Objective To investigate if the association between diet and lung function (LF) differs according to asthma or COPD status in the Lifelines Cohort Study. Methods: We included adults from Lifelines with valid dietary and spirometry data. Dietary quality was calculated at baseline using the Lifelines Diet Score (LLDS; range: 0–48, higher scores indicate a healthier diet). LF was assessed via pre-bronchodilator spirometry (FEV₁, FVC, FEV₁/FVC) at baseline and two follow-ups (∼10 years). Cross-sectional associations between diet and LF were examined using linear regression and longitudinal associations with linear mixed-effect models. Interactions between diet and asthma or COPD were included. Results Higher LLDS was associated with higher LF and slower decline. In cross-sectional analyses (n=83 460, 59% female, mean age 44y ±13), higher LLDS was associated with higher FEV 1 and FEV 1 /FVC levels in participants with asthma (FEV 1 βinteraction (β int )=2.48 mL 95% CI 0.68;4.27, FEV 1 /FVC β int =0.027% 0.003; 0.052) and COPD (FEV 1 β int =8.31 mL 6.93;9.69, FEV 1 /FVC β int = 0.094% 0.079; 0.109) compared to those without asthma or COPD. In longitudinal analyses (n=37 752, 59% female, age 46y ±11) in COPD-patients higher LLDS was associated with slower FEV 1 decline (β int =0.20 ml/yr 0.07;0.34), FVC (β int =0.26 ml/yr 0.09;0.43) and FEV 1 /FVC (β int =0.002%/yr 0.000;0.005) compared to those without COPD. Conclusions Higher diet quality was associated with better LF, particularly in those with asthma or COPD, and with slower decline in participants with COPD. These findings suggest that diet may be a modifiable factor in respiratory health.
Martinez-Rodriguez et al. (Thu,) studied this question.