The aim of this investigation was to examine the effects of tart Montmorency cherry juice on urinary 6-sulfatoxymelatonin and sleep quality using a double-blind, placebo-controlled, cross-over design.

The aim of the study is to examine the efficacy of tart cherry juice on sleep quality, quantity, and timing. Naturally circulating melatonin is instrumental in regulating sleep/wake schedules. Tart Montmorency cherries (Prunus Cerasus) contain high levels of melatonin and may be a useful intervention to supplement for realignment of circadian phase and by increasing the robustness of circadian amplitude. In normal healthy adults, with experimentally induced phase advanced circadian misalignment, the administration of a 3mg supplement of melatonin significantly increased sleep architecture characteristics. In this study we want to examine the efficacy of tart cherry juice in increasing urinary levels of melatonin and the subsequent impact this will have on sleep parameters.

Inclusion Criteria:

• Equal numbers of healthy, non-pathological males and females aged between 18-39.

Exclusion Criteria:

• history of epilepsy, current episode of major depressive disorder or anxiety disorder, or a current sleep problem or an inability to comprehend English, travel over two time zones within the last six months, excessive alcohol (over 3 units per day) or caffeine consumption (more than 6 caffeinated drinks or 1 after 6pm), a smoker, a shift worker, a familial history of diabetes, users of medication or supplements, or if the participant is pregnant or currently lactating.