Experts explain the question of human olfaction and body odor, such as 'Why do people not notice their own body odor?'


the saying goes, ``I don't know about my own odor,'' people are sensitive to other people's body odor and bad breath, but they are hard to notice when it comes to their own odor. The science news site Live Science explained the relationship between the sense of smell and body odor based on experts.

Why can't we smell ourselves as well as we smell others? | Live Science

Humans are often said to have an inferior sense of smell compared to animals such as dogs and pigs, but in reality, this does not mean that our noses are dull. According to Live Science, the human nose has the ability to distinguish between 10 types of odors using 400 olfactory receptors, and it is thought that ``smell is one of the first senses that humans evolved.'' We also know that because of their evolutionary history as hunter-gatherers, they are better at detecting aromatic compounds in plants than dogs.

Regarding the reason why humans with such an excellent sense of smell are insensitive to their own body odor, Hiroaki Matsunami, a molecular neurobiologist at Duke University in the United States, says, ``As you can tell from the fact that you can smell your own body odor when you turn your armpits, you are never aware of your own body odor.'' 'It's not that you can't smell body odor, but over time you become less sensitive to certain odors,' she tells Live Science. According to Matsunami, the same thing applies not only to body odor, but also to everyday smells such as perfume and the smells inside your home.

This phenomenon, called `` olfactory fatigue ,'' is not completely understood, and it is not known whether the olfactory receptors or the brain's response are changing.

In addition, Rachel Haas, a neurologist at Brown University in the United States, points out, ``Body odor can change depending on factors such as diet and physical condition, and in certain situations, the ability to detect one's own odor may increase.'' Masu.

For example, when you eat food with garlic or on days when you feel stressed, your sweat and saliva may smell bad. Other untreated diabetes patients are said to have bad breath that smells like rotten fruit, and typhoid patients' sweat can smell like freshly baked bread. That's what I'm talking about.

A woman who lost her husband to Parkinson's disease testified that she noticed a change in her husband's body odor even before he was diagnosed, and a subsequent experiment was able to accurately tell if he had Parkinson's disease based on the smell of his shirt. Ta. Taking inspiration from this woman's ability, scientists are conducting research into a technology that can quickly identify Parkinson's disease patients based on the components of their sebum.

Confession of a woman who can distinguish Parkinson's disease by smell may advance research on incurable diseases - GIGAZINE

by Dennis Wong

Body odor is deeply related not only to health conditions but also to social relationships. A 1995 study in which women were asked to smell men's shirts found that each woman had a strong preference for scent, which the researchers described as a protein that the immune system uses to identify pathogens. This is due to a series of genes called the major histocompatibility complex (MHC), which are associated with Women tended to prefer the scent of men with different MHC genes than themselves, and Dr. Matsunami explained this by saying, ``By having a child with a person with a different combination of MHC genes, may have immunity to more diseases.'

Just as we like the scent of genetically different people of the opposite sex, humans rely on scent to determine that the other person lives in a similar environment and build friendships with them. In fact, past research has found that close friends have similar body odor.

Good friends have similar body odor - GIGAZINE

Due to the novel coronavirus pandemic, many cases of patients losing their sense of smell have been reported, leading to increased interest in the sense of smell among people. According to Mr. Haas, it is unclear why the patient's sense of smell is lost because the patient's olfactory receptors and nerve cells related to smell are not destroyed. Mr. Haas said, ``I hope that interest in smell will not go away and that people will continue to recognize that ``smell is connected to our lives in general.'' .

in Science, Posted by log1l_ks