Editing Supertaster (section)

== Cause ==
In 2003, a significant breakthrough occurred when [[Allele|allelic]] variation in the bitter receptor gene [[TAS2R38]] was identified as the molecular basis for differences in PTC detection thresholds. This gene encodes a [[Receptor (biochemistry)|receptor]] on the tongue that binds to bitter compounds, influencing how strongly an individual perceives the taste of these substances.<ref>{{Cite journal |last1=Kim |first1=Un-kyung |last2=Jorgenson |first2=Eric |last3=Coon |first3=Hilary |last4=Leppert |first4=Mark |last5=Risch |first5=Neil |last6=Drayna |first6=Dennis |date=2003-02-21 |title=Positional Cloning of the Human Quantitative Trait Locus Underlying Taste Sensitivity to Phenylthiocarbamide |url=https://www.science.org/doi/10.1126/science.1080190 |journal=Science |language=en |volume=299 |issue=5610 |pages=1221–1225 |doi=10.1126/science.1080190 |pmid=12595690 |bibcode=2003Sci...299.1221K |issn=0036-8075|url-access=subscription }}</ref> The discovery of TAS2R38's role in taste perception was quickly extended to include sensitivity to propylthiouracil (PROP).<ref>{{Cite journal |last1=Duffy |first1=Valerie B. |last2=Davidson |first2=Andrew C. |last3=Kidd |first3=Judith R. |last4=Kidd |first4=Kenneth K. |last5=Speed |first5=William C. |last6=Pakstis |first6=Andrew J. |last7=Reed |first7=Danielle R. |last8=Snyder |first8=Derek J. |last9=Bartoshuk |first9=Linda M. |date=November 2004 |title=Bitter Receptor Gene ( TAS2R38 ), 6- n -Propylthiouracil (PROP) Bitterness and Alcohol Intake |journal=Alcoholism: Clinical and Experimental Research |language=en |volume=28 |issue=11 |pages=1629–1637 |doi=10.1097/01.ALC.0000145789.55183.D4 |issn=0145-6008 |pmc=1397913 |pmid=15547448}}</ref> Associations between TAS2R38 and the number of [[Fungiform papillae|fungiform papillae (FP)]] were suspected. However, a causal relationship with the supertaster phenomenon has not been established.<ref name=":1">{{Cite journal |last1=Hayes |first1=John E. |last2=Bartoshuk |first2=Linda M. |last3=Kidd |first3=Judith R. |last4=Duffy |first4=Valerie B. |date=March 2008 |title=Supertasting and PROP Bitterness Depends on More Than the TAS2R38 Gene |url=https://academic.oup.com/chemse/article-lookup/doi/10.1093/chemse/bjm084 |journal=Chemical Senses |language=en |volume=33 |issue=3 |pages=255–265 |doi=10.1093/chemse/bjm084 |pmid=18209019 |issn=1464-3553}}</ref>

Molecular genetics indicate that TAS2R38 alleles cannot explain supertasting.<ref name=":1" /> This seems intuitive, as polymorphisms in a specific bitter receptor gene are unlikely to account for heightened responses across multiple taste qualities, oral somatosensation, and retronasal olfaction.<ref>{{Cite journal |last1=Hayes |first1=John E. |last2=Keast |first2=Russell S.J. |date=October 2011 |title=Two decades of supertasting: Where do we stand? |journal=Physiology & Behavior |language=en |volume=104 |issue=5 |pages=1072–1074 |doi=10.1016/j.physbeh.2011.08.003 |pmc=3183330 |pmid=21851828}}</ref><ref>{{Cite journal |last1=Calò |first1=Carla |last2=Padiglia |first2=Alessandra |last3=Zonza |first3=Andrea |last4=Corrias |first4=Laura |last5=Contu |first5=Paolo |last6=Tepper |first6=Beverly J. |last7=Barbarossa |first7=Iole Tomassini |date=October 2011 |title=Polymorphisms in TAS2R38 and the taste bud trophic factor, gustin gene co-operate in modulating PROP taste phenotype |url=https://doi.org/10.1016/j.physbeh.2011.06.013 |journal=Physiology & Behavior |volume=104 |issue=5 |pages=1065–1071 |doi=10.1016/j.physbeh.2011.06.013 |pmid=21712049 |issn=0031-9384|url-access=subscription }}</ref>

In addition, environmental causes may play a role in sensitive taste. The exact mechanisms by which these causes may manifest, as well as possible evolutionary advantages to elevated taste sensitivity, are still unknown.<ref>{{cite journal | vauthors = Navarro-Allende A, Khataan N, El-Sohemy A | title = Impact of genetic and environmental determinants of taste with food preferences in older adults | journal = Journal of Nutrition for the Elderly | volume = 27 | issue = 3–4 | pages = 267–276 | date = 16 September 2008 | pmid = 19042575 | doi = 10.1080/01639360802261920 | s2cid = 44506616 }}</ref><ref>{{Cite web |last=McDonald |first=John H. |date=December 8, 2011 |title=Myths of Human Genetics: PTC tasting |url=https://udel.edu/~mcdonald/mythptc.html |archive-url=https://web.archive.org/web/20240226113809/https://udel.edu/~mcdonald/mythptc.html |archive-date=26 February 2024 |website=udel.edu |pages=54–60}}</ref> No clearcut benefit to the trait has been established: in some environments a heightened taste response, particularly to bitterness, would represent an important advantage in avoiding potentially toxic plant [[alkaloid]]s; however, an increased response to bitterness may limit approach behavior for various palatable foods. 

Moreover, the TAS2R38 genotype has been linked to a preference for sweetness in children,<ref>{{cite journal |vauthors=Mennella JA, Pepino MY, Reed DR |date=February 2005 |title=Genetic and environmental determinants of bitter perception and sweet preferences |journal=Pediatrics |volume=115 |issue=2 |pages=e216–e222 |doi=10.1542/peds.2004-1582 |pmc=1397914 |pmid=15687429}}</ref> avoidance of [[alcoholic beverage]]s,<ref name="Duffy 2004">{{cite journal |display-authors=6 |vauthors=Duffy VB, Davidson AC, Kidd JR, Kidd KK, Speed WC, Pakstis AJ, Reed DR, Snyder DJ, Bartoshuk LM |date=November 2004 |title=Bitter receptor gene (TAS2R38), 6-n-propylthiouracil (PROP) bitterness and alcohol intake |journal=Alcoholism: Clinical and Experimental Research |volume=28 |issue=11 |pages=1629–1637 |doi=10.1097/01.ALC.0000145789.55183.D4 |pmc=1397913 |pmid=15547448}}</ref> increased prevalence of [[Colorectal cancer|colon cancer]] (because of inadequate vegetable consumption),<ref>{{cite journal |vauthors=Basson MD, Bartoshuk LM, Dichello SZ, Panzini L, Weiffenbach JM, Duffy VB |date=March 2005 |title=Association between 6-n-propylthiouracil (PROP) bitterness and colonic neoplasms |journal=Digestive Diseases and Sciences |volume=50 |issue=3 |pages=483–489 |doi=10.1007/s10620-005-2462-7 |pmid=15810630 |s2cid=21099629}}</ref> and avoidance of cigarette smoking.<ref>{{cite journal |display-authors=6 |vauthors=Cannon DS, Baker TB, Piper ME, Scholand MB, Lawrence DL, Drayna DT, McMahon WM, Villegas GM, Caton TC, Coon H, Leppert MF |date=December 2005 |title=Associations between phenylthiocarbamide gene polymorphisms and cigarette smoking |journal=Nicotine & Tobacco Research |volume=7 |issue=6 |pages=853–858 |doi=10.1080/14622200500330209 |pmid=16298720 |doi-access=free}}</ref>