Lung Function Begins to Decline in Early 20s, Landmark Study Reveals
A major international study has upended longstanding assumptions about how our lungs age, revealing that lung function begins to decline shortly after its peak in the early twenties — much earlier than previously believed.
The research, led by the Barcelona Institute for Global Health (ISGlobal) in collaboration with Clínic-IDIBAPS and published in The Lancet Respiratory Medicine, offers the first comprehensive model tracking lung capacity from early childhood to old age. The findings establish a new framework for assessing and monitoring respiratory health throughout life.
Until now, medical models suggested lung function increased through adolescence, peaked between the ages of 20 and 25, and then remained stable until around age 40. This study challenges that view, showing that the decline in lung function begins almost immediately after the peak — with no plateau.
“We found that forced expiratory volume in one second (FEV1) — a key indicator of lung function — peaks at about age 20 in women and 23 in men,” said Judith Garcia-Aymerich, the study’s lead author and co-director of ISGlobal’s Environment and Health over the Life Course Programme. “Contrary to previous assumptions, there is no phase of stability. Lung function begins to decline right after this peak.”
The findings are based on pooled data from over 30,000 individuals aged 4 to 82, drawn from eight population-based cohort studies in Europe and Australia. This “accelerated cohort design” enabled researchers to map the life-course of lung function with unprecedented precision.
The Role of Asthma and Smoking
The study also examined how certain factors, such as asthma and smoking, influence lung health. Persistent asthma was associated with lower lung function throughout life and an earlier peak in FEV1. Smoking, on the other hand, was linked to a more rapid decline beginning at age 35.
“These distinctions are important for tailoring public health strategies,” said Rosa Faner, a co-author from the University of Barcelona and Clínic-IDIBAPS. “For instance, early-life lung function screening could help identify children and young adults at risk for chronic respiratory diseases later in life.”
Public Health Implications
The findings underscore the urgency of early intervention. Spirometry — a simple, non-invasive test to measure lung capacity — should be more widely used to monitor respiratory health from childhood.
“Promoting lung health early in life and identifying at-risk individuals could help prevent millions of cases of chronic lung disease,” Garcia-Aymerich emphasized.
As the world faces growing burdens from conditions like asthma, COPD, and long COVID, this study reinforces the importance of lifelong respiratory care — starting well before middle age.
