BADAJOZ, Spain, Oct. 2 (UPI) -- Spanish researchers recommend giving baby breast milk at the same time of day it was expressed.
The study, published in Nutritional Neuroscience, confirms that the composition of breast milk changes quite markedly throughout the day.
The study found content differences in milk samples taken from 30 women six to eight times a day depending on the time of day the sample was taken. These differences include variations in three nucleotides -- adenosine, guanosine and usine -- which excite or relax the nervous system and influence sleep.
"You wouldn't give anyone a coffee at night, and the same is true of milk -- it has day-specific ingredients that stimulate activity in the infant, and other night-time components that help the baby to rest," lead author Cristina Sanchez of the Chrononutrition Laboratory at the University of Extremadura in Spain said in a statement.
"It is a mistake for the mother to express the milk at a certain time and then store it and feed it to the baby at a different time."