Breast milk contains various ingredients, such as nucleotides, which perform a very important role in regulating babies' sleep. A new study from Chrononutrition Laboratory at the University of Extremadura confirms that the composition of breast milk changes quite markedly throughout the day.
The reserachers looked for three nucleotides in breast milk (adenosine, guanosine and uridine), which excite or relax the central nervous system, promoting restfulness and sleep, and observed how these varied throughout a 24-hour period.
The milk, collected from 30 women living in Extremadura, was expressed over a 24-hour period, with six to eight daily samples. The highest nucleotide concentrations were found in the night-time samples (8pm to 8am).
Christina Sánchez, lead author of the article, said that this made them realise that night time breast milk induced sleep in babies as it included components that helped the baby to rest which day time milk has day-specific ingredients that stimulate activity in the infant.
NB. The World Health Organisation says breast milk is the best food for the newborn, and should not be substituted, since it meets all the child's physiological requirements during the first six months of life. It not only protects the baby against many illnesses such as colds, diarrhoea and sudden infant death syndrome, but can also help prevent future diseases such as asthma, allergies and obesity, and promotes intellectual development.
The benefits of breastfeeding also extend to the mother. Women who breastfeed lose the weight gained during pregnancy more quickly, and it also helps prevent against anaemia, high blood pressure and postnatal depression. Osteoporosis and breast cancer are also less common among women who breastfeed their children.
