Oral treatment with L-lysine and L-arginine reduces anxiety and basal cortisol levels in healthy humans

Abstract

Dietary supplementation with an essential amino acid L-lysine has been shown to reduce chronic anxiety in humans with low dietary intake of L-lysine. A combination of L-lysine and L-arginine has been documented to normalize hormonal stress responses in humans with high trait anxiety. The present study was carried out in one hundred eight healthy Japanese adults. The aim of study was to find out whether a week-long oral treatment with L-lysine (2.64 g per day) and L-arginine (2.64 g per day) reduces trait and stress-induced state anxiety and basal levels of stress hormones. We confirmed that, without regard to gender, the amino acid treatment significantly reduced both trait anxiety and state anxiety induced by cognitive stress battery. In addition, we found that the treatment with L-lysine and L-arginine decreased the basal levels of salivary cortisol and chromogranin-A (a salivary marker of the sympatho-adrenal system) in male subjects. These results of this double-blind, placebo controlled and randomized study confirm the previous findings in humans and animals and point to a combination of L-lysine and L-arginine as a potentially useful dietary intervention in otherwise healthy humans with high subjective levels of mental stress and anxiety.

Physicochemical and functional properties of kidney bean albumin and globulin protein fractions

“…The albumin and globulin proteins in kidney bean proteins have shown high contents of lysine and arginine making this protein an important potential ingredient for food fortification. This is because dietary supplementation of foods with basic amino acids has been shown to normalize hormonal stress responses in human beings with high trait anxiety (Smriga, Ando, Akutsu, Furukawa, Miwa & Mo-rinaga, 2007). The results obtained for the globulin, including the amino acid composition, protein solubility, WHC, foaming capacity, foam stability, emulsion capacity, and emulsion stability compared favorably with those reported for most legume seeds.…”

Plasma metabolomic patterns in patients with exhaustion disorder

“…Lysine supplement has been shown to reduce trait anxiety and dampen the acute stress response in humans with lysine deficiency (Smriga, Ghosh, Mouneimne, Pellett, & Scrimshaw, 2004). In healthy males, state and trait anxiety as well as basal salivary cortisol were reduced after one week L-lysine and L-arginine supplementation (Smriga et al, 2007). L-lysine and L-arginine supplementation has also been found to increase neuroendocrine responses to acute psychosocial stress in subjects with high trait anxiety (Jezova, Makatsori, Smriga, Morinaga, & Duncko, 2005).…”

“…L-lysine and L-arginine supplementation has also been found to increase neuroendocrine responses to acute psychosocial stress in subjects with high trait anxiety (Jezova, Makatsori, Smriga, Morinaga, & Duncko, 2005). Smriga and colleagues hypothesized that lysine acts as a partial serotonin receptor 4 antagonist and simultaneously as a partial benzodiazepine agonist (Smriga et al, 2007). High lysine abundance in ED patients could indicate desensitization of receptors.…”

Influences of Casein Hydrolysate Ingestion on Cerebral Activity, Autonomic Nerve Activity, and Anxiety

“…In addition, previous studies have shown that intake of Llysine (Lys) and L-arginine (Arg) reduces state anxiety and lowered sympathetic nerve activity in healthy humans through the serotonin and benzodiazepine receptor (Smriga et al, 2007). Lys accounts for 7.4% and Arg accounts for 2.7% of the casein hydrolysate used in this experiment, and thus these compounds in the casein hydrolysate may play a role in controlling mood and physiological indicators.…”