Smoking Gun For the Young

Kids who smoke like to think that they're immortal--or at least that if they stop in time, their lungs will heal. But a report in last week's Journal of the National Cancer Institute suggests early smoking may trigger changes in DNA that put young smokers at higher risk for cancer even if they later quit. Researchers studying lung-cancer patients found that those with the worst genetic damage were not those who smoked longest but those who started youngest. What's more, the earlier they started, the more severe the damage.

The findings are particularly alarming because they arrived the same week as the results of a survey showing that American children seem to be taking up cigarettes at ever younger ages. The National Parents' Resource Institute for Drug Education, based in Atlanta, reported that 4% of fourth-graders, 7% of fifth-graders and nearly 15% of sixth-graders had already smoked. Add to this the more than 3 million teenagers with the habit, and you have a major health problem.

Doctors used to blame the higher incidence of lung cancer among those who started smoking in their youth on their prolonged exposure to tobacco. But the new study, involving 143 subjects in the Boston area--some of whom lit up as early as age seven--suggests a more insidious cause. Explains epidemiologist John Wiencke of the University of California at San Francisco: "Use of tobacco so early apparently permanently impairs normal processes of cell renewal. Otherwise, their DNA damage would long since have been repaired."

That's not to say kids who have the smoking habit shouldn't try to quit as soon as they can. After all, there are plenty of other tobacco-related diseases--for example, heart disease, stroke and emphysema--that only get worse the longer you smoke.

--By Frederic Golden