Interaction between air pollution and diet on cognitive function in schoolchildren

This study aimed to investigate the joint effects of air pollution exposure and dietary total antioxidant capacity (dTAC) on short-term memory and concentration among elementary school students in two regions of Tehran. A cross-sectional study was conducted on 300 female primary school students, aged 9–12 years, with 150 students selected from a more polluted district and 150 from a less polluted area. Dietary intake was assessed using a validated Food Frequency Questionnaire (FFQ) from the Tehran Lipid and Glucose Study (TLGS). Concentration was measured using the Continuous Performance Test (CPT), and memory was assessed with the Wechsler Memory Scale. Statistical analyses included Chi-square tests and two-way ANOVA to evaluate main effects and interactions. Demographic information such as students’ age, anthropometrics, outdoor activity, and parents’ socioeconomic characteristics was obtained via parental questionnaires. Students were categorized into low (TAC1) and high (TAC2) dietary antioxidant groups. Students in the TAC1 group spent less time outdoors and were slightly shorter and heavier, although the latter difference was not statistically significant. In this cross-sectional analysis, both dietary total antioxidant capacity (dTAC) and air pollution levels were significantly associated with concentration performance (P < 0.05). Higher dTAC and lower pollution exposure were linked to improved concentration scores. However, the interaction between dietary antioxidant capacity and air pollution on memory performance was not statistically significant, indicating no measurable buffering effect in this domain. Considering the observational design of the study, children with higher intake of antioxidant-rich foods—such as fruits and micronutrients including vitamins A, C, and B9—tended to show greater total antioxidant capacity (TAC). This higher TAC was modestly associated with improved concentration performance, particularly in models adjusting for dietary and sociodemographic factors. Although associations with memory outcomes were not statistically significant, consistent patterns across multiple adjusted models suggest a potential link worth further investigation. These findings highlight the relevance of dietary antioxidant intake in relation to cognitive functioning, particularly under varying air pollution exposures.