Idiopathic pulmonary fibrosis (IPF) is a progressive, age-related lung disease with few modifiable risk factors. While healthy dietary patterns have been associated with reduced risk of chronic diseases, their impact on IPF remains unclear. This study investigated the relationship between adherence to healthy dietary patterns and incident IPF and explored whether phenotypic age acceleration mediates this association.

We analyzed 196,473 participants from the UK Biobank. Dietary intake was assessed via repeated 24 -h recall questionnaires, and adherence scores were calculated for the DASH, MEDAS, and MIND dietary patterns. Cox proportional hazards models were used to estimate the association between dietary scores and incident IPF. Mediation analysis was conducted to examine the role of phenotypic age acceleration.

During a median follow-up of 12.4 years, 516 IPF cases were identified. Higher adherence to all three dietary patterns was significantly associated with a reduced risk of IPF. In fully adjusted models, hazard ratios for the highest vs. lowest quartiles were 0.75 (95% CI: 0.59–0.95) for DASH, 0.53 (0.37–0.75) for MEDAS, and 0.66 (0.51–0.86) for MIND. Phenotypic age acceleration partially mediated these associations.

Higher dietary scores were associated with a lower risk of incident IPF, partially mediated by reduced phenotypic age acceleration. These findings suggest that promoting healthy eating habits may contribute to reducing age-related lung disease burden in older adults.