A latest study by scientists on the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University suggests that a micronutrient in human breast milk provides significant profit to the developing brains of newborns, a finding that further illuminates the link between nutrition and brain health and will help improve infant formulas utilized in circumstances when breastfeeding is not possible.

The study, published July 11 within the Proceedings of the National Academy of Sciences (PNAS), also paves the strategy to study what role this micronutrient might play within the brain as we age.

Researchers found that the micronutrient, a sugar molecule called myo-inositol, was most outstanding in human breast milk throughout the first months of lactation, when neuronal connections termed synapses are forming rapidly within the infant brain. This was true whatever the mother’s ethnicity or background; the researchers profiled and compared human milk samples collected across sites in Mexico City, Shanghai, and Cincinnati by the Global Exploration of Human Milk study, which included healthy moms of term singleton infants.

Further testing using rodent models in addition to human neurons showed that myo-inositol increased each the dimensions and variety of synaptic connections between neurons within the developing brain, indicating stronger connectivity.

“Forming and refining brain connectivity from birth is guided by genetic and environmental forces in addition to by human experiences,” says Thomas Biederer, senior scientist on the Neuroscience and Aging Team on the HNRCA, senior writer on the study, and college member on the Yale School of Medicine, where he leads a research group within the Department of Neurology.

Diet is one in all the environmental forces that provides many opportunities for study. In early infancy, the brain could also be particularly sensitive to dietary aspects since 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, it’s intriguing to me how profound the consequences of micronutrients are on the brain. It is also amazing how complex and wealthy human breast milk is, and I now think it’s conceivable that its composition is dynamically changing to support different stages of infant brain development.”

Thomas Biederer, senior scientist on the Neuroscience and Aging Team on the HNRCA, senior writer on the study

Similar levels of myo-inositol across women in very different geographic locations point to its generally necessary 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 present in patients with major depressive disorders and bipolar disease. Genetic alterations in myo-inositol transporters have been linked to schizophrenia. In contrast, in individuals with Down’s syndrome and patients with Alzheimer’s disease and Down’s syndrome, higher than normal accumulations of myo-inositol have been identified.

“The present research does indicate that for circumstances where breastfeeding is just not possible, it might be helpful to extend the degrees of myo-inositol in infant formula,” Biederer says.

Nevertheless, Biederer says it is simply too soon to recommend that adults eat more myo-inositol, which will be present in significant quantities in certain grains, beans, bran, citrus fruits, and cantaloupe (but which is just not present in great quantities in cow’s milk). “We do not know why inositol levels are lower in adults with certain psychiatric conditions, or higher in those with certain other diseases,” he says.

A number of research questions remain: Are lower inositol levels in individuals with depression or bipolar disease a reason for those diseases, or a side effect of medicine used to treat them? Do higher than normal levels in individuals with Down’s syndrome and Alzheimer’s disease suggest that an excessive amount of myo-inositol is problematic? What’s the “right” level of myo-inositol to have in a single’s brain for optimal brain health at various stages of life?

“My colleagues on the HNRCA and I are actually pursuing research to check how micronutrients like myo-inositol may impact cells and connectivity within the aging brain,” says Biederer. “We hope this work results in a greater understanding of how dietary aspects interplay with age-related brain aberrations.”

This work was supported by Reckitt Benckiser / Mead Johnson Nutrition and a present from the Robert and Margaret Patricelli Family Foundation. Complete information on authors, funders, methodology, and conflicts of interest is on the market within the published paper.

Source:

Journal reference:

Paquette, A. F., et al. (2023). The human milk component myo -inositol promotes neuronal connectivity. PNAS. doi.org/10.1073/pnas.2221413120.