DNA Repair Polymorphisms and Frequencies of Genetic Aberrations among Indian Tobacco Chewers

Tobacco is a uniquely dangerous consumer product that is addictive and harmful to human health when used as intended. Smokeless tobacco practices are common in some parts of the world, especially in India (Pershagen, 1996). Nicotine exposure is similar in smokeless tobacco users and smokers (Ebbert et al., 2006) often leading to strong physical dependence. As a rule, smokeless tobacco products contain high levels of nitrosamines with carcinogenic potency in experimental animals (Phillips et al., 2004). Habitual use of oral tobacco can increase the risk of oral cancer, but the data are insufficient to assess in detail the risks associated with many types of smokeless tobacco. Tobacco induces DNA adducts and oxidative DNA damage in human tissues. Formation of carcinogen– DNA adducts in critical genes can lead to mutations that alter protein function and that cause the carcinogenic progression of cells from normality to neoplasias (Hainaut et al., 2001; Cooper, 2002). Goran Pershagen suggested that smokeless tobacco use is related to genotoxicity affecting DNA repair pathways (Pershagen, 1996).