Male presenter brings vials of chemical AND and yeast into the smell-proof room for the subjects to sniff. Credit: Claire Wyart

Friday, February 9th, 2007--

Attention men: Before you wipe your brow, you should know that a man's sweat can change a woman's body chemistry. Androstadienone (AND) is a testosterone-derived molecule found in the sweat of all men. Women have it too but in lower concentrations. Researchers found that AND in men elevates cortisol levels in women, according to a study published in the Journal of Neuroscience this week.

Cortisol is a hormone associated with physiological arousal—which translates to a measure of awakeness (but not specifically sexual arousal). "You have a peak of cortisol after you wake up, and then it goes down during the day," explains Claire Wyart, a post doctoral researcher at the University of California, Berkeley and lead-author on the study.

Wyart and her colleagues placed women in a smell-proof room, (such a room can be created, she says), and sent vials of pure AND and vials of yeast into the room for women to sniff. Yeast was used because on the pleasant-to-smell scale, AND and yeast rank about the same, according to Wyart. The scientists then incrementally measured the cortisol levels in the women's saliva, as well as other physiological responses, post sniffing.

After twenty sniffs of pure AND, cortisol levels increased significantly in the sniffers' saliva. Yeast didn't elevate cortisol. These results were consistent with previous studies that showed AND exposure can improve a woman's self-reported mood, alter her heart rate, breathing rate, body temperature, blood pressure and other parameters associated with general arousal. But this study, also demonstrated that AND can change a woman's hormone levels.

But before you start sniffing around for a good man, Wyart warns, many questions remain about how smelling the pure stuff from a jar in a laboratory relates to a real life sweat-sniffing situation. Wyart says: "We have no clue about how this relates to the natural stimulation we are exposed to, when you're actually smelling someone."

What did you think of the story? Send us some feedback.

--Flora Lichtman

Sources

Claire Wyart
Helen Wills Neuroscience Institute University of California, Berkeley Berkeley, CA

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