BACKGROUND AND AIMS: High blood pressure (BP), a key modifiable risk factor for cardiovascular disease, often begins in childhood. While adult meta-analyses have shown consistent associations between ultra-processed food (UPF) intake and elevated BP, findings in children remain inconsistent. Given that UPFs make up majority of Canadian children's diets, we examined associations between early childhood UPF intake and BP in mid-childhood, and assessed the impact of substituting UPFs with minimally processed foods (MPF).
METHODS AND RESULTS: In this study, among 1408 participants from the Canadian CHILD Cohort Study, UPF, defined based on the NOVA classification system, was assessed at three years of age. BP was measured at age eight. We examined associations using multivariable-adjusted mixed-effects linear regression, evaluated substitution models to estimate the effect of replacing UPFs with MPFs, and examined body mass index (BMI) as a potential mediator. At age three, UPFs contributed 44.3% of total daily energy intake. At age eight, mean systolic and diastolic BP were 104 (SD 9) and 59 (SD 6) mmHg, respectively. Each 10% increase in UPF intake was associated with 0.31 mmHg higher diastolic BP (95% CI: 0.01, 0.61), driven by "Breads and cereals" and "Ready-to-eat/heat mixed dishes" categories. Replacing 10% of energy from UPFs with MPFs, in simulated substitution analyses, was associated with 0.45 mmHg lower diastolic BP. The associations between UPF and diastolic BP were partially mediated (∼27%) by child BMI.
CONCLUSIONS: Higher UPF intake in early childhood was statistically associated with higher diastolic blood pressure at age eight, with simulated substitution models suggesting modest reductions in diastolic blood pressure when substituting energy contributed from UPFs with MPFs. While these effect sizes are small, these findings underscore the importance of early dietary guidance and UPF reduction in pediatric preventive care.
