A new study suggests that myo-inositol, a micronutrient found in human breast milk, is beneficial to newborns’ developing brains. The research opens the door to future research into the role of this micronutrient in the brain as we age.
The discovery also sheds new light on the relationship between nutrition and brain health and has the potential to improve infant formulas used when breastfeeding is not an option.
The micronutrient was found to be most abundant in human breast milk during the first months of lactation, when neuronal connections known as synapses are rapidly forming in the infant brain. This was true regardless of the mother’s ethnicity or background.
The researchers profiled and compared human milk samples collected by the Global Exploration of Human Milk study at locations in Mexico City, Shanghai, and Cincinnati, which included healthy mothers of term singleton infants.
Making Brain Connections
Using rodent models and human neurons, researchers discovered that myo-inositol increased the size and number of synaptic connections between neurons in the developing brain, indicating greater connectivity.
“Forming and refining brain connectivity from birth is guided by genetic and environmental forces as well as by human experiences. The impact of these factors is particularly important at two stages of life; during infancy, and later in life as one ages and synapses are gradually lost,”
says senior author Thomas Biederer, a senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University.
Diet is one of the environmental forces that provides numerous research opportunities. The brain may be especially sensitive to dietary factors in early infancy because the blood-brain barrier is more permeable, allowing small molecules taken in as food to pass more easily from the blood to the brain.
“As a neuroscientist, it’s intriguing to me how profound the effects of micronutrients are on the brain. It’s 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,”
said Biederer.
Brain Inositol Levels
Similar levels of myo-inositol in women from all over the world point to its importance in human brain development.
Previous 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.
Schizophrenia has been linked to genetic changes in myo-inositol transporters. In contrast, higher than normal accumulations of myo-inositol have been found in people with Down syndrome and patients with Alzheimer’s disease and Down syndrome.
“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 said.
Unanswered Questions
Biederer believes it is too early to recommend that adults consume more myo-inositol, which can be found in significant amounts in certain grains, beans, bran, citrus fruits, and cantaloupe. It is not present in large quantities in cow’s milk.
It is unknown why inositol levels are lower in adults with certain psychiatric disorders and higher in those with other diseases.
A slew of research questions remain unanswered:
- Are lower inositol levels in people with depression or bipolar disease a cause or a side effect of drugs used to treat them?
- Do elevated levels in people with Down syndrome and Alzheimer’s disease imply that too much myo-inositol is harmful?
- What is the “right” amount of myo-inositol in the brain for optimal brain health at different stages of life?
“My colleagues at the HNRCA and I are now pursuing research to test how micronutrients like myo-inositol may impact cells and connectivity in the aging brain. We hope this work leads to a better understanding of how dietary factors interplay with age-related brain aberrations,”
said Biederer. The work was supported by Reckitt Benckiser/Mead Johnson Nutrition and the Robert and Margaret Patricelli Family Foundation.
Reference:
- Andrew F. Paquette, Beatrice E. Carbone, Seth Vogel and Thomas Biederer. The human milk component myo-inositol promotes neuronal connectivity. PNAS July 11, 2023 120 (30) e2221413120