However, a new study finds their smell is more pleasant than that of their younger counterparts.
Researchers at Monell Chemical Senses Center had more than 40 volunteers of all ages sleep in T-shirts with nursing pads sewn in the armpits.
After sleeping in the shirts for five nights, they snipped out the pads and put them in jars, and had a separate group of volunteers rate the odors.
They found the smell of 75- to 95-year-olds was much more pleasant than the smell of young- and middle-age adults.
However, the participants were two times more likely to match the age with the scent of an elderly person.
The researchers also found men smelled worse than women -- especially those in the 45- to 55-year-old age group.