Background/Aims: TAS2R38 polymorphisms influence bitter taste phenotype. Both have been linked to alcohol consumption; however this has not been demonstrated in all cohorts tested. To date, this interaction has been studied in small cohorts (<100 participants) with males and females combined, with not consideration of a potential gender dimorphism. Therefore we used a larger cohort to assess the gender specificity of this relationship.
Methods: Blood was collected from patients undergoing routine colonoscopy (n=262). TAS2R38 genotype (A49P) was assessed using RFLP-PCR. Bitter taste phenotype (non-tasters vs. tasters) was determined using 6-n-propylthiouracil. Alcohol consumption was assessed using food frequency questionnaires. Frequencies of genotypes and phenotypes were compared by chi-squared tests. Pairwise comparisons were made using least squares means (adjusted for age and smoking status) and t-tests.
Results: Distribution of genotype and phenotype did not vary between genders (χ2=6.52, p=0.16 and χ2=4.67, p=0.13, respectively). Males were significantly older (60.4±1.0 vs. 64.4±1.2, p=0.009) and drank significantly more alcohol (5.0±0.8 vs. 21.1±2.6, p=0.0001). In males genotype and phenotype predicted alcohol intake, with carriers of the “P” variant and “tasters” drinking less (18.1±3.1g/day vs. 31.7±4.6g/day, p=0.01 and 19.1±2.9 vs. 34.2±5.6, p=0.02, respectively). No relationships were found in females. A significant interaction was found between gender and genotype (p=0.004) and phenotype (p=0.005).
Conclusions: A gender dimorphism exists in the relationships between TAS2R38 genotype, bitter phenotype and alcohol consumption. A significant interaction exists between gender and both genotype and phenotype when predicting alcohol intake.
Funding source: CSIRO