Child psychologist & Head of the Neurocognition group, Lausanne
Levels of cholesterol, gangliosides and iron in breast milk are associated with early brain myelination in 3-month-old infants – preliminary findings - Dr. Nora Schneider
Myelination, the wrapping of neuronal axons with a lipid-rich sheath, is critical for information processing and normal brain functioning. Starting within the caudal brain stem before birth, myelination progresses rostrally after birth to the forebrain, with the most rapid period of human brain myelination occurring within the first 2 years of postnatal life. This pattern of myelination corresponds to emerging cognitive functions with sensory and motor functions being amongst the first to mature. While previous studies indicate early life nutrition as a relevant influencing factor for myelination, little is known about the contribution of breast milk nutrients to myelin development in human infants.
Methods: Levels of breast milk nutrients (minerals, vitamins, fatty acids and lipids) were analyzed in mature maternal breast milk samples from N = 32 neurotypical and exclusively breast-fed infants. The data was extracted from an ongoing myelin Magnetic Resonance Imaging (MRI) study of 3-month-old infants. Mean motor system (including tracts from cerebellum through motor cortices) as well as whole-brain voxelwise myelin water fraction (MWF) measures, a marker of myelin quantity, were correlated with breast milk nutrient levels using multivariate analyses and including gender, gestational age, birth height and weight, maternal education, family size, parental stress (PSI-SF 4) and maternal IQ estimate (WASI-2) as covariates.
Results: Cholesterol (M = 14.53 mg/100g ± 6.65; range = 7.84 - 43.77 mg/100g; r = .57; p < .001), simple ganglioside (ganglioside subspecies GM3; M = 1.21 mg/100mL ± .51; range = .33 - 3.21 mg/100mL; r = .60 ; p < .001) and iron (M = .02 mg/100mL ±.02; range = .02 - .09 mg/100mL; r = .53; p = .002) levels in breast milk were significantly and positively associated with mean myelin content in the developing brain at 3 months of life. Similar associations were seen more diffusely throughout the brain (Fig. 1), with the addition of significant associations between ganglioside subspecies GD3 and brain myelin.
Conclusion: Our preliminary findings support the importance of early life nutrition in brain maturation, particularly with regard to connectivity and myelination. Cholesterol and gangliosides are abundant lipids in myelin and have been implicated to play an important role in early brain development. Iron is important for myelin production and myelin synthesis and deficiencies in early development have been associated with hypomyelination but also with a decrease in myelin lipids and proteins. Further research is needed to better understand the role of dietary cholesterol, gangliosides and iron in infant brain myelination and in particular, the relevance of those early life associations with later functional outcomes. The relevance of those nutrients for those benefits from other dietary sources than maternal breast milk remains to be investigated.