The old-time remedy has peptides that relieve stress and promote sleep, research found.
Sedatives such as zolpidem and benzodiazepines are used to treat insomnia but have sideeffects and are very addictive.
Many work by activating the GABA receptor, a brain protein that suppresses nerve signalling and slows brain activity.
Looking for alternatives, scientists found naturallysourced peptides in milk have the same effects.
Cow’s milk has tryptophan and other peptides known as casein tryptic hydrolysate (CTH) that relieve stress.
Together with a digestive enzyme called trypsin, they create a mixture of sleepenhancing peptides.
Within this milky combination, scientists discovered that a peptide known as alpha-casozepine may be responsible for these effects.
Study authors Prof Lin Zheng and Prof Mouming Zhao wanted to find stronger sleepenhancing peptides in CTH. A team funded by the National Natural Science Foundation of China found CTH had more promising sleep-enhancing effects in tests using mice.
This suggested that other properties helping sleep are in this mixture.
They then identified other bioactive properties released from the mixture once the milk was digested.
The team observed that a natural peptide known as YPVEPF increased the number of mice that fell asleep quickly by about 25 per cent and made their sleep four times longer.
This peptide confirmed that other properties of the CTH mixture should be explored to aid sleep via natural pathways instead of medicated ones.
The findings were published in the American Chemical Society’s Journal OFAGRICULTURAL and Food Chemistry.