Arginine and Ornithine: effects of a joint intake

The joint intake of arginine and ornithine is one of the most recent innovations in the field of sports food supplementation; based on what is mentioned in the labels of over-the-counter products, the association of arginine and ornithine seems to possess different indirect health characteristics, linked to the stimulation (or rather, the optimization of physiological production) of Somatotropic Hormone or Somatotropin (English acronym GH) . These include:

  • Improvement of muscle recovery
  • Improvement of muscular trophism
  • Reduction of adipose trophism
  • Improvement of immune effectiveness and efficiency
  • Ati-aging action (for cell renewal of all tissues)

Furthermore, the joint intake of arginine and ornithine appears to have a direct effect on post-exercise metabolic recovery, thanks to the detoxifying potential that these two molecules possess with respect to nitrogen groups resulting from the adenosine-mono-phosphate (AMP) catabolism.

On the basis of the scientific evidence of the experiments, carried out with the aim of evaluating the real ergogenic and healthy abilities of the two single amino acids, the beneficial effects that the supplement companies attribute to the association of arginine and ornithine are almost utopian; let's try to understand why.

Arginine is an essential amino acid ONLY for subjects under development, while in adults it is a semi-essential or conditionally essential. This means that the organism "should be able to synthesize it ex novo", but some pathological or malnutrition conditions (extreme or poorly balanced diets) could limit its production. The functions of arginine are multiple; among them we mention: precursor of nitric oxide (vosodilatory properties and stimulation of the immune system), creatine precursor, neoglucogenesis, ammonia chelator, GH stimulant in intravenous or enteral infusion with doses of 250mg / kg / day . By contrast, enteral doses> 30g / day of L-arginine may induce side effects such as: diarrhea, abdominal cramps and nausea.

Ornithine is often marketed as an alpha-keto-glutarate (OKG) salt, but on a physiological level it is an intermediate amino acid arginine molecule (by the enzyme arginase); the combination of ornithine to the keto-glutarate group (obtained from the deamination of glutamine) was designed to improve its anabolic effect. The beneficial effects of OKG are documented and comparable to those of arginine, but the field of application remains pathological and malnutrition with doses of 25g / day.

The joint intake of arginine and ornithine finds the same applications as the common supplements based on arginine, so it is recommended to take it before reaching the hormonal circadian peak (nocturnal) of GH.

Although the joint intake of arginine and ornithine is likely to emphasize the quality of a food supplement, the effects that can be obtained through the "rational" integration of these products cannot be perceived; the dosage limits completely negate the application in the athletic and sports field. On the contrary, it seems that the outcome of some experimental studies is to discredit the effects of the joint intake of arginine and ornithine in reference to the classic supplements based on arginine.