|Abstract or Summary
- Taste sensitivity has been considered the primary chemosensory factor in studies of chemical senses and ingestive behavior. However, recent research has shown that retronasal olfaction is at least equally important in food preference and selection. Additionally, taste has been shown to modulate perceived intensity of retronasally perceived odors. The objectives of this study were (1) to measure individual differences in retronasal olfactory responsiveness to food odors in the presence and absence of a congruent taste; and (2) to determine the effect of aging and gender on retronasal olfactory responsiveness. We hypothesized that when measured independently, variations 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, particularly for older individuals. Additionally, as taste and retronasal odor were being evaluated separately, it provided us a unique opportunity to compare responsiveness within and across modality. Two groups of subjects (young cohort, n=54, and old cohort, n=48) were asked to sample 2 tastants, 4 food odorants, and the
congruent taste-odor pairs, and rate intensities for appropriate categories. Results showed that responsiveness to odors varied greatly among 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, with greater effect in the old cohort. In addition, responsiveness to the tastes and odors were correlated. Furthermore, the degree of correlation was greater within taste or odor attributes than across modality. These findings imply that an individual's responsiveness to 1 or 2 prototypical tastants or food odors may be predictive of an individual's overall responsiveness for the given modality. The current data also suggest that older individuals, or those with low olfactory sensitivity in general may not recognize the reduced sensitivity when consuming foods.