Early-Life Cumulative Intake of Ultra-Processed Foods and Subcortical Brain Volume at Age Six Years: A Prospective...

Diet quality during early life may influence neurodevelopmental trajectories, but the associations between ultra-processed food (UPF) intake and neurocognitive outcomes has not been broadly examined.

To examine whether cumulative UPF intake from infancy through early childhood is associated with cognitive performance at 24 and 72 months and with subcortical brain volumes at 72 months.

In this prospective birth cohort study, multiple 24-hour dietary assessments were used to calculate the percentage of UPF-calorie intake, using the Nova classification system. Cumulative UPF intake from 6 to 24 and from 6 to 72 months was summarized as the area under the curve. Cognitive performance was assessed at 24 and 72 months, and subcortical brain volumes were derived from T1-weighted MRI scans at 72 months. Associations were examined using multiple univariate linear regressions with false discovery rate (FDR) correction.

Cumulative UPF intake was not associated with cognitive performance at either 24 months (n=144, 57% girls) or 72 months (n=93, 59% girls). In contrast, cumulative UPF intake from 6 to 72 months (n=79, 58% girls) was inversely associated with the volumes of the bilateral accumbens, left amygdala, bilateral pallidum, left putamen, and bilateral thalamus (all FDR-adjusted p < 0.05). On average, a 10% higher proportion of cumulative UPF intake was associated with a 1.92% lower subcortical volume (CI95% -3.29, -0.58). Associations were consistent across exposure windows (6-24 months compared with 72 months) and UPF subtypes (e.g., snacks, fast food).

Greater cumulative UPF intake from infancy through early childhood was associated with differences in neurodevelopment at age six years. These findings highlight this period as a potentially relevant window for nutrition-focused prevention efforts. Future studies are needed to clarify specific windows, neurobiological mechanisms, identify specific nutritional factors, and define long-term implications.