title: Randomised controlled trial of the effects of L-ornithine on stress markers and sleep quality in healthy workers.
abstract: BACKGROUND
  L-ornithine is a non-essential, non-protein amino acid. Although L-ornithine is contained in various foods, the amount is usually small.Recently, studies have shown that orally administered L-ornithine reduced the stress response in animals.From these findings, we speculated that L-ornithine may play a role in the relieve of stress and improve sleep and fatigue symptoms in humans. Through a randomised, double-blind, placebo-controlled clinical study, we asked if L-ornithine could be beneficial to stress and sleep in healthy workers.
  
  
  METHODS
  Fifty-two apparently healthy Japanese adults who had previously felt slight stress as well as fatigue were recruited to be study participants and were randomly divided into either the L-ornithine (400 mg/day) or placebo group. They orally consumed the respective test substance every day for 8 weeks. Serum was collected for the assessment of cortisol and dehydroepiandrosterone-sulphate (DHEA-S). Perceived mood and quality of sleep were measured by the Profile of Mood States (POMS), Athens Insomnia Scale (AIS), and Ogri-Shirakawa-Azumi sleep inventory MA version (OSA-MA).
  
  
  RESULTS
  Serum cortisol levels and the cortisol/DHEA-S ratio were significantly decreased in the L-ornithine group in comparison with the placebo group. Also, anger was reduced and perceived sleep quality was improved in the L-ornithine group.
  
  
  CONCLUSIONS
  L-ornithine supplementation has the potential to relieve stress and improve sleep quality related to fatigue, both objectively and subjectively.
authors.affiliation: Research Laboratories for Health Science & Food technologies, Research & Development Division, Kirin Co,, Ltd,, 1-13-5, Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-0004, Japan. m-miyake@kirin.co.jp.
authors.forename: Mika
authors.initials: M
authors.lastname: Miyake
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kirisako
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kokubo
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Miura
authors.forename: Koji
authors.initials: K
authors.lastname: Morishita
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Okamura
authors.forename: Akira
authors.initials: A
authors.lastname: Tsuda
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects*; D019314:Dehydroepiandrosterone Sulfate / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D005221:Fatigue / Q000188:drug therapy*; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D008297:Male; D008875:Middle Aged; D009952:Ornithine / Q000627:therapeutic use*; D010919:Placebos; D012890:Sleep / Q000187:drug effects; D013315:Stress, Psychological / Q000188:drug therapy*
chemical_list: D010919:Placebos; D019314:Dehydroepiandrosterone Sulfate; D009952:Ornithine; D006854:Hydrocortisone