Dietary Inflammatory Potential and Its Association with Asthma and Lung Function in a Korean Adult Population

Background: Diets with high inflammatory potential may contribute to asthma and impaired lung function, yet evidence from Asian populations is limited. Objective: We aimed to examine the association between the energy-adjusted Dietary Inflammatory Index (E-DII) and lung function in Korean adults, stratified by asthma status. Methods: Data were analyzed from 12,400 participants in the Korea National Health and Nutrition Examination Survey (2016-2018). The E-DII was calculated from 24-hour dietary recall using 21 validated food parameters. Lung function (FEV1, FVC) was measured by standardized spirometry, and current asthma was defined as both a physician diagnosis and the presence of current symptoms. Multivariable logistic and linear regression models adjusted for potential confounders were applied. Results: Higher E-DII scores were significantly associated with increased asthma prevalence and lower lung function. Notably, the magnitude of the association between E-DII and FEV1 % predicted was markedly stronger in the asthma group (beta = -0.613) than in the non-asthma group (beta = -0.147). This disparity suggests that individuals with pre-existing airway inflammation may be more susceptible to the adverse effects of a pro-inflammatory diet. Conclusions: A pro-inflammatory diet is associated with higher asthma risk and reduced lung function in Korean adults, with more pronounced effects observed in those with asthma. Dietary interventions targeting reduced systemic inflammation may be beneficial for respiratory health management.