2012 Annual Report
1a.Objectives (from AD-416):
The long-term objectives of this project are to determine the influence of dietary factors on growth, physiological, psychological and cognitive development and functioning in children. These objectives are being addressed in longitudinal studies documenting the effects of differences in early diet (breast feeding or infant formula) on these measures in preterm and term babies from infancy through childhood, and in cross-sectional studies in school-aged children assessing: a) the effectiveness of USDA School Breakfast and Lunch programs in maximizing neurophysiological and behavioral functions essential for learning, with the goal of understanding the relationship between diet and processes optimizing attention and learning while in school; and b) determining neurocognitive correlates and consequences of being overweight in children and how these factors may relate to the development of childhood obesity. Over the next 5 years we will focus on the following objectives:
Objective 1. Using a longitudinal study, evaluate the effects of infant diet (breast-milk, dairy- and soy-based formulas, and monosaccharide supplemented formula) on physiological, behavioral and cognitive development in infants and children.
Sub-Objective 1.A. Determine the growth and development of infants fed one of the three major infant diets (breast-milk, milk- or soy- based formula).
Sub-Objective 1.B. Determine the effects of monosaccharide-supplemented formula on the growth and development of healthy preterm and term infants.
Sub-Objective 1.C. Determine if early infant diet is predictive of later cognitive development and information processing abilities.
Objective 2. Determine the effects of diet composition, meal patterns and meal frequency on brain function and behavioral dynamics that are important for learning and school performance in well-characterized normal and overweight school children.
Sub-Objective 2.A. Determine the effects of variations in morning nutrition (skipping or eating different meals followed by a snack) on processes important for learning in normal weight and overweight children.
Sub-Objective 2.B. Determine the effects of lunch nutrition (skipping or eating different meals followed by a snack) on learning processes in normal weight and overweight children.
Objective 3. Characterize neurocognitive function that contributes to or is a consequence of obesity in children, including brain-function correlates of food-seeking behavior.
1b.Approach (from AD-416):
Children (infants, toddlers, and school-aged youths) will be studied longitudinally to evaluate the effects of infant diet (such as, breast-milk, dairy- and soy-based formulas, and other formulas) on physiological, behavioral and cognitive development in infants and children. Nutritional status assessments, anthropometric measurements, urine and blood analysis, and measures of psychological, neuropsychological, and cognitive measures will be obtained and analyzed. The effects of diet composition, meal patterns, and meal frequency on brain function and behavioral dynamics that are important for learning and school performance in normal and overweight school children will be assessed using validated survey instruments and state-of-the-art research equipment. Neurocognitive function will be characterized that contributes to or is a consequence of obesity in children, including brain-function correlates of food-seeking behavior.
During the year, research has primarily involved the ongoing longitudinal Beginnings study. In this investigation we are tracking the physical, behavioral, psychophysiological and neurocognitive development from birth through 6 years of infants and children who were fed one of the three major infant diets used in the United States (breast milk, milk-based and soy-based formula). This study is the world's largest prospective, longitudinal study of its kind, and is now in its tenth year. This year we met our target-population enrollment goal of 200/group and have completed data collection for all participants during the first year, the time when dietary control is greatest and children are studied most intensely (7 study visits). Assessments were made on 442 participants during 564 visits this year. These included 42 children who had their 6-year visits, bringing the number of subjects who have completed the full study protocol to 189. During these visits we studied various aspects of brain function (e.g., general mental development, language acquisition, and proficiency) and are relating these to measures of brain and physiological development (e.g., cortical neural networks, autonomic nervous system activity). Processing and updating age (2 mo-6 years)/diet group/paradigm-and measure-specific (EEG, autonomic, behavioral) datasets are ongoing, labor-intensive processes. Data obtained from these studies are providing answers to questions regarding how and the extent to which early nutritional status and diet influence growth, and brain and general physiological maturation and cognitive development during the formative period from birth through early childhood.
The longitudinal documentation of this development in infants fed soy formula is of particular importance in view of international concerns about the safety and efficacy of this plant-based formula. Arkansas Children's Nutrition Center studies provide an extensive dataset that includes measures from multiple physiological and neurobehavioral domains that have been needed but until now unavailable to address these concerns. To date, our results have shown that brain development, brain function, and other measures of physiological development are within normal ranges for all three diet groups. We are, however, detecting diet-related differences within the normal range that may have implications for future development. Importantly, the results to date involving substantial numbers of children have not revealed any adverse effects of soy formula on study measures.
Another component of the Beginnings study addresses the question of whether infant diet-specific influences on neurocognitive function are evident in children older than 6 years. In these studies, brain activity during language processing is measured using high density recordings of brain electrical activity and functional magnetic resonance imaging (fMRI) in 8-year-old children who were fed either breast milk, milk formula, or soy formula as infants. The emphasis on language processing was based on early findings in the Beginnings study indicating subtle diet-related differences in processing speech sounds. The combination of electrophysiological and fMRI methodologies allows us to more precisely identify regions within the brain that are activated during language processing and therefore to more clearly understand how diet-related effects on brain function are mediated. Twenty-one children were enrolled in this study this year, bringing total enrollment to 65. Of these, 49 have successfully completed the study protocol. We expect to reach the planned target population of 20/infant diet-type this year. We have been processing both imaging and electrophysiological data as they are collected, and will statistically analyze these data for group differences once the planned group populations have been reached.
This research project also includes studies designed to determine how variations in morning nutrition (skipping breakfast or eating meals differing in nutrient composition) influence cognitive functions that promote learning in school-aged children. We have obtained IRB approval for the next in our series of planned investigations in this area, and now that all the children in the above described Beginnings study are beyond age one year, the workload for the Brain Development Lab will subside to a level that allows time to start the breakfast study. Thus, this study will start early in the next fiscal year. However, analyses of the dataset generated by our initial study in this area, which guided our proposed studies, continue to provide insights into how morning nutrition influences neurocognitive processes important for learning in these children. This year we published results from those analyses indicating that brain neural network activity involved in the processing of numerical information is functionally enhanced and performance is improved in children who have eaten breakfast, whereas greater mental effort is required for mathematical thinking in children who skip breakfast. These findings continue to inform our planned studies and the public regarding how morning nutrition influences cognitive functions in children.
Do differences in postnatal diet affect behavioral and language development during infancy? Behavioral development during infancy establishes the foundation for later development, but there are no studies comparing the influence of the three major infant diets (breast-milk, milk-based formula, and soy formula) on this development. Scientists at the Arkansas Children's Nutrition Center in Little Rock, Arkansas, are addressing these issues in a longitudinal investigation of healthy infants fed these diets. Findings in 391 infants during the first year of life showed that all groups scored within the normal range on standardized developmental tests of mental, psychomotor, and language development. Analyses with adjustments for differences in potentially confounding background and environmental factors showed no differences between formula-fed groups on these measures, but a slight advantage was seen in cognitive development for breastfed compared with formula-fed infants. These findings provide new comparative information regarding the influence of infant diet on early mental, behavioral, and language development to parents and physicians and should help reduce the concerns of parents and industry regarding the use of soy formula.
Breakfast improves memory needed for solving math problems. Memory is critical for learning, but how brain processes regulating memory function are influenced by morning nutrition in school-aged children has not been determined. Scientists at the Arkansas Children's Nutrition Center in Little Rock, Arkansas, have recorded brain electrical activity during the performance of a complex mental function (mental arithmetic) in children (8 to 10 years old) who ate breakfast compared to those who skipped this meal. Researchers found that for those who ate breakfast, working memory during the tasks of solving math problems was made more efficient by increasing brain activity that prevents task-irrelevant information from gaining access to, and interfering with, working memory function. Brain activity measured in children who skipped breakfast showed they required greater mental effort to do the same mathematical processing. These results are important in identifying specific brain processes involved in information processing that are sensitive to a short-term variation in morning nutrition in well-nourished preadolescents, and provide evidence of beneficial effects of consuming breakfast on processes important in learning.
Diet influences the rate at which speech sound information is communicated within the brain. The integration of speech sound information across brain regions is fundamental to language comprehension. The brain first processes syllables in the speech perception area (Wernicke's Area), and this area then communicates (via neural impulses) with other brain regions, such as the speech production area (Broca's area). Just how infant diet may influence the development of these interacting brain networks is not known. Scientists at the Arkansas Children's Nutrition Center in Little Rock, Arkansas, studied this question by comparing the speed with which neural impulses reach these regions (Wernicke's and Broca's areas) in 3-month-old infants who were breastfed or formula-fed (milk-based or soy-based). We found earlier activation in Wernicke's region than Broca's region across diet groups, but with shorter activation times (i.e., greater processing speed) between these sites in milk-fed than breastfed and soy-fed infants, which suggests that infant diets can differentially modify the development of timing relationships in communication between these important brain regions. Although the significance of these effects is not clear, our data showing breast-fed infants score better on standardized measures of language development might suggest a disadvantage in language development for 3-month-old infants fed milk formula.