Objectives To determine what the tobacco industry knew about menthol cigarettes and the initiation of smoking.

Methods Based on Food and Drug Administration staff-supplied research questions we used a snowball sampling strategy to search the Legacy Tobacco Documents Library (http://legacy.library.ucsf.edu) between February and April 2010. Of the approximately 11 million documents available in the LTDL, the iterative searches returned tens of thousands of results. Researchers reviewed 2634 documents and 128 were deemed relevant to one or more of the research questions.

Results The documents show that menthol is added to cigarettes in part because it is known to be an attractive feature to inexperienced smokers who perceive menthol cigarettes as less harsh and easier to smoke and because of their availability from friends and family. Second, the tobacco industry found that some youths smoke menthols because they perceive them to be less harmful than non-menthol cigarettes. A key product design issue concerns whether to increase brand menthol levels to appeal to the taste preferences of long-term menthol smokers or keep menthol levels lower to appeal to inexperienced smokers. Marketing studies showed that the companies carefully researched the menthol segment of the market in order to recruit younger smokers to their brands. The industry tracked menthol cigarette usage by age, gender and race to inform product development and marketing decisions.

Conclusions Menthol is a prominent design feature used by cigarette manufacturers to attract and retain new, younger smokers.