CherryZZZ: A Protocol for a Randomized, Double-Blind, Placebo-Controlled, Cross-Over Pilot Study Testing Tart Cherry...

Introduction: Two small, preliminary pilot studies report that 2 weeks of daily tart cherry juice consumption (half of the dose in the morning, half of the dose at night) may increase sleep quantity (assessed via a sleep diary or 1 night of polysomnography) in older adults with insomnia. A study of longer duration, with doses closer to bedtime, and daily objective monitoring of sleep via a wearable device may potentiate the observed impact of tart cherry juice intake on sleep. With the proposed changes to the study protocol, it is paramount to evaluate the study's feasibility. Methods: The current study is a single-site, randomized, double-blind, cross-over pilot study in 20 older adults with self-reported insomnia. Eligible individuals will be randomly assigned to consume 16 oz. of tart cherry juice/day or placebo juice for 4 weeks each, separated by a 3-week washout period. Information on study feasibility, including recruitment rate, retention rate, safety, compliance, and study practicality, will be collected, as well as pre- and post-arm evaluations of sleep quantity/quality and biomarkers related to melatonin, cortisol, serotonin, and inflammation. Discussion: Identification of a dietary intervention that improves sleep quantity and quality may serve as a novel and feasible approach for older adults who suffer from insomnia. If successful, such a strategy would help mitigate the plethora of health consequences associated with poor sleep.