ABSTRACT
Abnormal or extreme bitterness tends to be equated with dietary danger (Rousseff, 1990; Drewnowski and Gomez-Carneros, 2000). Conditioned through evolution to avoid bitter plant alkaloids and other toxins, humans reject foods that are perceived as excessively bitter (Hladik and Simmen, 1996; Drewnowski and Gomez-Carneros, 2000). The instinctive rejection of bitter taste, most pronounced among children and pregnant women, was at one time critical to survival. One possible explanation for the persistence of 6-n-propylthiouracil-(PROP)-tasting genes in humans is the genetic advantage of being able to detect and avoid bitter poisons (Boyd, 1950). Studies have linked genetic sensitivity to phenylthiocarbamide (PTC) and PROP with a dislike of other bitter tastes and with more aversions to bittertasting foods (Glanville and Kaplan, 1965; Fischer et al., 1961,1984; Forrai and Bankovi, 1984).
