When we notice that our smell is a little average, we sometimes tend to approach our nose to that particular point of our anatomy, hoping to smell if this is really the case. Or we ask someone else.
It’s easy to guess if a friend’s breath smells bad or if their shirt is drenched in sweat after a subway ride, but it’s not as easy to guess our body odor. For what ?
As reported LiveScience, while our sense of smell is often compared (unfavorably for us) to that of highly odorous species such as dogs, mice, and pigs, humans are actually not bad at smelling and, in some cases, can outperform the animals they compete with. Our noses have around 400 different olfactory receptors capable of registering ten types of smells and over a billion scents, and smell is thought to be one of the first senses developed by humans.
Our nose has around 400 different olfactory receptors capable of registering ten types of smells and more than a billion aromas.
In fact, one study found that humans are better at detecting aromatic compounds in plants than dogs, thanks to our evolution as hunter-gatherers. So let’s not be so quick to praise our legged companions.
Although we can smell our own odors (just a quick glance under the armpit will confirm this), experts believe that over time we become desensitized to our own scent. It’s exactly the same as any smell we get used to, like the smell of our house (which, yes, has a distinctive smell, even if we don’t detect it). This process is known as olfactory fatigue and, although its cause is not fully understood (it is thought to be a change in olfactory receptors, or the way the brain responds to an odor), it can be restored by smelling less odorous areas. Sweat glands, such as those in the elbow or forearm.
Studies have linked smell to more than a dozen diseases.
Our ability to detect our own sense of smell also increases in certain situations. For example: if you eat something containing garlic. This is important because studies have linked smell to more than a dozen diseases. Breath that smells like rotten fruit? It could be a sign of untreated diabetes, while typhoid fever makes sweat smell like freshly baked bread. As for Parkinson’s disease, it gives off a “smell of wood and musk”.
Beyond health, our smell is also linked to our social relationships. In a famous 1995 study, scientists asked women to smell the T-shirts of men who had avoided scented products. The researchers linked these preferences to a set of genes called the major histocompatibility complex (MHC), which codes for peptides that the immune system uses to detect foreign invaders. Something about our body odor advertises our unique set of MHCs, and women preferred the smell of men with different MHC genes than their own. For what ? The question remains controversial, although there are hypotheses.
We use smell to judge the similarity of our friends, and we often prefer those who smell like us because they live in a similar environment.
Even when we seek out genetically different sexual partners, we use smell to judge the similarity of our friends and often prefer those who smell the same as us because they live in a similar environment. In other words, we use smell to choose the most suitable partner.
Yet, because humans are primarily visual creatures, smell simply has not received the same attention as the other senses, and many aspects of smell remain unknown. But the COVID-19 pandemic has reignited interest in smell, as many people lost the ability in the days, weeks, or even years after infection. However, smell is as important a sense as the others.
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