ABSTRACT
Background:
Genetic variation is implicated in individual preferences for bitter-tasting foods. However, previous studies have focused on candidate genes and limited varieties of bitter-tasting foods, and have treated food preference scale responses as continuous data.
Objectives:
The present investigation aimed to identify genetic variants associated with preferences for bitter-tasting foods utilizing ordinal multinomial regression models in genome-wide association studies (GWAS). In addition, post-GWAS functional annotation and mapping, genetic correlations, and associations with dietary intake were examined.
Methods:
Food preference and genome-wide genotyping data were utilized from the UK Biobank (n=125,578). Preference data from Likert scale rankings (from 1 to 9) for 12 individual foods were analyzed using ordinal multinomial regression GWAS. In addition, one composite continuous variable was created for preference of cruciferous vegetables as a group and analyzed with a linear mixed model GWAS to enable calculation of a polygenic score (PGS) for cruciferous vegetables preference. Convergent validity of GWAS results was assessed with dietary intake data for the same food items in the CARTaGENE cohort (n=8,176). Post-GWAS gene-level and pathway-level association analyses were conducted in MAGMA.
Results:
Forty-six single nucleotide polymorphisms (SNPs) were identified for preferences for 11 bitter-tasting foods at genome-wide significance level (p<7.14 x 10-9). Gene-set analysis for enrichment identified pathways related to caffeine metabolism and bitter taste perception for preference of coffee without sugar and grapefruit, respectively. Genes with higher expression in brain tissues showed stronger genetic associations with cruciferous vegetables preference. The PGS for cruciferous vegetable preference was weakly correlated with intake (r = 0.05, p < 0.0001), but individual SNPs were not associated with intake in a consistent manner.
Conclusions:
Genetic variation contributes to preferences for bitter tasting foods among adults, and some links with food intake are detectable. Nevertheless, effect sizes are small and inconsistent, reflecting the multi-factorial complexity of food intake.
