Premature Babies Who Are Breastfed May Have Larger Brains And Higher IQ


Ben Taub


Ben Taub

Freelance Writer

Benjamin holds a Master's degree in anthropology from University College London and has worked in the fields of neuroscience research and mental health treatment.

Freelance Writer

Breastfeeding may stimulate neurodevelopment in preterm babies. wong sze yuen/Shutterstock

A new study has revealed that breastfeeding as opposed to using infant formula could boost the neurodevelopment of “very preterm” babies. Publishing their findings in the Journal of Pediatrics, an international team of scientists discovered that infants born before 30 weeks gestation tended to have a higher IQ at the age of seven if fed predominantly with their mothers’ milk during the first month of their life, compared to those that received formula. This was also reflected in the volume of grey matter in certain key regions of the brain.

Because of its high nutritional value, breast milk is a vital component of the diet of newborn babies, helping them grow and develop. But premature babies often have different dietary requirement to those that are born after a full nine months in the womb, and therefore often struggle to gain weight when fed only on breast milk, which is why they are sometimes given preterm formula instead.


However, after analyzing data relating to 180 babies born prior to 30 weeks, the study authors found that by the time they reached term, those whose diets consisted of more than 50 percent breast milk during their first 28 days of life had higher volumes of grey matter in their deep nuclei. These are regions of the brain containing high concentrations of neurons, which play a major role in controlling brain activity and regulating cognition.

For instance, the thalamus and the basal ganglia, both of which are highly involved in coordinating the flow of neural activity that gives rise to consciousness, were among the brain regions found to be enlarged in those who had received higher proportions of breast milk.


Preterm babies often struggle to gain weight when fed only on breast milk. chuanpis/Shutterstock

The researchers then performed a second magnetic resonance imaging (MRI) scan on all 180 participants when they reached seven years of age, finding that in addition to having greater deep nuclear grey matter, those who received more than 50 percent breast milk during their first month of life also had larger hippocampi.


Since the hippocampus is involved in processes such as learning and memory, it is perhaps unsurprising that when conducting intelligence and cognition tests, those who had been fed on high proportions of milk were found to have a higher IQ than those who received mainly formula. In fact, for each extra day that breast milk made up more than half of a baby’s diet, IQ was 0.5 points higher by the age of seven.

It’s hard to pinpoint exactly how the nutrients in breastmilk stimulate this effect in preterm babies, although it may have something to do with the fact that those born prematurely are often at a different stage of neurodevelopment than those born at term. For instance, the final months of gestation usually see the creation of new neurons and brain connections, as neuronal branches called axons and dendrites rapidly develop at this time. In contrast, once a baby has been born, the brain enters a new phase of readjustment during which many of these connections are strategically “pruned” in order to make cognition more efficient.


The hippocampus, which plays a role in learning and memory, was larger by age seven among those who had received more than 50 percent breast milk during their first 28 days of life. decade3d - anatomy online/Shutterstock

  • tag
  • intelligence,

  • cognition,

  • breastfeeding,

  • hippocampus,

  • birth,

  • IQ,

  • grey matter,

  • thalamus,

  • basal ganglia,

  • preterm baby,

  • premature baby