Aflatoxin Exposure and Cognitive Performance in Mexican Adolescents.

BACKGROUND: Aflatoxins are neurotoxic compounds that can cross the blood-brain barrier and have detrimental effects on developing brains. Human studies examining associations between aflatoxin exposure and cognitive outcomes, particularly during adolescence, remain limited. OBJECTIVE: To examine the association between aflatoxin exposure and neurobehavioral and cognitive performance among Mexican adolescents. METHODS: Participants included adolescents from the Early Life Exposure in Mexico to ENvironmental Toxicants (ELEMENT) cohort. Aflatoxin-albumin adducts were measured in serum using the Enzyme-Linked Immunosorbent Assay (ELISA) method. Cross-sectional analyses examined associations between aflatoxin exposure and neurobehavioral performance measured using the Conners Continuous Performance Test, Third Edition (Conners CPT-3), at the early teen visit (N=472). We also examined whether baseline aflatoxin exposure at the early teen visit was associated with cognitive performance at the late teen visit (N=444) using three tests from the NIH Toolbox Cognition Battery (NIHTB-CB): Flanker, List Sorting, and Pattern Comparison. Multivariable linear regression models estimated associations between log-transformed aflatoxin-albumin adduct levels and cognitive outcomes. CPT-3 models were adjusted for school grade, body mass index (BMI), and socioeconomic status (SES), whereas NIHTB-CB models were adjusted for age, sex, school grade, BMI, and SES. RESULTS: Mean (SD) age at the early- and late-teen visits was 14.3 (2.1) and 16.3 (2.1) years, respectively. Median serum aflatoxin-albumin adduct level was 126.5 ng/mL (IQR: 101-163). Higher baseline aflatoxin exposure was significantly associated with lower List Sorting scores (β = -2.84; 95% CI: -5.50, -0.16; P = 0.038). No significant associations were observed for other outcomes. CONCLUSION: Higher aflatoxin exposure was prospectively associated with lower working memory performance among Mexican adolescents. These findings suggest a potential adverse association between aflatoxin exposure and cognitive function during adolescence that warrants further investigation in longitudinal studies.