More than a "characterizing flavor": Menthol at subliminal levels in tobacco products.

INTRODUCTION: In addition to imparting flavor, menthol in menthol-flavored cigarettes enhances nicotine addiction and increases experimentation, initiation, and progression to regular smoking. Menthol can be added to cigarettes at perceptible levels (so-called flavored cigarettes or characterized flavored cigarettes) or non-perceptible levels (subliminal). Our objective was to understand the reasons that tobacco companies use subliminal menthol. METHODS: We identified previously secret internal tobacco company documents dated 1955-2012 in the Truth Tobacco Industry Documents archive on menthol at subliminal levels. RESULTS: Beginning in at least the 1950s, tobacco companies used subliminal menthol to compensate the flavor loss caused by filters, reduce smoke harshness, reduce dryness, and increase smoke coolness. Varying menthol concentrations were considered to help convert people who smoke non-menthol to menthol brands, possibly because people who use menthol cigarettes have more harship quitting than people who use non-menthol cigarettes. CONCLUSIONS: Menthol is an important additive beyond its function as a "characterizing flavor." Tobacco companies use menthol in "non-menthol" cigarettes at subliminal (non-perceptible by the people who smoke cigarettes) levels to improve taste, make them easier to smoke and facilitate initiation, and possibly convert people who smoke non-menthol cigarettes to menthol cigarettes.

Population-Based Disease Odds for E-Cigarettes and Dual Use versus Cigarettes.

BACKGROUND: E-cigarettes are promoted as less harmful than cigarettes. There has not been a direct comparison of health effects of e-cigarettes or dual use (concurrently using e-cigarettes and cigarettes) with those of cigarettes in the general population. METHODS: Studies in PubMed, EMBASE, Web of Science, and PsychINFO published through October 1, 2023, were pooled in a random-effects meta-analysis if five or more studies were identified with a disease outcome. We assessed risk of bias with Risk Of Bias In Non-randomized Studies of Exposure and certainty with Grading of Recommendations, Assessment, Development, and Evaluations. Outcomes with fewer studies were summarized but not pooled. RESULTS: We identified 124 odds ratios (94 cross-sectional and 30 longitudinal) from 107 studies. Pooled odds ratios for current e-cigarette versus cigarette use were not different for cardiovascular disease (odds ratio, 0.81; 95% confidence interval, 0.58 to 1.14), stroke (0.73; 0.47 to 1.13), or metabolic dysfunction (0.99; 0.91 to 1.09) but were lower for asthma (0.84; 0.74 to 0.95), chronic obstructive pulmonary disease (0.53; 0.38 to 0.74), and oral disease (0.87; 0.76 to 1.00). Pooled odds ratios for dual use versus cigarettes were increased for all outcomes (range, 1.20 to 1.41). Pooled odds ratios for e-cigarettes and dual use compared with nonuse of either product were increased (e-cigarette range, 1.24 to 1.47; dual use, 1.49 to 3.29). All included studies were assessed as having a low risk of bias. Results were generally not sensitive to study characteristics. Limited studies of other outcomes suggest that e-cigarette use is associated with additional diseases. CONCLUSIONS: There is a need to reassess the assumption that e-cigarette use provides substantial harm reduction across all cigarette-caused diseases, particularly accounting for dual use.