1. Why do elderly people have a distinct "smell"? Can't they smell it themselves?
In 2012, the journal "Comprehensive Public Science Library" published a study indicating that elderly people indeed have certain distinctive odors. Researchers collected specific odors from three groups of people from different age ranges and found that the classification accuracy of odors from elderly individuals was significantly higher than that of younger and middle-aged individuals, making it easier to distinguish.
Researchers from countries such as the United States, Sweden, and Japan have also studied this phenomenon multiple times and found that the occurrence of the "old person smell" is mainly related to 2-nonenal produced by the body's metabolism.
