The study, conducted at the UCSF (University of California - San Francisco) and San Francisco General Hospital Medical Center, involved 20 healthy adult smokers who smoked their usual brand for a week and then followed it up with a six-week regimen of smoking cigarettes with progressively decreased nicotine content.
The researchers allowed the participants to continue smoking and gradually started decreasing the nicotine content over the next few weeks.
"This study supports the idea that if tobacco companies were required to reduce the levels of nicotine in cigarette tobacco, young people who start smoking could avoid becoming addicted, and long-time smokers could reduce or end their smoking," said Neal Benowitz a UCSF professor of medicine, psychiatry and biopharmaceutical sciences, and chief, Division of Clinical Pharmacology and Experimental Therapeutics at SFGH.
"This could spare millions of people from the severe health effects of long-term smoking," he added.
The researchers conducted the studies to test nicotine-reduction strategies by using commercial low-yield cigarettes. Such cigarettes did not reduce nicotine yield when tested by smoking machines because manufacturers have engineered the cigarettes to burn faster, and they have used highly porous paper and ventilation holes above the filter. These cigarettes contained significant levels of nicotine and such "cigarette engineering" did not lead to decreased nicotine intake, because smokers were easily able to obtain the nicotine by taking more frequent and bigger puffs.
The study provided a strong support for proposals now being considered in Congress to authorize FDA regulation of cigarette smoking, according to the research team.
The researchers said that the legislation giving the FDA authority to regulate tobacco products was currently under consideration by the Congress. Such regulatory authority empowers the agency to develop and enforce standards to make cigarettes less harmful -- including the reduction of the nicotine yields so that cigarettes would be less addictive.
The study was funded by the National Cancer Institute, National Institute on Drug Abuse, California Tobacco Research Program, and Division of Research Resources, National Institutes of Health and appeared in the November 14 issue of the journal "Cancer Epidemiology, Biomarkers & Prevention."