Do the lungs regenerate when you stop smoking?

The lungs are the vital organs that allow us to breathe. Throughout life, they become damaged. “After the age of 2, we live with our “lung capital” and we will only lose lung capacity as the years go by.” explains Professor Jesus Gonzalez, pulmonologist at the Pitié-Salpêtrière University Hospital (Paris). And even more so if we expose them to toxic or irritating substances like tobacco. But what happens if you stop smoking? Do our lungs clean themselves and can return to the way they were before?

With more than 60 carcinogens present in cigarette smoke, tobacco significantly damages lung cells. They mutate and can contain up to 10,000 genetic alterations, which promotes the appearance of pulmonary diseases such as COPD or lung cancer. And when you smoke for a certain amount of time, you can no longer recover your respiratory function. “On the other hand, by stopping smoking early, i.e. before the age of 40, a patient suffering from COPD who is discovered at the chronic bronchitis stage (formerly stage 0) or at stage 1 (modest impairment) can make the disease disappear. inflammation of the bronchi and recovery of respiratory function” warns our interlocutor.

But do we recover normal lungs? In the scientific journal NatureBritish researchers studied the lungs of 16 smokers by biopsy and compared them to the lungs of non-smokers and former smokers. They sequenced the genomes of bronchial epithelial cells (cells that cover the bronchi) and showed that stopping smoking promotes the reconstitution of the bronchial epithelium. In a person who had stopped smoking for at least 10 years, 40% of the cells were healthy, a ratio similar to that of the lungs of a non-smoker.

As Tabac Info Service points out, 1 to 9 months after smoking the last cigarette, the bronchial cilia in the lungs grow back. The ex-smoker is less and less out of breath. Five years after the last cigarette, the risk of lung cancer decreases almost by half. And 10 to 15 years later, life expectancy becomes identical to that of people who have never smoked.

Stopping smoking therefore makes it possible to recover respiratory function and improve the condition of the lungs but we cannot speak of “regeneration” in the literal sense, as we do with the liver because this would imply that the lung can “grow back” after being destroyed which is not the case. It is an organ which does not regenerate but which can “on the other hand, to heal and heal from lesions that are still reversible or from attacks that he suffers” concludes Professor Gonzalez.