Application, function, and effects of menthol in cigarettes: a survey of tobacco industry documents

Menthol cigarettes are the only cigarette market category identified by use of a flavor additive and constitute more than a quarter of the overall market. Menthol also is used at reduced levels in many nonmenthol brands. Public health research has suggested patterns of use of mentholated brands as a potential explanation for the health disparities between Black (largely menthol) and White (largely nonmenthol) smokers and has explored the effects of menthol on smoker behavior, consumption patterns, and consequent delivery of smoke constituents. However, relatively few published studies have directly examined the physiological impact and function of menthol delivery in cigarettes. In this study, we review internal tobacco industry documents to assess industry research on function and effects of menthol in cigarettes. Industry documents describe a range of physiological effects of menthol, with important implications for use and consumption patterns. These effects include altered perception of tobacco smoke and its constituents via cooling, smoothing, and anesthetic effects; increased impact through stimulation of trigeminal receptors; interaction with nicotine controlling its perception, delivery, and uptake; and increased respiratory irritation and toxic effects. Further studies are needed to evaluate these findings. We conclude that the unique differences between menthol cigarettes and nonmenthol cigarettes must be considered in research, cessation treatment, and enactment of tobacco product regulations.