Low nicotine cigarettes: cigarette consumption and breath carbon monoxide after one year

Subjects who took part in a 12-wk study of switching behavior were observed during the subsequent year. Data were obtained for 96 smokers every 3 mo. A sample of smokers who, at 12 wk, had switched to a brand delivering less than half the nicotine of their baseline brand were offered continued monetary incentives to participate for an additional 6 mo (maintenance study). In the maintenance study, subjects continued to smoke low-nicotine cigarettes during the 6-mo period in which money and contact reinforcement were continued; maintenance control subjects increased their tar and nicotine exposure significantly. In the follow-up study of those who had not changed by more than 50%, the original control group, nonswitchers, and moderate switchers did not significantly change their nicotine exposure from what it had been at the end of the initial 12-wk study. Carbon monoxide (CO) in breath showed remarkably little change across the year despite substantial changes in tar and nicotine exposure. To the extent that CO is involved in smoking-related disorders, switchers derived little if any benefit from switching to low-nicotine brands.