Sensory acceptance of Japanese green tea and soy products is linked to genetic sensitivity to 6-n-propylthiouracil.

Genetic sensitivity to 6-n-propylthiouracil (PROP), a heritable trait, has been linked to increased sensitivity to and increased dislike of other bitter compounds. Many phytochemicals with reputed chemopreventive activity have a bitter taste. This study tested the hypothesis that PROP-sensitive women would be more likely to reject Japanese green tea and selected soy products. Both foods contain bitter flavonoids that are thought to be useful in cancer prevention and control. Study subjects, 53 normal-weight, healthy young women, were divided into PROP nontasters (n = 14), regular tasters (n = 28), and supertasters (n = 11) on the basis of their PROP detection thresholds and mean response ratios to PROP compared with NaCl solutions. The subjects tasted a range of soy products, including tofu, miso, plain soymilk, vanilla-flavored soymilk, and five different concentrations of Japanese green tea. Taste intensity and hedonic preference ratings were measured using nine-point category scales. PROP sensitivity was linked to greater perceived bitterness and increased dislike of Japanese green tea. PROP tasters and supertasters preferred vanilla-flavored soymilk over other soy products. Genetic taste markers may alter dietary exposure to substances thought to affect cancer risk.