Give It Up: Cutting back helps, but even a cigarette or two a day carries risks
By Nathan Seppa
Roughly 90 percent of lung cancers stem from tobacco use, with cigarette smoking the main culprit. While cutting back has been known to reduce the overall risk of lung cancer, two long-term studies by separate Scandinavian research teams now show specifically the hazard induced by various amounts of smoking and the benefit that accrues from quitting.
One group reports that heavy smokers who halved their cigarette use reduced their lung cancer risk by more than one-fourth, but quitting decreased the risk more dramatically. The other group also finds that less is better, but its results show that even a cigarette or two each day significantly increases the chances of dying of lung cancer compared with not smoking at all.