Adults who score higher on a 0-to-48 diet quality scale tend to have modestly better lung function, and the link is strongest in people with chronic obstructive pulmonary disease (COPD), according to a new analysis of data from the Netherlands’ Lifelines cohort study. The research also tracked more than 37,000 participants for roughly a decade and found that COPD patients with better diets appeared to lose lung function more slowly.
What did the study measure?
Researchers analyzed data from 83,460 adults who completed a 110-item food questionnaire at the start of the Lifelines study. The responses were scored on a 0-to-48 scale, with points awarded for higher intakes of vegetables, fruit, whole grains, legumes, nuts, fish, unsaturated fats, unsweetened dairy, coffee, and tea, and points deducted for red and processed meat, butter, hard margarines, and sugary drinks.
Lung function was measured with spirometry, a standard breathing test that records how much air a person can force out of the lungs and how quickly. The researchers were specifically interested in whether diet related differently to lung function in people with asthma or COPD, a long-term condition in which airflow becomes increasingly limited over time.
What did the analysis find across the full group?
Across all 83,460 participants, each one-point increase on the diet score was associated with about 5 mL more air forced out in one second (FEV1). Among the subset of participants with COPD, the same one-point increase was linked to an 8 mL gain in FEV1, a larger effect than in the general group. In participants with asthma, the association was smaller but still present.
Over an average follow-up of about 10 years in 37,752 adults, COPD patients who started the study with higher diet scores showed slower decline across all three spirometry measures the researchers tracked. The pattern held in both mild and moderate COPD cases. The same longitudinal signal did not appear in participants with asthma.
Which individual foods and drinks stood out?
Looking at individual food groups, instead of the overall score, revealed specific patterns.
- Vegetables and fruit were associated with better lung function in participants with COPD or asthma.
- Tea intake was linked to better lung function.
- Butter and hard margarines were associated with worse lung function outcomes.
- Higher coffee intake was linked to faster lung function decline across the full group, even though coffee counted toward a higher overall diet score.
The study was observational, so the patterns show associations rather than proven cause-and-effect relationships between any single food and lung function.
What are the limits of the research?
Because the study was observational, it can identify correlations but cannot prove that changing diet will directly change lung function. Diet was only recorded once at baseline, so the analysis could not account for changes in eating habits during the roughly 10-year follow-up window.
For people already living with asthma or COPD, the researchers stressed that dietary changes are not a substitute for prescribed treatments, and called for more research to test whether diet can directly slow lung decline.
The overall eating pattern tied to better lung function in the data centers on plant foods, whole grains, legumes, nuts, fish, and unsaturated fats, while limiting red and processed meat, butter, hard margarines, and sugary drinks. That pattern overlaps with dietary approaches previously linked to lower inflammation and broader health benefits.
FAQ
What is the diet quality score used in this study?
It is a 0-to-48 score built from a 110-item food questionnaire. Higher scores reward intakes of vegetables, fruit, whole grains, legumes, nuts, fish, unsaturated fats, unsweetened dairy, coffee, and tea, and subtract points for red and processed meat, butter, hard margarines, and sugary drinks.
How many people were included in the study?
Researchers analyzed baseline data from 83,460 adults in the Dutch Lifelines cohort. Follow-up lung function data covered 37,752 of those participants over roughly 10 years.
Does the study prove that diet improves lung function?
No. The study is observational, so it can show that higher diet scores are associated with modestly better lung function, especially in people with COPD, but it cannot establish that changing diet causes the improvement.
