Like most people, we’ve noticed that the elderly have a distinctive, shall we say, fragrance. We’ve always blamed prune juice, but it looks like there is something more to it.

Johan Lundström of the Monell Chemical Senses Center in Philadelphia conducted an experiment in which volunteers of all ages slept in special t-shirts outfitted with cotton swabs in the armpit for five straight days. To make sure only their natural scents were being collected the volunteers were told to avoid spicy foods, nicotine and alcohol during the experiment.

Then another group of volunteers — also of all ages — sniffed the cotton swabs. Lundström found that 20 to 30-year-olds are almost always able to accurately guess if the swab came from somebody between 75 and 95.

The sniffers were also able to determine if a swab came from a young or middle-aged person, but without the same degree of accuracy.

Researchers had previously discovered that certain animals are able to make age distinctions based on smell, suggesting there are evolutionary reasons for this ability.

So how do old people smell? According to Lundström, their odor is very real, but “not necessarily unpleasant.”

So if you see an elderly person, don’t be afraid to take a big whiff.

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