Smoking creates mutations in lungs that eventually leads to cancer. Scientists used to believe that these mutations if once occurs remain permanent, even if you quit smoking.
But a new study published in Nature, tells us that our lungs have the ability to repair these mutations if we stop smoking. The study shows that few cells that escape the effects of damage can repair the lungs later. The researches cite seeing the healing effect even in patients who had smoked a pack a day for 40 years before giving up.
The study observed the slow transformation of mutated cells back into being healthy on a massive scale before they led to a cancerous state. An overwhelming majority of cells taken from the smoker’s airways had been mutated by tobacco, with cells containing up to 10,000 genetic alterations.
“These can be thought of as mini time bombs, waiting for the next hit that causes them to progress to cancer,” said Dr Kate Gowers, one of the researchers at UCL.
Among the mutation, few healthy cells managed to survive. The researchers are not so sure how they managed to survive. But when someone quits these cells start growing and replacing the other damaged cells in the lungs.
Interestingly for the people who quite 40% of their cells looked just like the ones from people who had never even smoked. “We were totally unprepared for the finding,” said Dr Peter Campbell, from the Sanger Institute.
“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.”
The researchers are assessing how much of the lungs got repaired in this way. The present study was focused on the major airways of the lungs and not the smaller structures in the lungs called alveoli. Alveoli is the site at which oxygen gets absorbed into our bloodstream.
Earlier studies have suggested that quitting smoking can reduce the risk of lung cancer by half. The assumption behind this had been that through this any further mutations caused by smoking were avoided. But the new study flashes light of the possibility of self-healing by the undamaged cells of the lungs.
Dr Rachel Orritt, from Cancer Research UK, said: “It’s a really motivating idea that people who stop smoking might reap the benefits twice over – by preventing more tobacco-related damage to lung cells, and by giving their lungs the chance to balance out some of the existing damage with healthier cells.”