Old People Smell Real but Not Unpleasant

 "Old people smell" exists but it isn't an unpleasant odor as assumed by people, says a new study.

For the research, scientists collected test samples from people belonging to three age groups. The age groups were 20-30, 45-55 and 75-95.

The participants were given special T-shirts during the experiment. These shirts had absorbent nursing pad sewn in the arm-pits. The participants were asked to sleep in the same shirt for 5 consecutive nights. Before going to bed they had to wash hair and body with an odorless shampoo and soap. They were even asked to refrain from alcohol, smoking and spicy food for these 5 days.

After 5 days the T-shirt pads were removed and put into air-tight jars. The evaluators had to then smell these samples and decide which jars contained samples from old people. They were even told to rate the intensity of odors as well as unpleasantness of the smell.

The evaluators not only identified which jars had pads with old people sweat but also rated it as more intense and less unpleasant than the rest.

"…akin to other animals, humans are able to discriminate old individuals from younger individuals based on body odor. The modest effects suggest a limited impact on our everyday interactions but does support previous reports of a unique ‘old person odor’. Further experimental work is clearly warranted to determine the mechanism and function of body odor-dependent age discrimination," write researchers Johan N. Lundström and colleagues.

Previous studies have shown the importance of body odor in animals. Young females are attracted to older males because their odor signifies they have a good and adaptive immune system and their strong genes have helped them live through old age. However, odor-based discrimination in humans is just a speculation at this stage, the researchers say.

The study is published in PLoS ONE.