PTC bitter taste genetic polymorphism, food choices, physical growth in body height and body fat related traits among adolescent girls from Kangra Valley, Himachal Pradesh (India)

Background: Bitter sensitivity among individuals and ethnic groups is partly due to polymorphic bitter taste receptor genes (TAS2Rs). PTC/PROP bitter taste responsiveness at locus TAS2R38 is a well-established index of individual variation in oral sensation that has been linked with predicting food liking and consumption. Previous studies suggest that the relationship between PTC/PROP and anthropometric traits remains controversial. Objectives: To explore the role of TAS2R38 locus in taste choices, adolescent growth trend for body height, weight and fat patterning among girls and to evaluate their growth status. Materials and methods: Cross-sectional data on 210 girls ranging in age from 11-18 years were collected from Palampur in the Kangra valley of Himachal Pradesh. Results: The proportion of PTC non-tasters was 19.52%. PTC tasters and non-tasters had some differences in their food choices and preferences. More sensitive PTC tasters had a low preference for raw cruciferous vegetables and bitter tasting foods (like bitter gourd) and beverages, while they had higher preference for sweet-tasting foods (p<0.05). PTC tasters overtook their PTC non-taster counterparts from age 14 through 16 years in having higher mean average skinfold, percentage body fat, fat mass index and fat-free mass index. PTC non-tasters had higher mean stature than tasters through all age groups. PTC tasters had slightly higher mean body weight than tasters at age 11, but in later years the advantage was lost; the total gain among non-tasters through adolescence was higher (78.20%) than tasters (66.92%). PTC thresholds significantly and negatively correlated with body height. Conclusions: TAS2R38 locus seems to have a role in food tastes, choices and preferences. Perceived bitterness of PTC/PROP thresholds were significantly and negatively correlated with body height and fat-free mass. These results, thus, tentatively suggest that the PTC non-taster gene may help in better absorption of calcium than its counter taster allele. Studies on differences in calcium metabolism between PTC tasters and non-tasters are needed to confirm these indications across cultures.