Puberty makes teenagers’ armpits smell of cheese, goat and even urine, scientists in Germany have discovered.
The particular chemical compounds that make up pubescent body odour have been singled out, should anyone want to bottle “eau du teenager”.
More usefully, the discovery could help the creation of deodorants that mask those particular smells. It has also explained why babies smell better.
The study compared infants under three years old with 14- to 18-year-olds and found teenagers had two particular chemical compounds that smell of sweat, urine, musk and sandalwood, which were not present in babies. Infants, on the other hand, had higher levels of a ketone that smells flowery and soapy.
Helene Loos, of the Friedrich-Alexander University in Germany, and her colleagues adapted T-shirts and babygrows with cotton pads sewn into the armpits. Children slept in these overnight after washing with odour-free products.
The pads from the teenagers’ armpits had two steroids present – 5alphaandrost-16-en-3-one and 5alphaandrost-16-en-3alpha-ol – which smell of sweat, urine, musk and sandalwood. They also had higher levels of six carboxylic acids, which give off unattractive smells including cheese, goat and wax.
Babies’ samples showed higher levels of the ketone alpha-isomethyl ionone, which smells of flowers and soap, with a hint of violet.
The hormonal changes that occur during puberty are associated with an increase in body odour, linked to the activation of sweat glands and the secretion of sebum. The chemical compounds in sweat easily turn into gas, which is then perceived as a smell.
Researchers at Erlangen-Nürnberg’s Aroma and Smell Research Facility said changing body odour in development was known to affect the interaction between parents and children. “Body odours of infants are pleasant and rewarding to mothers and, as such, probably facilitate parental affection,” they wrote.
“In contrast, body odours of pubertal children are rated as less pleasant and parents are unable to identify their own child during this developmental stage.”
The study used a sample of 36 children, half of whom were infants and half teenagers. Families were asked not to give them spicy or strong-smelling foods, such as onion, asparagus and cabbage, that day. They also had to wash their bodies and bed linen using perfume-free products.
The researchers extracted the chemical compounds absorbed by the armpit pads using a technique called mass spectrometry to identify them. Once the chemicals were extracted and further testing was complete, a trained assessor used their nose to detect odours.