According to a research study published recently in Nature, it is found that smokers can turn back time in their lungs when they quit smoking because healthy cells are able to emerge and replace some of their cancer-prone areas and tobacco-damaged areas.
Smokers have long been told that if they can quit smoking, there will be no new damage to the body and their risk of developing diseases like lung cancer will fall.
This study found that when smokers quit smoking, the body appears to draw on a reservoir of healthy cells for replacing the smoke-damaged ones in the smoker’s lungs.
“The results of this study should give new hope to smokers who want to quit”, said Peter Campbell of the UK-based Wellcome Sanger Institute, the study’s joint senior author.
In a statement issued by the institute, he said, ” People often say to me that it’s too late to stop smoking now – the damage is already done as they have been smoking heavily for 30, 40 or more years.”
“But it is so exciting to show from our study that it is never too late to quit smoking.”
He said, “There were some people in the study who had smoked more than 15,000 packs of cigarettes in their life. However, within a few years, we saw no evidence of damage from tobacco in many of the cells lining their airways. ”
There were lung biopsies from 16 people, including ex-smokers, current smokers, analyzed in the study and they also looked for mutations that could lead to cancer from analyzing adults and children who had never smoked.
A normal part of aging is the genetic changes that appear in the body’s cells and many of these mutations are so-called “passenger mutations” which are harmless.
Campbell told AFP, ” The behavior of the cells can dramatically change making them behave more like cancer if there is a mutation in the wrong gene in the wrong cell. The cell will become full-blown cancer if enough of these ‘driver mutations’ accumulate.”
It was found in the study that in nine out of every 10 lung cells in current smokers, there was the presence of some mutations including the ones which could cause cancer. While in ex-smokers, healthy cells, akin to the ones seen in people who had never smoked, had replaced many of those damaged cells in their lungs. It was seen that in ex-smokers, around 40% of the total lung cells were healthy which when compared with still-smoking counterparts, was four times higher.
“The damaged cells did not ‘magically repair themselves’, rather they are replaced by healthy cells that have escaped the cigarette smoke caused damaged.”
The study’s authors believe there may be a sort of reservoir of cells, waiting for a chance to emerge while the precise mechanism by which the replacement occurs still remains unclear.
Campbell said, ” The cells would gradually proliferate from this safe harbor to replace the damaged cells, once the person quits smoking.”
In a review published by Nature, a professor at the Van Andel Institute’s Center for Epigenetics, Gerd Pfeifer, praised the study.
The researchers could study only 16 samples of lung biopsies obtained from people who had undergone biopsies for separate medical reasons because obtaining lung biopsies raises ethical concerns.
Locating the reservoir of healthy cells and working on how they are able to replace the damaged ones is the key to our study now, said Campbell.
“Perhaps we will have opportunities to make the healthy cells even more effective at repair if we can work out where they normally live and what makes them expand when someone stops smoking.”