Researchers Prove Milk Makes You Sleepy, Less Anxious

Drinking a glass of warm milk is the age-old advice given to combat restless insomnia. Milk’s sleep-enhancing properties are commonly attributed to tryptophan. Still, scientists believe it might have to do more with milk peptides, named casein tryptic hydrolysate (CTH), a stress reliever that improves sleep. Researchers now believe that these peptides could be a healthy alternative to other sedatives, such as benzodiazepines, reported in the Journal of Agricultural and Food Chemistry.

A specific peptide, α-capsazepine (α-CZP), has been recognized to bind to the GABA receptor-like other sedatives and induce the same anti-anxiety and sleep-enhancing effects. Hence, researchers speculated if milk held more potent sleep-enhancing peptides in CTH.

Lin Zheng, Mouming Zhao and colleagues’ first contrasted CTH and α-CZP effects in mice, concluding that CTH presented better sleep-enhancing properties than just α-CZP alone. The team then utilized mass spectrometry to classify bioactive peptides released from CTH during a gastric digestion simulation. Then, they virtually screened these peptides for GABA receptor binding and to see if they could cross the blood-brain barrier. The most promising subject (called YPVEPF) showed an increased number of mice that fell asleep quickly by about 25 per cent and the sleep duration by more than 400 per cent.

The authors were granted funding from the Guangdong Provincial Key R&D Program, the Shandong Provincial Key R&D Program, the Specific Fund Program for Basic and Applied Basic Research of Guangdong Province, and China’s National Natural Science Foundation.