This HND piece focuses on the phenomenon of old-person smell. Yes, this is really a thing. Research indicates that it is caused by the compound 2-nonenal, which is a product of bacterial action on certain omega-7 fatty acids, that are more common in older individuals.
Ironically, this odor is not necessarily characterized as "bad," when compared to other human body odors. In fact, it is described as "similar to old pomade and candle wax, having a fishy or resin-like smell." The odor has also been described as unpleasant--greasy, grassy. While the compound is diffciult to remove from skin with conventional hygiene, research indicates that extracts of persimmon (containing tannin) are quite effective in its removal.
Read the complete article.