Did your grandmother encourage you to drink a cup of warm milk before bed? This folk remedy has been around for generations, and like many folk remedies, there is actually something to it. However, the type of milk – specifically when the milk was milked from the cow – may have more to do with its effect on our sleepiness than we ever thought.
Recent research indicates that cow’s milk that is milked at night may have more of a sleep-inducing effect on humans than milk that is milked during the day — and if you have trouble sleeping, that means it can actually make you healthier.
Researchers from Seoul, Korea’s Sahmyook University found that so-called “night milk” contains more tryptophan and melatonin, natural hormones that aid in regulating the sleep-wake cycle.
In the study, which was published in the Journal of Medicinal Food, mice were fed with dried powder made from cows milked during the day and the night. The mice who were fed night milk were less active than those who were fed the milk collected during daytime hours. Scientists noted that the night milk contained 10 times the amount of melatonin and 24 percent more tryptophan than daytime milk.
Mice fed on night milk also exhibited less anxiety and more of a willingness to explore open spaces than mice that had daytime milk.
“Considering the fact that tryptophan and melatonin are abundant in night milk, it is possible that the sedative effect of night milk may be attributable to these substances,” researchers theorized in a press release accompanying the 2015 research findings.
A German company has already capitalized on the sleep-inducing aspects of night milk. In 2010, Munich-based Milchkristalle GmbH released its “Nachtmilchkristalle” product (translated as night milk crystals). The powder is made from milk collected from dairy cows between the hours of 2 a.m. and 4 a.m.
The body converts tryptophan — an essential amino acid that we can only get through the foods we eat — into serotonin, a natural hormone in the body that helps make you sleepy. The body then uses serotonin to make melatonin, a hormone that helps regulate your sleep and wake cycles.
Tryptophan also is used by the body to make niacin, a B vitamin that is important for the skin and for the digestive system. Niacin also has been associated with calming anxiety.
Milk is not the only source of tryptophan. Poultry, meats, cheese, yogurt, fish and eggs contain the hormone, and pumpkin seeds are a good non-animal source.
Previous research studies have suggested that the calcium content of milk also makes it work as a sleep aid. Calcium can help some people to relax.
If you choose to drink milk before bed – whether it is daytime milk or nighttime milk — nutritionists recommend that you watch the fat content. The fat in whole milk can put a burden on your digestive system when you drink it before retiring for the night.
What do you think about the daytime milk vs. nighttime milk debate? Share your thoughts in the section below: