Intake of l-serine before bedtime prevents the delay of the circadian phase in real life

Michihiro Ohashi, Sang il Lee, Taisuke Eto, Nobuo Uotsu, Chie Tarumizu, Sayuri Matsuoka, Shinobu Yasuo, Shigekazu Higuchi

研究成果: ジャーナルへの寄稿学術誌査読


Background: It has been shown in laboratory experiments using human subjects that ingestion of the non-essential amino acid l-serine before bedtime enhances the advance of circadian phase induced by light exposure the next morning. In the present study, we tested the effect of ingestion of l-serine before bedtime on circadian phase in real life and whether its effect depends on the initial circadian phase. Methods: The subjects were 33 healthy male and female university students and they were divided into an l-serine group (n = 16) and a placebo group (n = 17). This study was conducted in a double-blind manner in autumn and winter. After a baseline period for 1 week, the subjects took 3.0 g of l-serine or a placebo 30 min before bedtime for 2 weeks. Saliva was collected twice a week at home every hour under a dim light condition from 20:00 to 1 h after habitual bedtime. Dim light melatonin onset (DLMO) was used as an index of phase of the circadian rhythm. Results: DLMO after intervention was significantly delayed compared to the baseline DLMO in the placebo group (p = 0.02) but not in the l-serine group. There was a significant difference in the amount of changes in DLMO between the two groups (p = 0.04). There were no significant changes in sleeping habits after intervention in the two groups. There were significant positive correlations between advance of DLMO and DLMO before intervention in the l-serine group (r = 0.53, p < 0.05) and the placebo group (r = 0.69, p < 0.01). There was no significant difference in the slopes of regression lines between the two groups (p = 0.71), but the intercept in the l-serine group was significantly higher than that in the placebo group (p < 0.01). The levels of light exposure were not significantly different between the two groups. Conclusions: Our findings suggest that intake of l-serine before bedtime for multiple days might attenuate the circadian phase delay in the real world and that this effect does not depend on the initial circadian phase. Trial registration: This study is registered with University Hospital Medical Information Network in Japan (UMIN000024435. Registered on October 17, 2016).

ジャーナルJournal of physiological anthropology
出版ステータス出版済み - 12月 2022

!!!All Science Journal Classification (ASJC) codes

  • 人的要因と人間工学
  • 生理学
  • 整形外科およびスポーツ医学
  • 人類学
  • 公衆衛生学、環境および労働衛生
  • 生理学(医学)


「Intake of l-serine before bedtime prevents the delay of the circadian phase in real life」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。