A large cohort study suggests that melatonin from everyday foods may mark dietary patterns associated with lower rates of obesity and depression, while showing no clear links to other chronic diseases.
Study: The Content of Dietary Melatonin in 119 Food Items and Its Relationship With Chronic Diseases: Results of the CUME+ Study. Image Credit: Tatevosian Yana / Shutterstock
In a recent study published in the Journal of Human Nutrition and Dietetics, researchers analyzed melatonin content in food items and its associations with several health outcomes using cross-sectional data from a cohort of Brazilian university graduates.
Melatonin, found in animal- and plant-based foods, has been linked to benefits for sleep, mood, and metabolic health in experimental, observational, and supplementation studies. Although melatonin concentrations are lower in foods compared to supplements, melatonin-rich diets can elevate circulating levels within physiological ranges. Increasing melatonin intake through diet may provide physiological doses that more closely align with endogenous rhythms than pharmacological supplementation and may avoid suprapharmacological exposure, according to prior evidence.
Rationale for Studying Dietary Melatonin
Given the burden of obesity, depression, and sleep disorders, dietary melatonin has been examined as a potential marker of dietary patterns associated with these conditions, rather than as a therapeutic intervention. Previous observational and experimental research suggests that melatonin is protective against inflammatory, metabolic, and neurobehavioral outcomes. Observational studies also report inverse associations with liver cancer incidence and all-cause mortality. However, few studies have directly examined melatonin intake within habitual diets or its associations with chronic conditions in adults.
Study Design and Population
In the present study, researchers analyzed melatonin concentrations in foods and their relationship with various health outcomes. Participants were included from the Cohort of Universities of Minas Gerais (CUME+) study, an open, prospective cohort assessing the impact of dietary patterns and nutrition transition on noncommunicable diseases.
The baseline questionnaire was administered in two parts, one assessing sociodemographics, clinical history, lifestyle, anthropometrics, and morbidity.
Dietary Assessment and Melatonin Estimation
The second part included a food frequency questionnaire (FFQ) and items on dietary habits, supplements, and cooking practices. Nutrient intake was determined using food composition tables, and dietary melatonin content was estimated from the literature and adjusted for total energy intake.
Health Outcomes and Definitions
The study outcomes included obesity, obstructive sleep apnea (OSA), hypertension, metabolic syndrome (MetS), type 2 diabetes (T2D), sleep duration, dyslipidemia, and depression.
Obesity was defined as a body mass index (BMI) ≥ 30 kg/m². Depression and OSA were based on self-reported medical diagnoses. Dyslipidemia was defined as at least one abnormal lipid parameter, including total cholesterol ≥ 200 mg/dL, triglycerides ≥ 150 mg/dL, high-density lipoprotein cholesterol (HDL-C) < 40 mg/dL (or < 50 mg/dL for females), or low-density lipoprotein cholesterol (LDL-C) ≥ 130 mg/dL.
Cardiometabolic Criteria
MetS was defined as central obesity plus any two of the following: elevated triglycerides or treatment, reduced HDL-C or treatment, increased blood pressure (BP) or treatment for hypertension, and elevated fasting plasma glucose (FPG) or T2D diagnosis.
Hypertension was defined as medication use, physician diagnosis, systolic BP ≥ 140 mmHg, or diastolic BP ≥ 90 mmHg. T2D was defined as self-reported or physician diagnosis, antidiabetic medication use, or FPG ≥ 126 mg/dL. Sleep duration was classified as short (less than 7 hours per day) or normal (7 hours or more per day).
Statistical Analysis
Logistic and Poisson regression models were used to estimate associations between dietary melatonin intake and health outcomes, adjusted for age, sex, family income, binge drinking, smoking, screen time, physical activity, medication use, and sleep duration.
Participant Characteristics
The study included 8,320 participants with a mean age of 35.9 years. Most participants were female and non-smokers. Approximately one-third reported short sleep duration. Dyslipidemia, depression, obesity, and hypertension were the most prevalent health conditions.
Melatonin Content and Dietary Sources
Melatonin content was estimated for 119 of 144 food items in the FFQ, with concentrations ranging from 0 to 169.9 ng/g. Mean daily melatonin intake was 25,554.7 ng and was significantly higher in males than in females.
Coffee, lentils and beans, and rice were the primary dietary sources of melatonin. Higher melatonin intake was associated with lower intake of protein, cholesterol, and saturated and monounsaturated fats, and higher intake of fiber and carbohydrates.
Associations With Health Outcomes
No significant associations were observed between dietary melatonin intake and OSA, hypertension, MetS, or T2D. Associations with sleep duration and dyslipidemia were attenuated and lost statistical significance after adjustment for age and sex.
In contrast, dietary melatonin intake was inversely associated with obesity and depression. Individuals with daily melatonin intake of 14,900 to 34,400 ng and 14,900 to 25,000 ng were less likely to have obesity and depression, respectively, with the strongest associations observed in intermediate intake quintiles rather than at the highest levels.
Conclusions and Implications
Dietary melatonin intake was inversely associated with depression and obesity in this population, while no significant associations were observed for other chronic conditions or sleep duration.
Overall, the findings support hypotheses regarding a potential role of dietary melatonin in metabolic and neurobehavioral regulation, possibly via anti-inflammatory pathways. However, due to the cross-sectional design, causal inferences cannot be drawn, and further experimental and longitudinal studies are required to confirm these associations and clarify underlying mechanisms.
Journal reference:
- Zanirate GA, Bressan J, Leal ACG, Pimenta AM, Hermsdorff HHM (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, 39(1), e70193. DOI: 10.1111/jhn.70193, https://onlinelibrary.wiley.com/doi/10.1111/jhn.70193