There appears to be some clue about age of a person from body smell,as some people are able to correctly guess a person's age just by the smell of their body.
The study also reveals that contrary to popular belief, the so-called 'old-person smell' is less intense and less unpleasant than body odors of middle-aged and young individuals.
Like non-human animals, human body scents contain a range of chemical components that can transmit various types of social information, and the composition of these odors changes across a person's lifespan.
To test if people can intuitively sense these changes, the researchers, led by Johan Lundstrom of the Monell Chemical Senses Center in Philadelphia, Pennsylvania, collected body odors from young, middle-aged, and old participants, in the form of a t-shirt with underarm pads which were slept in for five nights.
These scents were then evaluated by a different set of evaluators, who were asked to rate the intensity and pleasantness of each odor, identify which of two scents came from the older individual, and estimate the age of the individual who produced each sample.
The participants were able to distinguish between the three donor age categories, and the researchers found that it was odors from the old-age group that were driving this ability.
Interestingly, however, evaluators rated body odors from the old-age group as less intense and less unpleasant than the smells from the other two age groups.
"Elderly people have a discernible underarm odor that younger people consider to be fairly neutral and not very unpleasant," said Lundstrom.
"This was surprising given the popular conception of old age odor as disagreeable. However, it is possible that other sources of body odors, such as skin or breath, may have different qualities," he added.
This study has been published the open access journal PLoS ONE.