According to a Johan Lundstrom, Phd, a sensory neuroscientist at the Monell Chemical Senses Research Center, in Philadelphia who did a study...
He first went around collecting the smell from young people, between the ages of 20-30 (years of age), don't ask me how he did that. Then he sniffed middled aged men and women (45 to 55 years of age) old people, then he sniffed a bunch of old gezzers (75-90 years of age).
The evaluators, as they called themselves, noses the size of bananas, correctly identified which doors belong to the old age people. Surprisingly, they didn't find the smell unpleasant or nasty.
So they came to the conclusion that Yes, Old people do have a definite characteristic odor, but...
"The negative association with old people's body odor seems to come from our negative association with old age not the smell itself.
The evaluators possibly all male, (not verified) said the middle-aged women (45-55 year old) smelled the best. Then old men. Who would have guessed? Then young women, then old women, then young men and last middle aged men. It's odd in this age group, women smell the nicest, and men the worst.
The doc says, "Not to worry, nothing a little shower can't fix!"