10 Sources of Body Odor That Aren't Just Sweat

Old Age
Great-Aunt Martha's house might have a smell that has nothing to do with her musty books. Ralf Nau/Photodisc/Thinkstock

That odd aroma that you notice when you're visiting your great aunt isn't just from mothballs or musty, old books. Researchers at the Monell Chemical Senses Center in 2012 found that elderly people actually have a distinctive scent, which they believe is caused by changes in skin glands and their secretions as we grow older.

Old-person smell may be a sort of chemical signal developed during human evolution, which enables us to differentiate between younger, stronger individuals of breeding age and older, less healthy ones who may be less desirable partners.

On the plus side, the volunteer smell-testers rated the odor of old men as less pungent and unpleasant than the body odor of middle-aged men [source: Sifferlin].