It's never too late to give up smoking: Scientists discover mechanism for lung self-healing

Some people think that giving up smoking makes no sense, especially in middle or old age. It is believed that mutations that lead to lung cancer persist even after giving up smoking.

"We were totally unprepared for the finding," Dr Peter Campbell, from the Sanger Institute, told BBC News.

He added: "There is a population of cells that, kind of, magically replenish the lining of the airways.One of the remarkable things was patients who had quit, even after 40 years of smoking, had regeneration of cells that were totally unscathed by the exposure to tobacco."

However, a new study published in the journal Nature showed that a small number of intact cells can help restore lungs. And the lungs are self-healing even for those who smoked a pack of cigarettes a day for 40 years before quitting.

Scientists from University College London and the Sanger Institute analyzed lung biopsies of 16 volunteers; some smoked in the past, some continued to smoke at the time of the study, some never smoked.

Genetic changes occur in the cells of the body as they age, and this is considered normal, but some mutations that accumulate can lead to cancer. The study showed that 90% of lung cells in smokers contained up to 10,000 genetic changes, including those that could cause cancer.

However, those who give up smoking, up to 40% of the total number of lung cells were healthy. According to scientists, after giving up smoking in these people, apparently, healthy cells replaced those that were damaged by cigarette smoke.

The exact mechanism of this phenomenon is still unclear, but the authors of the study believe that there is a reservoir of cells that gradually multiply and replace damaged cells when a person gives up smoking.