A few cigarettes a day are enough for long-term lung damage. In fact, according to a study by the University of Columbia (USA), which has analyzed more than 25,000 people, the impact of tobacco on lung function lasts for decades, which contradicts that it only takes a few years for The rate of decreased lung function returns to normal after smoking is stopped.
"Many people think that smoking just 'some' cigarettes a day is not so bad, '' says Elizabeth Oelsner, author of the study. But it turns out, he adds, "that the difference in the loss of lung function between a person who smokes five cigarettes a day compared to the one who consumes two packages a day is relatively small."
To reach these conclusions, the researchers specifically analyzed lung function – the amount of air a person can inhale and exhale – in smokers, ex-smokers and in people who have never smoked.
It is known that lung function decreases naturally with age (after 20 years), and also that smoking accelerates this process.
Due to the large number of people analyzed, experts have been able to see differences in lung function between light smokers (minus 5 cigarettes / day) and contumant smokers (more than 30) that other studies have failed to detect.
The results showed that lung function in mild smokers decreases at a rate much more similar to that of persistent smokers than non-smokers. Compared to the rate of decrease in a non-smoker, set to zero for the analysis, the additional decrease for mild smokers is 7.65 ml / year, compared to 11.24 ml / year for heavy smokers.
That means that a mild smoker could lose about the same amount of lung function in a year that a heavy smoker could lose in nine months.
"Smoking a few cigarettes a day is much riskier than many people think," Oelsner warns. Everyone should be encouraged to quit smoking, no matter how many cigarettes per day they are using ».
The difference in the loss of lung function between a person who smokes five cigarettes a day versus the one who consumes two packages a day is relatively small
In addition, the study also proved an assumption, based on a 40-year-old study, which points out the rate of decreased lung capacity normalizes within a few years of quitting smoking.
Data from this new research show that, although lung capacity decreases at a much lower rate in former smokers than current smokers, the rate does not normalize for at least 30 years.
"This information reproduces what many biological studies indicate," says Oelsner. There are anatomical differences in the lung that persist for years after smokers quit smoking.
Smokers are more likely to develop chronic obstructive pulmonary disease (COPD) than those who have never smoked
This then explains the fact that smokers are more likely to develop chronic obstructive pulmonary disease (COPD) than those who have never smoked.
That is, 'occasional' smokers may have a higher risk of developing COPD than most researchers have thought so far, says Oelsner. Most COPD studies have analyzed only smokers with stronger habits (more than 10 years smoking a pack). . (tagsToTranslate) smoking (t) tobacco (t) epoc