The new research has found that for every 50 cigarettes smoked there is a mutation of DNA per lung cell.
These changes are permanent, and persist even if the individual stops smoking.
If we do the calculation, people who smoke a pack of 20 cigarettes a day for a year will cause the appearance of 150 mutations per lung cell, 97 mutations per cell of the larynx, 39 per cell of the pharynx, 18 per cell of bladder and 6 per liver cell.
Genetic mutations with trigger cells to become cancerous.
It is known that smoking dramatically increases the risk of lung cancer, but also increases the risk of other cancers such as those of oral cavity, larynx, pharynx, esophagus, liver, cervix, pancreas, bladder and kidney.
The new research compared the DNA of tumors from 2,500 smokers to 1,000 non-smokers. What allowed to identify which mutations were associated with smoking.
Each mutation in DNA has the potential to trigger a cascade of genetic damage that causes cells to become cancerous.
There are always cases of smokers who never develop cancer despite accumulating thousands of mutations, but according to the authors of the study, this is luck.
There will be people who, although they will smoke a lot, the mutations will not affect the correct genes and because they will never develop cancer.
Smoking is like playing Russian roulette.
The more you smoke, the more likely it is that mutations will affect the right genes and that cancer will develop.
These results should serve to discourage people from smoking. They also believe the myth that social smoking is harmless: every cigarette has the potential to cause genetic mutations.
Many smokers believe there is no point in quitting because the damage is already done. But although quitting smoking will not reverse the mutations that tobacco has produced, it will avoid the risk of adding more mutations.