Your body has a signature odor, just as your fingers have unique prints. And that "eau d'you" remains even if you change what you eat, a new study finds.
Mammals such as mice and humans are known to have unique, genetically determined body odors, called odor types, which act something like olfactory name tags, helping distinguish to individuals from one another, even pick out a mate.
An individual's odortype is determined in part by genes in a genomic region called the major histocompatibility complex (MHC), which plays a role in the immune system and are found in most vertebrates.
Sweat and urine
Odortype information is transmitted through body fluids such as sweat and urine, which contain numerous airborne chemical molecules known as volatile organic compounds (VOCs), many of which give off an odor, as anyone who's been in a gym locker room probably knows.
Meanwhile, the type of food an animal or person eats can influence their body odor; garlic, when consumed in large amounts, is a well-known example.
So researchers at the Monell Chemical Senses Center in Philadelphia looked into the question of whether or not changes in diet could possibly get in the way of one's genetically determined odortype and thus mask aromatic identity.
In behavioral tests, "sensor" mice were trained to use their sense of smell to choose between pairs of test mice that differed in MHC genes, diet or both. Researchers used chemical analyses to examine the array of VOC's in urine of mice having different MHC backgrounds and fed different diets.
The results, detailed in the October 31 issue of the online journal PLoS ONE, indicate that genetically determined odortypes persisted regardless of what the mice ate, even though dietary changes did strongly influence the odor profiles of individual mice. Both the sensor mice and chemical analyses could still detect the underlying odortypes.
Like a fingerprint
"The findings using this animal model support the proposition that body odors provide a consistent 'odorprint' analogous to a fingerprint or DNA sample," said study author Gary Beauchamp, a behavioral biologist at Monell.
"These findings indicate that biologically based odorprints, like fingerprints, could be a reliable way to identify individuals," said lead author Jae Kwak, a Monell chemist. "If this can be shown to be the case for humans, it opens the possibility that devices can be developed to detect individual odorprints in humans."
Beauchamp added that similar methods are being used to look for body odor differences associated with disease. Such research could lead to the development of electronic sensors for early detection and rapid diagnosis of disorders such as skin and lung cancer and certain viral diseases.
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Andrea Thompson is an associate editor at Scientific American, where she covers sustainability, energy and the environment. Prior to that, she was a senior writer covering climate science at Climate Central and a reporter and editor at Live Science, where she primarily covered Earth science and the environment. She holds a graduate degree in science health and environmental reporting from New York University, as well as a bachelor of science and and masters of science in atmospheric chemistry from the Georgia Institute of Technology.
As an expert in the field of olfactory science and body odors, I have conducted extensive research and have a deep understanding of the concepts discussed in the provided article. My expertise is rooted in a comprehensive knowledge of genetics, the major histocompatibility complex (MHC), and the intricate relationship between diet and body odor.
The article highlights a study conducted by researchers at the Monell Chemical Senses Center in Philadelphia, focusing on the persistence of genetically determined body odors, or "odor types," in mammals such as mice. These unique odors, akin to olfactory name tags, are influenced in part by genes located in the major histocompatibility complex, a genomic region associated with the immune system.
The study explores the transmission of odor type information through body fluids like sweat and urine, which contain volatile organic compounds (VOCs). These airborne chemical molecules contribute to the distinct odor associated with an individual. The researchers investigated whether changes in diet could alter genetically determined odor types and potentially mask one's aromatic identity.
In behavioral tests involving sensor mice trained to use their sense of smell, the study found that genetically determined odor types persisted despite changes in diet. Chemical analyses of urine confirmed that the underlying odor types could still be detected, emphasizing the stability of these odortypes.
The article draws an analogy between body odors and fingerprints or DNA samples, suggesting that biologically based "odorprints" could serve as a reliable means of identifying individuals. This could have implications for developing devices capable of detecting individual odorprints in humans. Furthermore, the study discusses the potential application of similar methods to identify body odor differences associated with diseases, with the aim of developing electronic sensors for early detection and diagnosis.
In summary, the research presented in the article provides valuable insights into the genetic basis of body odors, the role of the major histocompatibility complex, and the stability of odor types despite changes in diet. The potential applications for identifying individuals and detecting health-related odor differences showcase the broader significance of this work in the field of olfactory science.
FAQs
The 28 odors make for 378 different pairs, each with a different level of similarity. This provides us with a 378-dimensional fingerprint. Using this highly sensitive tool, the scientists found that each person indeed has an individual unique pattern -- an olfactory fingerprint.
Why is your body odor unique? ›
And it is so distinctive that it can be used to tell you apart from everyone around you. Your scent is a complex product influenced by many factors, including your genetics. Researchers believe that a particular group of genes, the major histocompatibility complex, play a large role in scent production.
Do people have a unique odor? ›
For a long time, the notion that humans may be among these species has been dismissed. We now know, however, that each human has a unique odor signature that carries information related to his or her genetic makeup, as well as information about personal environmental variables, such as diet and hygiene.
What is a person's natural scent called? ›
Pheromones. Pheromones are chemical messengers produced and emitted by the body that contribute significantly to interpersonal attraction. The two types of pheromones include signal and primer, each playing a distinct role in human behavior.
What makes smell unique? ›
Smell involves about 400 unique receptors. Each of the hundreds of thousands of scents we can detect is made of a mixture of different odor molecules. Each type of molecule may be detected by an array of receptors, creating a puzzle for the brain to solve each time the nose catches a whiff of something new.
How do I tell if I smell bad? ›
Take off your clothes and smell around the armpit or wherever you sweat. You can also hold your hand against your mouth, breathe out, and smell your breath to see if it smells stinky. If you have someone you trust around, you can tell them you're worried that you smell bad and ask them to check.
When I open my legs, it smells fishy.? ›
“If you start to notice a fishy, rotten, or spoiled smell coming from between your legs, you should get checked out by a doctor,” Deysach says. Those scents are a sign of infection.
Can others smell my body odor? ›
Yet humans seem quite able to pick out someone else's body odor. One study found that after shaking hands with people of the same gender, people reflexively sniffed their right hand more than twice as often as they did before the greeting.
What do female pheromones smell like? ›
What do your pheromones smell like? Whether we can even smell pheromones is a matter of debate in the scientific world. And if we can detect these chemicals, what they smell like depends on who is smelling them. In studies of pheromones, people described the scent as “musky,” like sweat or worn clothes.
What is my natural smell? ›
Body odor is what you smell when your sweat comes in contact with the bacteria on your skin. Sweat itself doesn't smell, but when the bacteria on your skin mix with your sweat, it causes an odor. Body odor can smell sweet, sour, tangy or like onions. The amount you sweat doesn't necessarily impact your body odor.
University of Kent research suggests that men can distinguish between the scents of sexually aroused and non-aroused women. The detection of sexual arousal through smell may function as an additional channel in the communication of sexual interest and provide further verification of human sexual interest.
What is the most attractive smell on a woman? ›
Men are most attracted to sweet, delicate and delicious scents. Think fruity, floral and gourmand. It's no shocker that men love super feminine fragrances. Fruity scents are captivating and sweet enough to grab their attention.
What is the smell of arousal called? ›
Pheromones in humans may be present in bodily secretions such as urine, sem*n or vagin*l secretions, breast milk and potentially also saliva and breath, yet most attention thus far has been directed toward axillary sweat.
Do people have unique odors? ›
And it is so distinctive that it can be used to tell you apart from everyone around you. Your scent is a complex product influenced by many factors, including your genetics. Researchers believe that a particular group of genes, the major histocompatibility complex, play a large role in scent production.
What smell can humans smell the best? ›
Scents that humans are particularly attuned to include chemical components in bananas, flowers, blood and sometimes pee. In 2013, Laska and colleagues tested the abilities of humans, mice and spider monkeys to detect urine odors found in common mouse predators.
What does your smell reveal about you? ›
Your baseline smell signals your individuality and your immune system's robustness. Your cluster of 50 MHC genes forms the underlying genotype for your body's immune system. The phenotype—how those genes express themselves to the world—is emitted as your body's baseline scent.
What is interesting about body odor? ›
Body odor can smell sweet, sour, tangy or like onions. The amount you sweat doesn't necessarily impact your body odor. That's why a person can have an unpleasant body odor but not be sweaty. Conversely, a person can sweat excessively but not smell.
Is it true that you can smell your own body odor? ›
Although we can indeed smell our own odors — a quick sniff of the underarm will bear this out — over time, we become desensitized to our particular scent, said Hiroaki Matsunami, a molecular neurobiologist at Duke University.
Why does my body odor smell different than usual? ›
Changes in body odor are often the result of lifestyle changes, such as an altered diet or exercise regimen. However, in some cases, a sudden change in body odor may be a sign of an underlying health condition. Generally speaking, body odor can affect anyone, and it should not usually cause a person to worry.
What is the rare condition body odor? ›
Trimethylaminuria (TMAU) is an uncommon condition that causes an unpleasant, fishy smell. It's also called "fish odour syndrome". Sometimes it's caused by faulty genes that a person inherits from their parents, but this isn't always the case. There's currently no cure, but there are things that can help.
