PHEROMONE Scent of a man: Nose knows

Should women follow their noses to sniff out Mr. Right?
By SOPHIA CARIATI
SOCIETY FOR WOMEN'S HEALTH RESEARCH
Tired of spending time and energy on men who sooner or later turn you off? A possible short cut to finding the perfect man may be to use your nose. New research shows that getting a good whiff of a man may be the most efficient way for women to meet their match.
Scientists have long agreed that a number of animals and insects use pheromones -- invisible airborne chemicals -- to communicate about sex, food and territory. In fact, several studies have shown that mice use pheromones to choose mates whose genes have different immunity than their own. Related research shows that this selection of genetically different mates increases the chance of producing healthy offspring.
Hard to prove: Proving that the human mating game is driven by pheromones has turned out to be much more difficult. Recent research, however, provides compelling evidence that human reproduction is in fact affected by these invisible odors. A groundbreaking study led by Swedish neurologist Ivanka Savic adds even more weight to the claim that romance is shaped by these unseen hormone-like scents.
Until Savic's study, the strongest proof of human pheromones came from the work of University of Chicago biopsychologist Martha McClintock. She took the sweat of women and swabbed it on the upper lips of other women. The result? Synchronized menstrual cycles. The monthly cycles of women who got a whiff of perspiration sped up or slowed down depending on when the sweat was collected -- before, during or after ovulation.
More recently, evidence of human pheromones came in the form of a gene. Researchers at Yale and Rockefeller Universities identified the first human gene linked to pheromones. They isolated a gene believed to code for a pheromone receptor.
Another study: Despite this convincing data, Savic and his colleagues sought proof of another cause and effect of pheromone communication: sex-specific production and reaction. They wanted confirmation that pheromones made by women must cause a certain response in men but not the same reaction in other women. The results of their study showed exactly this.
The researchers used positron emission tomography (PET) to scan the brains of 12 men and 12 women while they sniffed estrogen- and testosteronelike compounds. These sex-hormonelike substances are closely related to chemicals found in human sweat. PET scans showed increased blood flow indicating brain activity in different regions of the brain.
Only further research into human pheromones will unlock the secrets to the power of smell.
XFor more information, visit the Society for Women's Health Research's Web site at www.womens-health.org.