Effect of Genetic Variation on Salt, Sweet, Fat and Bitter Taste

Background: Taste is one of the primary determinants of food intake and taste function can be influenced by a number of factors including genetics. However, little is known about the relationship between genetic variation, taste function, food preference and intake. Objective: To examine the effect of variation in genes involved in the perception of salt, sweet, fat and bitter compounds on taste function, food preference and consumption. Methods: Subjects were drawn from the Toronto Nutrigenomics and Health Study, a population of healthy men (n=487) and women (n = 1058). Dietary intake was assessed using a 196-item food frequency questionnaire (FFQ) and food preference was assessed using a 63-item food preference checklist. Subsets of individuals were phenotyped to assess taste function in response to salt (n=95), sucrose (n=95), oleic acid (n=21) and naringin (n=685) stimuli. Subjects were genotyped for Single Nucleotide Polymorphisms (SNPs) in candidate genes. Results: Of the SNPs examined in putative salt taste receptor genes (SCNN1(A, B, D, G), TRPV1), the rs9939129 and rs239345 SNPs in the SCNN1B gene and rs8065080 in the TRPV1 gene were associated with salt taste. In the TAS1R2 gene, the rs12033832 was associated with sucrose taste and sugar intake. The rs1077242 SNP in the bitter taste receptor gene TAS2R19 was associated with naringin taste and both grapefruit intake and preference. In the putative fat taste receptor CD36 the rs1761667 and rs1984112 SNPs were associated with intake of total, polyunsaturated and monounsaturated fats as well as oleic acid taste. Conclusions: Our findings demonstrate that genetic variation is associated with differences in taste function, food preference and intake across a number of taste modalities.Ph.D