UC Davis

Emerging evidence suggests that early-life nutrition exposures may influence specific cognitive domains, such as attention and memory. This dissertation proposes that these effects are not solely intrinsic properties of nutritional factors (type) but also reflect neurodevelopmental windows during which group differences become measurable (timing), as well as the contexts in which they are observed. I examine these relationships using eye-tracking-based tasks as objective measures of domain-specific effects of nutrition. In Chapter 1, I introduce the domain-specific effects of early-life nutrition and propose that linking type, timing, and context can improve our ability to evaluate nutrition-cognition relationships. In Chapter 2, I synthesize existing research through a scoping review of maternal and child nutrition on child cognitive development measured using eye-tracking assessments. I identify eye-tracking assessments as feasible and promising methods for evaluating the effects of early-life nutrition on attention and memory domains. In Chapter 3, I evaluate eye-tracking assessments of attention and memory within a longitudinal study of growth trajectories among infants and young children from cohorts in Malawi and suburban California, USA. Sex-specific growth trajectories were identified using repeated anthropometric measures collected between birth and 15 months through latent class trajectory modeling. Associations between these trajectories and cognitive outcomes varied across developmental time points and contexts. In Chapter 4, I examine associations of anemia and iron biomarkers at 6–9 months with attention, memory, and social engagement six months later among children in Malawi. Hemoglobin and iron biomarkers were associated with later social engagement and memory, respectively, although associations were modest in this high-burden settings. Thus, an overarching conclusion from this dissertation is that our ability to measure the effects of nutrition on development require specificity in alignment between the nutrient-specific biological mechanisms, the developmental timing of both the effects of the nutritional exposure and the outcome assessment, and the contexts in which they occur.