Melatonin is a naturally occurring hormone primarily recognized for regulating the body’s internal clock and managing the sleep-wake cycle. While the pineal gland produces this substance, many plants and some animal products also contain it (often called phytomelatonin or exogenous melatonin). Interest in these dietary sources has grown as people seek natural ways to influence sleep patterns without relying on supplements. This article identifies foods that contain measurable amounts of this hormone.
Melatonin’s Biological Function and Rhythms
Endogenous melatonin acts as a time signal to the brain, communicating the presence of darkness. This hormone is synthesized and released by the pineal gland, with levels rising sharply in the evening and remaining elevated throughout the night. It is considered a “chronobiotic” agent because its main function is to synchronize the body’s 24-hour cycle, known as the circadian rhythm.
Exposure to bright light, especially blue light, suppresses the production and release of melatonin, serving as a signal of daytime. By binding to specific receptors in the brain, melatonin promotes the drive for sleep and helps regulate the timing of sleep onset. This rhythmic secretion ensures that physiological processes, including body temperature and hormone levels, align correctly with the environmental light-dark cycle.
Identifying Melatonin-Rich Foods
Various plant and animal products naturally contain melatonin, though concentrations vary widely depending on the species, ripeness, and growing conditions. Among fruits, tart cherries, particularly the Montmorency variety, are widely studied sources of dietary melatonin. An 8-ounce serving of tart cherry juice concentrate can contain a measurable amount of melatonin, sometimes exceeding 1 milligram.
Other fruits contributing to dietary intake include grapes, strawberries, and pineapples. Grapes have concentrations ranging from 0.28 to 3.9 nanograms per gram of fresh weight. Nuts and seeds are another category with high concentrations of the hormone. Pistachios are a particularly rich source, containing significantly more melatonin than most other nuts. Walnuts also provide a notable amount, offering approximately 3.6 nanograms per gram.
Melatonin is also found in grains, such as oats and rice, with whole grain and black rice varieties often containing concentrated amounts. Certain animal products, like eggs and fatty fish such as salmon, also contain measurable levels, as does cow’s milk.
Practical Considerations for Dietary Melatonin Intake
The amount of melatonin found in foods is typically measured in nanograms or picograms per gram, which is substantially lower than pharmacological doses found in supplements (often in the milligram range). For example, a common supplement dose is 1 to 10 milligrams, whereas most food servings offer only a fraction of that amount. The exception is concentrated tart cherry juice, which can deliver a dose closer to that of a low-dose supplement.
The presence of melatonin in food is influenced by processing and preparation methods. Roasting nuts, for instance, can potentially reduce their melatonin content compared to raw counterparts. The time of day a product is harvested also matters; milk from cows milked at night may contain higher melatonin levels because the animals’ natural production peaks during darkness.
While dietary sources contribute to overall intake and provide beneficial nutrients, they are generally considered to have a mild, supportive effect rather than an immediate sedative action. Regular consumption of these foods promotes a balanced diet that supports the body’s natural sleep-wake cycle. Eating these foods does not provide the same magnitude of effect as taking a synthetic supplement.