The condition of our lungs could hold vital clues about how well we age. A new international study, published in May 2025, is one of the first to examine how human lung function changes across the lifespan—and how this decline can influence wider health.
Drawing on data from around 30,000 men and women across the 20th century, researchers found that lung capacity typically peaks in our early to mid-20s, with women reaching their maximum a few years earlier than men. From this point, lung function gradually declines—a process experts say is biologically programmed.
According to Judith Garcia-Aymerich, professor at the Barcelona Institute for Global Health, factors such as smoking, air pollution, and asthma flare-ups can accelerate this loss. “If the decline becomes excessive, it can lead to conditions like chronic obstructive pulmonary disease (COPD),” she explains.
But the implications of lung ageing extend well beyond the chest. Research links reduced lung function with elevated blood pressure, autoimmune disorders, frailty, and even cognitive decline. This is partly because lungs are central to the body’s immune defences, says Dawn Bowdish, a professor of ageing and immunity at McMaster University, Canada.
Millions of immune cells within the lungs work to clear pollutants and fight infection. When this defence weakens, chronic inflammation can result, damaging not only lung tissue but also triggering disease elsewhere in the body.
Fortunately, experts stress that people can take practical steps to protect their lungs and slow the pace of decline. Simple home tests can give a rough idea of lung function. One involves measuring forced vital capacity (FVC)—the volume of air you can exhale—using little more than a bottle, water, and tubing.
Another method is to time how long you can slowly exhale after a full breath; a healthy adult should manage at least 11 seconds.
For a precise assessment, doctors use spirometry, which measures both FVC and the speed of airflow, offering a clearer picture of respiratory health. Experts recommend routine checks every decade in healthy adults, or sooner if experiencing unexplained breathlessness.
Lifestyle choices remain key. Regular aerobic exercise helps strengthen breathing muscles, while reducing salt intake and eating antioxidant-rich foods can protect lung tissue. Avoiding smoking and vaping is crucial, as both introduce harmful chemicals that accelerate inflammation and scarring.
Emerging therapies also show promise. Inspiratory muscle training (IMT)—breathing against resistance using a device such as the Powerbreathe—has been shown to boost lung strength, improve exercise capacity, and even aid recovery after surgery or Covid-19. Some hospitals now use IMT to prepare patients for major operations.
Other approaches can be surprisingly enjoyable: singing or learning to play a wind instrument also engages and strengthens respiratory muscles. Trials in Denmark and the US suggest these methods may benefit patients with asthma or COPD.
“Healthy lungs provide more than enough oxygen for life,” says John Dickinson of the University of Kent. “But by looking after them, we protect our overall health and improve how we age.”