A South Korean study published in the Journal of Medicinal Food, an American scientific journal, concluded that milk collected from cows at night contains high amounts of tryptophan and melatonin, substances that improve sleep and reduce anxiety. This means 24% more tryptophan and 10 times more melatonin than milk collected from cows during the day.
According to the researchers from Sahmyook University in Seoul, mice fed with powder milk taken from cows at night were less active and less likely to explore open spaces, reflecting low anxiety. These effects are comparable, according to the researchers, to the use of diazepam, an anxiolytic commonly used to treat anxiety.
A large scale study of the effects of milk collected from the cow at night in people has not been done yet, despite the apparent ease of implementation of the research. In 2010, however, the German company Milchkristalle GmbH has licensed the patent of so-called “night milk”, which is milk taken from cows between 2 and 4 a.m. and then made into powdered milk, and began to market the product.