Menthol is used as a flavouring agent in some brands of cigarette, and is probably known best for its cooling sensation. Some public health scientists have raised concerns that menthol in cigarette smoke masks the tobacco taste and anaesthetises the mouth, enabling smokers to take bigger puffs and inhale more deeply thereby increasing their intake of nicotine and toxicants. Menthol has therefore become the focus of some regulators, with Brazilian regulators recently banning its use in cigarettes. However, a scientific review by the US FDA concluded as part of its findings that menthol cigarettes are no more risky than non-menthol cigarettes. Researchers at British American Tobacco have examined in 800 smokers the effects of menthol in cigarettes on smokers’ mouth-level exposure to tar and nicotine, as well as their perceived levels of irritation to the mouth and throat (Regulatory Toxicology and Pharmacology, 2012: 63, 381–390).
Two study groups were established: each group consisted of smokers who regularly consume cigarettes, as well as sub-groups who regularly smoke menthol cigarettes versus those who only smoke menthol cigarettes occasionally.
Each smoker was given five products: one without menthol and the remainder with varying levels of menthol. Tar and nicotine exposure was measured using part-filters from each of the test cigarettes. The amount of tar and nicotine in the filters can be measured and used to determine what the smoker was exposed to at mouth level. Smokers also completed a questionnaire about smoking sensation, scoring each product on irritation, throat catch, strength of menthol taste and cooling effect.
The results of this analysis show that although adding menthol to cigarettes correlates with an increased perception of menthol taste and the ‘cooling effect’, there are no marked reductions in levels of irritation and no increases in mouth-level exposure to tar and nicotine.
‘The findings of this study are consistent with other research suggesting menthol in cigarettes does not affect smokers’ exposure to toxicants,’ said Dr Christopher Proctor, Chief Scientific Officer at British American Tobacco. ‘Regulation should be evidence-based and there is no evidence to support banning menthol cigarettes in relation to their relative health risks compared to non-menthol cigarettes.’