Published by: Scott Stewart, MSAc., Dipl. Ac., LAc.
Some recent research has shed light on some new benefits of consuming cherries and kiwi. A UK study found that drinking tart cherry juice concentrate, which contains elevated amounts of melatonin increased sleep duration. Another set of studies out of Spain had similar results when testing Jerte Valley cherries, which contain higher levels of tryptophan, melatonin and serotonin than other cherry cultivars. Both studies measured an increase in urinary melatonin. Melatonin is a hormone produced in the pineal gland and helps regulate circadian rhythms. If you try this form of sleep management you should just eat cherries, because juice is processed and inhibits digestion. If you are stubborn and must drink juice make sure it is unsweetened.
The Kiwi study found that eating 2 kiwi fruits 1 hour before bedtime for four weeks increased the quality of sleep and sleep time. Kiwis contain high levels of antioxidants and serotonin, which may be the reason why they affected the sleep patterns in this study. Serotonin is a neurotransmitter found in the pineal gland that helps regulate the sleep / wake cycle.
All of these studies were somewhat biased, because they had corporate sponsors; although it was noted that the sponsors did not participate in any of the studies designs. Either way, you can’t go wrong with eating either one of these healthy fruits!
1. Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality.
Howatson G, Bell PG, Tallent J, Middleton B, McHugh MP, Ellis J. Eur J Nutr. 2012 Dec;51(8):909-16. doi: 10.1007/s00394-011-0263-7. Epub 2011 Oct 30. PMID: 22038497 [PubMed - indexed for MEDLINE]
2. A Jerte valley cherry product provides beneficial effects on sleep quality. Influence on aging.
Garrido M, González-Gómez D, Lozano M, Barriga C, Paredes SD, Rodríguez AB. J Nutr Health Aging. 2013;17(6):553-60. doi: 10.1007/s12603-013-0029-4. PMID: 23732552 [PubMed - indexed for MEDLINE]
3. Jerte Valley cherry-enriched diets improve nocturnal rest and increase 6-sulfatoxymelatonin and total antioxidant capacity in the urine of middle-aged and elderly humans. Garrido M, Paredes SD, Cubero J, Lozano M, Toribio-Delgado AF, Muñoz JL, Reiter RJ, Barriga C, Rodríguez AB. J Gerontol A Biol Sci Med Sci. 2010 Sep;65(9):909-14. doi: 10.1093/gerona/glq099. Epub 2010 Jun 13. PMID: 20547498 [PubMed - indexed for MEDLINE]
4. Effect of kiwifruit consumption on sleep quality in adults with sleep problems. Lin HH, Tsai PS, Fang SC, Liu JF. Asia Pac J Clin Nutr. 2011;20(2):169-74. PMID: 21669584 [PubMed - indexed for MEDLINE]