Liz Gabor calls the odor "man sweat." And though she's loath to admit it, the aromatic scent makes her feel, as she calls it, a little frisky. "My friends think I'm crazy, but I think male sweat is kind of pleasant and, well, kind of hot," says Gabor, 28, a customer service rep and happily married mother of two young girls.
Gabor doesn't have a honker that's on the fritz. Rather, her penchant for "man sweat" is all in her genes, according to new research from Rockefeller and Duke Universities published this week in the journal Nature. Scientists have previously found an association between male sweat and female arousal, but this study is the first to find a gene that is linked to the ability to smell a specific chemical in the sweat. And that, they say, may be a revolution in the understanding of how our olfactory sense functions.
According to the Rockefeller and Duke researchers, about 70 percent of adult men and women have the genetic capacity to perceive a particular chemical called androstenone in male body odor. To them, the testosterone-laden substance can take on a pleasant bouquet similar to vanilla or other sweet or woodsy scents. Others who have a functional copy of the gene perceive androstenone as less than pleasurable, akin to the aromatic elixir of stale urine. About 30 percent of adult men and women can't smell androstenone at all, leading researchers to suspect they might be missing the gene responsible for smelling the aroma.
To figure out exactly who could smell the manly-man scent of androstenone, researchers presented 400 participants with 66 different odors, including woodsy scents like pine, strong scents like garlic, and esoteric odors like methanethiol, a man-made scent that is similar to the smell of urine after a person has eaten asparagus.
DNA taken from blood samples was then analyzed, and those individuals who could smell androstenone were found to have genetic variations in a single odorant receptor called OR7D4. Whether they perceived androstenone as pleasant or foul smelling was due to two tiny changes in the gene, called single nucleotide polymorphisms, that made the odorant receptor stop functioning.
For researchers who are trying to unravel the complicated way people perceive certain aromas, finding a genetic link to at least one smell—male body odor—is akin to finding a Rosetta Stone. "There is a mystery as to how the nose works, well beyond the whole realm of male sweat," says neuroscientist Charles J. Wysocki, Ph.D., a member of the Monell Chemical Senses Center in Philadelphia and one of the world's leading olfactory science researchers. "Quite frankly, I am jealous of them."
While being able to smell androstenone may seem like an attribute that you can live without, the chemical may have some broader implications than making us scream "ewwww." Or in the case of some women, "aaahhh."
But so far scientists know less about androstenone's effects on humans than its effects on pigs. And what they do know about pigs is enough to make any researcher blush. The chemical, which is found in large concentrations in the saliva of male pigs, acts like an aphrodisiac among the porcine set.
Once female pigs catch a whiff of androstenone they immediately assume a posture called lordosis, replete with a curved back and wiggly haunches. "Essentially, they ready themselves for mating," says Wysocki. Because of that rapid, well, response, human marketers have jumped on the androstenone bandwagon, hawking male deodorants and sprays that promise to make men irresistible to women.
"At this point there isn't any scientific evidence that a spray of androstenone is going to help any guy get lucky," says lead researcher Leslie Vosshall, Ph.D., the Chemers Family Associate Professor and head of the Laboratory of Neurogenetics and Behavior at Rockefeller University. "Plus, if the woman he's hot for doesn't have a functional copy of the gene, she won't even smell it." And of course there's always that pesky problem that she may simply perceive it as stale urine mixed with some Armani.
But men shouldn't give up yet. Researchers have already shown that the complex soup of chemicals that comprise "man sweat" can elicit some unusual physiological responses in some women: an increased heart rate, a better mood and sexual arousal. Male sweat can also effect the secretion of luteinizing hormone, which is involved in stimulating ovulation.
"There is a lot more to male sweat than it just being a funny anecdote," says Vosshall, who plans a series of studies that use the genetic find to determine the compound's role in social hierarchies. Since men with high levels of testosterone sweat out equally high levels of androstenone, "the question is, will a woman respond to those levels, will she, in a sense, sniff out the manliest man in a group?" says Vosshall.
Until that question is answered, getting rid of body odor may still be the best bet for men wanting to attract a woman. "There is a lot more to smell and human relationships than what we know as scientists," says Monell's Wysocki. "But there is no good evidence that if a happily married woman catches a whiff of a particular chemical found in male sweat that she'll up and leave her husband." That can only be good news for the Gabors.