Effects of early nutrition factors on baseline neurodevelopment during the first 6 months of life: An EEG study

Authors: GILBREATH, DYLAN - University Arkansas For Medical Sciences (UAMS); HAGOOD, DARCY - Arkansas Children'S Nutrition Research Center (ACNC); DOWNS, HEATHER - Arkansas Children'S Nutrition Research Center (ACNC); ALATORRE-CRUZ, GRACIELA - University Arkansas For Medical Sciences (UAMS); ANDRES, ALINE - University Arkansas For Medical Sciences (UAMS); LARSON-PRIOR, LINDA - University Arkansas For Medical Sciences (UAMS)

Submitted to: Nutrients
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2023
Publication Date: 3/22/2023
Citation: Gilbreath, D., Hagood, D., Downs, H., Alatorre-Cruz, G.C., Andres, A., Larson-Prior, L.J. 2023. Effects of early nutrition factors on baseline neurodevelopment during the first 6 months of life: An EEG study. Nutrients. 15(6):1535. https://doi.org/10.3390/nu15061535.
DOI: https://doi.org/10.3390/nu15061535

Interpretive Summary: Throughout infancy, the brain undergoes rapid changes in structure and function that are sensitive to environmental influences such as diet. Breastfed (BF) infants score higher on cognitive tests throughout infancy and into adolescence than formula fed (FF) infants, and these differences in neurocognitive development are reflected in higher concentrations of white and grey matter as measured by MRI. To further explore the effect diet has on cognitive development, electroencephalography (EEG) is used as a direct measure of neuronal activity and to assess specific frequency bands associated with cognitive processes. Task-free baseline EEGs were collected from infants fed with human milk (BF), dairy-based formula (MF), or soy-based formula (SF) at 2, 3, 4, 5, and 6 months of age to explore differences in frequency bands in both sensor and source space. Significant global differences in sensor space were seen in beta and gamma bands between BF and SF groups at ages 2 and 6 months, and these differences were further observed through volumetric modeling in source space. We conclude that BF infants exhibit earlier brain maturation reflected in greater power spectral density in these frequency bands.

Technical Abstract: Infancy is marked by the rapid emergence of cognitive, behavioral, and social-emotional functions that have been shown to be sensitive to environmental influences during this critical period of development.1 Infant diet is increasingly recognized as crucial for optimal myelination, neurogenesis, structural development of early anatomical architecture,4,5 and cognitive development.4,6,7 As such, the influence of diet on neurodevelopment could have lifelong effects on the structure and function of the brain. While the structural and functional effects of specific nutrient deficiencies such as iron4,8,9 and docosahexaenoic acid (DHA) on the developing brain have been well-studied in infants, the more subtle differences resulting from infant feeding behaviors are not yet fully elucidated. It is thought that the emergence of oscillatory frequency bands, known as spectral power, mirrors the underlying maturation of cortical networks. These frequencies in adults are delta (2-4 Hz), theta (5-7 Hz), alpha (8-12 Hz), beta (15-29 Hz), and gamma (30-45 Hz). In general, higher frequency oscillations such as beta and gamma increase with age, while the lower frequency bands such as delta and theta tend to decrease into early adulthood. The higher frequency bands are associated with cognitive processing, although the majority of studies examining the power spectrum in infants and children focus on the lower spectra, with alpha being the most commonly studied frequency as it correlates strongly to known visual cues. The power spectrum is actively developing during infancy and lower frequencies predominate for the first decade of life, so some studies shift the canonical adult frequencies to those that have known behavioral and functional correlates in infants. Many studies in infants and early childhood, however, choose to preserve the adult frequencies for two reasons 1) the literature concerning when and how the power spectrum develops is sparse and 2) both activation and co-activation of higher frequency bands in the adult range such as beta and gamma have been shown in infants. This co-activation or cross-frequency-coupling has been demonstrated in infants in the 1-3 month age range, with beta and gamma coupling observed as a mechanism for early speech discrimination. While the power in gamma and beta is low during infancy, it does exist and has been shown to be responsible for a number of developing cognitive processes, including the perceptual binding of objects. For these reasons, this paper will use the adult power spectrum in order to remain consistent with the literature, and to avoid potential changes in these frequencies as we compare them across development. The primary aim of the current study was to determine whether differences arose in the power spectra in both sensor and source space reconstructions between BF, MF, and SF infants at 2, 3, 4, 5, and 6 months of age using a high density 128 channel EEG. Because previous work in diet and cognition report a slight cognitive advantage in BF infants, we predict that the BF group will have a greater global concentration of the high frequency bands associated with cognitive processing -- beta and gamma -- across age ranges, and this concentration will be reflected in the prefrontal cortex in our source reconstructions. 2. Materials and Methods: Data was collected from 536 healthy term infants (>37 weeks gestational age, between 2.73-4.09 kg) that were enrolled in the Beginnings study (www.clinicaltrials.gov, ID#: NCT00616395), a longitudinal cohort study examining the effect of infant diet on physiological and cognitive development. Infants were recruited between 1 and 2 months of age, and as a result many missed their 2-month-old visit for EEG collection leading to fewer participants in this particular age group. Parents selected to exclusively provide their infants a BF,