According to the research conducted by the scientist Iriti Marcello at the University of Milan it was found that grapes used in the making of red wine have high levels of melatonin. The study results were published in the journal of science of food and Agriculture. This is a hormone which is secreted by the pineal gland in the brain in all mammals. But now the hormone's existence in plants has shocked the researcher. It is otherwise called the sleep hormone. It is produced by the body in the night and it regulated the circadian rhythm meaning it tells the body when it is time to sleep. Hence the researches in Italy explain the reason as to why people fall asleep after drinking wine.
The hormone plays a vital role in the sleep-wake patterns and also has antioxidant properties. Some of the grape varieties which have high content of melatonin are Nebbolo, Merlot, Cabernet Savignon, Sangiovesse and Croatina. According to the researchers it was found that the melatonin content could be enhanced in grapes by treating them with a plant vaccine Benzothiadiazole. But Richard Wurtman of the brain and cognitive science department at MIT feels that further in depth investigation has to be done to prove that the substance found in the grapes is melatonin and not any other substance which is similar to the hormone.