Eyes on Development: Exploring the Impact of Early Life Nutrition Exposures on Child Cognition Through Eye-Tracking Assessment

Abstract Background The effects of certain nutrients on cognition in early life are hypothesized to be domain specific. Previous studies have examined the associations between child nutrition and cognitive, motor, or socio-emotional development, but the assessment methods are often insensitive to the specific functional domains affected by nutrition. Objective This scoping review had 2 objectives: (1) to synthesize evidence on the impact of early life nutrition exposures on child cognition evaluated using eye-tracking assessment and (2) to describe the use of eye trackers for child cognitive assessment and to provide recommendations for eye-tracking implementation in future research. Methods A systematic search was performed using the databases PubMed, Embase, and Food Science and Technology Abstracts, from database inception to April 2024. Additionally, we hand searched reference lists of eligible studies to identify additional relevant publications. We included studies of any nutrition exposures (intervention or assessment) involving pregnant or lactating mothers or children aged 0-5 years, with child cognitive outcomes assessed using eye-tracking assessments. The review was conducted following the PRISMA-ScR checklist. Results A total of 1140 article titles and abstracts were screened, with 9 articles included in this review (3 randomized controlled trials, 5 prospective cohort studies, and 1 cross-sectional and prospective cohort study nested in a trial). The majority of the studies were conducted in low- and middle-income countries. Despite the limited number of nutrition studies using eye-tracking assessments, 5 of the 9 studies demonstrated significant relationships between nutrition exposures and attention and memory outcomes. Eye-tracking assessments were also found to be feasible across multiple settings. Conclusion Eye-tracking assessment is a feasible and promising method for evaluating the effects of early life nutrition exposures on attention and memory outcomes across settings. However, the selection of eye-tracking–based tasks should be tailored to the type of nutrition exposures, the desired long-term outcomes, and the feasibility of proper training for local staff.