Plant-based diets and the risk of lung cancer: a large prospective cohort study.

Abstract

Purpose: Plant-based diets are increasingly recognized for cancer prevention, yet their specific impact on lung cancer (LC) risk remains insufficiently examined. This study aims to assess the relationship between plant-based diets adherence and the incidence of LC.

Methods: Data from the Prostate, Lung, Colorectal, and Ovarian cancer screening trial were analyzed. The plant-based diet index (PDI) was developed to assess adherence to plant-based diets. Multivariable Cox regression model was performed to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Restricted cubic spline (RCS) model was performed to examine risk across the PDI spectrum. Prespecified subgroup analyses identified potential modifiers, and sensitivity analyses tested the association's robustness.

Results: Of the 98,459 participants included, 1,642 developed LC over an average follow-up of 8.83 years. Higher PDI scores were associated with a lower LC risk (HR _{quartile 4 vs. 1}: 0.75, 95% CI: 0.65-0.87, P _trend < 0.001), evident in both non-small cell lung cancer (HR _{quartile 4 vs. 1}: 0.76, 95% CI: 0.65-0.88, P _trend < 0.001) and small cell lung cancer (HR _{quartile 4 vs. 1}: 0.73, 95% CI: 0.49-1.09, P _trend = 0.046). RCS analyses further confirmed these relationships. The association was stronger among participants with lower BMI, smokers, those without a history of emphysema or diabetes, those without a family history of LC, and those with lower physical activity (all P _trend < 0.001). Sensitivity analyses consistently supported these findings.

Conclusion: Our findings reveal an inverse correlation between PDI and LC risk, supporting the potential benefits of plant-based diets in LC prevention.

Clinical trial registry number: ClinicalTrials.gov ID: NCT00339495 (URL: https://www.

Clinicaltrials: gov/study/NCT00339495 ).