Human beings have internal clocks. Locked in a room with no source of daylight nor regularly scheduled stimulation, our bodies cycle automatically through periods of slightly longer than 24 hours, sleeping and waking more or less as if the sun were rising and falling over a horizon that we could see. But we are not born this way. Instead, infants develop body clocks gradually. Researchers investigating this aspect of development have recently wondered how much human milk contributes to the process, in the knowledge that its levels of nutrients and hormones vary over the course of the day. Read More...

Consuming a glass of warm milk before bed is supposed to make you sleep well. This old wives’ tale is repeated on websites that offer health and nutritional advice, often backed up by the detail that milk contains tryptophan, the amino acid that is the reason eating turkey purportedly makes you sleepy. But the reality is much more complex. In fact, several compounds in milk appear to have a soporific effect. And perhaps the most intriguing thing about them is that their levels alter with the time of day that the milk is produced. Read More...