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.
In the study, 117 (2%) of the subjects were lucky enough to carry this gene that allows them to never have to worry about using deodorant. However, the researchers discovered that over 75% of those people with the gene who do not produce under-arm odor still put deodorant on anyway.
Results showed that about 5% of people who do produce odor in their armpits do not use deodorant, while over a fifth (26 out of 117) of those who are not able to produce an odor under their arms do not use deodorant. The scientists pointed out that the difference is statistically significant.
Surprisingly, 78% of people who are not capable of producing an odor still apply deodorant on most days, if not every day.
Professor Ian Day explained:
"An important finding of this study relates to those individuals who, according to their genotype, do not produce under-arm odor. One quarter of these individuals must consciously or subconsciously recognize that they do not produce odor and do not use deodorant, whereas most odor producers do use deodorant.
However, three quarters of those who do not produce an odor regularly use deodorants; we believe that these people simply follow socio-cultural norms. This contrasts with the situation in North East Asia, where most people do not need to use deodorant and they don't."
"These findings have some potential for using genetics in the choice of personal hygiene products. A simple gene test might strengthen self-awareness and save some unnecessary purchases and chemical exposures for non-odor producers," added researcher Dr. Santiago Rodriguez.
The researchers noted that people who carry this unusual genetic variant also have a higher likelihood of having dry (as opposed to sticky) ear wax.
A good indicator of whether or not a person produces a smell under their arms is to check their ear wax, the experts explained.
Prior research has demonstrated an association between a genetic variant located in the ABCC11 gene and odor under the arm.
Smell under the arm comes from sweat glands, which produce sweat, which combine with bacteria. The production of smell relies on whether an active ABCC11 gene exists.
Scientists have known, however, that the ABCC11 gene is inactive in some individuals.
For the first time, this report analyzed the use of deodorant in connection with ABCC11 genotype and also when compared to other elements, including:
- general household hygiene
The experts concluded, "The statistical support for the ABCC11 finding was extremely strong - the random chance of getting the same answer was less than one in a million million million odds."