Effectiveness of Melatonin-Containing Foods on Promoting Sleep: A Scoping Review.

Area of Science:

• Nutritional Science
• Sleep Medicine
• Dietary Interventions

Background:

• Melatonin is vital for the sleep-wake cycle.
• Dietary sources of melatonin are being explored for sleep improvement.
• Existing research shows mixed results on food-based melatonin and sleep.

Purpose of the Study:

• To conduct a scoping review on the impact of consuming melatonin-rich foods on sleep quality.
• To identify key findings and limitations in current research.
• To highlight areas for future investigation in dietary melatonin and sleep.

Main Methods:

• Scoping review of 19 articles (14 interventional, 5 cross-sectional) from major databases (PubMed, Scopus, CINAHL, Web of Science).
• Data extraction on melatonin sources, dosages, sleep assessment, and outcomes.
• Quality appraisal using Joanna Briggs Institute (JBI) tools.

Main Results:

• Interventional studies suggest melatonin-rich foods (tart cherries, kiwifruit) may enhance sleep quality, duration, and efficiency in disturbed sleepers, but findings are heterogeneous.
• Observational studies indicate potential associations between higher intake of melatonin foods and better sleep quality, circadian regulation, and reduced social jetlag, though results vary.
• Significant limitations include variability in populations, consumption timing, dosage, intervention length, and sleep assessment tools.

Conclusions:

• Melatonin-rich foods show potential for improving sleep, but evidence is heterogeneous and limited by study design and narrow food selection.
• Further research with objective sleep measures and diverse dietary sources is needed to understand melatonin's role in sleep regulation.
• Current studies highlight specific foods like cherries and kiwifruit but overlook other potential dietary melatonin sources.