Study finds how micronutrient in human breast milk linked to newborns brain development

The findings of the study published in theProceedings of the National Academy of Sciences (PNAS),also paves the way to study what role this micronutrient might play in the brain as we age.

The micronutrient, a sugar molecule known as myo-inositol, was shown to be most prevalent in human breast milk during the early months of lactation, when synapses, or connections between neurons, are rapidly forming in the developing brain. The researchers profiled and analyzed human milk samples gathered across sites in Mexico City, Shanghai, and Cincinnati by the Global Exploration of Human Milk study, which comprised healthy mothers of term singleton infants. This was true regardless of the mother's ethnicity or origin.

Further testing using rodent models as well as human neurons showed thatmyo-inositol increased both the size and number of synaptic connections between neurons in the developing brain, indicating stronger connectivity.

Forming and refining brain connectivity from birth is guided by genetic and environmental forces as well as by human experiences, saysThomas Biederer, senior scientist on the Neuroscience and Aging Team at the HNRCA, senior author on the study, and faculty member at theYale School of Medicine, where he leads a research group in the Department of Neurology.

Diet is one of the environmental forces that offers many opportunities for study. In early infancy, the brain may be particularly sensitive to dietary factors because the blood-brain barrier is more permeable, and small molecules taken in as food can more easily pass from the blood to the brain.

As a neuroscientist, its intriguing to me how profound the effects of micronutrients are on the brain, says Biederer. Its also amazing how complex and rich human breast milk is, and I now think it is conceivable that its composition is dynamically changing to support different stages of infant brain development.

Similar levels ofmyo-inositol across women in very different geographic locations point to its generally important role in human brain development, he observes.

Research by others has shown that brain inositol levels decline over time as infants develop. In adults, lower than normal brain inositol levels have been found in patients with major depressive disorders and bipolar disease. Genetic alterations in myo-inositol transporters have been linked to schizophrenia. In contrast, in people with Downs syndrome and patients with Alzheimers disease and Downs syndrome, higher than normal accumulations ofmyo-inositol have been identified.

The current research does indicate that for circumstances where breastfeeding is not possible, it may be beneficial to increase the levels of myo-inositol in infant formula, Biederer says.

However, Biederer says it is too soon to recommend that adults consume moremyo-inositol, which can be found in significant quantities in certain grains, beans, bran, citrus fruits, and cantaloupe (but which is not present in great quantities in cows milk). We dont know why inositol levels are lower in adults with certain psychiatric conditions, or higher in those with certain other diseases, he says.

A host of research questions remain: Are lower inositol levels in people with depression or bipolar disease a cause of those diseases, or a side effect of drugs used to treat them? Do higher than normal levels in people with Downs syndrome and Alzheimers disease suggest that too muchmyo-inositol is problematic? What is the right level ofmyo-inositol to have in ones brain for optimal brain health at various stages of life?

My colleagues at the HNRCA and I are now pursuing research to test how micronutrients likemyo-inositol may impact cells and connectivity in the aging brain, says Biederer. We hope this work leads to a better understanding of how dietary factors interplay with age-related brain aberrations. (ANI)