When given whiffs from pieces of pads worn under the armpits of young, middle-aged and elderly people for five consecutive nights, study participants could reliably distinguish the body odor of the elderly, who were 75 and older, the researchers found. …

The notion that the elderly have a distinct smell exists in multiple cultures, and usually the odor is said to be unpleasant. But this probably has more to do with negative perceptions of old age, rather than with the odor itself, according to study researcher Johan Lundström, an assistant professor at the Monell Chemical Senses Center in Philadelphia.

In the study, participants rated the smell of the elderly people as less intense and less unpleasant than the body odor of young people (20 to 30 years old) and middle-aged people (45 to 55 years old). This effect was driven by how the participants rated the body odor from men, who appeared to smell the worst and the strongest in middle age. The odor from women of all ages was rated as less intense than men, and closer to neutral smelling for the young and middle-aged.