Association between ultra-processed and minimally processed foods consumption and asthma risk: an analysis of NHANES 2005–2018

Background Ultra-processed foods (UPFs), characterized by excessive fats, sodium, refined sugars, and food additives, may elevate asthma risk. Minimally processed foods (MPFs) are generally considered healthier. This study investigates the association between UPFs/MPFs consumption and asthma risk.Methods Using data from the National Health and Nutrition Examination Survey (NHANES), we analyzed the relationship between UPFs/MPFs intake and asthma. Weighted logistic regression models evaluated associations between food processing levels and asthma risk. Restricted cubic splines (RCS) explored dose-response relationships. Subgroup analyses assessed consistency across populations, and mediation analyses examined the roles of Life’s Essential 8 (LE8) and eosinophil counts.Results Among 28,157 participants, higher UPF intake was associated with increased asthma risk (OR = 1.54, 95% CI: 1.13–2.08, P = 0.006), while higher MPF intake correlated with reduced risk (OR = 0.48, 95% CI: 0.26–0.87, P = 0.017). RCS revealed a linear positive association between UPF intake and asthma risk (P-nonlinear = 0.383, P-linear < 0.001) and a linear negative association for MPFs (P-nonlinear = 0.229, P-linear < 0.001). Subgroup analyses confirmed robustness across populations. The LE8 score showed a 10.0% mediation effect between UPFs intake and asthma risk (P = 0.002), with eosinophils mediating 5.3% (P = 0.008); between MPFs intake and asthma risk, LE8 mediated 6.8% (P = 0.002), while eosinophils showed no significant mediation (P = 0.136).Conclusions Multiple statistical analyses approved our hypothesis of the significant associations of UPFs and MPFs with the risk of asthma. UPFs consumption positively correlates with asthma risk, whereas MPFs intake shows an inverse association. Prospective studies are needed to validate these findings.