Dietary melatonin intake was inversely associated with obesity and depression, with a non-linear dose-response pattern observed for depression, but no significant associations were found with other chronic conditions or sleep duration.
Key Findings
Results
Obesity was inversely associated with dietary melatonin intake across multiple quintiles in multivariate models.
Inverse association observed 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)
The association was not statistically significant in Q5, suggesting a non-linear pattern
Models were adjusted for potential confounders using Poisson regression with robust variance
Analysis was conducted across quintiles of melatonin intake among 8320 participants
Results
Depression was inversely associated with dietary melatonin intake in a non-linear dose-response pattern.
Significant inverse associations were found in Q3 (IRR 0.79, 95% CI 0.67–0.93) and Q4 (IRR 0.79, 95% CI 0.67–0.94)
No significant association was observed in Q2 or Q5, indicating a non-linear dose-response relationship
Poisson regression models with robust variance were used, adjusted for potential confounders
The paper describes this as 'suggesting a nonlinear dose-response pattern'
Methods
Mean dietary melatonin intake among participants was 25554.7 ± 13876.2 ng/day.
Melatonin content was assigned to 82.6% of the 144-item FFQ items
Concentrations among food items ranged from 0 to 169.9 ng/g
Dietary intake was estimated based on published melatonin concentrations in foods
119 food items were assessed for melatonin content
Results
No significant associations were found between dietary melatonin intake and hypertension, type 2 diabetes mellitus, metabolic syndrome, dyslipidemia, obstructive sleep apnoea, or sleep duration.
Eight health outcomes were examined: depression, obesity, hypertension, type 2 diabetes mellitus, metabolic syndrome, dyslipidemia, obstructive sleep apnoea, and sleep duration
Sleep duration was assessed through the same Food Frequency Questionnaire
Logistic regression and Poisson regression models with robust variance were used for analysis
Only obesity and depression showed statistically significant inverse associations across quintiles
Methods
The study population consisted of 8320 university graduates, predominantly women, with a mean age of approximately 36 years.
67.7% of participants were women
Mean age was 35.9 ± 9.6 years
48.1% were single
Data were baseline cross-sectional data from an open cohort (CUME+ Study) of university graduates
Dietary intake was evaluated using a validated 144-item Food Frequency Questionnaire (FFQ)
Discussion
The study design was cross-sectional, limiting causal inference, and the authors called for longitudinal and experimental studies to confirm findings.
Data represent baseline measurements from an open cohort of university graduates
The authors stated: 'Longitudinal and experimental studies are needed to confirm these findings and clarify underlying mechanisms'
The cross-sectional design precludes conclusions about causality
Melatonin concentrations were estimated from published values rather than directly measured in consumed foods
What This Means
This research suggests that eating foods naturally containing melatonin — a compound found in both plant- and animal-based foods — may be linked to lower rates of obesity and depression. The study analyzed dietary data from over 8,300 Brazilian university graduates and estimated how much melatonin participants consumed through their regular diets based on known concentrations in 119 different foods. On average, participants consumed about 25,555 nanograms of melatonin per day through food, and those who consumed moderate-to-higher amounts were less likely to have obesity or depression compared to those who consumed the least.
Interestingly, the relationship between melatonin intake and depression was not straightforwardly linear — the benefit appeared at moderate intake levels but was not clearly stronger at the very highest intake levels. Despite examining eight different health conditions (including hypertension, diabetes, metabolic syndrome, sleep apnea, and sleep duration), only obesity and depression showed statistically significant inverse associations with dietary melatonin intake.
This research is observational and cross-sectional, meaning it captures a snapshot in time and cannot prove that eating more melatonin-containing foods directly causes reductions in obesity or depression. The authors emphasize that follow-up studies tracking people over time, as well as controlled experiments, are needed to confirm these findings and understand the biological mechanisms involved. The study adds to growing interest in how naturally occurring compounds in everyday foods might influence long-term health outcomes.
Zanirate G, Bressan J, Leal A, Pimenta A, Hermsdorff H. (2026). The Content of Dietary Melatonin in 119 Food Items and Its Relationship With Chronic Diseases: Results of the CUME+ Study.. Journal of human nutrition and dietetics : the official journal of the British Dietetic Association. https://doi.org/10.1111/jhn.70193