Two things we will never fully understand, the human body, and olfaction, together.
Researchers explain the dissimilar smells of babies and teenagers
Mar 2024, phys.org
The researchers recruited the parents of 18 children aged up to 3 years old to wash the youngsters with a fragrance-free gel and to take swap samples of the armpits of their pajamas prior to sleep. They did the same with 18 teenagers between the ages of 14 and 18. All the cotton pads were then collected and analyzed in a lab setting.The research team used mass spectrometry to identify the chemical compounds in the pads, and used gas chromatography along with a human sniffer to assess the odorousness of the smells associated with each chemical compound.The researchers found that most of the chemicals responsible for body odor were similar between the two groups of volunteers. But there were a few that made the difference. Teenage sweat, for example, had high levels of many kinds of carboxylic acids, which the assessors described as "earthy, musty or cheesy."They also found two steroids in the teen sweat not present in the baby sweat, one of which resulted in "musk or urine-like" emanations - the other, the assessors suggested, smelled more like "musk and sandalwood." Without such chemicals, the sweat of babies smelled much sweeter.
via a team of aroma chemists at Friedrich-Alexander-Universität Erlangen-Nürnberg with psychologists from Technical University of Dresden: Diana Owsienko et al, Body odor samples from infants and post-pubertal children differ in their volatile profiles, Communications Chemistry (2024). DOI: 10.1038/s42004-024-01131-4
Image credit: AI Art - Machu Picchu Face Girl - 2025
Clothes are like your second skin, so we can also call this body odor:
Textile scientists offer fresh insights on why some clothes get smellier
Jul 2024, phys.org
Cotton and viscose, which are cellulosic, or plant-derived fibers, absorbed - and consequently released - smaller amounts of odor-causing compounds than polyester, nylon and wool."Although we know that polyester is smellier after being worn next to sweaty armpits compared to cotton T-shirts, we haven't really known why.""If you had a sweaty armpit that never actually touched the shirt you're wearing, then the fabric wouldn't get very smelly." The researchers soaked the fibers in the sweat solution for different periods of time, then examined the release of various odor-causing compounds.Sweat is mostly made up of water but also has oily compounds that bacteria transform to form odors, and these oily compounds in watery sweat can interact differently with textiles, depending on the fiber chemistry."While water-loving cellulosic fibers such as cotton and viscose absorb more of the water from sweat than polyester does, polyester doesn't want to absorb the water. It's more oil-loving, and it absorbs more of the odorants, which don't dissolve in water, and more of the oily compounds.The research also showed that although nylon and wool initially took in a lot of the odorants from the sweat, they dissipated them more quickly than polyester. After 24 hours, wool and nylon had much lower intensities of the odorants and were more similar to the cellulosic fibers."That tells us that while polyester still needs to be washed, for nylon and wool garments, people might be able to freshen them by just airing them out rather than laundering every time."
Bonus:
"The study's method of using simulated liquid sweat also offers an important fresh approach to exploring the issue."
via New University of Alberta and University of Otago in New Zealand: Rachel H McQueen et al, Textile sorption and release of odorous volatile organic compounds from a synthetic sweat solution, Textile Research Journal (2024). DOI: 10.1177/00405175241249462
Does fertility affect a woman's body odor? Study finds no evidence
Jul 2024, phys.org
The researchers took samples of underarm odor from 29 women on 10 days spread over a menstrual cycle. A group of 91 men were then asked to rate the odor samples. In 16 of the women, the research team also looked at whether the chemical composition of the odor samples differed between the women's fertile and infertile days.The results of both tests pointed in the same direction: there was no evidence from the odor ratings that men found a woman's odor more attractive on her fertile days than on her infertile days.Chemical analysis of the odor samples also showed no correlation between the composition of the underarm odor and the women's current fertility status.
via Leipzig University, the Max Planck Institute for Evolutionary Anthropology and the University of Göttingen: Madita Zetzsche et al, Combined perceptual and chemical analyses show no compelling evidence for ovulatory cycle shifts in women's axillary odour, Proceedings of the Royal Society B: Biological Sciences (2024). DOI: 10.1098/rspb.2023.2712
