The Possible Importance of Glutamine Supplementation to Mood and Cognition in Hypoxia from High Altitude

Abstract

Hypoxia induced by low O2 pressure is responsible for several physiological and behavioral alterations. Changes in physiological systems are frequent, including inflammation and psychobiological declines such as mood and cognition worsening, resulting in increased reaction time, difficulty solving problems, reduced memory and concentration. The paper discusses the possible relationship between glutamine supplementation and worsening cognition mediated by inflammation induced by high altitude hypoxia. The paper is a narrative literature review conducted to verify the effects of glutamine supplementation on psychobiological aspects. We searched MEDLINE/PubMed and Web of Science databases and gray literature by Google Scholar for English articles. Mechanistic pathways mediated by glutamine suggest potential positive effects of its supplementation on mood and cognition, mainly its potential effect on inflammation. However, clinical studies are scarce, making any conclusions impossible. Although glutamine plays an important role and seems to mitigate inflammation, clinical studies should test this hypothesis, which will contribute to a better mood and cognition state for several people who suffer from problems mediated by hypoxia.

Supplementation of L-glutamine enhanced mucosal immunity and improved hormonal status of combat-sport athletes

“…A clinical study providing 40 g of L-glutamine to patients undergoing transplantation reported an improvement of mood [ 53 ], while another study of the elderly showed that 0.3 g/kg b.w./day of L-glutamine supplementation for 30 days increased anti-inflammation and anti-oxidation abilities [ 54 ]. Furthermore, a review article suggested that glutamine supplementation could attenuate mood- and cognitive-worsening in hypoxia while reducing the inflammatory mediators released during injury and stress conditions [ 55 ]. The role of L-glutamine to reduce inflammation mediated by a leaky gut during exercise can contribute to the changes in the central nervous system [ 56 , 57 ].…”

Acute Benefits of Acidified Milk Drinks with 10-g and 15-g Protein on Shifting and Updating Performances in Young Adults: A Randomized Controlled Trial

“…For example, tryptophan is the precursor of serotonin; tyrosine and phenylalanine are precursors of dopamine, noradrenaline, and adrenaline [ 54 ]; branched-chain amino acids, such as leucine, isoleucine, and valine, can also be converted into glutamate [ 55 ]. Leucine is an important donor for glutamate synthesis in the brain [ 56 ], and serotonin, dopamine, and glutamate levels are positively associated with cognitive performance [ 57 , 58 ]. Based on previous evidence, we hypothesized that (1) the acidified milk protein drinks would be quickly absorbed [ 18 ] and lead to an increase in amino acid levels in the body [ 14 , 17 , 59 ], (2) amino acid levels in the brain are increased after milk protein intake because several amino acids can pass through the brain–blood barrier [ 60 ], and (3) amino acids can be converted to neurotransmitters.…”

The Oxygen Cascade from Atmosphere to Mitochondria as a Tool to Understand the (Mal)adaptation to Hypoxia

“…Among the paths involving amino acids, the glutamine/glutamate balance is relevant for its implications in regulating the brain cognitive function and the ventilatory rate. Indeed, low glutamate stimulates ventilation to compensate lower O 2 saturation [ 292 ], and high glutamine may affect the brain cognitive function by disrupting the ammonia vs. glutamate balance [ 293 ]. Such a disruption with decreased N-acetylputrescine, spermine, and ornithine also affects angiogenesis and reproductive physiology [ 294 ].…”