Marc S. Schneider, M.D.
Table of Contents
If you’ve just begun your fitness journey or you’ve been working out for a little while, chances are you’ve heard a few new acronyms and phrases that might sound a little foreign at first. One commonly referenced supplement in the health and fitness world is “BCAA”.
There’s a reason for the prevalence and popularity of BCAAs, which stands for branched-chain amino acids. We’re going to break down what they are, how they work, and why they benefit your health and fitness goals.
What Are BCAAs?
Branched-chain amino acids are the building blocks of protein. There are 20 different amino acids that you get from different parts of your diet – and branched-chain amino acids represent three specific amino acids that stand out due to their differing structure.
According to clinical nutritionist and personal trainer Autumn Bates, CCN, “Any complete protein will automatically have BCAAs. If you’ve had Greek yogurt, lean meats, or peanut butter on some whole wheat toast recently, you’ve already been consuming BCAAs.”
Amino acids are the building blocks of protein — there are 20 amino acids that you get from different parts of your diet. Branched-chain amino acids are a subgroup of three amino acids (“branched-chain” references their chemical structure): leucine, isoleucine, and valine. Each serves a different purpose, but together, they can help aid in muscular recovery.
Do BCAAs Work?
If BCAAs are present in food and play a role in protecting our body, why are BCAA supplements growing in popularity?
Here’s the catch — your body makes some amino acids (known as nonessential amino acids). But the body does not make BCAAs. This is why they must be consumed through the diet and supplementation.
So why do you need BCAAs? BCAAs can serve specific purposes metabolically and physiologically and can serve as a supportive supplement when you’re looking to reach certain goals. “Supplemental forms of BCAAs are isolated, concentrated forms of these particular amino acids,” says Bates.
How BCAAs work metabolically
Metabolically, BCAAs promote formation and turnover of proteins in all tissues. The proteins are used by the cells to build other proteins, enzymes, hormones and all the tools cells need to grow and be healthy.
BCAAs are also used in creating signaling pathways between cells. Glucose (sugar) is used by the body for energy, and BCAAs are used to drive the process. BCAA oxidation plays a role in the breakdown of fatty acids.
How BCAAs work physiologically
Physiologically, BCAAs take on roles in the immune system and in brain function.
BCAAs are broken down effectively by dehydrogenase and decarboxylase enzymes expressed by immune cells. They are required for lymphocyte growth and proliferation and cytotoxic T lymphocyte activity – which are key factors for the immune system.
Lastly, BCAAs share the same transport protein into the brain with aromatic amino acids (Trp, Tyr, and Phe). Once in the brain BCAAs may have a role in protein synthesis, synthesis of neurotransmitters, and production of energy.
The impacts of BCAAs can aid in many body activities like increasing muscle growth, decreasing muscle soreness and supporting immune function.
Benefits of BCAAs
BCAAs are mostly known to help with muscle recovery and have shown to decrease soreness after a strenuous workout. Think faster and more comfortable recovery, quicker gains, and fewer injuries.
Let’s break down the details on each of the three different BCAAs: leucine, isoleucine, and valine.
- Leucine. Leucine is a branched chain amino acid that helps your muscles grow. Additionally, leucine can aid immune function and the body’s immune response to pathogens.“Leucine is generally the limiting factor when it comes to muscle synthesis,” says Bates. “Leucine is needed to stimulate protein synthesis in muscle tissue. Without leucine, muscle growth may not be as effective.”
- Isoleucine. Isoleucine is found in similar food sources as leucine. It increases levels of β-defensin, an antimicrobial compound, in the body. Isoleucine supplies energy to the muscles, thus increasing endurance.
- Valine. Valine can support your nervous system and liver. One study from the American Journal of Gastroenterology found that BCAAs may reduce hepatic encephalopathy — the loss of brain function due to cirrhosis of the liver or poor liver function.
Valine increases the cell functions that regulate the immune system and signal the presence of toxic substances in the body to the immune system.
Here are some functions that BCAAs have shown to support:
Increased Muscle Growth
BCAAs are best known for their use in building muscle and strength. Your body uses BCAAs to support muscle protein synthesis – the process through which your body build muscle.
Muscle protein synthesis (MPS) is the process where muscle cells are stimulated to produce proteins that increase cellular growth. This is typically stimulated by eating a meal containing protein. MPS is the way in which muscles repair themselves after microtrauma and also the way that they grow and add size and strength.
Within the protein that you eat is an amino acid called leucine that provides much of the stimulus to the cell to kick muscle protein synthesis into gear. Leucine is one of 3 aminos called branched chain amino acids that work better together at stimulating MPS than they do individually.
When you eat a protein that is low in BCAAs (most plant proteins except for soy), the amount of MPS that is stimulated is low. But, when you eat a protein that is high in BCAAs, MPS gets really stimulated.
Animal proteins are high in BCAAs. Whey is also high in BCAAs. This means that supplementing with BCAAs allows you to add an even bigger dose of BCAAs to your system than food alone can produce.
Preventing Muscle Protein Breakdown
The Journal of Nutrition published a study in 2004 that pointed to BCAA’s ability to decrease “exercise-induced muscle damage, promoting muscle-protein synthesis.”
“Since muscles are constantly in a state of breaking down and rebuilding, all of the amino acids must be present in adequate amounts in order to synthesize new muscle protein,” says Letchford. She noted that as a former vegan, she herself used BCAA supplementation to ensure she got enough of her essential amino acids.
“In order to gain muscle, the rate of protein synthesis must be faster than the rate of muscle protein breakdown,” Letchford said. To outpace the breakdown, consider using BCAA supplementation.
Decreased Muscle Soreness and Aided Recovery
Working new muscles or intensive training can lead to muscle soreness that lasts for days.
A 2006 study published in the Journal of Nutrition notes, “BCAAs before exercise can reduce delayed onset muscle soreness (DOMS) and muscle fatigue for several days after exercise.” Supplementing with BCAAs before and after workouts can bring less muscle breakdown and less damage post exercise.
Aiding muscle recovery is a top reason many athletes supplement with BCAAs. Whether you’re training for a race or another kind of endurance event in which the training leaves you feeling brutalized day in and day out, BCAAs help many athletes push through.
“If you want a higher metabolism, you’ve got to hang on to as much muscle as possible,” says Letchford. “In order to hang onto that muscle, you’ve got to ensure the building blocks of muscle are readily available in your bloodstream.”
Holding onto these building blocks equates to having consumed a solid base of BCAAs. BCAAs have been shown to regulate the stress hormone, cortisol. This impact could contribute to an increase in muscle mass, which increases your resting metabolic rate.
How Are BCAAs Different From Other Supplements?
Walk into your local supplement store and you’ll see many different products boasting numerous benefits for your health and workouts.
With so many supplements to choose from, how can you differentiate? We’re sharing the differences between BCAAs and other common supplements you find on store shelves.
BCAAs vs. Whey Protein
As mentioned, BCAAs are building blocks of protein, but the macronutrient protein has an array of different amino acids within it, including BCAAs. “Whey protein is a complete protein, which means that it contains all essential amino acids, including BCAAs,” says Bates. “So by having whey, you’re also having BCAAs.”
What is whey? “The liquid left after milk curdles,” says Letchford. “It contains 15-20 percent of the total protein in milk. This protein contains essential amino acids and is readily absorbed by the system.”
BCAAs vs. Glutamine
Glutamine is actually an amino acid, like leucine, valine, and isoleucine — but because it naturally occurs in your body, it is not branched. Though glutamine is not an essential amino acid.
Bates says, “it can become conditionally essential, which means your body temporarily isn’t able to make it (or make enough) depending on certain stressors or illnesses.”
When athletes are tested on micronutrients, many are found to be deficient in glutamine. Why? Because exercise tends to cause glutamine deficiencies, that can lead to cognitive impairment (lack of focus, lack of motivation), impaired digestion, mental and physical fatigue, and increased inflammation.
BCAAs vs. Creatine
BCAAs and creatine are both derived from amino acids. So, how do they differ?
While BCAAs are not made in our bodies – creatine is. Creatine, which is found mostly in our muscles, consists of the amino acids arginine and methionine. According to Bates, “Creatine is a non-essential amino acid that is used to provide energy in the form of phosphate bonds for very quick, explosive movements. Your body makes its own creatine in the liver.”
Creatine is a fantastic supplement for producing increased energy supply for the muscle. It increases muscular ATP. ATP works in the same manner that gasoline works in your engine.
The more a muscle is able to work, the greater it will be prepared for turning on muscle protein synthesis. BCAAs fill a different role. They are used by the muscle to initiate the repair and build process. Creatine and BCAAs work differently, but when stacked together, they form a potent combination for fitness, athletic recovery, and performance.
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How To Consume BCAAs
There are easy ways you can incorporate BCAAs into your diet. Incorporating BCAA supplementation with BCAA-high foods can give you an optimal amount of BCAAs to support your well-being.
BCAAs in Food
Consuming complete proteins in your regular diet will ensure you get healthy amounts of branched-chain aminos. Some examples of foods high in BCAAs are:
- Whey and milk protein
- Dairy products and eggs
- Lean beef
- Soy protein, edamame, tofu
- Beans and legumes (lima beans, chickpeas, and lentils)
- Peanut Butter
- Whole wheat bread
- Brown rice
- Brazil nuts, cashews
- Pumpkins seeds
BCAAs in Supplements
Since the body doesn’t produce BCAAs on its own, supplementing with BCAAs is a fantastic method for consuming optimal BCAAs to stimulate muscle building.
If you’re a vegan or vegetarian, it can prove particularly difficult to get the right amount of BCAAs in your diet — especially if you’re an athlete. Vegans who have a soy intolerance have an even tougher time, leading some athletes to a daily dose of BCAA powder before a workout.
The benefits don’t stop for omnivorous athletes. BCAAs are a powerful supplement for people looking to increase muscle quickly or cut down on soreness during a time of intense training.
Ensure that your BCAAs are in a 2:1:1 or 3:1:1 ratio of leucine, isoleucine, and valine. Opt for supplements without added sugar. Use a raw/unflavored powder to add into smoothies, or opt for a fruity flavor to create your own healthy sports drink.
BCAAs are building blocks (amino acids) of protein — leucine, isoleucine, and valine — that are not inherently manufactured by the body and thus must be consumed from diet and supplementation.
Because BCAAs make up 35% of the essential amino acids in muscle protein, consuming the right amount of these amino acids can bring many benefits to our overall health.
BCAAs have been shown to increase muscle growth, help recovery, assist weight loss, and support immune functions. Make sure you’re taking in a solid amount of BCAAs in your diet, as well as supplementing with BCAA to help reach your wellness goals.