A high-quality, plant-based diet slows the decline in lung function

A2530 – Association of a plant-based diet with reduced lung function in early to mid-adulthood: the CARDIA study.

Research background and purpose

Lung function trajectory over life is a major determinant of future chronic lung disease. Diet quality in adulthood may be a modifiable risk factor for impaired lung function later in life. The aim of this study was to investigate the association between a high-quality, plant-based diet in early and mid-adulthood and lung function trajectories among participants in the Coronary Artery Risk Development in Youth (CARDIA) Study.

Research methods:

The researchers assessed participants’ diet at baseline and follow-up at years 7 and 20 using the validated CARDIA dietary history questionnaire. The quality of the plant-based diet was scored with the A Priori Diet Quality Score (APDQS), which measures adherence to nutritional Degree of rich, plant-based diet, with higher scores indicating better diet quality. The follow-up cumulative mean score was divided into quintiles. The primary endpoint was decline in lung function, including forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) measured at 0, 2, 5, 10, 20, and 30 years.

We assessed the association of APDQS with annual lung function change in linear regression models, adjusting for clinically relevant covariates; and used a group-based trajectory modeling approach to generate lifetime trajectories of percent predicted lung function. Participants were assigned to one of five trajectories derived from the model, stratified by APDQS quintiles.

Research result:

The study included 3,787 black and white men and women aged 18-30 in 1985-1986 and followed them for 30 years. In multivariate repeated measures regression models, APDQS was significantly associated with annual changes in both FVC and FEV1. FEV1 decline in the lowest quintile of APDQS was 1.6 ml/yr higher than in the highest quintile (33.4 vs 35.0 ml/yr, p=0.009, FVC decline was 2.4 ml/yr higher than in the highest quintile (37.0 vs 34.6 ml /year, p<0.001). There was no significant correlation between APDQS and FEV1/FVC. In the group of participants who maintained good and ideal lung health, the proportion of the highest quantile of APDQS was higher than that in the group with poor sustained lung function, while the latter had the highest proportion of the lowest quantiles of the APDQS

Relative distribution of APDQS quintiles in different lung function trajectories (FEV1% predicted value)

In conclusion:

This 30-year longitudinal study found that adherence to a nutrient-dense plant-based diet was significantly associated with slower decline in lung function. These results highlight a high-quality, plant-based diet as a treatable feature to support long-term lung health.