The state of a person’s lungs may play a far greater role in healthy ageing than previously thought, according to new research published in May 2025 by an international team of respiratory experts.
Drawing on data from around 30,000 men and women tracked over the 20th century, the study found that lung function typically peaks in the early to mid-20s, with women’s capacity reaching its maximum slightly earlier than men’s, before declining steadily with age.
“This decline appears to be a biologically programmed part of ageing,” said Judith Garcia-Aymerich, professor at the Barcelona Institute for Global Health and lead author of the study. “But smoking, air pollution, asthma flare-ups and other factors can accelerate this loss.”
The findings suggest that those with higher lung capacity at their peak enjoy greater resilience later in life, lowering their risk of developing chronic respiratory conditions. Researchers also linked lung health to a wide range of other issues, including immune strength, weight regulation and even cognitive performance.
Dawn Bowdish, professor at McMaster University in Canada, explained that the lungs’ role in immunity may be central to these connections. “The lungs contain millions of immune cells tasked with clearing pollution particles, fighting infections and repairing damage,” she said. “If they fail, inflammation builds up, leading not only to lung scarring but also to systemic effects such as cardiovascular disease, diabetes and memory decline.”
Simple at-home tests can provide an indication of lung capacity, though experts recommend clinical spirometry for accuracy. According to the American Lung Association, a healthy vital capacity — the maximum amount of air exhaled after a deep breath — ranges between three and five litres, but naturally declines by about 0.2 litres per decade.
Despite this gradual decline, specialists stress that lung health can be improved. Regular exercise, a balanced diet rich in antioxidants, and avoiding smoking or vaping can help slow age-related deterioration. Research also points to inspiratory muscle training (IMT) — breathing against resistance using a device — as an effective way to strengthen respiratory muscles. The method has been adopted by hospitals worldwide, and even highlighted by the World Health Organization as a tool to aid recovery after Covid-19.
“Healthy lungs have more than enough capacity to meet the body’s needs throughout life,” said John Dickinson, head of the exercise respiratory clinic at the University of Kent. “But if decline accelerates, it can have a real impact on quality of life.”
Experts recommend that adults have lung function tested every 10 years, or immediately if they experience unexplained breathlessness. Strengthening and protecting the lungs, they argue, is not only vital for respiratory health but also for supporting overall longevity.
