Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality.
BACKGROUND
Tart Montmorency cherries have been reported to contain high levels of phytochemicals including melatonin, a molecule critical in regulating the sleep-wake cycle in humans.


OBJECTIVE
The aim of our investigation was to ascertain whether ingestion of a tart cherry juice concentrate would increase the urinary melatonin levels in healthy adults and improve sleep quality.


METHODS
In a randomised, double-blind, placebo-controlled, crossover design, 20 volunteers consumed either a placebo or tart cherry juice concentrate for 7 days. Measures of sleep quality recorded by actigraphy and subjective sleep questionnaires were completed. Sequential urine samples over 48 h were collected and urinary 6-sulfatoxymelatonin (major metabolite of melatonin) determined; cosinor analysis was used to determine melatonin circadian rhythm (mesor, acrophase and amplitude). In addition, total urinary melatonin content was determined over the sampled period. Trial differences were determined using a repeated measures ANOVA.


RESULTS
Total melatonin content was significantly elevated (P < 0.05) in the cherry juice group, whilst no differences were shown between baseline and placebo trials. There were significant increases in time in bed, total sleep time and sleep efficiency total (P < 0.05) with cherry juice supplementation. Although there was no difference in timing of the melatonin circardian rhythm, there was a trend to a higher mesor and amplitude.


CONCLUSIONS
These data suggest that consumption of a tart cherry juice concentrate provides an increase in exogenous melatonin that is beneficial in improving sleep duration and quality in healthy men and women and might be of benefit in managing disturbed sleep.
School of Life Sciences, Northumbria University, Northumberland Building, Newcastle upon Tyne, NE1 8ST, UK. glyn.howatson@northumbria.ac.uk
Glyn
G
Howatson
Phillip G
PG
Bell
Jamie
J
Tallent
Benita
B
Middleton
Malachy P
MP
McHugh
Jason
J
Ellis
D056044:Actigraphy / Q000379:methods; D000293:Adolescent; D000328:Adult; D001628:Beverages / Q000032:analysis*; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D027861:Prunus / Q000737:chemistry*; D012890:Sleep / Q000187:drug effects*; D012893:Sleep Wake Disorders / Q000503:physiopathology / Q000628:therapy*; D011795:Surveys and Questionnaires; D055815:Young Adult
C054513:6-sulfatoxymelatonin; D008550:Melatonin