Is There Really Such Thing as a Sweet Tooth?
Do you suffer from a ‘sweet-tooth’? Or, have you ever had a patient tell you: “Doc, I just don’t like vegetables!” Albeit an oversimplification, there is a real genetic variation that in fact influences people to prefer sweets or be more averse to the phenols in coniferous veggies.
Consider this from a 2010 study:
“Dental caries is influenced by a complex interplay of genetic and environmental factors, including dietary habits. Previous reports have characterized the influence of genetic variation on taste preferences and dietary habits. Statistically, significant associations were seen in TAS2R38 (bitter) and TAS1R2 (sweet) for caries risk and/or protection.”
TAS2R38 gene is known as the supertasters, children avoid bitter tastes (broccoli) and prefer sweets. It was significantly associated with dental caries in primary dentition, TAS2R38 sensitivity is known to decrease with age, and in fact this gene was not related to caries in mixed and permanent dentitions.
So it appears having a ‘sweet tooth’ is in fact a legitimate genetically influenced thing (at least in young people). How does this impact our interaction with these patients? We can’t simply let them off the hook and throw in the towel can we? Knowing there may be genetic forces at play can be used to your advantage. We want our patients to own their disease; yet they consistently want to push ownership on us. If there is a third party present in the conversation (genetics) it could be the perfect imputes for change.
Let’s see how a conversation may play out:
Doc: “Susie, you know this is the fourth time you have missed school because of cavities right? Have you been able to do the things we talked about? Limiting treats and brushing and flossing?”
Susie: “I have been brushing, but I just have a sweet tooth! All I want to eat are sweets, and I just can’t help it!”
Doc: “Sweets are delicious. In fact, you may actually have a genetic predisposition to liking sweets more than most of your friends, which can make it much harder for you to say no. The problem is, if you do, you have a higher risk of tooth decay and other diseases of your mouth and body.”
Susie: “So my genes make me want sweet food?”
Doc: “Possibly. If that is the case you have to be even more careful about your food choices. Every time you want to have a treat, remind yourself that even though your brain or body seem to really want it, your teeth can’t handle it. Think you can try that?”
Susie: “Yeah, that makes sense.”
If anything, it allows the patient to name the struggle they are facing and instead of it simply being about willpower or rules, it becomes a predisposition to a certain behavior, which when made aware of the possibility, can help them stop and think before having the doughnut or drinking the soda.
Here is a more recent study regarding the association of TAS1R3 and TAS1R2 with dental caries:
Sweet taste is a powerful factor influencing food acceptance. The peripheral taste response to sugar is mediated by the TAS1R2/TAS1R3 taste receptors. The aim of the study was to determine the relationship between TAS1R2 (rs35874116 or rs9701796) and/or TAS1R3 (rs307355) single nucleotide polymorphisms with dental caries experience in schoolchildren. A total of 184 schoolchildren aged between 7 and 12 years (101 girls, 83 boys) were included in the study. Genomic DNA was extracted from saliva samples and the genotypes were identified by qPCR. The genotype frequencies were as follows: 6.6% for homozygous wild type, 41.8% for heterozygous and 51.6% for homozygous polymorphic genotype carriers of TAS1R2 gene rs35874116; 27.8% for heterozygous and 72.2% for homozygous polymorphic genotype carriers of TAS1R2 gene rs9701796, and 83.1% for homozygous wild type and 16.9% for heterozygous genotype carriers of TAS1R3 gene rs307355 polymorphism. A significant association was observed between total caries experience (dft + DMFT – decayed filled primary teeth + decayed, missing and filled permanent teeth) and TAS1R2 rs35874116 (p = 0.008) and TAS1R3 rs307355 (p = 0.04) gene polymorphisms but not for TAS1R2 gene rs9701796 polymorphism. TAS1R3 gene rs307355 polymorphism has been found to be an independent risk factor for dental caries experience by logistic regression analysis and to have increased the risk of caries. Moderate caries experience (4-7 caries) was found to be associated with TAS1R3 rs307355 heterozygous genotype, whereas high-risk caries experience (>8 caries) was found to be associated with TAS1R2 rs35874116 homozygous polymorphic genotype.
“Caries experience (4-7 caries) was found to be associated with TAS1R3 rs307355 heterozygous genotype, whereas high-risk caries experience (>8 caries) was found to be associated with TAS1R2 rs35874116 homozygous polymorphic genotype.”
- Wendell S, Wang X, Brown M, Cooper ME et al. Taste genes associated with dental caries. JDR November 2010. 89(11):1198-1202.
- Haznedaroğlu E, Koldemir-Gündüz M, Bakır-Coşkun N, Bozkuş HM, et al.
- Association of sweet taste receptor gene polymorphisms with dental caries experience in school children. Caries Res. 2015;49(3):275-81. 184 7-12 DMFT.