Influence of Smoking Fewer Cigarettes on Exposure to Tar, Nicotine, and Carbon Monoxide

In the hope of reducing the adverse health consequences of smoking, physicians frequently advise their patients who cannot quit to smoke fewer cigarettes. Habitual smokers may compensate for the reduced number of cigarettes, however, by taking in more smoke per cigarette. We measured the intake of tar (estimated as mutagenic activity of the urine), nicotine, and carbon monoxide during short-term cigarette restriction. With a reduction from an average of 37 cigarettes to an average of 5 cigarettes per day, the intake of tobacco toxins per cigarette increased roughly threefold and daily exposure to tar and carbon monoxide declined only 50 percent. We conclude that smoking fewer cigarettes may reduce exposure to toxins and related adverse health consequences. However, consistent with a tendency to maintain intake of nicotine, the magnitude of the benefit is much less than expected. Whether “oversmoking” persists during long-term restriction of cigarettes requires further investigation. (N Engl J Med 1986; 315:1310–3.), WHEN faced with smokers who refuse to stop smoking, physicians frequently advise their patients to switch to low-yield brands and to cut down on the number of cigarettes smoked daily. Recent research, however, has shown that switching to low-yield cigarettes is of limited value, because smokers compensate for lower yields by increasing their intake of mainstream smoke from each cigarette.