Amino acids have been one of the premier performance supplements for nearly 40 years. Branched-chain amino acids (BCAAs) are particularly popular among athletes, who swear by their effects on muscle gain, recovery, and athletic performance.
However, new research has revealed that BCAAs aren’t nearly as beneficial as people think they are. In fact, they could actually be slowing the rate of muscle gain and may even have deleterious effects on overall health.
While the wrong kind of amino acid supplement can be detrimental to your well-being, the right kind can support your health and accelerate your fitness goals. Cue essential amino acids (EAAs). EAAs carry all of the benefits of BCAAs without any of the drawbacks, and the scientific literature backs them up as one of the best supplements you can take to optimize your athletic performance, recovery, and overall health.
But don’t just take our word for it – you’re about to learn what the science has to say about how EAAs can optimize your well-being.
What Are Amino Acids?
Amino acids are the building blocks of protein and serve as the catalyst for nearly every chemical process in the body. Most people associate amino acids purely with protein synthesis and muscle gain, but they’re also necessary for nearly every other physiological function, including enzyme production, hormone regulation, cognitive ability, neurotransmitter balance, and metabolism. There are 20 amino acids in total, and all of them are required to make these vital processes happen.
What Are the Essential Amino Acids (EAAs)?
Of the 20 amino acids, nine are classified as essential. Essential amino acids are the ones that the body can’t produce itself; they must be acquired through diet, specifically from protein-rich foods like meat, fish, and eggs, and of course, amino acid supplements. EAAs support the body in several critical ways:
- Lysine plays a role in growth hormone secretion, which supports muscle repair and recovery. It’s also a critical component of structural proteins like collagen and elastin, which are important for building strong connective tissue.
- Methionine helps the body process and eliminate fat, promotes cardiovascular health, and supports liver function to help the body eliminate toxins.
- Phenylalanine has a pain-killing and antidepressant effect and is necessary for the synthesis of norepinephrine and dopamine. It also stimulates the release of adrenaline and noradrenaline, which are critical for nervous system function.
- Threonine supports fat metabolism and immune function. Like lysine, it’s also a crucial component of structural proteins and connective tissue.
- Tryptophan is a precursor for serotonin, which regulates sleep, appetite, and mood. It also has pain-suppressing qualities and can increase pain tolerance during hard workouts or competitions.
- Leucine is critical for protein synthesis, blood sugar regulation, and growth hormone production.
- Isoleucine helps prevent muscle from breaking down during exercise, which could lead to faster recovery. It’s also important for immune function, hemoglobin production, and energy regulation.
- Valine helps stimulate muscle regeneration and is involved in energy production.
- Histidine is a precursor to histamine, which can help you fight off the cell-damaging free radicals you produce during exercise. It’s also a precursor to carnosine, which helps turn lactic acid back into useable fuel and reduce soreness. Histidine’s status as “essential” is debatable since it can be easily produced in the presence of the other essential amino acids.
What Are the Branched Chain Amino Acids (BCAAs)?
Three of the essential amino acids – leucine, isoleucine, and valine – are known as the branched-chain amino acids (BCAAs), named for their branched chemical structure.
The BCAAs are unique because they are metabolized in the muscle instead of the liver. This means that they’re available in the bloodstream soon after ingestion and can be used for quick energy during exercise. BCAA supplements are popular among athletes because they’ve been linked with increased muscle mass, decreased fatigue, and improved glycogen storage.
However, the supposed benefits of BCAAs are often embellished, misunderstood, and some even flat out wrong.
The Problem with BCAAs
A recent meta-analysis of research conducted between 1985 and 2017 revealed zero human studies in which BCAAs alone were responsible for more efficient protein synthesis or improved athletic performance.
In fact, the meta-analysis detailed two studies which found that BCAAs decreased muscle protein synthesis and actually accelerated the catabolic rate of lean tissue. This means that muscle was being broken down faster than it could be repaired.
The catabolic state was so aggressive in the presence of BCAAs because the body was rapidly trying to derive the other essential amino acids to complete protein synthesis. Without a complete profile of essential amino acids, the body was left with no choice but to break down muscle to derive the six that were missing.
In other words, BCAAs do not work in isolation; all of the essential amino acids are required to complete protein synthesis.
The study concluded that the idea that BCAA supplements stimulate muscle growth or produce an anabolic response is entirely unwarranted. And that’s just the beginning. In addition to being ineffective for building muscle or faster recovery, BCAAs can also have deleterious effects on overall health:
- High doses of BCAAs can deplete B vitamins. The utilization of BCAAs requires several B vitamin cofactors. This siphoning of B vitamins can disrupt the hundreds of other biological functions that require them including digestion, nervous system function, cognition, and hormone production.
- An overabundance of BCAAs can hinder serotonin production. The BCAAs and tryptophan both use the same carrier system to get to the brain. This means an overabundance of BCAAs will disrupt the brain’s uptake of tryptophan and therefore create a shortage of serotonin. Low serotonin can cause depression, anxiety, sleep problems, carbohydrate cravings, attention disorders, and more.
- BCAAs may cause insulin resistance and interfere with blood glucose regulation. Increased BCAA levels are associated with a high risk of metabolic disorder and insulin resistance, and may even predict the development of type 2 diabetes
Why EAAs Are Superior to BCAAs
Despite all of this, BCAAs are still essential for human health and actually serve as a good source of fuel for workouts.
They simply don’t build muscle in isolation.
You need adequate levels of all of the essential amino acids to optimize health and complete protein synthesis. Think of it this way: BCAAs begin the process of protein synthesis, and the other six EAAs complete the process.
This is why it’s best to choose supplements that contain all of the essential amino acids if you truly want to maximize performance, recovery, and well-being.
Health Benefits of Essential Amino Acids
What else are EAAs good for, other than packing on the muscle and gettin’ swole? Well, as it turns out, a lot of things:
- Muscle Maintenance: EAAs have significant muscle-preserving effects, especially when training in a fasted state. These include decreased indicators of muscle damage and the maintenance of a healthy inflammatory response.
- Exercise Recovery: Supplementing with EAAs post-workout increases muscle protein synthesis and net muscle protein balance. This may stimulate faster recovery and reduce fatigue after training.
- Appetite Regulation: Having a sufficient balance of amino acids may help normalize appetite because EAAs activate the brain cells that regulate hunger and satiety.
- Cognitive Function: Appropriate levels of tryptophan are necessary to produce serotonin and optimize cognitive performance.
- Improved Sleep: Amino acid supplementation has been shown to improve sleep and mood and reduce symptoms of depression.
- Metabolic Health: Proper ratios of amino acids could increase red blood cell count, hemoglobin, hematocrit, and serum albumin. They can also lower fasting blood glucose, support better red blood cell formation, and improve glycogen replenishment
- Fasting and Ketosis: Ingestion of high amounts of leucine triggers an insulin spike, which may “break a fast” and interfere with ketosis. However, this only happens when leucine levels aren’t balanced by the other EAAs, which help buffer the glycemic response. The insignificant insulin response from a supplement with the proper ratios of EAAs won’t interfere with fasting or ketosis, and might even make them easier!
The verdict is in: EAAs beat out BCAAs as the best amino acid supplement, and their benefits go far beyond building muscle. EAAs are a true nutritional powerhouse that can help you optimize your training, recovery, sleep, mood, and so much more.
What other questions do you have about EAAs? What’s the most interesting benefit you’ve experienced from them? Leave your comments, questions, and feedback below!