ABSTRACT
Background
Dietary melatonin, naturally occurring in plant- and animal-based foods, has been linked to beneficial effects on sleep, mood and metabolic health. Although evidence suggests that food-derived melatonin may elevate circulating levels, few studies have assessed its intake through habitual diets or explored associations with chronic disease outcomes in adults.
Methods
We conducted a cross-sectional analysis within an open cohort of university graduates (baseline data). Dietary intake was evaluated using a validated 144-item Food Frequency Questionnaire (FFQ), and melatonin intake was estimated based on published concentrations. Sleep duration was also assessed through the questionnaire. Associations between dietary melatonin and selected health outcomes, including depression, obesity, hypertension, type 2 diabetes mellitus, metabolic syndrome, dyslipidemia, obstructive sleep apnoea and sleep duration, were examined across quintiles of intake using logistic regression and Poisson regression models with robust variance, adjusted for potential confounders.
Results
Melatonin content was assigned to 82.6% of the FFQ items, with concentrations ranging from 0 to 169.9 ng/g. Among 8320 participants, most were women (67.7%), with a mean age of 35.9 ± 9.6 years; 48.1% were single. Mean dietary melatonin intake was 25554.7 ± 13876.2 ng/day. In multivariate models, obesity was inversely associated with melatonin intake in Q2 (IRR 0.81, 95%CI 0.69–0.96); Q3 (IRR 0.72, 95%CI 0.60–0.86) and Q4 (IRR 0.79, 95%CI 0.67–0.94). Depression was inversely associated in Q3 (IRR 0.79, 95%CI 0.67–0.93) and Q4 (IRR 0.79, 95%CI 0.67–0.94), suggesting a nonlinear dose–response pattern.
Conclusion
Dietary melatonin intake was inversely associated with obesity and depression, with a non-linear dose–response pattern observed for depression. No significant associations were found with other chronic conditions or sleep duration. Longitudinal and experimental studies are needed to confirm these findings and clarify underlying mechanisms.
Journal of Human Nutrition and Dietetics, Volume 39, Issue 1, February 2026. Read More