If you’re on a mission to improve your muscle tone or overall health, you may have heard a little something about amino acids. But what exactly are they? And, is it necessary to take amino acid supplements to get their benefits? To find out, we asked nutritionist Jo Woodhurst, director of nutrition at British supplement brand Ancient+Brave. Read on for everything we learned. And, spoiler alert: Amino acids might just be exactly what the doctor ordered—as long as you keep a few key factors in mind.
What are amino acids?
Amino acids are absolutely essential to our health—and for life itself. They are the so-called “building blocks” of proteins. They play a key role in the growth, repair, and maintenance of almost every body tissue and system, including energy production, muscle growth, regulation of the immune system, metabolism, and mood, and the production of enzymes, hormones, collagen, and elastin.
You can think of amino acids as a bit like the letters of the alphabet, with each amino acid serving a unique role. When strung together in certain combinations, amino acids form peptides and proteins—much like letters form words and phrases. Some of these proteins and peptides support the production of hormones; some, the synthesis of neurotransmitters; others, the metabolic processes.
For example, both collagen and keratin are composed of amino acids, and are thus essential for the strength, elasticity, and structure of the skin, nails, and hair. These tissues are constantly regenerating and depend on a constant supply of amino acids to maintain elasticity and vitality.
What are essential amino acids?
Our body needs 20 different amino acids to function. Of those 20, nine are considered “essential” amino acids (EAAs) because the body doesn’t make them naturally. Instead, these nine essential amino acids must be consumed via food.
Each amino acid has different functions. When combined into a protein, the role expands further. The human body is believed to contain between 10,000 and 50,000 different proteins—each with a unique purpose, including:
- Structural materials such as muscles, skin, blood, ligaments, tendons, bones, collagen, and the walls of intestines and arteries.
- Enzymes that catalyze reactions essential for digestion, energy production, and detoxification.
- phenylalanine
- isoleucine
- histidine
- leucine
- lysine
- methionine
- threonine
- tryptophan
- valine
What foods contain essential amino acids?
Essential amino acids cannot be produced by the body and must be consumed from the foods we eat. Luckily, plenty of foods that contain essential amino acids:
- Fish
- Meat
- Poultry
- Eggs
- Milk and dairy products
- Soybeans and derivatives (tofu, tempeh, miso)
- Quinoa
- Buckwheat
- Hemp seeds
- Peanuts
- Peas
What are the non-essential amino acids?
If nine of the 20 amino acids can’t be made by the body naturally, that means the remaining eleven amino acids can. As you may have guessed, these eleven are thus called “non-essential amino acids”—not because they aren’t necessary, but because the body needs them conditionally, like during times of stress, illness, or intense physical demands such as pregnancy.
The eleven non-essential amino acids are alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, and tyrosine.
When to take essential amino acid supplements
It should go without saying that it’s important to consume enough protein through food from a variety of plant and animal sources in order to cover the full spectrum of necessary nutrients—including amino acids. That said, taking isolated amino acids (such as tryptophan, taurine, or glutamine) can have powerful effects on neurotransmitters, metabolism, and even immune responses.
That said, it’s important to note that because amino acids compete for absorption, taking an isolated amino acid supplement long-term can create imbalances. Therefore, supplementation should be targeted and professionally guided and is only recommended when:
- You’re experiencing an increase in physical demand or have a particularly active lifestyle, as in the case of athletes and professional athletes.
- You’re recovering from injury or surgery.
- You want to support specific wellness goals such as improving gut health, skin repair, cognitive support, or sleep. In this case, it is recommended to opt for a combination of amino acids like creatine, a compound that’s derived from amino acids (and extremely well researched, safe, and effective) or collagen peptides, which provide a specific blend of amino acids to support skin, joints and connective tissue. These “complexes” contain amino acids in proportions and forms that the body recognizes and can use efficiently.
Remember, for a targeted and personalized approach to amino acid intake, it is always advisable to consult a specialist or medical professional.
Single amino acid supplements
- Glycine: Promotes sleep and relaxation.
- L-Glutamine: A “gut repairing” amino acid critical for intestinal mucosal restoration.
- Tryptophan: Helps regulate and improve mood.
- L-Theanine: A non-protein amino acid naturally found in green tea leaves and matcha not used to build protein in the body. Instead, it has powerful neuromodulatory effects—especially on mood, concentration, and stress response.
Complex amino acid supplements
- Creatine: A peptide of glycine, arginine, and methionine, creatine is widely studied for physical performance, strength, and cognitive health. Women in particular may benefit from this supplement.
- Collagen: A chain composed of repeated patterns of amino acids: its structure gives skin, joints, and tissues strength and flexibility.Look for hydroloyzed collagen peptides, which are already broken down into smaller chains of amino acids making them easier for the body to digest and absorb. Once in the bloodstream, they act as building blocks for the formation of new collagen, and signal cells to increase collagen production.
- BCAAs: These “branched-chain amino acids”—the three essential amino acids of valine, leucine, and isoleucine—are prized by athletes for their ability to improve athletic performance, relieve fatigue and muscle soreness after intense exercise, and reduce recovery time. They are also used after surgery because they support post-surgery recovery, help the body after injuries such as fractures, or in cases of muscle mass loss.
- EAAs: Several supplements offer all the essential amino acids and are recommended for those who do not consume enough EEAs through their diets—like vegetarians and vegans—and for athletes who want to maintain or improve muscle mass, for those who do work that requires physical exertion, or for those who want to prevent decreased muscle mass or sarcopenia because of restricted diets or advanced age.
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