COLUMN ONE : Trying to Make Sense of Smell : Scientists are getting nosy about how scents may affect everything from worker productivity to romance. Some scoff, but others may soon be dabbing bakery aromas behind their ears.

OK, so it isn’t exactly haute science. And maybe it is a little bit risque. But of all the trips Dr. Alan Hirsch has taken during his wacky journey from the tip of the nose to the center of the mind, his study of male “blood enhancement” is surely the most provocative.

Hirsch is a Chicago neurologist who treats people with smell disorders. But his passion is investigating the murky arena of how smells affect behavior. For this euphemistically titled experiment, he asked the question perfume makers have spent decades--and untold dollars--trying to answer: What scents turn men on?

Hirsch recruited a group of male medical students. Monitors, similar to those that measure blood pressure, were strapped to their genitals. Hirsch then had the men sniff an array of odors. He tested delicate flowery scents--lily of the valley and rose. He tested the earthy aroma of musk. He tested Chanel No. 5 and Obsession by Calvin Klein.

And now, the untold secret, the only fragrance that consistently increased blood flow:

Fresh-baked cinnamon buns.

“That,” Hirsch jokes, “told us one of two things: No. 1, medical students are always hungry. Or No. 2, the way to a man’s heart really is through his stomach.”

Hirsch’s olfactory adventure reflects a growing fascination among a tiny corps of researchers--not to mention the perfume-buying public--with the mysterious, untapped powers of smell.

The questions are intriguing: Can odors take the jitters out of a hospital visit? Can they jolt us awake and lull us to sleep? Can they make us run faster, jump higher, think smarter or slim down? If you like a store’s scent, are you more likely to spend money there? Do fragrances shape behavior even when they are too subtle to detect?

Answers are elusive, and commercial ventures are running way ahead of scientific proof. In the United States, the booming aromatherapy business is expected to rake in $230 million in sales this year, up from virtually nothing a decade ago.

In Upstate New York, a professor has patented a desktop air filter that emits fragrances such as citrus and peppermint that are believed to make people more alert.

In Japan, a construction company is installing odor-release mechanisms in its buildings’ heating and air-conditioning vents so employers can pump in lemon scent to make workers more productive.

Does any of this work? Nobody knows, and many mainstream scientists are skeptical. Richard Doty, a highly respected smell researcher at the University of Pennsylvania, says: “There’s a lot more fiction out there than there is fact.”

Hirsch, for one, is a believer. The frenetic neurologist with slicked-back hair and a penchant for junk food (he works 18-hour days, fueling himself largely on bottled iced cappuccino, Nestle’s Crunch bars and packaged brownies) is a maverick, to be sure. He can talk excitedly for hours about the wonders of smell.

“You have heard of love at first sight?” he asks, practically breathless. “Well, a large part of it is love at first sniff. Smell has the most powerful impact of any sense. . . . We have a whole universe at the tip of our nose that we are not even thinking about, that has been virtually unexplored.”

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“Nothing is more memorable than a smell,” author Diane Ackerman wrote in her bestseller “A Natural History of the Senses.” “Smells coat us, swirl around us, enter our bodies, emanate from us. We live in a constant wash of them.”

In the animal world, where creatures rely on sense of smell to survive, social interaction is governed by the nose. Among marmosets, rank within the troop is distinguished by subtle nuances in odor. After red-sided garter snakes mate, the male marks the female with a “pheromone”--a chemical that is often scented--to make her unattractive to future suitors. Queen honeybees secrete pheromones to keep worker bees on the job.

Whether pheromones work in people--whether it is, in fact, love at first sniff--is a matter of intense debate. And although evolution has left people less dependent on smell than animals, odors still alert us to danger--gas leaks, fire, spoiled food.

As a species, humans have been obsessed with smell at least since the time of Cleopatra, when Egyptian priests burned aromatics to help heal the sick. Anthropologist Margaret Mead reported that in some cultures, tribes went to war because they hated each other’s odors.

As Ackerman notes in her book, smells transport people back in time--to grandmother’s kitchen, or summers at the beach. Hirsch says many a nursing mother has told him that if she sprinkles the crib with her perfume, the baby sleeps easier; there is extensive scientific literature on the ability of infants to recognize their mother’s scent.

But ask people what the most important senses are and most will say sight and hearing. These sentiments have long been reflected in medical research. The National Institutes of Health spends an estimated $916 million each year on hearing research and more than $275 million on vision, but just $16 million on smell.

Little, if any, of this money is devoted to exploring the link between smell and behavior; with such limited resources, experts say, there are more pressing matters to investigate. Among them: basic research into how people smell, new methods of treating smell loss and the exciting discovery that a huge family of genes--perhaps thousands, or as many genes as there are odors--controls human ability to detect different scents.

Still, there is good scientific reason to believe that smell has the power to shape emotions and behavior, according to neurologist Richard Costanzo, a smell researcher at the Medical College of Virginia. Vision, hearing and touch travel a convoluted path to the limbic system, the emotional center of the brain. But smell--and its close cousin, taste--are directly wired to it.

When a scent is inhaled, it travels through the nostrils to the olfactory bulb, which fires a fast message to the limbic system--too fast to be translated into language. Some experts believe this is why smell lacks its own vocabulary. Odors are not red or blue, like colors. Rather, they are described as what they smell like--a mint leaf, a rose.

“Smell and taste are more primitive in the development of the brain,” Costanzo said. “They have a more privileged access.”

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In Chicago, at his Smell and Taste Treatment and Research Foundation--a one-doctor operation in a suite atop an elegant downtown shopping tower--Hirsch is trying to unlock the potential of this privileged access.

And he’s got just the nose for the job. Although his sense of smell has never been the same since a bicycle accident some years back, he says he can still tell a green apple from a red Delicious. He has an uncanny ability to detect smells no one else can.

“He can pick up anything,” one of his nurses says.

During a rare break from work, Hirsch takes an “olfactory safari” through the mall below. At a cosmetics counter, he examines a tube of bright red Chanel lipstick. “They have white roses in them,” the clerk volunteers, “which is reminiscent of Chanel No. 5.”

Hirsch is nonplussed. “Smells like baby powder to me,” he says.

Still wearing his white lab coat, he drops by Victoria’s Secret, the lingerie store, to examine a new aromatherapy line. “Hah!” he says picking up a bottle of blue liquid labeled Sensual Harmony. “I suspect it doesn’t smell like cinnamon buns!” The saleswomen eye him suspiciously. In fact, the scent is of sandalwood, ylang-ylang and cloves.

At 38, Hirsch has been in the smell research business for 10 years. He got involved, he says, because he was “too stupid to know better.” After medical school at the University of Michigan, he completed residencies in psychiatry and neurology, and discovered that many psychiatric patients had also lost their sense of smell. By the time he discovered that the smell loss was a side effect of drugs--and not some physiological failure--he says he was hooked.

His research, funded largely by drug companies seeking to develop medicines to combat smell loss, is quirky and admittedly commercial. (On one assignment for a garbage bag manufacturer, he investigated what odors might make people buy more bags.) His flair for what captures the public’s imagination has earned him few friends in the more serious and cautious world of academia.

To say they look down their noses at Hirsch is putting it mildly.

They complain that he does not publish in respected scientific journals, where his work would be subjected to the rigors of peer review. (Some of his studies have been published in little-known journals, and Hirsch talks about his results before they appear in print--a definite no-no in science.) His experiments aren’t well-controlled, his critics sniff. He couldn’t get government funding if his life depended on it, they say.

“A charlatan,” one calls him, declining to be identified. “Don’t quote me on it,” says another, “but there is no science going on there.” Counters a respected perfume industry researcher: “The people in academia, they would like to kill him if they had a clean shot at him. There’s a lot of professional jealousy. . . . The other side is that he continues to come out with new, interesting and controversial ideas.”

Hirsch shrugs off the sniping as sour grapes from “purists who work with salamander olfactory bulbs.” If his critics want to repeat his work and prove him wrong, he says, let them. “If people are critical, so be it.”

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His walk on the wild side of smell has made the following contributions to science:

* People were more willing to buy Nike sneakers--and pay more for them, an average of $10.33 per pair--when they tried on the shoes in a floral-scented room. The same was true even when the scent was so faint that people could not detect it.

* Gamblers plunked 45% more quarters into slot machines when a Las Vegas casino was scented with a pleasant artificial smell. When Hirsch increased the odor level, he found spending increased 53%.

* Students in a Portland, Ore., high school calculus class, asked to connect numbers in a maze, performed better when they wore surgical masks with a sweet springtime scent. These students worked three times faster than the others.

But the study that really brought Hirsch attention is his work on smell and weight loss. He says he noticed that patients gained weight, as much as 20 pounds, after losing their sense of smell. Maybe, he reasoned, if we give people more smells, they’ll eat less. The concept might contradict common sense--Don’t people get hungry when they smell food?--but it seemed to work.

For the study, 3,193 people were given inhalers containing an odor that vaguely resembled Fritos corn chips. At the outset, their average weight was 217 pounds. Some were so heavy--up to 600 pounds--that they weighed in at a hospital loading dock. Hirsch told them to sniff whenever they felt like eating.

The more they sniffed, he discovered, the more weight they lost--an average of 30 pounds over six months. Some took 285 sniffs a day, the equivalent of one every three minutes during waking hours--and lost more than 100 pounds.

Of course, such research has its pitfalls. In preparation for this experiment, Hirsch handed out Hershey’s chocolate bars to medical students and told them to sniff the bars when they felt hungry.

That study flopped. The would-be doctors ate the chocolate.

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Academic research seems tame by comparison.

At Duke University, researchers have found that fragrance improves the mood of middle-aged women--regardless of whether the women liked the odors. At Memorial Sloan-Kettering Cancer Center in New York, doctors are using a relaxing vanilla scent to ease anxiety among patients undergoing magnetic resonance imaging.

At Rensselaer Polytechnic Institute in Upstate New York, psychology and management professor Robert A. Baron has demonstrated that odors can make people happier and more willing to do favors for others. And, he says, the specific scent--lemon, flowers--doesn’t matter, as long as people like the smell.

Baron put two groups in separate rooms--one scented, the other not--and paid them to perform meaningless tasks. At the end, he asked them to fill out questionnaires and return them--on their own time--”as a favor” to him. Those in the scented room, he said, were more likely to send the forms back.

And in Philadelphia, at the Monell Center, environmental psychologist Susan Knasko is studying “congruency effects”--how people are affected by odors that match the environment. In one study, she asked people to choose a chocolate assortment or flower arrangement. When the odors were congruent--for instance, when the subjects were picking chocolate in a chocolate-scented room--the consumers asked more questions and were more thorough in making a decision.

Such studies, Knasko said, require her to simply follow her own hunches about what works and what doesn’t: “When you do this work, you’re sort of going on your own. There’s not a lot of previous research to base it on.”

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Hirsch has taken this wide-open field and claimed it as his own. Late one warm night in May, for example, he launched into his latest foray: a look at whether odors could relieve claustrophobia.

He had had a long day seeing patients--a man who lost his sense of smell after injuring his head in a motorcycle crash; a fortysomething high school teacher who has never been able to smell, and a woman whose nose picks up nothing but petunias. The doctor and his nurses rummaged through tiny vials of liquid odors, trying to select 10 for the next day’s experiment.

They hemmed and hawed over cucumber, evergreen, spring rain, seashore, lemon tree. They giggled over a scent called nasty. Instead, they picked barbecue smoke. Hirsch said: “It’s much more nasty than nasty.”

This was for the control subjects in the study, from whom Hirsch hoped to learn how--or if--these scents affect people who are not claustrophobic.

The next day, the subjects--assorted friends and relatives of Hirsch’s nurses--were put into a tiny booth, where they sniffed scented masks. As the nurses monitored their heart rates, the patients filled out questionnaires designed to determine which smells made them nervous and which made them calm. The smells that most relaxed the subjects turned out to be a light, breezy odor called seashore, and cucumber. The loser: barbecue smoke.

Hirsch plans to repeat the test soon on claustrophobics, using just these scents. He has one problem: How is he going to get people who hate closed spaces to go into that little booth?

That is but a minor detail for a doctor who is thinking big. Hirsch has a vision of the future--10 or 20 years into the next millennium--and this is it:

Ten minutes before you are scheduled to wake up, the alarm clock sprays a scent to make you more alert. Kitchen appliances emit one smell to make you hungry, another to suppress your appetite. Your office is scented to make you more productive. At the gym, another scent increases your exercise rate. At night, an odor relaxes you before bed.

Of course, no one has yet precisely identified such odors, and there is no universal agreement about what smells good. But who knows? Perhaps, on the perfume counter of tomorrow, alongside the Obsession and the Chanel No. 5, there will reside a high-priced bottle containing the sticky sweet scent of . . . cinnamon buns.