A new study has confirmed what many people have long suspected: old people do have a specific smell.
But surprisingly the research, which shows humans can identify another person’s age group on smell alone, has found that older people have a less intense and unpleasant smell than that of young and middle aged people.
Although often masked with deodorants and perfume, body odour is thought to send out an array of messages that people receive on an unconscious level.
“Signals in body odour can help us identify kin from non-kin, choose a suitable partner and also determine age,” says Assistant Professor Johan Lundström, an experimental neuropsychologist at the Monell Chemical Sciences Centre in the United States, and senior author of the paper published today in PLoS One.
It is widely believed that body odour changes as people get older. Previous studies found that rats could identify different ages based on smell and researchers wanted to see if humans also have this ability.
In the study, scientists gathered data from three age groups – young (20 to 30 years), middle-aged (45 to 55 years), and old-aged (75 to 95 years).
The participants slept in t-shirts with pads located under the armpits. After five nights the armpit pads were removed and placed in jars. Other participants were then asked to rate the scent and group the jars according to age.
Dr Lundström says the research found that people were easily, and correctly, able to group the armpit pads according to age categories.
“These results indicate that we are much better at using our noses than we previously thought,” Dr Lundström said.
Mellowing with age
And he says it debunks popular misconceptions that old people smell bad.
“Elderly people have a discernible underarm odour that younger people consider to be fairly neutral and not very unpleasant,” he said.
“This was surprising given the popular conception of old age odour as disagreeable.
“However, it is possible that other sources of body odours, such as skin or breath, may have different qualities.”
The team found that the old-age group had a characteristic odour which, contrary to common beliefs, was rated as less intense and more pleasant than the younger age groups.
The results also showed that in the young and middle-age groups, people were able to identify differences between genders.
Overall, middle-aged men were reported to have the strongest and most unpleasant smell.
Associate Professor David O’Carroll, a neuroscientist from the University of Adelaide, describes the findings as “very interesting”.
“This study shows quite clearly that as we get older we smell better,” he said.
Professor Lundström says body odour is a complex chemical mixture with between 120 to 200 individual molecules, and he hopes further research will be able to pinpoint which molecules are responsible for providing information about a person’s age.
He is also keen to discover what other messages are hidden in a person’s scent and investigate how this impacts our behaviour in everyday life.