Toddlers Smell Like Flowers, Teens Smell ‘Goatlike,’ Study Finds

Few parents would describe the smells emanating from their adolescent children as redolent of sandalwood. But one of the distinct components of teenage body odor is a compound that evokes that warm, woody fragrance, according to a small new study, which compared the scents of adolescents to those of infants and toddlers.

Unfortunately, that’s just about where the good news ended for teenagers (and their parents). Although there were many similarities between the chemicals wafting from teens and tots, the differences tended to favor the younger children, whose body odor samples had higher levels of a compound with a flowery fragrance. Adolescents, on the other hand, produced a compound that smelled like sweat and urine and had higher levels of substances described as smelling cheesy, musty and “goatlike.”

The authors of the study, which was published in the journal Communications Chemistry on Thursday, would not go so far as to say that the results proved that adolescents smelled worse than babies. But the differences they documented “may contribute to a less pleasant body odor of teenagers,” said Diana Owsienko, who conducted the study as part of her doctoral research at the University of Erlangen–Nuremberg in Germany. (She is now a researcher at RISE Research Institutes of Sweden.)

Body odor is a complex blend of airborne chemicals, many of which are produced when sweat and sebum, an oily substance typically secreted through hair follicles, are broken down by skin microbes or react with other compounds in the air. The differences in scent between young children and teens probably stem from puberty-driven changes in sweat and sebum production, the researchers said.

The study was based on samples from 18 young children, who were age 3 or younger, and 18 adolescents who had gone through puberty. To collect the body odor samples, the scientists sewed small cotton patches into the armpits of T-shirts and body suits, which the children and teens wore overnight. (Participants were asked to refrain from using scented hygiene products and eating especially fragrant foods, such as onions and garlic, for 48 hours beforehand.)

In the lab, the scientists extracted and analyzed the chemical compounds that had permeated the patches, pooling together samples from multiple children in the same age group.

Odor samples from young children contained most of the same chemical ingredients as the samples from teenagers, the researchers found.

But there were two compounds, both steroids, that were present only in the adolescent samples. Sweat glands that do not become active until puberty secrete precursors to these compounds, which skin microbes convert into the steroids in question.

Characterizing scents is tricky. “There is no global consensus on how to describe odors,” said Helene Loos, who is an aroma and smell researcher at the University of Erlangen–Nuremberg and an author of the new paper.

Odor experts at the university had previously developed a standard vocabulary for characterizing the smells of different compounds, with an initial focus on food aromas. “We now also extended this flavor language to substances occurring in body odors,” Dr. Loos said.

Careful whiffs of the adolescents’ steroids revealed that one of the compounds smelled of sandalwood and musk. The other also had musk-like qualities, with the unfortunate additions of sweat- and urinelike aromas.

The teens also had higher levels of compounds called carboxylic acids. They included the musty, cheesy and goatlike substances — as well as some with less offensive aromas, variously described as earthy, fruity or waxlike.

Carboxylic acids are contained in sebum, which also includes other compounds that can be converted into carboxylic acids by microbes or various chemical processes. Sebum production increases during puberty.

The researchers theorize that, in combination, the two musky steroids plus the higher levels of carboxylic acids may explain why the body odor of adolescents can be off-putting to some people.

“I think it’s difficult to determine that one odor is always pleasant for everyone and to say another odor is always unpleasant for every person,” Ms. Owsienko said. “So this is an assumption from our side.”