L-Arginine

What is it?
It helps relieve memory loss in which is one of the most disheartening aspects of ageing.
Arginine is the precursor of spermine and spermidine.

L-Arginine is one of the most metabolically versatile amino acids. In addition to its role in the synthesis of nitric oxide, l-arginine serves as a precursor for the synthesis of polyamines, proline, glutamate, creatine, agmatine and urea. Several human and experimental animal studies have indicated that exogenous l-arginine intake has multiple beneficial pharmacological effects when taken in doses larger than normal dietary consumption. Such effects include reduction in the risk of vascular and heart diseases, reduction in erectile dysfunction, improvement in immune response and inhibition of gastric hyperacidity. This review summarises several positive studies and personal experiences of l-arginine. The demonstrated anti-aging benefits of l-arginine show greater potential than any pharmaceutical or nutraceutical agent ever previously discovered.

L-arginine  is a very important semi-essential amino acid.
That means and can be produced by the body, but is often needed in larger quantities so the body relies on extra supplementation via the diet.
The most important characteristic of Arginine is that it is the only reactant for the molecule NO (nitric oxide), which is a vasodilator. One of the characteristics of NO is to regulate vascular tone, ensuring, so to say, the flexibility of blood vessels and a healthy cardiovascular system.

Arginine can improve the blood flow in the arteries of the heart and improve symptoms of coronary artery disease, chest pain, clogged arteries and angina. Arginine also helps the kidneys remove waste products from the body and maintains immune and hormone function. Some more benefits of Arginine amino acid are as follows.

 

• Good for body building, muscle growth.
• Helpful in the treatment of Cancer or tumours.
• Helpful in exercise and athletic performance.
• Used to increase the level of growth hormones.
• Good for heart disease.
• Help in improvement of heart transplant patients.
• Help in reducing the hypertension and high blood pressure.
• Beneficial for the gestational hypertension and proteinuria
• Improves the hemodynamic responses to stress and reduces plasma homo cysteine.
• Affects the hemodynamic, glucose, insulin, or C-reactive protein.

L-Arginine and sexual function

 

 

 

Arginine is required for normal spermatogenesis. Over 50 years ago, researchers found that feeding an arginine-deficient diet to adult men for 9 days decreased sperm counts by ∼90% and increased the percentage of non-motile sperm approximately 10-fold. Oral administration of 500 mg arginine–HCl per day to infertile men for 6–8 weeks markedly increased sperm counts and motility in a majority of patients, and resulted in successful pregnancies.

There are only very few reports on the improvement of erectile function by l-arginine administration. A study by Chen et al revealed a significant subjective improvement in sexual function in men with organic erectile dysfunction (31% of cases) after oral intake of 5 g l-arginine for 6 weeks, but only if they had decreased NOx excretion or production. Other studies have shown that long-term oral administration of pharmacological doses of l-arginine improves the erectile response in the aging rat as well as in patients with erectile dysfunction and. However, Klotz et al reported in a controlled crossover study that oral l-arginine at 3× 500 mg/day was not better than a placebo as a first line treatment for the mixed type of impotence.

In general, studies in this area are scarce and provide inconsistent results. Further studies, particularly of long-term usage of l-arginine, are needed to distinguish the group of patients that can most benefit from this supplement. The theoretical basis of these studies is furnished by the established crucial role of NO from nerves and possibly endothelia in initiating and maintaining intracavernous pressure increase, penile vasodilatation, and penile erection that are dependent on cyclic GMP synthesised with activation of soluble guanylyl cyclase by NO in smooth muscle cells.

The aphrodisiac properties of l-arginine have not been adequately studied, despite the noticeable presence of l-arginine in most aphrodisiac and sexual stimulation formulas commercially available in the international market.

 

Other effects of l-arginine

Other than the benefits in the above stated conditions, l-arginine has been demonstrated to improve peripheral circulation, renal function, and immune function. It also possesses anti-stress and adaptogenic capabilities. l-Arginine stimulates the release of growth hormone as well as the release of pancreatic insulin and glucagon and pituitary prolactin. The antioxidant property of l-arginine has been well documented in several reports and. An interesting article by Grasemann et al has demonstrated an acute and transient improvement of pulmonary function in cystic fibrosis patients by a single inhalation of l-arginine. Nebulised l-arginine significantly increased exhaled nitric oxide concentrations.

Additional observations at the end of the 4-week study reported by some subjects.

1. Adjustment of blood pressure in mild hypertension.

2. High energy, especially in the morning when waking up.

3. Clear mind.

4. Stamina and resistance to depression and anxiety.

5. Increase in urine output.

6. Improvement of hair and nail growth and hardness.

7. Improvement of skin texture and appearance.

8. Increase in night dreams.

9. Improvement of circulation and temperature of extremities.

10. Reduction of hyperacidity.

11. Overall improvement of GIT system and defecation.

12. Improvement of most vital activities greatly affected in diabetics, including: reduction of neuritis, improvement of glucose metabolism, enhancement of libido and sexual performance and adjustment of body weight.

Arginine is an essential amino acid involves in cell division and protein synthesis, thus must be obtained from the diet. Arginine intake is increased during the periods of growth like in childhood and pregnancy, when body is actively using amino acid for protein synthesis. Although there are many Arginine supplements available on the market, yet the natural ways of obtaining Arginine are the best way. There are many food sources of Arginine amino acid.

 

 

Some of them are as follow.

 

 

 

 

 

a) Nuts: Plant products like nuts are the richest sources of Arginine which contains around 1 to 3 g per 100 g of nuts. Some nuts with their arginine content are as follow.                              

 

Peanuts  - 3.1 g per 100 g

Almonds - 2.5 g per 100 g

Walnuts -  2.3g per 100 g  

Hazelnuts - 2.2 g per 100 g  

Cashews -2.1 g per 100 g 

Pistachios -2.03 g per 100 g 

Brazil nuts -2.15 g per 100 g

Pecans -1.18 g per 100 g                                    
                      

b) Spinach and Lentils: Vegetables are very good sources of protein, particularly they have a concentration of Arginine. Spinach and lentils are most common vegetables rich in Arginine content. Frozen spinach contain 3.3 g of arginine per 100 g and lentils have 2.1 g per 100 g of the raw vegetable. 

Some other vegetable sources of Arginine are as follow.

 

• Flax seed -1.93 g
• Raw kidney beans -1.46 g
• Raw French beans -1.17 g
• Raw green soybeans -1.04 g
• Raw garlic -0.63 g
• Blueberry muffins -0.30 g
• Raw onion -0.10 g

c) Whole Grains: Cereal grains like whole wheat contains the highest content of arginine, around 650 mg per 100 g. Hence breads and pastas made from whole grain are rich in arginine.

 

d) Soya: Soya-based proteins contain a high content of arginine.100 g of tofu contains 600 mg of Arginine and a 200 calorie serving from soy proteins isolate has more than 4 g of Arginine.

 

e) Seafood: Sea food like crustaceans is the best animal-based sources of arginine. A 200-calorie serving of food like crabs, shrimps or lobsters contains 3.6 to 3.8 g of arginine. Tuna and salmon fishes contain maximum amount of arginine 1.7 g per 100 g and 1.2 g per 100 g respectively. Chicken and pork have even greater amount of Arginine compare to sea food.

f) Eggs: The yolk part of eggs is very rich in this amino acid. Around 1.10 g of arginine present in 100 g of raw egg yolk while 0.65 g per 100 g is in raw egg white. Some other food sources with Arginine content are as follows.

 

	Food items	Arginine content (g/100 g edible portion)
1	Seeds, sesame flour, low-fat	7.44
2	Seeds, cottonseed flour, low fat (glandless)	6.73
3	Soy protein isolate, PROTEIN TECHNOLOGIES INTERNATIONAL, SUPRO	6.70
4	Soy protein isolate, potassium type	6.67
5	Soy protein isolate	6.67
6	Seeds, cottonseed meal, partially defatted (glandless)	6.63
7	Gelatines, dry powder, unsweetened	6.62
8	Soy protein isolate, PROTEIN TECHNOLOGIES INTERNATIONAL, ProPlus	6.50
9	Peanut flour, defatted	6.24
10	Seeds, sesame flour, partially defatted	5.98
11	Seeds, cottonseed flour, partially defatted (glandless)	5.53
12	Seeds, pumpkin and squash seed kernels, roasted, with salt added	5.42
13	Seeds, sunflower seed flour, partially defatted	5.70
14	Mollusks, whelk, unspecified, cooked, moist heat	4.94
15	Seeds, watermelon seed kernels, dried	4.90
16	Nuts, butternuts, dried	4.86
17	Snacks, pork skins, plain	4.84
18	Egg, white, dried, powder, glucose reduced	4.81

Therapeutic use of l-arginine supplement

l-Arginine is available commercially in several countries in variable dosage forms and mostly indicated as a nutritional supplement. It is available as capsules, tablets, powder, effervescent granules, injection, infusion, and cream with a very wide range of doses. The indications also are quite inconsistent. Amongst the many indications provided on the commercial forms of l-arginine are: prevention and improvement of ischemic heart disease, improvement of microcirculation, improvement of erectile function, improvement of physical exercise capacity, reduction of high blood pressure, improvement of local tissue blood supply and oxygenation, improvement of creative transport, increase of energy levels, antioxidant, stimulation of dopamine, adrenaline and noradrenaline release, increase of growth hormone production, improvement of wound healing, enhancing immunity, help to reverse atherosclerosis, management of metabolic alkalosis, aphrodisiac, enhancement of sperm mobility and viability, and treatment of interstitial cystitis. l-arginine is also available commercially as a vaginal lubricant and sexual enhancer cream.

 References: L.E. Holt Jr., A.A. Albanese, Bull Osaka Med School,  A. Melman, N. Toda, K. Ayajiki, T. Okamura, R.H. Boger, S.M. Bode Boger, B. Lubec, M. Hayn, E. Kitzmuller, H. Vierhapper, G. Lubec, K.G. Park, P.D. Hayes, P.J. Garlick, H. Sewell, O. Eremin, S.R. Collier, D.P. Casey, J.A. Kanaley, A. Mugge, S. Kienke, R. Brandes, A. Dwenger, et al.