Summary:
This study is a prospective birth cohort analysis investigating how early exposure to ultra‑processed foods (UPFs) relates to brain and cognitive development in young children. UPFs are industrially produced foods designed for taste and convenience, and they make up a large portion of energy intake among US children aged one to five. Because infancy and early childhood are periods of important brain development, diet quality during this time may influence long‑term health. The study examined whether accumulative UPF intake from infancy to six years of age was associated with cognitive performance and brain health. Dietary data was ongoingly collected from six months to six years, and cognitive testing occurred at two and six years. The results showed no relationship between UPF intake and cognitive performance at either age. However, higher accumulative UPF consumption was linked to smaller volumes in several subcortical regions of the brain. A 10% increase in UPF intake corresponded to roughly a 2% reduction in total subcortical volume. These associations were consistent across the exposure periods and types of food. In summary, this study found that greater UPF consumption from infancy through early childhood was associated with structural differences in the developing brain. The findings highlight early childhood as a critical window for utilising nutrition as a protective factor for neurodevelopment.
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Abstract:
Background: 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. Objective: 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. Methods: 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. Results: 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). Conclusions: 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.
Article Publication Date: 02/06/2026
DOI: 10.1016/j.ajcnut.2026.101350
