Aim: 

To evaluate the effect of 7 different varieties of Jerte Valley cherries (Bourlat, Navalinda, Van, Ambrunés, Pico limón, Pico negro, and Pico colorado), in which we previously detected tryptophan, serotonin, and/or melatonin, on the sleep-wake cycle of middle-aged (35-55 yr-old) and old (65-85 yr-old) volunteers.

Methods: 

Participants consumed 200 g of cherry fruits twice a day (as the lunch and dinner desserts) for 3 days. Actigraphic monitoring was used to record and display the temporal patterns of the individuals' activity and rest (Actiwatch^®, Cambridge Neurotechnology Ltd., U.K.). Each subject wore on a wrist an actimeter that logged activity during 3 days before the beginning of the treatment (basal values), during the 3 days of treatment, and 1 day following its termination. These actimetry data were then analyzed with the Sleep Analysis^® (Cambridge Neurotechnology Ltd., U.K.) software to give the following parameters: Sleep efficiency, real time of sleep, number of awakenings, total activity, sleep latency, assumed sleep, and minutes of immobility.

Results: 

In a general fashion, the cherry intake increased the real time of sleep and the minutes of immobility as well as decreasing the total nocturnal activity. None of the 7 varieties analyzed provoked adverse effects on the volunteers' sleep.

Conclusion: 

The consumption of 200 g of cherries twice a day exerted positive effects on the sleep of both the middle-aged and old individuals that participated in the study.

Supported by Agrupación de Cooperativas Valle del Jerte (Re: 067/07 Julio 2007-Diciembre 2008). S.D. Paredes, I. Bejarano, and M.P. Terrón are beneficiaries of grants by Junta de Extremadura (POS07012, PRE06070, and REI07004, respectively).