TOPLINE

A healthier diet was linked to better lung function in adults with asthma or chronic obstructive pulmonary disease (COPD), compared with those without either condition. It was also linked to a slower decline in lung function in adults with COPD, compared with those without COPD.

METHODOLOGY

• Researchers conducted a prospective cohort study using data from the Lifelines cohort in Netherlands to determine whether the association between diet quality and lung function differed according to asthma or COPD status.
• The cross-sectional analysis included 83,460 participants and the longitudinal analysis included 37,752 participants, with all participants having valid dietary and spirometry data. The mean age of the participants ranged from 44 to 46 years, and about 59% were women; about 9% had a diagnosis of asthma and 15% had COPD.
• Dietary quality was quantified at baseline using the Lifelines diet score, which covered 12 food groups (range, 0-48) and was derived from a 110-item food frequency questionnaire; higher scores indicated a healthier diet.
• Lung function was measured using pre-bronchodilator spirometry — with measurements of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and the FEV1-to-FVC ratio — at baseline and two follow-up visits approximately 5 years apart.

TAKEAWAY

• In cross-sectional analyses, a higher Lifelines diet score was associated with significantly higher FEV1 among participants with asthma (beta interaction per unit increase in diet score = 2.48 mL; 95% CI, 0.68-4.27) or COPD (beta interaction per unit increase in diet score = 8.31 mL; 95% CI, 6.93-9.69) than among those without either condition.
• A higher diet score was also associated with a higher FEV1-to-FVC ratio among participants with asthma (beta interaction per unit increase in diet score = 0.027%; 95% CI, 0.003-0.052) or COPD (beta interaction per unit increase in diet score = 0.094%; 95% CI, 0.079-0.109) than among those without either condition.
• In longitudinal analyses, a higher baseline diet score was associated with a significantly slower decline in FEV1 (beta interaction per unit increase in diet score = 0.18 mL per year; 95% CI, 0.04-0.33), FVC (beta interaction per unit increase in diet score = 0.23 mL per year; 95% CI, 0.04-0.41), and the FEV1-to-FVC ratio (beta interaction per unit increase in diet score = 0.002% per year; 95% CI, 0.000-0.005) among participants with COPD than among those without COPD.
• A higher consumption of vegetables, fruits, and tea was associated with better lung function among participants with COPD, and a higher consumption of tea was associated with better lung function among those with asthma, with both associations observed compared with those without these conditions.

IN PRACTICE

"Our findings suggest that adhering to a healthy diet (eg, higher consumption of fruits, vegetables, whole grains, legumes, and unsaturated fats and lower intake of red and processed meats, butter, and sugary drinks) may be a low-cost and accessible strategy to preserve LF [lung function] both in the general population and among patients with COPD alongside existing pharmacological and lifestyle treatments," the researchers wrote.

SOURCE

The study was led by Arturo F. Martinez-Rodriguez, University of Groningen, Groningen, Netherlands. It was published online on August 17, 2026, in ERJ Open Research.

LIMITATIONS

Dietary intake was measured only at baseline, precluding the assessment of changes in dietary habits over time. Food frequency questionnaires are prone to recall, response, and social desirability biases. Residual confounding from unmeasured factors could not be ruled out. Moreover, a notable proportion of participants were lost to follow-up, and these participants had higher smoking rates and lower educational attainment and income than participants who were retained.

DISCLOSURES

The Lifelines Biobank initiative was supported by multiple sources, including the Dutch Ministry of Health, Welfare and Sport, the Dutch Ministry of Economic Affairs, and the University Medical Center Groningen. The authors reported having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.