08/12/07
Do you believe that if you quit smoking, time will eventually heal the damage in your lungs? A recent study by the University of California San Francisco warns this may not be entirely true, particularly if you started smoking before age 20.
The study investigated lung cancer risk factors by measuring changes in cell DNA, called adducts. Adducts cause mutations in DNA, altering how the cell functions and increasing the risk of it becoming cancerous.
In an attempt to predict the smoking-related risks of lung cancer, the researchers compared the adduct levels in the lungs of both current and former smokers with the adduct levels of nonsmokers.
In current smokers, adduct levels are eight times higher. For former smokers, the risk depends on when they began smoking. How long or how heavily they smoked didn’t appear to make as big a difference.
For former smokers who started before age 15, the adduct level was more than five times higher than normal. If smoking began between ages 15 and 20, the adduct level was three and a half times higher. However, in people who began smoking after age 20 and subsequently quit, researchers found adduct levels a little more than twice as high as those of a nonsmoker. This means that the measured lung damage in smokers who began after age 20 is less than half that of those who began smoking earlier.
Immature lungs may be more susceptible to the genetic changes caused by the toxins in cigarette smoke because they are still growing, just like the rest of a child’s or teen’s body. Previous studies have shown that smoking prevents lungs from reaching their full maturity and that teens are addicted to smoking more easily. In addition, those who begin smoking during this time are less likely to quit.
Teen smoking is on the rise in the United States.