subject: Old People Have Their Own Body Odors [print this page] Both human and non-human animal body odors are rich with chemical components that can transmit useful social information, the scientists say. And many animals, including mice, rabbits, owls and monkeys, are known to undergo changes to the chemical composition of their body odor as they age. It is similar that the odor of a new ball mill and an old one can be distinguished.
Similar to other animals, humans can extract signals from body odors that allow us to identify biological age, avoid sick individuals, pick a suitable partner and distinguish kin from non-kin, said senior author Johan Lundstrm, a sensory neuroscientist at Monell, in a statement.
Lundstrm became interested in studying the effect of age on human body odor when he noticed that old people in the U.S. seemed to smell just the way did back home in Sweden. For Lundstrms study, researchers collected body odor samples from 44 volunteers of three different age groups: 20 to 30 years old (young), 45 to 55 (middle-aged), and 75 to 95 (old). Researchers acquired the samples by sewing nursing pads into the armpits of unscented T-shirts and asking each body odor donor to sleep in the same shirt for five consecutive nights. The pads were then removed, cut into quadrants and placed into individual glass jars. Next, 41 young (20 to 30 years old) participants were given two glass jars in nine combinations to evaluate the scents.
Participants were able to single out old-person smell better than the odors of the younger age groups. When people tried to categorize the sample odors by age, they had trouble distinguishing between the young and middle-aged, but they were often instantly able to identify old peoples scents.
The old-person smell detected in the study couldnt be explained by the donors lifestyle or environment. The donors were all instructed to wash with unscented soap and shampoo before bed each night. They were also asked to refrain from drinking alcohol, smoking and eating spicy foods or any other type of food that could affect body odor.
