Decreased discrimination of food odors in the elderly

Sixteen young students, aged 19-25, and 16 healthy elderly subjects, aged 72-78, rated the odor similarity for all 91 combinations of pairs of 14 commercial food flavors. Hedonic ratings were also obtained. Two multidimensional scaling procedures, INDSCAL (Carroll & Chang, 1970) and SSAI-MINISSA (Guttman, 1968; Lingoes, 1965), were applied to the similarity data, yielding flavor spaces or maps which were similar to one another. INDSCAL, an individual difference model, provided weights for each subject on each of the dimensions of a multidimensional space common to all subjects; the weights indicated that the young subjects, but not the elderly ones, were well represented by the common multidimensional arrangement with some idiosyncratic stretching along the axes. The weights and individual subject spaces suggested that the ability of subjects to judge qualitative odor differences between food flavors may decrease with age. Elderly subjects were best at discriminating fruits from the rest of the stimuli.