Melatonin, a sleep hormone, is secreted from the brain's pineal gland. Melatonin levels rise in the evening to help regulate sleep and lower at daybreak to regulate wakefulness. Now researchers report that grapes may contain melatonin.
The study, published in the Journal of the Science of Food and Agriculture, analyzed different varieties of grapes in Italy for melatonin levels. Researchers from the University of Milan in Italy, tested eight varieties of grape extracts including Nebbiolo, Croatina, Sangiovese, Merlot, Marzemino, Cabernet Franc, Cabernet Sauvignon, and Barbera. Some of the grapevines were treated with benzothiadiazole, a chemical that helps prevent disease.
The researchers found different amounts of melatonin concentration among the grapes. Nebbiolo grapes had the greatest melatonin concentration, followed by Croatina, then Merlot. The researchers suggest that benzothiadiazole may increase melatonin concentration in grapes. This may indicate a possible way to raise the concentration of melatonin in plants, while helping to defend against disease.
"The finding of this compound in grape suggests that the well-established pharmaconutritional properties of this fruit are due not only to the presence of polyphenolic nutraceuticals, such as resveratrol, anthocyanins and proanthocyanidins, but also to the powerful antioxidant activity of melatonin," the study authors write.
REFERENCES:
1. Iriti M et al. Melatonin content in grape: myth or panacea? Journal of the Science of Food and Agriculture 2006;86(10):1432-1438.
Posted by Elaine Gavalas on November 7, 2006 03:40 PM
