Associations Between Nutrient Intake and Cognitive Performance Across Multiple Domains in Healthy School-Aged Children

Background and objective: Evidence regarding dietary intake of specific macronutrients, dietary fiber, and fatty acids in relation to cognitive performance during school age remains limited. We examined these associations among healthy Arab children in Israel. Methods: This cross-sectional analysis included 146 children aged 10–12 years from a prospective cohort. Dietary intake was assessed using a single 24 h dietary recall. Cognitive performance was assessed using the Arabic version of the Wechsler Intelligence Scale for Children, Fourth Edition. Full-scale intelligence quotient (FSIQ) was the primary outcome, whereas verbal comprehension (VCI), perceptual reasoning (PRI), working memory (WMI), and processing speed (PSI) indices were exploratory secondary outcomes. Multivariable linear regression models adjusted for age, sex, village, socioeconomic status, and total energy intake. Results: No statistically significant associations were found between the examined dietary exposures and FSIQ scores. Among 48 exploratory comparisons involving 12 dietary exposures and four specific cognitive domains, higher dietary fiber intake was associated with higher WMI (B = 0.430, 95% CI 0.067–0.794), and this association remained consistent across sensitivity analyses. Higher polyunsaturated fatty acid intake was associated with higher PRI (B = 0.312, 95% CI 0.021 to 0.604), and higher linolenic acid intake with higher PSI (B = 3.325, 95% CI 0.081 to 6.569). However, both findings were sensitive to alternative exposure specifications. In a sensitivity analysis, any calculated trans-fat intake versus zero calculated intake was associated with lower PRI (B = −6.290, 95% CI −10.766 to −1.814). Conclusions: We found no evidence of associations between the examined nutrient intakes and FSIQ, the primary outcome for overall intellectual functioning. Exploratory analyses identified domain-specific associations, particularly a consistent positive association between dietary fiber intake and working memory. These findings provide new evidence on nutrient intake and cognitive performance among healthy school-aged children from an underrepresented population. Given the study limitations, these associations should be interpreted cautiously and confirmed in larger prospective studies using repeated dietary assessments.