Individual Differences in Retronasal Odor Responsiveness: Effects of Aging and Concurrent Taste

Abstract

Individual differences in taste sensitivity have been considered the primary chemosensory factor in studies of chemical senses/ingestive behavior. Recent findings suggest, however, that retronasal odor perception is equally important in food preference and selection and, furthermore, the presence of a congruent taste can modulate responsiveness to retronasally perceived odors. The primary objective of this study was to measure individual differences in responsiveness to food odors in the presence and absence of a congruent taste. In order to achieve this goal, we experimentally manipulated the way taste and odor stimuli are presented. We hypothesized that when measured independently, variations across subjects in responsiveness to retronasal odors are greater than those of tastes, but that these variations are effectively reduced by the presence of a congruent taste, especially for the older cohort.

Two groups of subjects (young vs. old cohorts) were asked to sample two tastants, four food odorants, and the congruent taste-odor pairs, and rate intensities for appropriate categories.

Results showed that responsiveness to odors varied greatly across individuals compared to that of tastes and further that variations in odor responsiveness were greater for old compared to young cohort. In the presence of a congruent taste, however, the variations in responsiveness to the odors were significantly reduced, in particular for the old cohort.

The current data suggest that older individuals and those with low olfactory sensitivity may not recognize the reduced sensitivity when consuming foods.