Quitting smoking can reverse the damage caused by smoking, a recent study shows – regardless of how much you previously smoked.

Often, people who have smoked for many years believe that “there’s no point in quitting because the damage has been done”.

However, a recent study, published in the journal Nature, challenges this and gives a new hope to people who want to quit.

When you smoke, the majority of the cells in our lungs are mutated, with cells containing up to 10,000 genetic alternations. It was previously believed that these mutations were permanent and persisted even after a person has stopped smoking.

But according to the study, a small number of cells remain unharmed and healthy, therefore allow our lungs to repair some of the damage caused by smoking – but only once we quit.

Peter Campbell of the Wellcome Sanger Institute is the study’s joint senior author. He is surprised and excited by the results:

“There is a population of cells that, kind of, magically replenish the lining of the airways. We were totally unprepared for this!

“Some of the people in the study had smoked more than 15,000 packs of cigarettes in their life, but within a few years of quitting, many cells lining their airways showed no evidence of damage from tobacco.”

Lung biopsies were analysed from 16 different people, including people who used to smoke and people who still smoke, as well as people who have never smoked and children, looking for specific mutations that can lead to cancer.

The study found that in the lungs of people who used to smoke, damaged cells were replaced by healthy cells, similar to those found in people who have never smoked. The cells in the lungs of ex-smokers were also found to be nearly four times healthier than the cells of those who still smoked.

Paula Chadwick, chief executive of Roy Castle Lung Cancer Foundation, hopes the study will spurs more people to quit:

“The news could be just the motivation people looking to stop smoking need.

“Quitting smoking is not easy, but this study shows you could still reap the benefits and reduce your risk of getting lung cancer – no matter how long you have smoked.”

Here to help you quit

For 30 years, we have been helping people quit smoking. Our dedicated forum, Quit Support, provides essential support from others who know just what they’re going through.

Ben Davis is just one of thousands who used our Quit Support service to stop smoking for good, and make some new friends in the process:

“Quit Support has been fantastic because everyone is on the same journey. You can sound off, have a rant and the reaction is always caring, non-judgemental and positive.”