Summary
Some recent work out of the Monell Center determined if the smell of old people was an actual odor created from the body, and set out to see if research participants could figure out the age of the person from which the odor was sourced. They speculate that the nonenal and nonanal (yes, this is in fact a compound for all you gigglers) are some potential contributors to the odor.
One particularly interesting insight gleaned from the study demonstrated odor participants perceived old-age odors to be neutral in the pleasant-unpleasant spectrum, whereas common reports suggest that many people perceive the odors of the elderly to be unpleasant. The authors suspect that the visual presence of an old person modifies the quality of the odor to the perceiver, pointing out that the high social value in our culture placed on visual cues of youth greatly impacts our olfactory input. Also, participants were not able to discriminate between young (20-30 years) and middle-aged (45-55 years) odor donors in a statistically meaningful fashion.
More work is needed to see if these odors are not coming from pharmaceutical metabolites that are commonly taken by the elderly. In addition, other future studies could work on figuring out the impact of artificial scents on masking natural body odors that point to age.
Abstract
Our natural body odor goes through several stages of age-dependent changes in chemical composition as we grow older. Similar changes have been reported for several animal species and are thought to facilitate age discrimination of an individual based on body odors, alone. We sought to determine whether humans are able to discriminate between body odor of humans of different ages. Body odors were sampled from three distinct age groups: Young (20?30 years old), Middle-age (45?55), and Old-age (75?95) individuals. Perceptual ratings and age discrimination performance were assessed in 41 young participants. There were significant differences in ratings of both intensity and pleasantness, where body odors from the Old age group were rated as less intense and less unpleasant than body odors originating from Young and Middle-age donors. Participants were able to discriminate between age categories, with body odor from Old-age donors mediating the effect also after removing variance explained by intensity differences. Similarly, participants were able to correctly assign age labels to body odors originating from Old-age donors but not to body odors originating from other age groups. This experiment suggests that, akin to other animals, humans are able to discriminate age based on body odor alone and that this effect is mediated mainly by body odors emitted by individuals of old age.
Citation
Mitro, S.; Gordon, A.R.; Olsson, M.J.; Lundstr?m, J.N. (2012). The smell of age: perception and discrimination of body odors of different ages. PLoS ONE, 7, e38110.
Link
PLOS ONE: The Smell of Age: Perception and Discrimination of Body Odors of Different Ages
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