[B]URLINGTON – New research from the University of Vermont appears to lend support to federal Food and Drug Administration plans to lower nicotine levels in cigarettes to make them less addictive.
The effort by the FDA is the first time the government has tried to curb addiction through regulating nicotine, instead of relying on just taxes and warning labels.
“Envisioning a world where cigarettes would no longer create or sustain addiction, and where adults who still need or want nicotine could get it from alternative and less harmful sources, needs to be the cornerstone of our efforts – and we believe it’s vital that we pursue this common ground,” FDA Commissioner Scott Gottlieb said in a news release.
The Vermont Legislature has attempted to reduce tobacco use in recent years: A bill that would have raised the smoking age to 21 was voted down in March, after being introduced for the second time.
The study by the Vermont Center on Behavior and Health at UVM was conducted in partnership with Brown University, Johns Hopkins University School of Medicine and the University of Kansas.
This is the first large, controlled study to look at the impacts of reduced nicotine levels in cigarettes on smoking in vulnerable populations.
The research team was led by Stephen Higgins, a professor of psychiatry and the director of the UVM center.
“There had been studies in the general population of cigarette smokers saying that lower nicotine levels reduce addiction … but it hadn’t been been done with populations that are vulnerable to tobacco addiction,” Higgins said in an interview Thursday.
The UVM center is home to one of 14 Tobacco Centers of Regulatory Science around the country. It received a grant for the nicotine study from the National Institutes of Health and the FDA. Vermont’s center focuses primarily on the impact of potential policies on vulnerable portions of the population.
The study, which ran between March 2015 and April 2016, included 169 daily smokers: 120 women and 49 men. Of the Vermont participants, 56 were diagnosed with affective disorders, 60 with opioid dependence, and 53 were socioeconomically disadvantaged women.
Study participants completed 14 sessions, ranging from two to four hours each time, and abstained from smoking six to eight hours prior to a session. The study was organized into three phases.
Phase One included sampling of cigarettes, beginning with the participants smoking a regular brand cigarette and ending with a research cigarette that contained varying levels of nicotine. The protocol used double-blind conditions, where the participant and the individual working with her or him are unaware of the nicotine levels.
Participants used a plastic cigarette holder that recorded data on number of puffs, length and speed of each puff. Questionnaires were used to track nicotine withdrawal, smoking urges, research cigarette evaluation and nicotine dependence.
Researchers asked smokers how much they would smoke cigarettes at different nicotine levels, based on a range of prices. These measures are associated with how dependent and addicted the user is, according to Higgins.
He described the results as a “dose effect curve.” Participants tended not to have interest in purchasing the low nicotine level cigarettes but lost interest in the higher level cigarettes when they were paired with high prices.
Smokers clicked a mouse a certain amount of times to receive a the nicotine dose they wanted in their cigarette. The number of clicks started at around 50 and went up to well over 400.
“What the implication is, is that these biases and preferences that people have for the higher dose cigarette, is malleable depending on what the price is,” Higgins said of the findings.
Participants selected a preferred cigarette to smoke in Phase Two, choosing from six different nicotine dose combinations. A computer program recorded which of the two cigarettes participants preferred for that session, and whether or not they wanted to continue smoking it after two puffs or abstain.
The final phase followed the same process as Phase Two, but only measured the highest and lowest nicotine doses.
The study found that although participants tended to prefer the higher nicotine dose research cigarettes, researchers found that the low-nicotine level cigarettes could serve as safer and less-addictive substitutes for commercial cigarettes with higher nicotine levels.
“The overarching finding is that these smokers, and I think it’s true in the general population, are highly controlled by the nicotine in the cigarette,” Higgins said.
He said the idea of looking at whether nicotine reduction could reduce addiction is relatively new. The idea was first raised by researchers in the New England Journal of Medicine in the 1990s, according to Higgins, but wasn’t moved forward until the FDA received legal authority over the regulation of tobacco products in 2009 with the passing of the Tobacco Control Act.
He said a common concern is that a lower-nicotine level cigarette might not reduce withdrawal, or could prompt smokers to consume more cigarettes.
Higgins said the findings refute both ideas. Participants had not smoked for six to eight hours prior to a session, and researchers observed reduced withdrawal with the low dose cigarettes, and no increases in depression.
Higgins said if consumers were to smoke higher quantities of cigarettes, there would be evident changes in how they smoke, such as larger puffs. No data supporting these changes was recorded.
“If you had a policy where the nicotine was reduced in cigarettes, it would reduce the likelihood that you would have addiction, even in these vulnerable populations,” Higgins said.
He suggests that nicotine levels be kept as low as possible. Federal law states that the FDA can recommend reduction in dose if there is proof that it is beneficial to public health. The UVM study examined levels ranging from the average cigarette nicotine dose of of 16 mg. all the way down to 0.4. mg.
Higgins also suggested an alternative approach: The FDA could make lower-nicotine cigarettes easier to obtain, and confine sales of more addictive ones to in special stores, similar to the operation of liquor outlets in several states.
Limitations of the study include brief participant exposure to the research cigarettes. Extended exposure field-testing with vulnerable populations is currently underway, according to the UVM researchers.
“Everything we see in the initial study suggests we’re going to see a similar thing with longer exposure to the research cigarettes,” Higgins said.
