Breastmilk sugar molecule boosts infant brains: Study

Breastfeeding has a variety of known health benefits — for mother and baby alike. Breastmilk contains a range of antibodies that protect the infant's yet-to-develop immune system from infections. And mothers who nurse have a lower risk of both breast and ovarian cancers and metabolic diseases, such as diabetes.

Now, researchers at the Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Massachusetts, USA, have discovered a link between a sugar molecule contained in breastmilk and infant brain development.

Their study suggests that a micronutrient called myo-inositol is prominent in breastmilk during the first months of lactation. That's precisely the time when neuronal connections form rapidly in a child's brain.

The researchers examined breastmilk samples collected from healthy mothers in Mexico City, Cincinnati and Shanghai. The concentration of myo-inositol was found to be consistent across the mothers' ethnic and social backgrounds.

Further tests involving rodents and human neurons showed that myo-inositol increased both the size and number of neuronal connections in the developing brain. The results from the Global Exploration of Human Milk study were published in the Proceedings of the National Academy of Sciences.

Micronutrients pass rapidly into the infant's brain

"Forming and refining brain connectivity from birth is guided by genetic and environmental forces as well as by human experiences," said Thomas Biederer, senior author of the study, in a Tufts University press release.

The impact of these factors, added Biederer, was "particularly important at two stages of life — during infancy, and later in life as one ages and synapses are gradually lost."

The study suggests that diet and nutrition play a crucial role in the development of infants and young children. Their so-called blood-brain barrier is more permeable than it is in adults. That means that micronutrients from food can pass more easily to the brain in younger people.

"As a neuroscientist, it's intriguing how profound the effects of micronutrients are on the brain," said Biederer.

The sugar molecule myo-inositol is also found in some grains, beans, bran and melons.

Previous studies have shown that inositol levels in the human brain decline as the child develops. In the case of babies that are not breastfed, the neuroscientist said that "it may be beneficial to increase the levels of myo-inositol in infant formula."

In adults, researchers have found that people with major depression or bipolar disorder also have lower inositol levels. But it's unclear whether a lower inositol level causes mental health illnesses, or whether the decline in inositol is a side effect caused by the medication that's used to treat depression or bipolar disorder.

In light of such unanswered questions, Biederer did not recommend that adults pay particular attention to how much myo-inositol they consume.