Melatonin, a molecule with antioxidant properties that is widely distributed in the animal kingdom, has now been shown to exist in the plant kingdom, including edible plants. Our findings show that melatonin is not only an endogenously produced antioxidant, but that it is also consumed in the diet. Since melatonin concentrations in the blood correlate with the total antioxidant status of this fluid, it is likely that dietary melatonin could be important in protecting against oxidative damage.