Compounds that are often referred to as the building blocks of proteins, amino acids play several important roles in your body.

These compounds are necessary for the synthesis of hormones and neurotransmitters, building of proteins, and other vital processes. Taken in supplement form, they help improve mood or boost athletic performance.

Depending on several factors, they are categorized as conditionally essential or non essential.

Here we will tell you everything you need to know about essential amino acids, including amino acid benefits, amino acid functions, and possible food sources.

What are essential amino acids?

Composed of oxygen, hydrogen, nitrogen, and carbon, along with a variable side of the chain group, amino acids are organic compounds that are essential for your body to grow and function properly.

Your body needs 20 amino acids; however, only 9 of them are classified as essential: leucine, lysine, histidine, phenylalanine, isoleucine, tryptophan, methionine, valine, and threonine.

Essential amino acids are different from non essential amino acids, which can be made by your body. You must obtain them through your diet.

Poultry, eggs, and meat are just some of the best sources of essential amino acids.

The proteins that you consume are broken down into amino acids, which are then used to help your body regulate immune function, build muscle, and other essential processes.

Conditionally essential amino acids

Several non essential amino acids can also be classified as conditionally essential under specific circumstances such as stress or illness.

For instance, arginine is classified as non essential; however, your body can’t meet demands when fighting with cancer or any other diseases, necessitating supplements through diet to meet your body’s needs in certain situations.

Functions of essential amino acids in your body

The nine essential amino acids have several and various functions in your body:

Methionine: Methionine helps in detoxification and metabolism. In addition, it is vital for the absorption of essential minerals, such as selenium and zinc, as well as for tissue growth.

Leucine: A branched-chain amino acid, leucine is essential for muscle repair and protein synthesis. Moreover, it also stimulates wound healing, helps regulate blood sugar levels, and produces growth hormones.

Valine: Having a chain branching off to one side of its molecular structure, valine is one of three branched-chain amino acids. It is also involved in energy production and helps stimulate muscle growth and regeneration.

Isoleucine: Involved in muscle metabolism, isoleucine is heavily concentrated in muscle tissue. This is the last of the three branched-chain amino acids and is vital for hemoglobin production, energy regulation, and immune function.

Phenylalanine: A precursor for the neurotransmitters dopamine, tyrosine, norepinephrine, and epinephrine, phenylalanine plays a key role in the production of other amino acids as well as the function and structure of proteins and enzymes.

Threonine: Threonine plays a role in immune function and fat metabolism. It is also a principal part of structural proteins, including elastin and collagen, which are essential components of the skin and connective tissue.

Tryptophan: Although tryptophan is often associated with causing drowsiness, it has various essential functions. It is a precursor to serotonin, a key hormone regulating your sleep, appetite, and mood. Moreover, it is also needed to maintain proper nitrogen balance.

Lysine: A building block for protein, lysine plays key roles in hormone and enzyme production, calcium absorption, and protein synthesis. It’s also vital for collagen and elastin production, energy production, and immune function.

Histidine: Used to produce histamine, a neurotransmitter involved in digestion, sleep-wake cycles, sexual function, and immune response, histidine is vital for maintaining the protective barrier surrounding your nerve cells—the myelin sheath.

Essential amino acids, which are most recognized for their role in muscle repair and development, play key roles in many vital processes. Your body is dependent on them for so much more.

Thus, essential amino acid deficiencies can adversely affect your entire body including your immune, digestive, nervous, and reproductive systems.

Health benefits of using essential amino acid supplements

Essential amino acids are found in many foods, but taking concentrated doses in supplemental form has been found to result in several health benefits.

It may help improve sleep and mood

Tryptophan is involved in the production of serotonin—a neurotransmitter needed in mood, behavior, and sleep regulations.

Low levels of serotonin have been found to cause sleep disturbances and depressed mood. Several studies have found tryptophan supplementation to boost mood, reduce symptoms of depression, and improve sleep.

In fact, a 19-day study in 60 older women suggested that taking a 1-gram tryptophan every day resulted in improved happiness and increased energy, compared to a placebo.

It may lead to weight loss

Branched-chain essential amino acids have been found in some human and animal studies to be effective in stimulating fat loss.

For example, supplementing with a 14-gram branched-chain amino acid every day has been found in an eight-week study in 36 strength-trained men to significantly reduce body fat percentage, compared to a sports drink or whey protein.

However, other studies on the potential link between weight loss and branched-chain amino acids have been inconsistent, necessitating further studies.

It may boost exercise performance

The three branched-chain essential amino acids are commonly used to stimulate muscle recovery after exercise, improve athletic performance, and alleviate fatigue.

In fact, a study in 16 resistance-trained athletes found branched-chain amino acid supplements to reduce muscle soreness and improve performance and muscle recovery, as compared to a placebo.

It prevents muscle loss

Prolonged illnesses and bed rest can cause muscle loss, especially in older adults. Essential amino acids help preserve lean body mass and prevent muscle breakdown.

A 10-day study in older adults on bed rest found that a 15-gram consumption of mixed essential amino acids maintained muscle protein synthesis.

Food sources and recommended dosage intake of essential amino acids

Since essential amino acids cannot be produced by your body, you must obtain them through your diet.

Good thing, there are several foods rich in essential amino acids, so you can easily meet your daily needs.

The US recommended daily allowances for every 1 kg of body weight for histidine is 14 mg; isoleucine is 19 mg; leucine is 42 mg; lysine is 38 mg; threonine is 20 mg; tryptophan is 5 mg; valine is 24 mg; methionine (+ the non essential amino acid cysteine) is 19 mg; and phenylalanine (+ the non essential amino acid tyrosine) is 33 mg.

Foods rich in all nine essential amino acids, such as meat, seafood, poultry, eggs, and dairy products, are referred to as complete proteins.

Plant-based foods containing all nine essential amino acids include buckwheat, quinoa, and soy; they are complete protein sources as well.

Beans, nuts, and other plant-based sources of protein that lack one or more of the essential amino acids are considered incomplete.

If you’re following a plant-based diet, eating a variety of plant proteins each day can help you ensure proper intake of all essential amino acids.

For example, you can eat a variety of incomplete proteins like seeds, nuts, beans, vegetables, and whole grain to ensure that you meet all your essential amino acid needs, even without eating animal products.

Conclusion

Essential amino acids are vital for several body functions, including nutrient absorption, protein synthesis, and tissue repair. Some may also promote weight loss; improve athletic performance, sleep, and mood; and prevent muscle loss.

You must get through your diet all the nine essential acids: leucine, histidine, isoleucine, lysine, threonine, tryptophan, methionine, valine, and phenylalanine.

Fortunately, these essential amino acids are found in several plant- and animal-based foods, including buckwheat and meat, which makes it easier for you to meet your daily needs.