Potential Health Effects of Menthol: A White Paper
The objective of this paper is to assess tobacco industry views and research on potential health effects of menthol and menthol cigarettes. A search was conducted among the documents included in the Legacy Tobacco Documents Library. An initial set of words was used, followed by snowball design search. Relevant documents addressed the following subject areas: (1) pharmacology of menthol; (2) menthol’s effect on nicotine metabolism; (3) short and long-term effects of menthol and menthol cigarette use, including carcinogenesis; (4) role of menthol on disease risk; and (5) menthol’s effects on biomarkers of smoking exposure. It is important to underscore that, regarding the health effects of menthol, most of the information tobacco companies used and based their decisions on came from the biomedical literature and not from studies carried out by the companies themselves, who seem to have conducted very little in-house research on the subject. Although menthol pharmacology is well documented, the effect of menthol on levels of biomarkers of smoke exposure is less well examined; however, results collected in the present white paper suggest that menthol does not seem to modify them. In addition, menthol itself appears to be non-carcinogenic, though no documents related to in-house studies analyzing its role in absorption of other carcinogens were found. Reported short-term effects were rare. The tobacco industry documents did not discuss long term long term studies on menthol’s health effects, making it difficult to assess any link to disease risk. We conclude that the tobacco industry works under the assumption that menthol is an innocuous and widely use additive without adverse effects.