Objective: To determine if individuals who taste 6-n-propylthiouracil (PROP), one marker of genetic variation in taste, as exceptionally bitter can also perceive sugars as sweeter, other bitters as more intense, and dietary fats as more creamy and/or viscous than do individuals who taste PROP as weakly bitter. This study examined the association between genetic variation in taste and acceptance for sweet, high-fat, and bitter foods and beverages.
Design: Genetic variation was measured by perceived bitterness of PROP (influenced by genetic, hormonal, and pathologic factors) and density of fungiform papillae on the anterior portion of the tongue (influenced primarily by genetic factors). Four sweet, 3 fat, and 3 bitter groups were derived from principal components analyses of questionnaire items.
Subjects: Convenience sample of healthy adults (24 women, 22 men; mean age +/- standard deviation = 21 +/- 6 years) who did not report high dietary restraint.
Statistical analyses: Pearson product moment correlations between genetic taste measures and food and beverage groups.
Results: The sample showed diversity in genetic taste measures: perceived bitterness of 0.0032 mol/L PROP ranged from "weak" to well above "very strong"; fungiform papillae densities ranged from 33 to 156 papillae per square centimeter. Distribution of perceived bitterness of PROP and fungiform papillae density differed in women and men. The association between genetic taste measures and acceptance of sweet and high-fat groups differed in women and men. In women, liking of sweet and high-fat food and beverage groups decreased with increasing perceived bitterness of PROP. In men, liking of these foods and beverages increased but with increasing papillae densities. Genetic taste measures were not associated with a dislike of bitter food and beverage groups.
Applications: The influence of genetic variation in taste on food intake depends on how perceptible sweet, fat, or bitter components are in foods and beverages, as well as the value of sensory factors vs other factors (e.g., health, convenience) on personal dietary choices. Female supertasters of PROP bitterness may avoid high-fat or sweet foods because these oral sensations are too intense and thus less pleasant. Supertasters may taste more bitterness in vegetables but still enjoy eating them because of their healthfulness and because condiments (especially those that are salt based) can block bitterness.