Phenylthiocarbamide (PTC) is a chemical substance that some people can taste and others can’t. The ratio of tasters to non-tasters varies by ethnic and racial group around the world, but generally, around 25% of people can’t taste PTC, 50% of people taste it somewhat, and 25% taste it strongly. When tasted, PTC has a bitter taste.
In 1931, the chemist Arthur Fox discovered by accident that he could not taste the bitterness in PTC, while a colleague of his could. The “PTC gene” was discovered in 2003. The ability to taste PTC and to what level is coded in a single gene that effects taste receptors on the tongue.
One theory for why some people can taste PTC and others can’t is that being more sensitive to bitter tastes is an evolutionary benefit. Many toxins and poisons are bitter to the taste, so our ancestors who could taste the bitterness especially well may have been more likely to avoid poisonous plants. PTC isn’t the only chemical that tastes bitter, however. People who can’t taste PTC may be more sensitive to other bitter chemicals that pose similar evolutionary benefit.
“Super tasters,” or people who taste strong bitterness in PTC, may be less likely to consume things that taste bitter, such as broccoli, and are less likely to smoke.
