SOURCES: Dorothy Hatsukami, Ph.D., associate director, cancer prevention and control, University of Minnesota's Masonic Cancer Center, Minneapolis; Eric Donny, Ph.D., associate professor, psychology, University of Pittsburgh; Norman Edelman, M.D., senior scientific advisor, American Lung Association; Amy Lukowski, Psy.D., clinical director, health initiatives, National Jewish Health, Columbus, Ohio; Oct. 1, 2015, New England Journal of Medicine
WEDNESDAY, Sept. 30, 2015 (HealthDay News) -- Smokers are more likely to cut back or quit if they switch to cigarettes made from tobacco containing very low levels of nicotine, new research shows.
In the study, the participants smoked nearly one-third fewer cigarettes a day and were twice as likely to try to quit, compared with smokers of regular cigarettes, the investigators found.
The best results came with cigarettes containing 0.4 milligrams of nicotine per gram of tobacco.
"That's about 97 percent less than what you'd find in a traditional cigarette," explained senior study author Dorothy Hatsukami, associate director of cancer prevention and control for the University of Minnesota's Masonic Cancer Center.
Nicotine is the addictive agent in tobacco products, and for two decades some researchers have argued that drastically cutting nicotine content could render cigarettes non-addictive, the study authors said in background notes.
The U.S. Food and Drug Administration could use the results of the clinical trial to justify ordering an across-the-board reduction in nicotine content for all U.S. tobacco products, said study author Eric Donny, an associate professor of psychology at the University of Pittsburgh.
"The FDA has the authority to set product standards for tobacco products," Donny said. "They can require tobacco companies to reduce nicotine levels."
Very-low-nicotine cigarettes are not the same as "light" cigarettes, which Congress removed from the market under the 2009 Family Smoking Prevention and Tobacco Control Act, Donny said.
The tobacco in "light" cigarettes contained the same amount of nicotine as regular cigarettes, but tried to reduce the amount of nicotine that smokers received through product design tricks such as ventilated filters or different types of paper, Hatsukami said.
"Light" cigarettes failed to help because smokers would just puff harder and inhale more deeply, and wound up getting the same dose of nicotine as they would have in a normal cigarette, Donny and Hatsukami said.
With very-low-nicotine cigarettes, smokers cannot change the way they smoke to get more nicotine because most of the nicotine has been flushed from the tobacco. "People can't really adjust their behavior to receive the same amount of nicotine anymore," Donny said.
Dr. Norman Edelman, senior scientific advisor for the American Lung Association, explained it this way: "The only way they could do that would be to smoke more, and in this study they did not do that."
In this study, funded by the U.S. National Institutes of Health, 840 smokers at 10 different sites were asked to smoke either their usual brand or one of six other types of cigarettes containing various doses of nicotine. All of the smokers involved said they had no interest in quitting smoking anytime soon.
Normal cigarettes contain about 15.8 mg of nicotine per gram of tobacco (mg/g), Hatsukami said. Participants were given cigarettes containing that dose, as well as 5.2 mg/g, 2.4 mg/g, 1.3 mg/g and 0.4 mg/g. As a final alternative, people were given 0.4 mg/g cigarettes that also contained high tar.
After six weeks, researchers found that people provided cigarettes with a nicotine dose of 2.4 mg/g or less smoked 30 percent fewer cigarettes per day, on average, compared with people smoking regular cigarettes.
Smokers using lower-nicotine cigarettes also had less nicotine dependence, and experienced fewer cravings when they quit smoking for a spell, Donny said.
People smoking cigarettes with 5.2 mg/g or more smoked an average of 21 cigarettes per day, which was about the same as people who kept smoking their own brand, the findings showed.
But smokers with 0.4 mg/g cigarettes only smoked about 15 cigarettes a day, the researchers found.
About 35 percent of people with 0.4 mg/g cigarettes reported an attempt to quit during the follow-up period, compared with 17 percent of people smoking normal-strength cigarettes, according to the report.
The findings were published Oct. 1 in the New England Journal of Medicine.
Amy Lukowski, clinical director of health initiatives at National Jewish Health in Columbus, Ohio, said the results are "really promising" but need to be verified.
"My approach is wait and see, since it was such a short-term study, but I think there's lots of promise in it," Lukowski said.
Tobacco companies already have the technology to mass-produce very low-nicotine cigarettes, Donny said, comparing it to the process that creates decaffeinated coffee.
But Lukowski and Edelman see one potential downside if the FDA orders tobacco companies to lower nicotine levels in their products.
Such a move might signal to the public that cigarettes are now safer, and it's OK to light up, Edelman said. Even though low-nicotine cigarettes are less addictive, they still contain the same carcinogens that make regular cigarettes a threat to human health.
"Some people will be less afraid to smoke," he said. "They'll think that cigarettes have been made safe."
For more on tobacco and nicotine, visit the U.S. National Institute on Drug Abuse.