Nutritional Modulation of Sleep Latency, Duration, and Efficiency: A Randomised, Repeated-Measures, Double-Blind Deception Study

Carl Langan-Evans*, Mark A. Hearris, Chloe Gallagher, Stephen Long, Craig Thomas, Andrew D. Moss, William Cheung, Glyn Howatson, James P. Morton

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Downloads (Pure)


Purpose: To test the hypothesis that a novel nutritional blend comprised of tryptophan, glycine, magnesium, tart cherry powder and L-theanine, enhances subjective and objective measures of sleep during free living conditions.

Methods: In a randomised, repeated measures crossover and double blind deception design, participants (n = 9 male and 7 female; age: 24 ± 3 years; body mass: 69.8 ± 11.6 kg; stature: 170.8 ± 9.1 cm) completed a 3 day familiarisation period, followed by 3 day intervention and placebo trials. Subjective Pittsburgh Quality Sleep Index, Core Consensus Sleep Diary and Karolinska Sleepiness Scale survey tools, alongside objective actigraphy measures of sleep were assessed, with daily nutritional intake, activity and light exposure standardised between trials. Participants provided daily urine samples for assessment of targeted and untargeted metabolomes.

Results: The intervention trial reduced sleep onset latency (-24 ± 25 mins; p = 0.002), increased total sleep time (22 ± 32 mins; p = 0.01) and sleep efficiency (2.4 ± 3.9 %; p = 0.03), whilst also reducing morning sleepiness (p = 0.02). Throughout the study, 75 % of participants remained blinded to sleep assessment as a primary outcome measure, with 56 % subjectively indicating improved sleep during the intervention trial. Metabolomic analysis highlighted several significantly altered metabolomes related to sleep regulation between trials, inclusive of 6-sulfatoxymelatonin, D-serine and L-glutamic acid.

Conclusions: Data demonstrate that employing the proposed blend of novel nutritional ingredients during free living conditions reduced sleep onset latency, increased total sleep duration and increased sleep efficiency, leading to reduced perceptions of morning sleepiness. These effects may be mediated by the upregulation of key metabolites involved in the neurophysiological modulation of the sleep/wake cycle.
Original languageEnglish
JournalMedicine & Science in Sports & Exercise (MSSE)
Early online date12 Sept 2022
Publication statusE-pub ahead of print - 12 Sept 2022


Dive into the research topics of 'Nutritional Modulation of Sleep Latency, Duration, and Efficiency: A Randomised, Repeated-Measures, Double-Blind Deception Study'. Together they form a unique fingerprint.

Cite this