In 2023, the news community Reddit ranked the top 20 countries with the worst body odor based on related posts. India was identified as having the most severe body odor, with 8 out of 10 individuals reportedly emitting unpleasant smells.
What exactly does this odor resemble? Some explain it as a sour odor akin to fermented or rotten radishes.
Is this heavy body odor due to poor hygiene practices?
A long-time resident of the United States, an Indian, countered:
"This is definitely not a personal hygiene issue. I feel like many people in China have worse hygiene habits than us. The reason why Indians have a strong odor is firstly because of natural body scent, and secondly because of the abundance of spices in our diet. Personal hygiene comes after that."
Finally, this netizen emphasized, "I believe Indians don't have the strongest body odor; many Europeans have a more deadly natural musk!"
Indeed, body odor is very common globally, affecting at least 80% of people, and it exhibits very distinct regional characteristics.
For example, some people perceive the body odor of European countries mostly as sour, similar to that of Russia. Others feel that the odor from French and African individuals is more intense, resembling the scent of camels commonly encountered.
In East Asian countries like South Korea, China, and Japan, there's almost no unpleasant body odor, and the prevalence of body odor caused by apocrine glands is very low!
Why do people have completely different body odors, and why do they exhibit such distinct regional characteristics?
Body odor, what exactly is it composed of?
In nature, every living being has its own body odor.
Animals have their own distinct scents, which they emit for mating, marking territory, and deterring predators (pheromones being one aspect).
Humans also have their own body odor, and each person's scent is unique. Some people smell bad, some people don't have any odor at all, and some even smell pleasant.
The human body contains three types of sweat glands: eccrine glands, apocrine glands, and sebaceous glands.
Apocrine glands, mainly concentrated in the armpits, groin, and genital areas, are responsible for what we commonly refer to as body odor. The armpits are particularly problematic, hence the term "body odor," which is reminiscent of the musky scent of foxes.
So, what exactly causes body odor?
On March 21, 2024, a study published in the journal "Chemical Communications" focused on why teenagers smell so bad while babies smell so good.
It was found that infant sweat contains a compound similar to violets, while teenage sweat contains high concentrations of acidic substances and two types of steroids with distinctive odors.
The smell of body odor primarily comes from various volatile fatty acids and thiols, as well as some steroids with inherent odors.
People with body odor have active secretion from their apocrine glands, which produces a milky "sweat."
This sweat is originally odorless, but when it undergoes fermentation by bacteria in the armpits, primarily staphylococcus, the lipid and protein components of the milky sweat are broken down into various compounds with inherent odors.
These compounds include 3-methyl-2-hexenoic acid, giving off a "goaty" smell, 3-hydroxy-3-methylhexanoic acid with a scent resembling "cumin," and 3M3SH, emitting a rotten onion smell, among others.
It's the combination of these various substances that creates the unpleasant body odor.
Since the symbiotic bacteria on each person's body are different, body odor also varies from person to person, resulting in a unique scent for each individual.
Why do Chinese people hardly have body odor?
Chinese people rarely have body odor because their sweat glands are not as developed, so they produce very little or no apocrine sweat, which is the type of sweat that bacteria break down to create body odor molecules.
Scientifically, research teams have conducted global statistics and found:
In the world, Koreans have the lowest probability of body odor, at only 5%, followed by Chinese, at less than 10%, and then Japanese at around 20%.
Among them, people of African descent in America have the most prevalent body odor, with almost 100% affected, followed by Africans and Latin Americans, with probabilities exceeding 90%.
In 2009, a paper published in Dermatology Research revealed that regional differences in body odor are primarily caused by a genetic mutation in the ABCC11 gene. In East Asia, 80-95% of people carry the mutated ABCC11 gene, while in Africa, it's the opposite - almost everyone has the normal ABCC11 gene expression.
So, how does this gene determine body odor? Well, let's break it down. Imagine body odor components as 'a', which are produced from 'b' through bacterial breakdown. 'b', once produced by the body, is transported to the skin surface by a transporter protein 'c'.
The mutated ABCC11 gene primarily affects two things: firstly, it controls the transporter protein 'c', so 'b' can't be properly secreted onto the skin surface. Secondly, it reduces the synthesis of 'b', reducing its variety or quantity.
Simply put, most of us have the mutated ABCC11 gene. With this gene, there's less variety and quantity of 'b', the precursor to body odor, compared to those with normally functioning ABCC11 genes. Hence, our body odor tends to be milder and less noticeable.
Scientists also suggest that this genetic mutation emerged later in human history. Initially, everyone likely had body odor. However, as humans migrated from hot regions to relatively cooler ones, the ABCC11 gene gradually mutated to adapt to the new climate.
Final Thoughts
If we were to rank body odor based on genetic predisposition alone, Africa would likely top the list. However, according to online polls, the ranking of body odor is as follows: India > Black skin > Latin America > White skin > Asia. This suggests that body odor is influenced by various factors, with genetic predisposition being just one part of the equation. Diet, hygiene, and living environment also play significant roles.
Areas like the armpits produce abundant sweat, but timely management to maintain dryness and cleanliness can significantly reduce body odor. Conversely, someone who doesn't sweat much but consumes curry and garlic daily without paying attention to hygiene won't smell any better than someone with what's commonly referred to as "body odor".
Note: The above viewpoints are solely about body odor and do not intend to discriminate against any individual or group.
