Lurking among us are foolish folks who fork out cash for deodorants even though their armpits don’t smell.
This is the take-home message of an article in the Journal of Investigative Dermatology that’s been making the rounds of science news sites and blogs. It’s a fun study, but the results aren’t really that surprising.
Researchers have known for years that some people in Europe (2% of the population) and most people in China, Japan, and Korea are fortunate enough to have two copies of a recessive gene that makes their armpits relative* stink-free zones.
That’s because the gene codes for a protein involved in transporting molecules out of special sweat glands that appear in your armpits at puberty. These stink-producing glands are called apocrine glands, and they differ from eccrine glands, which are found all over your body and produce the salty fluid we commonly associate with sweat and body temperature regulation.
Apocrine glands typically excrete all manner of waxy molecules that armpit bacteria love to feast on. It’s the leftover, metabolized molecules, such as trans-3-methyl-2-hexanoic acid, which give many human bodies that oh-so-ripe odor.
Because the difference between stinky and stink-free folks is a gene involved in transporting armpit molecules, it’s pretty likely that people without body odor have a dysfunctional transporter. Although that’s not yet been proven, it’s a reasonable theory.
For example, people with odorless armpits also produce a dry white earwax, instead of a yellowish wet version. Presumably, the transport machinery that isn’t exporting bacteria food in the armpit isn’t exporting a yellowish fluid in the ears either.
What’s really new in the article is simply the observation that among the 2% of folks in the UK who probably don’t need to apply deodorant, 78% still do.
OK, so why is this not really surprising?
For one, the UK is dominated by people who have stinky armpits. If you are stink-free, it’s because you have two copies of the recessive, odorless allele of the gene, which behaves in a rather Mendelian fashion, says Ian Day, the University of Bristol researcher who led the study.
Being stink-free is rare in the UK, so both parents of an odorless child are probably heterozygous. That means they carry one stinky allele of the gene and one stink-free allele, but they are stinky themselves. Statistically, only one quarter of these parents’ kids will be stink-free.
So you can imagine that stinky parents are likely to give their awkward teenagers deodorants in anticipation of that day when their bodies start announcing adulthood. And they probably do it prematurely, so that their teenagers don’t suffer ridicule from other, more well-prepared schoolmates.
The second reason the study findings are intriguing is that advertisers have spent the better part of the past century putting the fear-of-stink into humanity. They had to, because back in the 1910s, nobody was buying the newly invented deodorants or antiperspirants, in part because people didn’t think they needed the products. (Most people washed regularly, applied perfume and wore cotton-rubber pads in their shirts to absorb sweat and its stinky by-products.)
It was only an amazing advertising strategy from 1919 that turned the sweaty tide, making the deodorant and antiperspirants an $18 billion industry today. Here’s an excerpt from that advert, published in the Ladies Home Journal:
Within the Curve of a Woman’s arm.
A frank discussion of a subject too often avoided.
A woman’s arm! Poets have sung of it, great artists have painted its beauty. It should be the daintiest, sweetest thing in the world. And yet, unfortunately, it isn’t always.
Advertisers went on to tell folks that they were stinky and didn’t know it, and worse, that people were gossiping about it behind their backs. The horrifying consequence of body odor was that you wouldn’t land a husband or a job.
Turns out the advertising worked. I expect many deodorant users among the stinkless 2% have simply drunk the Kool-Aid or are just hedging their bets.
*And here comes the stink disclaimer. Folks with two copies of the recessive gene, “won’t produce as much body odor as a guy like me, but they still may produce some odor under some conditions,” says George Preti, who has characterized the chemistry of human body odor at the Monell Chemical Senses Center. It seems that even when the transporter doesn’t work, some of those nefarious molecules can still sometimes sneak out. Most people probably can’t smell the body odor “at social distances,” Preti says, but it doesn’t mean the stink molecules aren’t there.
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