The Five Senses and Beyond: The Encyclopedia of Perception - Jennifer L. Hellier 2017

Supertaster

A supertaster is an individual who experiences the sensation of taste to a far greater intensity than that of the average person. Taste can be defined in terms of the lowest detectable concentration, known as the threshold, and at the highest detectable concentration, known as the suprathreshold response. Supertasters are members of a phenotype whose tasting abilities stretch past that of the average suprathreshold response. In the past, this phenomenon has been tested through individuals using the bitter chemical propylthiouracil (PROP) in order to determine the bitterness suprathreshold response in individuals of the supertaster phenotype. Recent studies have shown, however, that supertasting stretches beyond the scope of just bitterness and may involve somatosensation, as well as retronasal olfaction.

History

The term supertaster was coined in 1991 by American psychologist Linda Bartoshuk (1938—) in an article she published in the journal Food Technology, after she and her research team noticed that people with the ability to taste would report perceived perception to a highly variable degree. The initial test used to test for supertasters was the PROP suprathreshold response; however, recent studies have suggested that bitterness is not the only taste sensation involved in supertasting, suggesting that general supertasters may have different sensory responses than those of the PROP supertasters.

Beyond Bitterness

New evidence has emerged to suggest that supertasting is not only limited to orosensory functions, but may also be linked to chemosensory function as well. Most notably, supertasters are able to differentiate between smaller changes in ingredient levels than a “normal” taster. A challenge arises in determining whether supertasting is linked with liking and disliking food in the sense that many people tend to report a distaste for a certain flavor when that taste increases in intensity, whereas others report proportionality between the two. There is currently a hypothesis reported by Calò and colleagues (2011) that a polymorphism in the TAS2R38 bitterness receptor in addition to polymorphisms in the gustin gene known as the gustin polymorphism may act as a genotypic marker for the PROP supertaster phenotype, which, if true, would provide for great advancement in studying the chemosensory influences in supertasting and on eating behavior.

Taste Mechanism

The majority of the oral cavity is lined with papillae, which contain taste receptors. These taste receptors synapse with afferent fibers and are activated whenever a chemical enters the oral cavity. After stimulation of the taste receptors, the afferent fibers project information to the cortex of the brain, encoding an impulse for taste perception. It is believed that it is somewhere in this pathway that the increased perception in supertasters lies. It was long believed that the increase in taste sensation was simply due to the fact that supertasters may have had a higher density of taste receptor genes. However, new evidence shows that polymorphisms in RAS2R38 and gustin genes, both involved in bitterness taste perception, lead to a much higher degree of taste perception to low concentrations of PROP in individuals identified as supertasters.

Associated Issues

Rutgers University food scientist Beverly Tepper found a correlation between supertasters and excessive weight loss, especially in women. She found that women in their 40s who were known to be supertasters were 20 percent thinner than nontasters (people without the ability to taste). This is likely due to the fact that many people who are known supertasters report that foods and beverages that the general public tends to enjoy are too sweet or too bitter. Because of this sensation that normally perceived tastes are too strong for their liking, many supertasters are more likely to limit their eating. This has led many researchers to further develop their knowledge of the correlation between taste sensation disabilities and body mass.

Gage Williamson

See also: Bartoshuk, Linda; Hyperguesia; Hypoguesia; Taste Aversion; Taste Bud; Taste System

Further Reading

Calò, Maria Carla, Alessandra Padiglia, Andrea Zonza, Laura Corrias, Paolo Contu, Beverly J. Tepper, & Iole Tomassini Barbarossa. (2011). Polymorphisms in TAS2R38 and the taste bud trophic factor, gustin gene co-operate in modulating PROP taste phenotype. Physiology & Behavior, 104(5), 1065—1071.

Hayes, John E., & Russell S. J. Keast. (2011). Two decades of supertasting: Where do we stand? Physiology & Behavior, 104(5), 1072—1074.

Webb, Jordannah, Dieuwerke P. Bolhuis, Sara Cicerale, John E. Hayes, & Russell S. J. Keast. (2015). The relationships between common measurements of taste function. Chemosensory Perception, 8(1), 11—18.