De Geus . ( ) carried out a systematic review and meta-analysis of the results obtained in the studies on DNA damage induced in oral (buccal) cells of smokeless tobacco users. The authors mentioned that “most of the recent studies have shown that the frequency of micronucleus (MN) is significantly higher in chewing tobacco [better to write “in tobacco chewers”] and snuff users than in non-users, but there is still a controversy in the literature”. The first part is completely true but the second one not at all. Indeed, the authors cited 3 papers which (in their opinion) reflect “controversy in the literature” (refs. 16 – 18). But two of them reported about positive results (increased MN levels in buccal cells of users) and only one (ref. 17) presented negative findings in buccal cells of 'maras' powder users but significant increase of MN frequencies (1.44-fold; < 0.01) in exfoliated inner lip cells. It is important to mention that “maras” powder (one portion is 0.5 – 1.0 g) is applied to the lower lip mucosa and has no direct contact with buccal cells.
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