Old person smell is the characteristic

odor An odor (American English) or odour (English in the Commonwealth of Nations, Commonwealth English; American and British English spelling differences#-our, -or, see spelling differences) is caused by one or more volatilized chemical compounds ...

of elderly humans. Much like many animal species, human odor undergoes distinct stages based on chemical changes initiated through the

aging Ageing ( BE) or aging ( AE) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal. In ...

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 2-Nonenal is an unsaturated aldehyde. The colorless liquid is an important aroma component of aged beer and buckwheat. Odor characteristics The odor of this substance is perceived as orris, fat and cucumber Cucumber (''Cucumis sativus'') ...

, an unsaturated

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl grou ...

which is associated with human

body odor Body odor or body odour (BO) is present in all animals and its intensity can be influenced by many factors (behavioral patterns, survival strategies). Body odor has a strong genetic basis, but can also be strongly influenced by various diseases ...

alterations during

; however, there are other hypotheses. Another study failed to detect 2-nonenal at all, but found significantly increased concentrations of

benzothiazole Benzothiazole is an aromatic heterocyclic compound with the chemical formula . It is colorless, slightly viscous liquid. Although the parent compound, benzothiazole is not widely used, many of its derivatives are found in commercial products or ...

, dimethylsulphone, and

nonanal Nonanal, also called nonanaldehyde, pelargonaldehyde or Aldehyde C-9, is an aldehyde. A colourless, oily liquid, nonanal is a component of perfumes. Although it occurs in several natural oils, it is produced commercially by hydroformylation of 1- ...

on older subjects. In 2012, the

Monell Chemical Senses Center The Monell Chemical Senses Center is a non-profit independent scientific institute located at the University City Science Center campus in Philadelphia, in Pennsylvania. Monell conducts and publishes interdisciplinary basic research on taste, Olfa ...

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." Old person smell is known as in Japan, where much social value is placed on personal grooming, and specific upmarket odor-eliminating soaps are targeted at more elderly consumers.

References

{{Reflist Old age Gerontology Fatty aldehydes Body odor