Genetic Epidemiology of Taste Perception and Cigarette Use

Cigarettes and other tobacco products contain bitter compounds including nicotine, which contribute to the chemosensory properties of tobacco and stimulate multiple sensory systems, including taste transduction pathways. Since bitter taste has evolved to identify potentially toxic compounds, and thus protect against harmful foods, our hypothesis is that aversion to this taste may prevent smoking and nicotine dependence. The goal of this research was to investigate the role of inherited differences in taste perception in smoking behaviors. We sought to determine whether such genetic variation could account for the well-known differences in flavored tobacco use among different U.S. ethnic groups. For example, around 80% of African-American smokers report that they prefer menthol cigarettes, compared to only 30% of European-American smokers who express this preference. We recruited subjects from four different populations, comprising a total of 9871 individuals, purified DNA’s from some saliva or blood samples and used a candidate gene approach to sequence taste-related genes. We identified several genetic associations between polymorphisms in taste-related genes and different smoking behaviors. We have shown that the frequency of the TAS2R38 taster haplotype differs between smokers and non-smokers in European-American populations. In addition, we identified two SNPs, one located in the menthol receptor TRPM8 and one in the menthol reactive gene TRPA1, that are strongly associated with menthol smoking in a study group of African-Americans. Moreover, we found that the taster haplotype of the TAS2R38 bitter taste receptor gene is less common in European-American smokers and that the non-taster haplotype of this gene is significantly lower in menthol smokers compared to non-menthol smokers. Overall, these findings support the hypothesis that variations in taste-related genes play a role in the choice of cigarettes when smoking. Understanding genetic differences in taste perception in tobacco use could help inform the development of more effective tobacco control policies.