Menthol cigarettes are no harder to quit than nonmenthol cigarettes, and they may actually be less likely to cause lung cancer, according to a new study.
The findings stand in sharp contrast to the FDA advisory committee report released last week that called menthol cigarettes a public health threat.
The study, published Wednesday in the Journal of the National Cancer Institute, found that menthol cigarettes are no more harmful to the health of smokers than regular cigarettes and comes as the FDA is mulling what to do about menthol cigarettes. The 2009 Family Smoking Prevention and Tobacco Control Act barred tobacco manufacturers from adding candy-like flavors to their products — such as cloves and vanilla — but the law left a determination on menthol to the FDA.
“These findings should inform any decision-making process by the Food and Drug Administration to single out menthol cigarettes as uniquely more harmful than nonmenthol cigarettes,” wrote the authors of the new study, led by William Blot, PhD, of the International Epidemiology Institute in Rockville, MD.
More Addictive or Not?
Last week, the FDA’s Tobacco Products Scientific Advisory Committee (TPSAC) concluded that it is “biologically plausible” that adding menthol to cigarettes makes them more addictive and harder to quit.
Menthol is an alcohol that stimulates cold receptors. Found naturally in peppermint and corn oil, it masks the harshness of tobacco smoke and provides a cooling effect.
The TPSAC report is currently being reviewed by experts at the FDA Center for Tobacco Products, which is expected to provide a progress report on its review in 90 days.
In this week’s study, Blot and his team of researchers used data from the Southern Community Cohort Study (SCCS), an ongoing prospective cohort study implemented to examine racial disparities in cancer and other chronic diseases. The study involved nearly 80,000 residents of 12 southern states from 2002 to 2009; participants, who were between the ages of 40 and 79, were administered a computer-assisted personal interview by researchers.
Two-thirds of participants were African American and the rest were mostly white. The study participants were recruited through mailings to samples of the general population and at a community health center.
Smoking rates were very high in the cohort: 33% for black women; 36% for white women, 57% for black men; and 41% for white men.
Menthol Popular Among Blacks
Consistent with previous data, the SCCS data showed that 86% of blacks smoked menthol cigarettes, compared with only 23% of whites.
Opponents of menthol cigarettes have accused tobacco companies of targeting African Americans with their advertising, a claim that was supported by the TPSAC report.
Of those who reported smoking at least 100 cigarettes in their lives, 35% had already quit smoking by the time they enrolled in the study.
The prevalence of quitting among blacks who smoked menthols was the same as for blacks who smoked nonmenthols after adjusting for age, income, education, recruitment source, pack-years smoked, and body mass index. That contradicts what the TPSAC report concluded: that nonwhite smokers who smoke menthol cigarettes have more difficulty quitting than those who smoke nonmenthol cigarettes.
Among whites in the study, people who smoked menthols were actually more likely — 55% more likely — to quit smoking than whites who smoked nonmenthols (95% CI=1.41 to 1.70).
Follow-Up on Quit Rates, Lung Cancer
In 2008, researchers attempted to follow up with everyone in the SCCS database who had reported being a smoker when they were first surveyed. The survey also asked whether each participant smoked menthols or nonmenthols. To date, about 60% of the smokers have been contacted.
Among smokers who were followed for an average of 4.3 years, the odds of quitting smoking were the same for menthol smokers and nonmenthol smokers (OR 1.02, 95% CI=0.89 to 1.16).
Researchers then looked at lung cancer rates in the follow-up cohort, and found, not surprisingly, that lung cancer rates were higher for all smokers, regardless of menthol or nonmenthol status: The mortality rates were increased 10- to 16-fold among nonmenthol smokers and 5- to 14-fold among menthol smokers compared with those who reported never smoking.
When comparing menthol smokers to nonmenthol smokers, the overall risk of lung cancer among smokers of menthol cigarettes was actually 45% lower than for smokers of nonmenthol cigarettes (95% CI=0.47 to 0.90) across all races and genders.
Some have theorized that because menthol masks the harshness of tobacco smoke, it allows smokers to take longer drags, which could be worse for the lungs.
When comparing lung cancer death rates between smokers of the two types of cigarettes, researchers found that the pack-years-adjusted risk of lung cancer mortality was statistically significantly lower for smokers of menthol cigarettes compared with smokers of nonmenthol cigarettes (hazard ratio of mortality=0.69, 95% CI=0.49 to 0.95).
“The findings provide important new evidence that does not support claims that menthol cigarettes impart a greater lung cancer burden than nonmenthol cigarettes,” the study authors wrote. “Cigarette smoking remains the leading cause of premature death in the U.S., but undue emphasis on reduction of menthol relative to other cigarettes may distract from the ultimate health prevention message that smoking of any cigarettes is injurious to health.”
TPSAC Panel: Insufficient Evidence
In its report, the TPSAC panel said there was insufficient evidence to conclude whether smokers of menthol cigarettes have an increased risk of disease caused by smoking compared with smokers on nonmenthol cigarettes.
A spokesman for the FDA said the agency’s tobacco division is not granting interviews at this time.
The TPSAC report looked at more factors than just quit rates and lung cancer. It also determined that cigarette companies that sell menthol cigarettes target minorities and kids with their advertising; and that because menthol reduces the harshness of tobacco smoke, it might be more appealing to kids and get them hooked at an early age.
In the TPSAC report, the SCCS study was mentioned briefly, but TPSAC members said one of its weaknesses is its older study population “which may limit the generalizability of results.”
The authors of the SCCS study said some weaknesses of their study include the inability to tease out smokers who may have switched from one cigarette type to another; the possible misclassification of cigarette type; and the reliance on self-reporting of smoking status.
The study was funded by the National Cancer Institute. None of study authors have financial conflicts of interest and none have ever received funding from the tobacco industry, Blot told MedPage Today.