Contrary to what has been thought, adults who smoke reduced-nicotine cigarettes do not smoke with more intensity to compensate for the lower levels of nicotine and therefore were not exposed to more toxic chemicals, according to a study available online ahead of print in Cancer Epidemiology, Biomarkers & Prevention (doi: 10.1158/1055-9965.EPI-13-0957).
"As a result of the 2009 Tobacco Act, the U.S. Food and Drug Administration has the mandate to reduce nicotine levels in cigarettes to negligible amounts," the first author, David Hammond, PhD, Associate Professor in the School of Public Health and Health Systems of the University of Waterloo in Ontario, noted in a news release. "One of the primary barriers to doing so has been a concern that individuals who continue to smoke will be exposed to greater amounts of toxic chemicals in smoke as they try to extract more nicotine from cigarettes. The current study suggests that this may not be the case.
"Our study suggests that smokers are unable or unwilling to compensate when there is markedly less nicotine in the cigarette and when the experience of smoking is far less rewarding," he continued. "Our study may help regulators anticipate the possible consequences of mandatory nicotine reductions in cigarettes."
He and his coauthor, Richard J. O'Connor, PhD, recruited 72 adult smokers, ages 18 to 65, 42 female and 30 male. After completing a smoking history and demographic data survey, participants smoked their usual brand of cigarettes for one week.
During the next three weeks, they smoked Quest 1, Quest 2, and Quest 3 brand cigarettes, in that sequence, one brand a week. Participants provided urine and breath samples at the end of each week.
Quest 1, Quest 2, and Quest 3 cigarettes have nicotine emission levels of 0.6, 0.3, and 0.05 mg or less, respectively, as opposed to the typical amount of about 1.2 mg in regular cigarettes.
At the end of the study, the researchers found no difference in the number of cigarettes used by the participants, irrespective of the brand; no difference in the number of puffs they took from different brands; no difference in the amount of post-cigarette carbon monoxide levels in their breath; and no difference in urine levels of 1-hydroxypyrene, a chemical in cigarettes with cancer-causing potential.
Cotinine, a breakdown product of nicotine often measured to estimate nicotine levels, however, fell by 34 percent and 55 percent in the participants' urine, after smoking Quest 2 and Quest 3 cigarettes, respectively.
About 44 percent of the study participants reported smoking non-Quest cigarettes during the Quest 3 study period.
The study was funded by the Health Canada Tobacco Control Program, a Canadian Institutes of Health Research New Investigator Award, and a Canadian Cancer Society Research Institute Junior Investigator Award.