Ultra-Processed Foods and Markers of Systemic Inflammation in Children.

Diets high in ultra-processed foods (UPF) have been associated with negative health outcomes in adults; however, UPF's impact on children's health and their underlying mechanisms remain underexplored, despite the rising prevalence of their intake in younger populations. We aimed to investigate the association between UPF intake and systemic inflammation in primary school children. This study included 450 children aged 7-10 years participating in a birth cohort in Arica, Chile (2023). Using the NOVA food classification system, we calculated the intake of UPF (expressed in %kcal) from a 44-item food frequency questionnaire (FFQ). The associations between UPF intake (exposure) and an array of cytokine levels (IL-6, IL-8, IL-10, IL-12, IL1β, TNF-α) were assessed using multiple linear regression models, adjusted for relevant covariates. The mean (SD) UPF intake was 29% (10.5%) of the total energy intake. Some of the associations appeared non-linear; therefore, participants were grouped into tertiles of UPF intake. In adjusted models, a suggestive trend across tertiles was observed for IL-1β (trend -value 0.01). Stratified analyses by age suggested an association between UPF intake and IL-6 in older children (≥ 9 years) only (-value for interaction = 0.02). We found potential associations between UPF intake and cytokine levels in school-aged children. These results may suggest inflammation as a mechanism underlying the adverse health consequences of UPF consumption in children.