It used to be thought that the lungs couldn't regenerate, but we now know that is not the case. Broadly speaking, they can repair when you quit smoking, says Dr Charlotte Dean, head of the lung development and disease group at Imperial College London.
How Lungs Heal Themselves
Smoking damages your lungs, but the lungs have a substantial capacity to heal themselves. They have evolved to cope with pollution or infections from bacteria or viruses. Because they are so vital, you cannot survive without your lungs, so they needed to have this capacity, explains Dean.
Limitations of Regeneration
Dean warns that this should not be used as an excuse to smoke. Smoking and vaping expose your lungs to more toxic particles than they can cope with. Importantly, everyone is different. Some people's lungs will not be able to regenerate as well as others and will be much more susceptible to permanent tissue damage from smoking.
While it is broadly true that if you stop smoking you can revert to having much better lung health, it does not mean you are completely out of the woods. You may well have triggered mutations, genetic changes, or tissue damage, and those things can affect your overall lung health, meaning that the decline as you age will come quicker or could lead to cancer.
Importance of Quitting Early
Dean encourages smokers to quit as early as possible. Similar to how your bones do not mend as well as you age, your lung tissue gets less effective at repairing itself as you get older. A healthy lifestyle can help. Exercise is really important. Just like how when you exercise you keep your muscles healthy, in a way the lungs are the same. You build up the capacity for gas exchange to happen more effectively, to provide oxygen around the body.
