Hongkui Jing

Early Infant Diet and the Omega 3 Fatty Acid DHA: Effects on Resting Cardiovascular Activity and Behavioral Development During the First Half-Year of Life

This investigation evaluated variations in resting heart rate (HR) measures during the first half year of life in healthy, full-term infants who were either breast-fed (BF), or fed formula with (milk-based: MF; soy-based: SF) or without (soy-based: SF−) commercially supplemented DHA (decosahexaenoic acid). In infants fed the DHA-deficient diet, higher HR and lower values for heart rate variability measures were observed, indicating decreased parasympathetic tone in this group. These effects, appearing at 4 months and continuing for the remainder of the study period, are consistent with suggestions that the 3–5-month postnatal interval may be an important period in the development of cardiovascular regulation. The absence of these effects in SF infants receiving the DHA-supplemented formula suggests that neither soy protein nor the associated phytochemicals in soy formula contribute to these effects to any appreciable extent. In general, the results do not indicate differences in any of the study variables attributable to soy formula per se.

A longitudinal study of differences in electroencephalographic activity among breastfed, milk formula-fed, and soy formula-fed infants during the first year of life.

BACKGROUND The extent to which adequate nutrition from infant diets differentially influence developmental outcomes in healthy infants has not been determined. AIM To compare the effects of the major infant diets on the development of brain electrical activity during infancy. STUDY DESIGN Scalp EEG signals (124 sites) recorded from the same infants during quiet wakefulness at 3, 6, 9, and 12months. SUBJECTS Healthy, full-term infants (40/group; gender matched) either breastfed (BF) or fed milk formula (MF) or soy formula (SF) through the first 6months. OUTCOME MEASURES Power spectral values for frequencies in the 0.1-30Hz range. RESULTS Significant diet-related differences were present across frequency bands and included effects that were time- [peaks in 0.1-3Hz at 6 (MF,SF) and 9months (BF); 3-6Hz at 6months (MF, SF>BF); increases in 6-9Hz from 3 to 6months (MF>BF) and from 6 to 9months (MF>SF)] and gender-related (9-12Hz and 12-30Hz: at 9months BF>MF, SF boys, and MF>SF girls). CONCLUSIONS The development of brain electrical activity during infancy differs between those who are breastfed compared with those fed either milk or soy formula, but is generally similar for formula-fed groups. These variations in EEG activity reflect diet-related influences on the development of brain structure and function that could put infants on different neurodevelopmental trajectories along which cognitive and brain function development will proceed.

A new scaling method for topographical comparisons of event-related potentials

Recent studies have demonstrated that comparisons of scalp topographical distributions of event-related potentials (ERPs) between experiment conditions may not correctly indicate underlying changes in neural sources if the signals are not scaled prior to the comparisons. This important issue was re-evaluated in this paper using both simulated and experimental data. Simulated data were generated according to 16 different brain models containing 2-4 dipole sources varying in strength, orientation, origin and number. The changes made in the strength, orientation and origin included relative changes between the sources or symmetrical changes in the sources. Experimental data were ERPs collected from 45 infants at 3 months of age. Influences of linked-ear and average references were examined. A scaling method based on relations of signal amplitudes between conditions was devised and compared with the vector method (McCarthy and Wood, 1985). While real topographic differences generated by complex changes in underlying sources were preserved, interactions between condition and electrode site due to mere strength changes were successfully identified by the new method, irrespective of reference method used. However, the vector method was not always reliable because failure to differentiate or mistakenly indicate changes in sources may occur when a linked-mastoid reference was used. The method presented in this paper is reliable and recommended prior to topographic comparisons to distinguish different types of changes in underlying neural sources.

Cortical responses to speech sounds in 3- and 6-month-old infants fed breast milk, milk formula, or soy formula.

Controversy exists about the safety of soy formula, with the main concern relating to potential estrogenic effects of soy protein. Since estrogens influence early brain development, we compared behavioral development and cortical responses (event-related potentials; ERPs) to speech sounds in infants fed either breast milk or formula (milk- or soy-based). Across-groups ERP measures were generally similar and behavioral measures were within normal ranges, suggesting no important influences of soy formula on behavioral development and brain function during the study period. Analyses relating ERP and behavioral measures revealed diet- and gender-specific emphases that may reflect differences in developmental trajectories of brain–behavior relationships.

No difference indicated in electroencephalographic power spectral analysis in 3‐ and 6‐month‐old infants fed soy‐ or milk‐based formula

Increasing concern has been recently raised on the possible effects of soy-derived phyto-oestrogens on the development of cognitive functions in infants. However, limited studies have been conducted to date, and no data have been made available for determining whether infant soy formula can affect normal development of the human brain. We compared electroencephalographic (EEG) spectral power derived from high-density recordings of infants fed milk-based or soy formula (46 fed milk-based formula and 39 fed soy formula) at 3 and 6 months of age. The spectral parameters included absolute power, relative power and spectral edge frequency (SEF) at 85%, 90% and 95% levels. The frequency domain contained four bands (0.1-3, 3-6, 6-9 and 9-12 Hz). EEG signals were collected from eight brain areas in each hemisphere. The results showed that the highest spectral power was mainly distributed in the low-frequency bands and was predominant in the frontal and anterior temporal areas. None of the spectral variables significantly differed between the soy- and milk-fed infants (anova, all P > 0.2). However, significant effects were indicated on the SEFs for factors of sex, age and brain area (all P < 0.01). Hemispheric differences in the absolute and relative power were also indicated. Our results suggest that the EEG power spectral development of soy-fed infants does not differ from that of infants fed milk-based formula. In addition, EEG spectral development appears more advanced in female than in male infants at 6 months.

The influence of infant diet on early developmental changes in processing human voice speech stimuli: ERP variations in breast and milk formula-fed infants at 3 and 6 months after birth.

The purpose of this investigation was to determine if processing of language stimuli during the first half year of life in breast-fed infants differs from that of formula-fed infants. This question was addressed by examining the brain event-related potentials of healthy infants receiving breast milk (n = 15) or milk-based formula (n = 18) recorded in response to consonant vowel syllables presented in an oddball paradigm. The same infants were studied when they were 3-months and 6-months-old. The two groups were comparable on several measures relating to biological and home environment variables previously reported to influence development, including gestation period, birth weight, mothers IQ, and family socioeconomic status, and did not differ in weight or mental or motor development at the times of the visits. In general, ERP response features previously documented in studies of syllable processing in 3–6-month-old infants were observed in this study, including positive components at ∼ 190 msec (P1), ∼ 370 msec (P2), and ∼ 600 msec (P600), and negative components at ∼ 250 msec (N250), ∼ 450 msec (N450), and a late, negative going slow wave between 655 and 995 msec (LSW). For both groups there were instances where specific components were either poorly defined, e.g., P1 and N250 to the infrequent syllable at 3 months, N450 and P600 to this syllable at both ages, or not present in many infants, e.g., the P600 to the frequent syllable at 6 months. These variations appeared to be related to individual differences in development or paradigm-related features, i.e., ISI and frequency of syllable occurrence. Developmental variations (changes from 3 to 6 months) common to both feeding groups included latency decreases for P1, decreased P2 amplitude, and increased amplitudes for N250 and LSW components. Within this framework, group differences were detected in areas involving the development of response components, the development of processing capabilities, and syllable discrimination. In all cases, these effects related to components following initial stimulus registration, i.e., to the processing of sound content rather than sound acoustic features. The pattern of these differences suggests advantages for BF infants in the development and processing of language stimuli during the first 6 months of life.

Effects of Breast Milk and Milk Formula Diets on Synthesized Speech Sound-Induced Event-Related Potentials in 3- and 6-Month-Old Infants

Effects of breast milk and milk formula supplemented with docosahexaenoic acid and arachidonic acid on speech processing were investigated by recording event-related potentials (ERPs) to synthesized /pa/ and /ba/ (oddball paradigm, 80%:20%) at 3 and 6 months of age. Behavioral assessment was also obtained. A major positive component (P200) was elicited by both types of sounds. It had a maximal scalp distribution in the fronto-central areas in both groups of infants. The mean latencies did not differ between the groups or between the stimulus types. However, the latencies decreased across age in both groups. The mean P200 amplitude in the formula-fed infants was lower than that in the breast-fed infants, but the difference was not significant. The between-stimulus differences in frontal P200 amplitudes were positively correlated with the behavioral scores of Bayley Index of Infant Development. These data suggest that the processing of the present speech stimuli is not affected by the investigated diets in the early infancy.