L-Arginine, a very important amino acid

The benefits of arginine for the cardiovascular system have been scientifically proved. In fact, its intake is usually advised to prevent cardiovascular diseases.

What is Arginine?

It is one of the most versatile amino acids when it comes to its properties and metabolic functions. Actually, apart from its popular function as a nitric oxide precursor, arginine is also involved in the synthesis of polyamine, proline, glutamate, creatine, agmatine and urea.

The studies performed both in human and animals have proven that the exogenous arginine support can provide many positive effects. Above all, it plays a fundamental role in a series of cell functions, including muscle growth, fat loss, liver detoxification and better immune system.

Moreover, it is indispensable for the heart and blood vessels. Arginine ensures a healthy blood pressure, improves the erection and sperm production, while supporting muscle growth and agility.

Unfortunately, we do not meet the requirements of this amino acid for our body.

Moreover, there are specific situations such as growth periods and pregnancy, diseases, or physical exercise, that can increase the arginine demands.

Arginine Supplements

Despite having many vegetable and animal sources of this amino acid, more and more athletes are choosing powder or capsule supplements. This is due to the fact that it can improve the physical performance and stimulate the muscle growth.

Arginine amino acid

L-arginine is a conditionally essential amino acid: it is essential essential during childhood, while it becomes non-essential in adulthood. However, this amino acid has more benefits for other periods and stages that we are going to discuss now.

The hemostasis of the plasma l-arginine levels will depend on the amount of said amino acid that we eat from the diet, its synthesis and metabolism.

Functions of arginine

Arginine or L-arginine is a conditionally essential amino acid produced by the body from the food we eat. Its main natural sources are nuts, legumes, meat, fish, eggs and dairy products

Effects of arginine

Without arginine, our body cannot produce nitric oxide, which is vital to perform many tasks in the organism.

For example, some of these essential functions are the vasodilation, reducing platelet clumps and the neurotransmission in the brain.

In addition, it stimulates the collagen synthesis and improving the wound healing. It also plays an essential role in the detoxification of the body while ensuring the ammonia elimination through the urine.

Importance of arginine

it has a series of properties related to many benefits that are important for our health. Currently, it is one of the most sold sport nutrition products in the world. The main reasons why it is so important are due to:

It can relieve some of the following symptoms: obstructed arteries, chest pain or angina pectoris, possible coronary failure.

Therefore, one of the most important effects of arginine is its ability to improve the blood flow. Consequently, it will improve the heart response, reducing the effort of each heartbeat. Another effect of improving the blood flow would improve the sexual function and treat cases of erectile dysfunction.

NO (nitric oxide) increases the diameter of the blood capillaries

Benefits of arginine

Arginine can be used for:

Where is arginine?

The endogenous arginine synthesis mainly occurs in the kidneys. There, the body synthesizes it from citrulline, which is released by the small bowel later on.

The liver can also produce a considerable amount of arginine. However, it tends to be re-used for the urea cycle, which is why it will not increase the blood plasma levels.

Types of arginine

There are many types of arginine that will vary depending on the absorbability and effectiveness that we are looking for.

Arginine Alpha-Ketoglutarate (AAKG) is a combination of the amino acid with alpha-ketoglutarate (AKG). This is a molecule from the Krebs cycle, also known as the citric acid cycle.

The Krebs cycle is a process that produces a metabolic pathway through different chemical reactions produced by cell breathing. Above all, this process is responsible for the energy release of the organism. Moreover, said process is truly important for the oxidation of macronutrients such as carbohydrates, fats and protein.

Therefore, binding alpha ketoglutarate with the amino acid arginine will have more absorbability than other types.

Arginine Alpha-Ketoglutarate AAKG

Nitric oxide is responsible for the dilation of the blood vessels. Therefore, it improves the absorption of blood in the muscle, as well as in the remaining organs. Moreover, it contributes to the nutrient supply to the body, which enhances the muscle growth, strength and resistance.

For the nitric oxide synthesis, arginine also stimulates this process through the nitric oxide synthase cytoplasmic enzyme (NO Synthase).^[1]

Sport performance

Taking a L-arginine alpha ketoglutarate supplement (AAKG) could increase the Krebs cycle flow, enhancing the acetyl-CoA oxidation.^[3]

In addition, alpha ketoglutarate supplementation can help us save glutamate in the body. This is important since AKG can be recharged through the glutamate transamination. Said amino acid is necessary for protein anabolism apart from being an important neurotransmitter.^[4]

Therefore, alpha ketoglutarate supplementation has ergogenic, neurological and metabolic properties.

Wound healing

Alpha-Ketoglutarate (AKG) increases the levels of glutamine and arginine, which are involved in the immune response.

Consequently, another property of AAKG is its ability to produce amino acids that have immunomodulating properties, specially to treat burns.^[5]

Arginine and hair loss

Once again, nitric oxide produces this benefits by increasing the blood flow to the scalp. This will open the potassium channels, stimulating the hair growth from the root.

Arginine as sport supplement

It has other benefits that can be very useful, even though their are not directly connected to bodybuilding. For instance, arginine enhances the immune system, reducing the risk of suffering an injury due to an intense workout. This is due to the fact that this type of workout tends to weaken our defenses, so we are more vulnerable against any external agent.

Arginine can also increase the muscle resistance during the workout. Moreover, it enhances the transport of important nutrients like amino acids or glucose to the muscle tissues that are being used.

Sources of arginine

Those foods that contain arginine are wheat, walnuts, raisins, soy seeds, grapes and chocolate. In addition, the supplements of this amino acid are available in powder, capsules or liquid format.

Another source of l-arginine is seafood, including blue crab, Alaskan king crab, lobster, shrimp, crab, molluscs, orange roughy, tuna, tilapia and cod.

Sunflower seeds, pumpkin seeds and soy beans also contain l-arginine, as well as spinach, mustard leaves, mung bean and watercress.

Beef, pork, lamb and poultry also have different amounts of l-arginine.

Sources of arginine in vegetable and animal foods

Symptoms of an arginine deficiency

Dose and intake of arginine

We can take arginine during the day with the different meals to increase the blood plasma levels. However, we can concentrate the dose in two important moments in order to enhance the performance and improve the recovery.

Arginine before training

Athletes tend to take between 3 and 5g of arginine daily as part of their pre-workout supplementation. Consequently, it will shorten the recovery of the damaged muscles and enhance the muscle growth.

Moreover, it increases the blood flow even more, which will improve the nutrient supply to the muscles.

Arginine before sleeping

If you want, you take it before going to bed to enhance the GH production (Growth Hormone) while you sleep. Some people have experienced benefits from taking arginine before going to sleep, specially for tired legs.

Fitness enthusiasts also look for an esthetic effect with really defined muscles, to the point that you can see their veins if they have a low fat percentage.

Side effects of arginine

Arginine supplements can worsen the symptoms of sickle-cell disease. Moreover, it can increase the blood sugar levels which is why people who are taking medicines to control them should not take this supplement.

We suggest consulting your doctor before taking any supplement, specially if you are taking some medication.

What do the experts think about arginine?

Medicine Nobel Prize

The scientists Robert F. Furchgott, Louis Ignarro and Ferid Murad, received the Nobel Prize in 1998 for a study regarding the connection between nitric oxide and a healthy cardiovascular system. The only source of volatile nitrogen monoxide is arginine.

Effect on heart diseases and cholesterol levels

Prof. Dr. Doc. Stefanie M. Bode Bögerfrom the Institute of Clinical Pharmacology at the University of Magdeburg claims that: There are many studies that prove that taking low doses of this amino acid can improve the vascular function. More specifically, this has been tested on patients who suffer vascular disorders (17 studies), heart failure (39 trials), coronary heart disease (43 studies) and high cholesterol (20 studies).

Where can I purchase arginine?

Bibliography

1. Ulrich Förstermann y William C. Sessa. Nitric oxide synthases: regulation and function. Eur Heart J. 2012 Apr; 33(7): 829–837.
2. Poco JP, Forbes SC, Candow DG, Cornish SM, Chilibeck PD. Creatine, arginine alpha-ketoglutarate, amino acids, and medium-chain triglycerides and endurance and performance. Int J Sport Nutr Exerc Metab. 2008 Oct;18(5):493-508.
3. Brown AC, Macrae HS, Turner NS. Tricarboxylic-acid-cycle intermediates and cycle endurance capacity. Int J Sport Nutr Exerc Metab. 2004 Dec;14(6):720-9.
4. Ciruela F, Gómez-Soler M, Guidolin D, Borroto-Escuela DO, Agnati LF, Fuxe K, Fernández-Dueñas V. Adenosine receptor containing oligomers: their role in the control of dopamine and glutamate neurotransmission in the brain. Biochim Biophys Acta. 2011 May;1808(5):1245-55. doi: 10.1016/j.bbamem.2011.02.007.
5. Le Boucher J, Eurengbiol, Farges MC, Minet R, Vasson MP, Cynober L. Modulation of immune response with ornithine A-ketoglutarate in burn injury: an arginine or glutamine dependency? Nutrition. 1999 Oct;15(10):773-7.
6. Jung YP, Earnest CP, Koozehchian M, Cho M, Barringer N, Walker D, Rasmussen C, Greenwood M, Murano PS, Kreider RB. Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males. J Int Soc Sports Nutr. 2017 Jan 3;14:1. doi: 10.1186/s12970-016-0158-3.

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