Supertaster

A supertaster is a person who experiences taste with far greater intensity than average. Women are more likely to be supertasters, as are Asians and Africans. Among individuals of European descent, it is estimated that about 25% of the population are supertasters. [BBC [http://www.bbc.co.uk/science/humanbody/body/articles/senses/supertaster.shtml "Science of supertasters"] , "BBC". ] The cause of this heightened response is currently unknown, although it is thought to be, at least in part, due to an increased number of fungiform papillae. [Bartoshuk, L. M., V. B. Duffy, "et al." (1994). "PTC/PROP tasting: anatomy, psychophysics, and sex effects." 1994. "Physiol Behav" 56(6): 1165-71.] The evolutionary advantage to supertasting is unclear. In some environments, heightened taste response, particularly to bitterness, would represent an important advantage in avoiding potentially toxic plant alkaloids. However, in other environments, increased response to bitter may have limited the range of palatable foods. In a modern, energy-rich environment, supertasting may be cardioprotective, due to decreased liking and intake of fat, but may increase cancer risk via decreased vegetable intake. It may be a cause of picky eating, but picky eaters are not necessarily supertasters, and vice versa.

The term originates with experimental psychologist Dr. Linda Bartoshuk who has spent much of her career studying genetic variation in taste. In the early 1990s, Bartoshuk and her colleagues noticed some individuals tested in the laboratory seemed to have an elevated taste response and took to calling them supertasters. [Bartoshuk, L. M. (1991). "Sweetness: History, Preference, and Genetic Variability." Food Technol. 45(11): 108,110, 112-113.] This increased taste response is not the result of response bias or a scaling artifact, but appears to have an anatomical/biological basis.

A brief history of genetic variation in taste

In 1931, A.L. Fox, a DuPont chemist, discovered that some individuals found phenylthiocarbamide (PTC) to be bitter while others found it tasteless. [Fox AF. Six in ten "tasteblind" to bitter chemical. "Sci News Lett" 1931;9:249.] Bartoshuk, L. M. (2000). "Psychophysical advances aid the study of genetic variation in taste." Appetite 34(1): 105.] At the 1931 meeting the of American Academy for the Advancement of Science, Fox collaborated with Blakeslee (a geneticist) to have attendees taste PTC: 65% found them bitter, 28% found them tasteless and 6% described other taste qualities. Subsequent work revealed that the ability to taste PTC was genetic in nature. In the 1960s, Roland Fischer was the first to link the ability to taste PTC, and the related compound propylthiouracil (PROP), to food preference and body type. Today, PROP has replaced PTC in taste research due to a faint sulfurous odor and safety concerns with PTC. As described above, Bartoshuk and colleagues discovered that the taster group could be further divided into medium and supertasters. Most estimates suggest 25% of the population are nontasters, 50% are medium tasters, and 25% are supertasters.

The bitter taste receptor gene TAS2R38 has been associated with the ability to taste PROPDuffy, V. B., Davidson, A. C., Kidd, J. R., Kidd, K. K., Speed, W. C., Pakstis, A. J., Reed, D. R., Snyder, D. J. and Bartoshuk, L. M. (2004) Bitter receptor gene (TAS2R38), 6-n-propylthiouracil (PROP) bitterness and alcohol intake. Alcohol Clin Exp Res, 28, 1629-1637.] and PTC, [Bufe, B., Breslin, P. A., Kuhn, C., Reed, D. R., Tharp, C. D., Slack, J. P., Kim, U. K., Drayna, D. and Meyerhof, W. (2005) The molecular basis of individual differences in phenylthiocarbamide and propylthiouracil bitterness perception. Curr Biol, 15, 322-327.] however it cannot completely explain the supertasting phenomenon. Still, the T2R38 genotype has been linked to sweet preference, [Mennella, J. A., Pepino, M. Y. and Reed, D. R. (2005) Genetic and environmental determinants of bitter perception and sweet preferences. Pediatrics, 115, e216-222.] alcohol intake, colon cancer (via inadequate vegetable consumption) [Basson, M. D., Bartoshuk, L. M., Dichello, S. Z., Panzini, L., Weiffenbach, J. M. and Duffy, V. B. (2005) Association between 6-n-propylthiouracil (PROP) bitterness and colonic neoplasms. Dig Dis Sci, 50, 483-489.] and cigarette smoking.Fact|date=September 2007

Identifying a supertaster

Supertasters were initially identified on the basis of the perceived intensity of PROP compared to a reference salt solution. However, because supertasters have a larger sense of taste than medium or nontasters, this can cause scaling artifacts. Subsequently, salt has been replaced with a non-oral auditory standard. That is, if two individuals rate the same physical stimulus at a comparable perceptual intensity, but one gives a rating twice as large for the bitterness of a PROP solution, the experimenter can be confident the difference is real and not merely the result of how the person is using the scale.

However, many studies do not include a cross-modal reference and simply categorize individuals on the basis of the bitterness of a concentrated PROP solution [Prescott, J., N. Ripandelli, "et al." (2001). "Binary taste mixture interactions in prop non-tasters, medium-tasters and super-tasters." Chem Senses 26(8): 993-1003.] Lanier, SA, JE Hayes, VB Duffy. (2005). "Sweet and bitter tastes of alcoholic beverages mediate alcohol intake in of-age undergraduates." Physiology & Behavior 83(5): 821-831.] or PROP impregnated paper. [Sipiora, M. L., M. A. Murtaugh, "et al." (2000). "Bitter taste perception and severe vomiting in pregnancy." Physiol Behav 69(3): 259-67.] It is also possible to make a reasonably accurate self-diagnosis at home by careful examination of the tongue and looking for the number of fungiform papillae (see external links section). Blue food dye can make this easier. Being a supertaster or nontaster represents normal variation in the human population like eye or hair color, so no treatment is needed.

Problem foods

As a whole, supertasters are less likely to enjoy and thus consume certain foods, although individual supertasters can certainly enjoy and consume these foods. Documented examples for either lessened preference or consumption include:

* alcoholic beverages
* "Brassica oleracea" cultivars
** Brussels sproutsDrewnowski, A, SA Henderson, "et al." (1999). "Taste and food preferences as predictors of dietary practices in young women." Public Health Nutr 2(4): 513-9.] Drewnowski, A, SA Henderson, "et al." (2001). "Genetic taste markers and food preferences." Drug Metab Dispos 29 (4 Pt 2): 535-8.] Dinehart, ME, JE Hayes, "et al." (2006). "Bitter taste markers explain variability in vegetable sweetness, bitterness, and intake." Physiol Behav 87(2): 304-13.]
** cabbage
** kale
* coffee
* grapefruit juice
* green tea
* spinach
* soy products
* carbonation as in carbonated water [http://www.abc.net.au/rn/talks/8.30/helthrpt/stories/s369.htm] Other foods may also show altered patterns of preference and consumption, but only indirect evidence exists:
* chili peppers - capsaicin burn is more intense in supertasters
* tonic water - quinine is more bitter to supertasters
* olives - for a given concentration, salt is more intense in supertasters

ee also

*Somatosensory amplification
*Tetrachromacy

References

External links

* [http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1698869 Diverse tastes: Genetics of sweet and bitter perception] : Genetics of sweet and bitter perception.
* [http://www.sfn.org/index.cfm?pagename=brainBriefings_tasteIntensity Society for Neuroscience - Taste Intensity] : Further reading on taste intensity, including photographs of supertaster vs. nontaster tongue tips illustrating the disparity in the density of fungiform papiliae.
* [http://www.bbc.co.uk/science/humanbody/body/interactives/supertaster/ BBC Supertaster Test]
* [http://faculty.uca.edu/~jmurray/baw2004/taste.pdf Fungiform papillae examination directions]
* [http://www.apa.org/monitor/jan98/food.html What predicts which foods we eat?]
* (thiourea testing)