Why you shouldn’t take BCAAs

BCAA’s or branched-chain amino acids have been a staple for many who are looking to boost their exercise performance & recovery. They have a molecular structure that includes a branched chain, hence the name.  This structure allows the to bypass organs such as the liver and be quickly digested and metabolised into muscle tissue.

 BCAA’s consist of just 3 of the 9 Essential Amino Acids. They are Leucine, Valine & Isoleucine.  

 Leucine is responsible for Muscle Protein Synthesis (the process in which cells make proteins and the body maintains & builds muscle). It also helps to regulate blood sugar levels, stimulate wound healing and produce growth hormones. 

Valine also helps to stimulate muscle growth, stimulate muscle regeneration and is involved in the process of energy production.

 Isoleucine is involved in muscle metabolism, which is the consumption of energy by all cells, including those of muscle tissue, to perform work. Isoleucine is heavily concentrated in the muscle tissue, and also responsible for haemoglobin production and energy regulation. 

On the surface it would seem that these 3 BCAA’s are both beneficial to us & important when It comes to building muscle, increasing exercise performance & optimising recovery.  

However, what many don’t know is that taking BCAA’s in isolation to all the other Essential Amino Acids makes them inefective for building muscle, but also may lead to an amino acid imbalance and other adverse side affects.

 A 2018 review in the journal 'Nutrients', named: Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training, said this:

“While it is true that leucine is capable of stimulating MPS in the absence of other amino acids, it should be emphasized that protein synthesis will eventually become limited by the availability of other essential amino acids.”

 When all the BCAA studies between 1985 - 2017 were reviewed by a researcher named Robert Wolfe, he found zero studies involving humans where BCAA’s in isolation were responsible for more efficient Muscle Protein Synthesis. To take this further, two of the studies that Wolfe looked at were to found to actually decrease muscle protein synthesis and increase catabolic effects on lean muscle mass.  

This leads us to the point that if the body has excess BCAA’s, it will breakdown its own muscle tissue to free up the other six Essential Amino Acids and bring back a balance.

 This is the reason why you should not take BCAA’s in isolation to the other six Essential Amino Acids. The three BCAA’S - Leucine, Valine & Isoleucine are effective when taken in an optimal formula with all other EAA’s, this allows them to be processed and uses by the body in a much more natural, effective manner. 

 

BCAA Side Effects

It doesn't end there. Unbeknown to many, taking BCAA's is isolation to the other Six Essential Amino Acids can brings about the possibility of other side effects.  

BCAAs Can Deplete B Vitamins

B Vitamins are essential for many body processes such as converting what we eat into fuel for the body, as well as giving us healthy skin, hair & nails. Not only that, they are needed for our nervous system, cognition and hormones.

However, B Vitamins such as B1, B2, B3, B5 & B6 are needed to use and breakdown BCAAs (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071262/).

 If you’re taking high doses of BCAA’s in isolation to EAA’s, you may be using up vital B Vitamins. 

BCAAs Can Lower Serotonin Levels

 Interestingly, BCAAs and the Amino Acid Tryptophan compete against each other for the same carrier system in the body. One of the reason's BCAAs can help to stave off fatigue during workouts is because they block the uptake of said Tryptophan. 

When the concentration of BCAAs in the body are high, its clear then that the brain doesn't get much Tryptophan.  This means you can lower your serotonin levels, which can lead to a whole host of problems such as risk of depression, anxiety & sleep problems to name a few. 

 BCAAs May Lead To Higher Risk Of Metabolic Disease

BCAA's promote the uptake of glucose by the muscles, which is another reason why they have a positive effect on performance when exercising.  High doses in isolation, though, have shown that they may lead to insulin resistance, dysregulated blood sugar and possibly increase the risk of more serious diseases such as diabetes 

• Independent of body weight, the addition of BCAAs to a high-fat diet contributes to the development of insulin resistance and impaired glucose homeostasis
• Higher levels of BCAAs have a significant association with the future development of diabetes
• Increased fasting concentrations of circulating BCAAs are associated with an increased risk of type 2 diabetes and insulin resistance in humans

While the mechanism between BCAAs and dysregulated glucose metabolism isn’t quite clear, some researchers hypothesize it could be a result of a metabolic burden driven by an amino acid imbalance.

 

 Replace BCAAs with Essential Amino Acids

 Research shows that an Essential Amino Acid formula, which is leucine-enriched, can be very effective in improving muscle protein synthesis, muscle growth, athletic performance & recovery. 

In a 2011 randomized controlled trial, eight adults completed two separate bouts of cycling for 60 minutes for 13 days. 10 g of LEAAs (3.5 g leucine) were consumed during one bout, and 10 g of a standard EAA supplement (1.87 g leucine) during the other. The results showed that LEAAs increased MPS by 33% more than traditional EAAs (though both were effective).

Another randomized controlled trial from 2018 on post-stroke patients with sarcopenia (a condition characterized by loss of skeletal muscle mass and function) showed that supplementation with as little as 3 g of LEAAs resulted in increased muscle mass, strength, and physical function. 

In terms of athletic recovery, the research is also very promising. A 2019 study in the Journal of Physical Therapy Science examined the effects of LEAA supplementation (3.6 g, 3x/day) on post-exercise muscle damage in 10 young, healthy males. The results of the study showed that LEAAs significantly suppressed exercise-induced muscle tissue damage, suggesting that LEAAs can aid in muscle recovery.

In April 2020, a randomized, double-blind, placebo-controlled, parallel-group design study (whew, say that five times fast) was published in which 20 active young men on a controlled diet (1.2 g/kg/d of protein) were given either 4 g of LEAAs (1.6 g leucine) or a placebo three times a day for four days following an acute bout of lower-body resistance exercise. LEAAs were shown to preserve muscle force production and attenuate muscle soreness more than placebo, even when combined with an already high protein diet.

 Source: bengreenfieldlife.com

It seems clear, a Leucine-enriched Amino Acid formula will not only greatly assist with lean mass, reduced soreness, better performance and faster recovery. You'll also get all the acclimated benefits of Essential aminos and avoid any issues by taking BCAA's in isolation.