Genetic Sensitivity to Phenylthiocarbamide -Effect on Body Mass Indices and DNA damage

As sensitivity to bitter taste (phenylthiocarbamide [PTC] perception) has been maintained at high frequency worldwide, its use as a potential genetic marker for food preferences and dietary choices and its influence on body weight/adiposity which in turn maybe a contributor to various co-morbidities including malignancy needs to be explored in the Punjabi context where there is higher per capita income, an adapted ‘western’ dietary pattern with traditional culinary habits and reduced physical activity. Since studies linking PTC tasting status, indices of obesity and DNA damage have not come to attention, the present study, using the alkaline Single Cell Gel Electrophoresis assay was carried out to assess genomic damage in peripheral blood leukocytes (PBL) of 144 individuals, both obese (n=96, as determined by body mass index [BMI] and waist-hip ratio [WHR]) and normal weight healthy (n=46) subjects. Their PTC status revealed 73 tasters and 69 non-tasters. The odds ratio revealed a 2.51 times increased risk in non-tasters (OR=2.51; 95%CI 1.20-5.25) for having BMI≥ 25.0 kg/m2 in comparison to risk in tasters while the risk ratio revealed a 1.32 times increased probability of non-tasters for having BMI≥ 25.0 kg/m2 in comparison to tasters (RR=1.32; 95%CI 1.05-1.66). The genetic damage in the obese group (characterized on the bases of their gender and PTC tasting ability) was very highly significant (p<0.001) compared to the values in the matched control group (healthy, normal weight subjects). In both the taster and non-taster groups, BMI and WC (waist circumference) significantly correlated to genetic damage indices though PTC tasting ability did not appear to influence BMI, WHR and WC.