Is the association between sweet and bitter perception due to genetic variation?

Hwang, Liang-Dar, Breslin, Paul A. S., Reed, Danielle R., Zhu, Gu, Martin, Nicholas G. and Wright, Margaret J. (2016) Is the association between sweet and bitter perception due to genetic variation?. Chemical Senses, 41 9: 737-744. doi:10.1093/chemse/bjw083


Author Hwang, Liang-Dar
Breslin, Paul A. S.
Reed, Danielle R.
Zhu, Gu
Martin, Nicholas G.
Wright, Margaret J.
Title Is the association between sweet and bitter perception due to genetic variation?
Journal name Chemical Senses   Check publisher's open access policy
ISSN 1464-3553
0379-864X
Publication date 2016-11-01
Year available 2016
Sub-type Article (original research)
DOI 10.1093/chemse/bjw083
Open Access Status Not yet assessed
Volume 41
Issue 9
Start page 737
End page 744
Total pages 8
Place of publication Oxford, United Kingdom
Publisher Oxford University Press
Language eng
Abstract Perceived intensities of sweetness and bitterness are correlated with one another and each is influenced by genetics. The extent to which these correlations share common genetic variation, however, remains unclear. In a mainly adolescent sample (n = 1901, mean age 16.2 years), including 243 monozygotic (MZ) and 452 dizygotic (DZ) twin pairs, we estimated the covariance among the perceived intensities of 4 bitter compounds (6-n-propylthiouracil [PROP], sucrose octa-acetate, quinine, caffeine) and 4 sweeteners (the weighted mean ratings of glucose, fructose, neohesperidine dihydrochalcone, aspartame) with multivariate genetic modeling. The sweetness factor was moderately correlated with sucrose octa-acetate, quinine, and caffeine (rp = 0.35-0.40). This was mainly due to a shared genetic factor (rg = 0.46-0.51) that accounted for 17-37% of the variance in the 3 bitter compounds' ratings and 8% of the variance in general sweetness ratings. In contrast, an association between sweetness and PROP only became evident after adjusting for the TAS2R38 diplotype (rp increased from 0.18 to 0.32) with the PROP genetic factor accounting for 6% of variance in sweetness. These genetic associations were not inflated by scale use bias, as the cross-trait correlations for both MZ and DZ twins were weak. There was also little evidence for mediation by cognition or behavioral factors. This suggests an overlap of genetic variance between perceptions of sweetness and bitterness from a variety of stimuli, which includes PROP when considering the TAS2R38 diplotype. The most likely sources of shared variation are within genes encoding post-receptor transduction mechanisms common to the various taste G protein-coupled receptors.
Formatted abstract
Perceived intensities of sweetness and bitterness are correlated with one another and each is influenced by genetics. The extent to which these correlations share common genetic variation, however, remains unclear. In a mainly adolescent sample (n = 1901, mean age 16.2 years), including 243 monozygotic (MZ) and 452 dizygotic (DZ) twin pairs, we estimated the covariance among the perceived intensities of 4 bitter compounds (6-n-propylthiouracil [PROP], sucrose octa-acetate, quinine, caffeine) and 4 sweeteners (the weighted mean ratings of glucose, fructose, neohesperidine dihydrochalcone, aspartame) with multivariate genetic modeling. The sweetness factor was moderately correlated with sucrose octa-acetate, quinine, and caffeine (rp = 0.35-0.40). This was mainly due to a shared genetic factor (rg = 0.46-0.51) that accounted for 17-37% of the variance in the 3 bitter compounds' ratings and 8% of the variance in general sweetness ratings. In contrast, an association between sweetness and PROP only became evident after adjusting for the TAS2R38 diplotype (rp increased from 0.18 to 0.32) with the PROP genetic factor accounting for 6% of variance in sweetness. These genetic associations were not inflated by scale use bias, as the cross-trait correlations for both MZ and DZ twins were weak. There was also little evidence for mediation by cognition or behavioral factors. This suggests an overlap of genetic variance between perceptions of sweetness and bitterness from a variety of stimuli, which includes PROP when considering the TAS2R38 diplotype. The most likely sources of shared variation are within genes encoding post-receptor transduction mechanisms common to the various taste G protein-coupled receptors.
Keyword IQ
Personality
Sweetener
TAS2R38
Taste
Twins
Q-Index Code C1
Q-Index Status Provisional Code
Grant ID R01 DC014286
S10 OD018125
Institutional Status UQ

 
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