Do you have a sweet tooth? What about your family and friends? Sweets have a strong appeal, especially to children and adolescents. Although carbohydrates and sugars are important nutrients for humans, it is generally known that eating too many sweets could lead to diseases such as obesity and diabetes. Sweet taste preference is one of the most influential factors for food choice and is known to be affected by various factors such as social, psychological, physiological, and genetic factors. However, previous studies show that an individual's sweet preference is influenced by genetic factors, with a heritability of approximately 50%.
Several candidate gene studies have identified genetic variants associated with food preferences, the majority of which were taste receptor genes (TAS1R2). Moreover, variants in the taste G protein gene GNAT3, and in DRD2 and GLUT2 have been reported to be associated with human sweetness perception and consumption, respectively. Although at the same time, sweet preference is known to vary among ethnicity for example, young African Americans tend t have a greater preference than young European Americans, and in the East Asian population, preference remains scarce.
To gain a better understanding of the genetic factors associated with sweet taste preference, researchers performed a genome-wide meta-analysis to investigate the association of the self-reported score of sweet taste preference with genetic variants in Japanese populations.In this study, participants were enrolled from “HealthData Lab,” which is a Japanese direct-to-consumer (DTC) genetic testing service, and Genequest Inc. The participants (n= 12,312, aged ≥ 18 years old) filled out internet-based questionnaires asking, “Please tell us about your taste for sweet food.” The participants provided their responses on a five-point scale: “Dislike a lot” (score of 1), “Dislike” (2), “Neither like nor dislike” (3), “Like” (4), and “Like a lot” (5). In addition, alcohol consumption and smoking status were also recorded as adjustment variables. The genome-wide meta-analysis revealed a strong positive association between the A allele of rs671 in the aldehyde dehydrogenase 2 (ALDH2) gene and sweet taste preference. However, this gene, when combined with alcohol habits, weakened the likelihood of sweet preference. They further investigated the association between rs671 and sweet taste preference score in males and females independently through subgroup analysis. It revealed that the association was stronger in males than in females. Moreover, ten additional loci were detected with a criterion of suggestive significance, which include rs2448140 in the LOC105375657-MTDH gene and rs56404116 in the KIF16B gene.
An association between alcohol drinking and sweet taste preference has been suggested in previous studies involving non-East Asian populations in which individuals who more strongly preferred sweet taste tended to consume more alcohol and were at a higher risk for alcohol problems. Intriguingly, results in this study in Japanese populations showed a different trend from these previous studies. A high score of sweet taste preference was associated with a reduced amount of alcohol consumption and a lower frequency of drinking. This contradiction might reflect an ethnic difference or point to the complex architecture of factors regulating taste preference. Read more about the study here: https://pubmed.ncbi.nlm.nih.gov/32572145/
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