Conditional Essential Amino Acids: Benefit, Deficiency, Side Effect and Food Contain It

conditional essential amino acid benefit deficiency side effect and food contain it -Essential amino acids are needed to maintain proper function within our body. However, there are also other amino acids that the body may need a small amount of it since they also have specific benefits for our health called conditional essential amino acids. In fact, several types of these amino acids can be self-made within our bodies. However, in some conditions such as deficiency or disease complications are needed an external source to keep up with body needs. How to have enough of this substance for our body? Don’t worry, meat and egg are common foods that are rich in this compound.

We overview conditional essential amino acids in this article as beneficial information to maintain health and prevent its deficiency before happened. Check it and you would know why is also as important as essential amino acids.

Conditional Essential Amino Acid

The amino acids in this category have specific contributions and some of them also can be produced in the body. However, the certain condition could affect their level within the body such as take medical or surgical treatment and genetic disorders [1]. Here are amino acids that could be categorized as conditionally essential amino acid as follow:


cysteine is good to prevent early aging

This protein is important to make skin tissue, hair, and even nail. It also has an important role in collagen production. If you have enough of this protein, it can improve skin elasticity and prevent early aging. Studies also believe that cysteine has antioxidant content to protect skin cells from being damaged by free radical scavengers.

The cysteine-based dressing also could be used to improve healing wounds in post-surgical treatment [2]. As further information, the amount of cysteine is related to the number of antioxidants in the liver since it is the main component of glutathione and taurine. Moreover, it also contributes to helping other functions such as treating lung and cardiovascular disease.

Deficiency of cysteine

There is a small case of this protein deficiency since it can be produced within our bodies. The deficiency could occur in some conditions such as decreased immune and toxin regulation function. Moreover, a long-term deficiency could cause wrinkles at an early age or even premature white hair. However, it is still being researched to find out the main cause besides cysteine deficiency.

The side effect of cysteine

cysteine also has a supplement form to treat cysteine deficiency or to improve skin health. However, too much of it could disturb metabolism in the body. Moreover, it also causes problems in the kidney and may lead to having stones kidney. Excessive consumption also has a degenerative growth effect in children. Don’t take any medication with this protein if you have diabetes or cystinuria disease.

Natural Food rich in cysteine compound

Foods that contain cysteines such as meat like turkey and its eggs. There are also other sources such as nuts (chickpeas, walnut, lentils) and wheat-based food (oats and whole grain).


tyrosine is important component to make thyroid hormone to maintain body's function

Tyrosine is commonly used to make other functionalize proteins such as thyroxine, an important thyroid hormone to maintain several functions within the body. Children need enough of it to grow properly. This amino acid also could be made by another amino acid such as phenylalanine. This substance also can help melanin production to enhance skin health.

The other benefit of tyrosine is to control stress and other related neurological systems because this amino acid could affect neurotransmitter hormones such as dopamine and adrenaline [3]. Moreover, consuming tyrosine supplements could relieve depression symptom, based on some studies. Furthermore, it also could treat people with phenylketonuria disease.

Deficiency of tyrosine

Tyrosine deficiency is commonly related to other forms of it, tyrosine hydroxylase. This deficiency could be detected in childhood and it is also a rare disease that occurs caused by mutation genetic from their parent.

Tyrosine hydroxylase deficiency could deplete dopamine or adrenaline hormone and reduce nerve function within the body. The symptom is more like have neurodegenerative diseases such as seizure, abnormal eye, leg, or hand movement, and tremor.

The side effect of tyrosine

There are also side effects of consuming tyrosine supplements that could vary depending on each individual such as heartburn, fatigue, nausea, and muscle ache, especially in the tendon area. Graves disease or hyperthyroidism are common diseases that could occur caused by too much tyrosine in the body that make excess thyroid hormone and inflate the thyroid gland. Reducing food containing tyrosine may slightly relieve its symptoms.

Food that contains tyrosine

Typical poultry food like chicken, turkey, and their eggs are the best source of tyrosine. However, other food like soybean, peanut, pumpkin seeds, sesame seeds, banana, avocado, and fish also contain a moderate amount of it. For children, this compound is important to their growth health. So, a fortified supplement could be added to their meal to make it more healthy.


glutamine could be used as energy source during exercise

This amino acid falls into conditional essential amino category acid because it uses in several important functions and could be self-produced within the body. Some essential functions of this amino acid such as regulated toxic substances like ammonia to the kidney and balancing pH in that place, serving as an energy source, controlling nitrogen level in the blood, and producing mucus as lining coating in the digestive tract.

Some studies find that glutamine levels could control or suppress cancer cell development because cancerous substances need this amino acid as an energy source to invade the body [4]. Moreover, this amino acid could relieve cancer symptoms like reducing inflammation, easing vomiting, and alleviating nausea. Furthermore, controlling glutamine intake also improves growth in babies and promotes healing.

Deficiency of glutamine

It is a rare case to have glutamine deficiency unless having a genetic disorder such as congenital glutamine deficiency. This condition has impaired glutamine synthetase within the body. Moreover, some cases could cause a lack of glutamine such as infection, immune disorders, overwork exercise, and have chemotherapy treatment.

Alcoholics are also prone to this deficiency since alcohol level in the blood has raised and disturbed liver metabolism to make ammonia. Moreover, if this condition isn’t treated well, it causes symptoms like vomiting, nausea, chronic hangover, and lead damaging the liver and kidney.

The side effect of glutamine

Taking glutamine supplements for a long time could lead to a serious condition since it isn’t normal intake for the body and became addicted to eating it in high consumption. If you cease the supplement in that state, your body would possess some risky disease especially related to bowel movement.

Other severe side effects also could occur if have too much glutamine such as dizziness, irregular heartbeat, change color in urine (might contain blood in it), and have muscle pain, especially in the backbone area. You should control glutamine intake if you don’t have these symptoms happen to you.

Food that contains glutamine

Our routine daily intake is enough to have glutamine since it is commonly found in meat and dairy products such as beef, chicken, fish, and eggs. Legumes also have high in glutamine such as lentils and beans. Moreover, vegetables like kale, spinach, carrot, cabbage, beet, etc, also have this amino acid in small to moderate amounts.


arginine have benefit to reduce high blood pressure

The main function of arginine is to build some protein that is necessary to keep the body stay healthy. During protein synthesis, it also makes nitric oxide within the blood vessel and loosens it to help blood circulation and maintain blood pressure. There is also some information to reduce high blood pressure with various food that may have arginine inside of them.

Although it mainly functions in cardiovascular function, arginine also has myriad functions such as repairing wounds, reducing inflammation, regulating blood sugar, and improving fertility in males [5]. Some researchers believe that taking arginine supplements could treat people with anxiety and kidney disorder.

Deficiency of arginine

We may doesn’t have this deficiency since it is present in our daily meals. However, some genetic conditions may trigger this deficiency. People with arginase deficiency may have built up ammonia in the blood and couldn’t release it. A high concentration of ammonia could affect the nervous system and cause symptoms such as tremors, seizures, slower growth development, and even intelligence decline could occur.

The side effect of arginine

Excessive arginine is linked to gout disease since mineral build-up could occur. Moreover, too much consume arginine can cause nausea, fatigue, headache, and gastrointestinal disorder such as bloating or even diarrhea. In some cases, this condition also could trigger asthma and inflame the lining of the respiratory tract.

Food that contains arginine

Naturally, food like red meat, eggs, and fish contain the highest arginine component besides other food. However, if you are a vegan person, you also can consume high arginine food in seeds, nuts, and whole-grain products to fill up your needs.


keep enough proline compound within your body could keep your young appearance

Proline is usually come together with lysine or glycine that contributes to collagen production. It also helps skin regeneration and improves its elasticity. Moreover, collagen can be found in other muscle tissue such as joints and bones [6]. Keeping enough proline within your body could speed up the healing process and retain your young appearance since it also has an anti-aging effect. Besides it uses for skin health, it also has benefits to treat fatigue and induce deep sleep. However, its lack of evidence for proof this benefit

Deficiency of proline

There are almost no cases of lack of proline substance since the body could make it and dairy meal also contain adequate proline. However, people with hyperprolinemia could have proline deficiency. This condition has impairment proline synthesis that makes proline can’t be broken down properly and build up in blood vessels. Moreover, the symptom could occur such as seizures and neurological disorders.

The side effect of proline

If someone has high proline in their body, it may have the same symptom as hyperprolinemia do such as cognitive disorder and seizure. There are no cases of intoxication caused by proline supplement since it usually applies to the skin as dressing. However, if it accidentally being ingested, it might have an effect on the stomach like vomiting and nausea.

Food that contains proline

If there is food with high gelatin content, it also has high proline. Gelatin generally has two main components, glycine, and proline. Moreover, gelatin is commonly found in livestock such as cows, chickens, goats, etc. Other sources of proline also can be found in vegetables (spinach, cabbage, mushroom, and asparagus), seeds (sunflower seeds), and spirulina (seaweed).


gelatin contain glycine that good for skin health

As we mentioned before, Glycine and proline are also commonly found together and have a similar function in skin health [7]. Moreover, studies found that this amino acid has other functions to improve growth cells and contribute to making antioxidants such as glutathione. furthermore, it could have the benefit to promote better sleep, providing muscle strength, and protecting the liver from oxidative stress. However, this claim needs further research to prove it.

Deficiency of glycine

In rare cases, people with glycine synthase deficiency couldn’t break down glycine properly and build up glycine in the body. This condition could be worse and lead to damaged brain function. In fact, this disease is genetic and rarely occurs unless has a parent that has the same condition. Seizure, irregular jerking movement, and neurodegenerative disorder sometimes could occur.

The side effect of glycine

You can find glycine supplements that could be used to improve muscle training. However, some people may overconsume it and cause side effects from it. The symptom if you have too many glycines such as stomach upset, nausea, and vomiting.

Food that contains glycine

The biggest glycine content is in the meat since its abundant in gelatin. However, you can have enough glycine by eating tofu and tempeh because these foods also have adequate glycine to keep the body’s needs. If you don’t like both of them, you can consume nuts and seeds that also have a medium amount of glycine.


Conditional essential amino acids are specific purpose amino acids that can be produced in the body. However, it still needs an external source since some specific conditions may doesn’t be enough of it. Moreover, some crucial functions such as maintaining or reducing high blood pressure and retaining skin health are several jobs of this amino acid to take care of the body.

Even though essential amino acids are one factor the body needs to maintain its function, conditional essential amino acids can complete other tasks and secure essential functions within the body. There are also other amino acids that may have several beneficial effects to keep our body stay healthy.

In the next article, we explore non-essential amino acids and find out why it is still be needed in our body.


[1] – Amino acid in general

[2] – cysteine compound that used to treat a wound

[3] – tyrosine compound for stress relief

[4] – glutamine metabolism and benefit for health

[5] – Arginine benefit and safety

[6] – Proline metabolism in animal and human

[7] – Benefit of Glycine as non-essential amino acid


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