Old person smell is the characteristic odor of elderly humans. Much like many animal species, human odor undergoes distinct stages based on chemical changes initiated through the aging process. Research suggests that this enables humans to determine the suitability of potential partners based on age, in addition to other factors.
One study suggested that old person smell may be the result of 2-nonenal, an unsaturated aldehyde which is associated with human body odor alterations during aging; however, there are other hypotheses, such as change of the monounsaturated fatty acid composition of skin surface lipids and the increase of lipid peroxides associated with aging. Another study failed to detect 2-nonenal at all, but found significantly increased concentrations of benzothiazole, dimethylsulphone, and nonanal on older subjects.
In 2012, the Monell Chemical Senses Center published a press release claiming that the human ability to identify information such as age, illness, and genetic suitability from odor is responsible for the distinctive "old man smell". Sensory neuroscientist Johan Lundström stated, "Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant."
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- Haze, S.; Gozu, Y.; Nakamura, S.; Kohno, Y.; Sawano, K.; Ohta, H.; Yamazaki, K. (2001). "2-Nonenal Newly Found in Human Body Odor Tends to Increase with Aging". Journal of Investigative Dermatology. 116 (4): 520–4. doi:10.1046/j.0022-202x.2001.01287.x. PMID 11286617.
- MacMillan, Amanda. "Scientists Confirm Existence of 'Old Person Smell'". Health.com. Health Media Ventures, Inc. Archived from the original on 8 September 2015. Retrieved 30 May 2012.
- Stücker, M.; Struk, A.; Altmeyer, P.; Herde, M.; Baumgärtl, H.; Lübbers, D. W. (2002). "The cutaneous uptake of atmospheric oxygen contributes significantly to the oxygen supply of human dermis and epidermis". The Journal of Physiology. 538 (3): 985–994. doi:10.1113/jphysiol.2001.013067. PMC 2290093. PMID 11826181.
- Gallagher, M.; Wysocki, C.J.; Leyden, J.J.; Spielman, A.I.; Sun, X.; Preti, G. (October 2008). "Analyses of volatile organic compounds from human skin". British Journal of Dermatology. 159 (4): 780–791. doi:10.1111/j.1365-2133.2008.08748.x. PMC 2574753. PMID 18637798.
- "The special scent of age". EurekAlert! (Press release). Monell Chemical Senses Center. 30 May 2012. Archived from the original on 20 June 2015.
- Levenstein, Steve (6 August 2008). "Japan's Aging Population Deals with Old Man Smell". Inventor Spot. Halcyon Solutions Inc. Archived from the original on 6 September 2015.