Smoking fewer than five cigarettes a day might not seem like a lot. But new research shows that even a small amount of smoking can cause lung damage and accelerate lung-function decline even decades after quitting.
For some people, there’s a perception that modest smoking isn’t so bad. Not so, say Columbia University Medical Center researchers. In fact, when it comes to loss of lung function, the five-cigarettes-a-day smoker isn’t all that different than someone with a two-pack-a-day habit.
The researchers analyzed the health characteristics of more than 25,000 people. The group included current and former smokers as well as those who never smoked.
Among light smokers, lung function declined at a rate that was closer to heavy smokers than the nonsmokers. Quite simply, so-called light smokers felt much of the same effects as more frequent smokers. A light smoker might lose the same amount of lung function in one year as a heavy smoker loses in nine months.
The study also addressed another perception about smoking, that declines in lung function begin to stabilize some years after a smoker quits. Former smokers did experience lung capacity declines that were about six times smaller than those who continued to smoke. But those lung-capacity declines continued for years after the person quit smoking.
The new findings may also explain why light smokers are at greater risk of developing chronic obstructive pulmonary disease, or COPD. Most prior COPD studies focused on longer-term smokers with heavier habits.
For light smokers, the researchers had this observation: Just a few cigarettes a day may be riskier than you think.