While only 2 percent of Europeans lack the genes for smelly armpits, most East Asians and almost all Koreans lack this gene, Day told LiveScience.
ABCC11: the “no body odor gene”
People with the ABCC11 non-functioning gene variant have dry earwax and little or no body odor.
Although there is some controversy on the subject of "racial" variation in body odor, it is determined that African blacks probably produce the greatest amount of apocrine sweat, which is the known substrate for axillary odor.
According to a group of researchers from the University of Bristol in the UK, 2 percent of people (at least in their survey) carry a rare version of the gene ABCC11 that prevents their armpits from producing an offensive odor.
Two percent of people carry an unusual form of a specific gene (ABCC11) that means their armpits never smell. The finding came from new research involving 6,495 women who are enrolled in the Children of the 90s study at the University of Bristol, England, and was published in the Journal of Investigative Dermatology.
More than half of the Vietnamese males and females have concerns on their body odor. Besides from showering daily, deodorant products have been widely used to prevent the body odor. 92% takes bath at least once/ day.
This study was published in the Journal of Investigative Dermatology, and according to it, the gene is the only determinant of whether your underarm smell or not. What's interesting is that almost all Koreans lack the ABCC11 gene. In other words, they are “genetically mutated” to have stink-free pits.
The frequencies of the A and G alleles vary markedly across different ethnic groups. The A allele is very common in East Asians, and as expected, most people in this population don't need to use deodorant. And so they don't use it—it's estimated that only 7% of North East Asians regularly use deodorant.
But your own underarms could reek and you might not be able to tell: Humans are prone to what scientists call olfactory fatigue; our sense of smell just gets plain tired out by familiar odors and stops detecting them. Believe it or not, that can actually be a good thing.
As the sweat evaporates, it helps cool your skin and regulate your body temperature. It doesn't produce a smell. When your body temperature rises due to physical exertion or being hot, the evaporation of sweat from your skin produces a cooling effect.
One large study failed to find any significant differences across ethnicity in residual compounds on the skin, including those located in sweat. If there were observed ethnic variants in skin odor, one would find sources to be much more likely in diet, hygiene, microbiome, and other environmental factors.
Studies have shown that body odor is strongly connected with attraction in heterosexual females. The women in one study ranked body odor as more important for attraction than “looks”. Humans may not simply depend on visual and verbal senses to be attracted to a possible partner/mate.
But it turns out that Koreans are "genetically mutated" to have less of a sweating problem than others, according to research. The University of Bristol research suggested only 0.006 percent of the Korean population have the ABCC11 gene, a major culprit behind the odor problem.
At about age 40, the body subtly changes the way omega-7 unsaturated fatty acids on the skin are degraded. These acids get exposed to the air and create a compound called “nonenal.” Nonenal most likely gets produced due to hormone imbalances.
Every person has a unique scent. “It's like a fingerprint,” says Johan Lundström, a neuroscientist at the Karolinska Institute in Sweden. “There is a large genetic component to body odor. Even trained sniffer dogs have a hard time distinguishing between identical twins, unless the twins are on different diets.”
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.
Hair is another place where bacteria like to hide. If you still smell a strong body odor after a shower, consider shaving the hair in your armpits, groin, and chest. The hair's surface is a perfect place for bacteria to call home, and it's harder to eliminate them from the hair than your bare skin.
But, of course, we Aussies love our great outdoors all year round, from days at the beach to hikes through our stunning national parks. So it goes without saying that deodorant is a staple of our daily routine.
Scientists in recent years have shown that many East Asians, a group that includes China's ethnic Han majority, have a gene that lowers the likelihood of a strong “human axillary odor” — scientist-speak for body stink.
Traditionally, Asians have been thought to age more gracefully than Caucasians. The resistance to aging in the Asian patient was credited to the thicker dermis of Asian skin that contains greater collagen and the darker pigment that protects against photoaging.
Smelly genes
"This key gene is basically the single determinant of whether you do produce underarm odor or not," Day said. While only 2 percent of Europeans lack the genes for smelly armpits, most East Asians and almost all Koreans lack this gene, Day told LiveScience.
Why Chinese don't use deodorant? It's because many Chinese actually don't have westerners' body odor issues, which means that Chinese do not sweat nearly as much as westerners do, even when the weather is quite hot and humid.
Very often people use much more than they actually need. 2% of the population on Earth doesn't even need deodorant because they do not produce any odor. Developed countries are much more likely to use deodorant than developing countries. Factors like these will determine who actually uses deodorant.