Wednesday, April 22, 2015

The Scientific Case for Regulating Menthol: Next to Nothing

Ever since the FDA started regulating tobacco in 2009, a principal objective of tobacco opponents has been a menthol cigarette ban.  Congress could have banned menthol in its authorizing legislation, but Matthew Myers, president of Tobacco-Free Kids and principal architect of the legislation, knew that menthol was a congressional poison pill.  Instead, Congress directed the FDA to conduct a special investigation that prohibitionists hoped would lead to a ban.

The FDA is obligated to act in an unbiased fashion and base its actions on credible scientific evidence.  When, in 2011, the FDA Tobacco Products Scientific Advisory Committee found, on weak evidence, that menthol had a negative impact on public health, a federal judge barred the agency from acting because the committee was tainted by conflicts of interest.

In 2013, the FDA tackled menthol again, issuing a “Preliminary Scientific Evaluation of the Possible Public Health Effects of Menthol Versus Nonmenthol Cigarettes.”  As I pointed out, the agency’s case against menthol was entirely unconvincing. A subsequent filing by Lorillard underscored that fact.    

Late last year, investigators from Reynolds American and Environ International published a series of articles on the impact of menthol cigarettes on current smoking patterns, smoking initiation, measures of dependence and smoking cessation.  While previous reports from anti-tobacco activists used cherry-picked data from various sources, the Reynolds-Environ studies utilized well-documented methods to analyze data from four major surveys: the National Health Interview Survey (NHIS), the National Survey on Drug Use and Health (NSDUH), the National Health and Nutrition Examination Survey (NHANES) and the Tobacco Use Supplement to the Current Population Survey (TUS-CPS).  Following are topline results from the Reynolds-Environ studies, published in Regulatory Toxicology and Pharmacology.

Current Smoking Patterns

“In summary, the current analyses examine menthol cigarette use, overall and within demographic strata, among four nationally representative samples of U.S. adults, and in some instances among youth. Findings from these analyses confirm that adult female smokers are more likely to use menthol cigarettes compared to male smokers, and that a majority of adult non-Hispanic Black smokers use menthol cigarettes; these patterns persist regardless of smoking frequency. Smokers in other race/ethnicity groups may be more likely to use menthol cigarettes compared to non-Hispanic White smokers, but are not more likely to use menthol cigarettes compared to smokers overall. Finally, higher proportions of younger adult smokers (aged 18–25 years) report using menthol cigarettes compared to older adult smokers (aged 26–29 years and 30+ years), but statistically significant differences are inconsistent and numerical differences are small in magnitude; the limited data for youth smokers do not provide consistent patterns of menthol cigarette use.”

Smoking Initiation

“Results from the analyses provided herein indicate that menthol cigarette use is not associated with an earlier age of initiating smoking or a greater likelihood of being a daily versus non-daily smoker; and, that menthol cigarette preference is not greater among new, less-experienced compared to more-established youth smokers.”

Measures of Dependence

“In summary, findings from the current analyses that examine number of cigarettes smoked per day, time to first cigarette after waking and HSI [the Heaviness of Smoking Index], coupled with evidence from previous studies based on nationally representative populations do not support an evidence-based conclusion that menthol in cigarettes increases dependence among U.S. smokers. Results from the current analyses indicate that menthol smokers do not report smoking a greater number of cigarettes per day compared to non-menthol smokers; that the distribution of menthol compared to non-menthol smokers into categories of time to first cigarette after waking is nearly identical; and, that menthol smokers are generally more likely to be in a lower versus higher HSI (i.e., dependence) category.”

Smoking Cessation

“Data from the NHIS (2005 and 2010) generally suggest no statistically significant association between menthol cigarette use and being a former versus current smoker for any of the three race/ethnic groups, while data from TUS-CPS (2010/11) generally suggest a statistically significant inverse association between menthol cigarette use and having quit smoking, particularly among non-Hispanic Blacks…[The analyses] provided inconsistent results with regard to menthol cigarette use and quitting, both within surveys (i.e., comparing race/ethnicity groups) and between surveys (i.e., same race/ethnicity group across surveys).”

In summary, these comprehensive analyses document that menthol cigarettes are more popular among women, blacks and younger smokers.  The surveys show that menthol plays virtually no role in smoking initiation and dependence.  With respect to whether menthol affects cessation, the NHIS and the TUS-CPS reveal inconsistent results.

Earlier studies of menthol cigarettes showed that they may be associated with lower risk for lung cancer (here) and stroke (here), although this does not mean that they are safer than nonmenthol cigarettes.  The Reynolds-Environ studies provide evidence that there are no significant differences between menthol and regular cigarettes with respect to smoking initiation, addiction to nicotine, or cessation. 
This set of publications use publicly available data; the methods are completely transparent and comprehensive; the findings are broad and highly credible.   

There is no justification for FDA action to ban or otherwise restrict menthol in cigarettes.

No comments: