Do taste genes influence how much alcohol we drink and our body fat?

A recent Nutrients journal study explores the association between polymorphisms in the bitter taste receptor genes, alcohol consumption, and body fat percentage.

Study: The Influence of Taste Genes on Body Fat and Alcohol Consumption. Image Credit: kimberrywood / Shutterstock.com

The genetics of taste

Taste significantly influences the quality and quantity of food consumed. Humans can sense five different tastes, including bitterness, sourness, sweetness, saltiness, and umami.

Bitter taste is extremely sensitive and might have evolved to identify toxic compounds. The Taste 2 receptor (TAS2R) family of receptors is involved in detecting bitter taste; therefore, polymorphisms in these genes could alter the perception of bitter taste.

Previous research has reported that the TAS2R38 gene mediates the bitter taste of thiourea compounds like phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP). Both are synthetic compounds structurally similar to bitter compounds found in cruciferous vegetables, leafy greens, and certain herbs and spices. The TAS2R13 gene also corresponds to bitter taste.

Both TAS2R13 and TAS2R38 have also been closely associated with dietary behaviors. For example, TAS2R38 has been shown to mediate an association between body fat percentage and PROP in six-year-old girls, with this association not observed in boys of the same age.

About the study

The present study explored the associations between TAS2R13 and TAS2R38 haplotype distribution, body fat percentage, and alcohol consumption. Among college students, the frequency distribution of TAS2R13 (rs1015443) was assessed, and the association between polymorphisms in TAS2R38 (rs1726866, rs10246939, and rs713598) and TAS2R13 (rs1015443) and their effect on body fat percentage and alcohol consumption was determined.

A total of 402 participants from diverse socioeconomic backgrounds were included in the current study, 297 of whom were Caucasian and 105 were African American. About 85% of the study participants were women.

Data were obtained between February 2016 and November 2020. All study participants completed a food frequency questionnaire that provided information on food intake and portion sizes over the last year.

To determine alcohol consumption behavior, the World Health Organization’s 10-item Alcohol Use Disorders Identification Test (AUDIT) screening tool was used. Body fat percentage was determined using a bioelectrical impedance analysis.

Study findings

No significant differences in major nor minor allele frequencies were observed between the study population and the general population. Likewise, there was no significant association between the TAS2R38 gene (rs1726866, rs10246939, and rs713598) and alcohol consumption.

Comparatively, the researchers observed an association between the TAS2R13 gene (rs1015443) and the number of drinks consumed on a typical day, the frequency of consumption during the day, and the number of times more than five drinks were consumed in a day. A significant association was also observed between the grams of alcohol consumed and the allelic distribution of TAS2R13 for both Caucasians and African Americans. 

One prior study on head and neck cancer patients reported a significant association between alcohol consumption and rs1015443. Another study noted that the intensity of ethanol taste in the mouth is related to TAS2R13 (rs1015443).

In the current study, alcohol consumption per gram was significantly predicted by age; however, the effect of TAS2R13 rs1015443 was insignificant.

Being African American was associated with lower alcohol consumption. Moreover, a significant combined effect of TAS2R13 (rs1015443) and ethnicity on the percent of body fat was observed; however, the independent impact was insignificant.

The association of body fat with ethnicity and gender was significant across several regression models. The association between TAS2R13 (rs1015443) and body fat was not significant.

Conclusions

The study findings on TAS2R38 polymorphisms contradict previously published research, which reported their significant association with body fat percentage.

Furthermore, no consistent relationship was observed between alcohol consumption and TAS2R13 (rs1015443) despite controlling for demographic factors. Across ethnicities, there was a significant difference in TAS2R13 (rs1015443) allele frequencies; however, this was not true for gender.

Nevertheless, future research is needed to validate these findings in more extensive studies exploring a wider range of bitter and sweet taste receptor genes.

One limitation of the present study is due to the gender imbalance, as about 85% of the sample was female, thus limiting the generalizability of the findings. A test of bitter taste perception could have also been included to strengthen the findings further.

The main strength of the current study was its data collection strategy, which combined objective and subjective measures, including self-reported questionnaires, DNA genotyping, and body composition measurements.