The Bitter Taste of Discovery
The term "supertaster" was coined by experimental psychologist Dr. Linda Bartoshuk during her research at Yale University in the 1990s. This research built upon a curious incident from 1931, when a DuPont chemist named Arthur Fox accidentally released a cloud of a chemical, phenylthiocarbamide (PTC). A colleague complained of an intensely bitter taste, but Fox tasted nothing at all. This revealed a genetic variation in taste perception that fascinated scientists.
Bartoshuk's team at Yale used a related, safer chemical called 6-n-propylthiouracil (PROP) to explore these differences. They discovered the population divides into three groups: roughly 25% are "non-tasters" who are insensitive to PROP. Another 25% are "supertasters," who find PROP unbearably bitter. The remaining 50% are "medium tasters" who perceive some bitterness.
The physical basis for this variation lies on the tongue surface, in the density of fungiform papillae—the mushroom-shaped bumps that house our taste buds. Supertasters have a much higher density of these papillae. While numbers vary, some studies define supertasters as having 35 to 60 papillae in a 6-millimeter circle (about the size of a pencil eraser), compared to 15 to 35 for medium tasters and fewer than 15 for non-tasters. The gene responsible for this trait is TAS2R38, which codes for a bitter taste receptor. The specific variation of this gene determines how strongly an individual perceives the bitter compounds in both PROP and many common foods.
A World of Intense Sensation
Being a supertaster affects the taste of a laboratory chemical. The heightened sensitivity to bitter compounds makes foods like broccoli, kale, grapefruit juice, and coffee intensely bitter. This genetic trait can directly influence dietary habits. Because of their aversion to many bitter vegetables, some supertasters may have an increased risk for certain types of cancer, such as colon cancer.
The high density of papillae also means a higher concentration of pain receptors. This makes supertasters more sensitive to the burn of chili peppers (capsaicin) and the sting of alcohol. They are less likely to smoke or drink heavily. This same sensitivity can make them averse to high-fat foods, and some studies show female supertasters tend to have a lower body mass index.
The distribution of supertasters is not uniform across the globe. Women are more likely to be supertasters than men. People of Asian, African, and South American descent also have a higher prevalence of the trait. This suggests a possible evolutionary advantage, where heightened bitterness detection could have helped ancestors avoid ingesting poisonous plants.