAA content in the blood is high, it can seize the "channel" for tryptophan to be transported to the brain, so that tryptophan can be "squeezed out" and its inhibition on the corresponding receptors of the central nervous system can be weakened, thereby relieving muscle fatigue.
Huge market and "bright future"
As of 2022, BCAA has a global market of 256 million US dollars, and it has occupied 65% of the total market of fitness supplements by itself, which is worthy of being a rising star in the medical field. It is worth noting that BCAA not only appears in the market as a fitness supplement, but also in many fields such as drug synthesis and animal husbandry.
Unlimited cross-border potential
In addition to the main business of fitness supplements, BCAA also shows great potential in improving the survival of patients with advanced tumors and improving major medical hot issues such as cirrhosis.
Cachexia is a common complication of various advanced malignant tumors. Patients will have symptoms such as metabolic changes, weight loss, anorexia, and systemic inflammation. About 20% of tumor patients die from cachexia. Patients with cachexia consume much more protein than ordinary people, and it is difficult to supplement sufficient essential amino acids by eating big fish and meat when their appetite decreases due to cancer. At this time, BCAA can show its skills to improve the physical condition of patients with advanced cancer.
Related studies have shown that BCAA can inhibit hepatocyte apoptosis and enhance hepatocyte regeneration. Branched-chain amino acids (BCAA) are particularly suitable for patients with liver cancer and cirrhosis, and can improve the patient's inherent immune status; clinical studies have shown that oral supplementation of branched-chain amino acids (BCAA) during radiotherapy and medication can improve the biochemical indicators of patients with cirrhosis, while preventing the recurrence of cirrhosis and protecting liver function.
Summary
BCAA mainly appears in the market as a fitness supplement, with functions such as inhibiting muscle breakdown, increasing muscle synthesis, and relieving sports fatigue. Its effects and safety have been widely recognized by the nutrition community. Taking BCAA in moderation under normal physical conditions has many benefits for the human body. At the same time, in addition to the fitness supplement function that has been widely commercialized, BCAA has also been developed as a potential auxiliary agent for the treatment of liver cancer and cachexia, with good pharmaceutical development potential.