Science / Medicine : On the Nose : Scientists Say Aromas Have Major Effect on Emotions
Perhaps it has always been apparent. As plain as the nose on your face. But nobody was paying much attention.
“From an evolutionary point of view, we typically don’t think of the nose as very important,” said Dr. Gary Schwartz, professor of psychiatry and psychology at the University of Arizona. “But it is stuck square in the middle of the face. Why would something that was less relevant to normal activities be so prominent? It implies there is something more important there than we may have realized.”
Indeed, scientists are learning that fragrance affects us more than previously thought. New research indicates that smells influence our minds, our moods and our bodies.
But smell remains one of the least-understood senses. Although we know a great deal about the eyes and ears, we only partly understand smell. According to Charles Wysocki, an olfactory scientist at the Monell Chemical Senses Center in Philadelphia, we do know that an odor is first detected by the olfactory epithelium, a sort of receptor sheet located in the nose. This starts a chain of events that leads to an information flow to the olfactory bulb and limbic system of the brain, which plays a key role in regulating body functions and the emotions.
Smell, Wysocki said, is the only sensory system to directly project into the limbic system, making it perhaps our most basic, primitive sense. (Other senses reach the limbic system, but travel first to other brain regions.)
Some of the most significant new findings about smell and scent come from William Dember and Joel Warm at the University of Cincinnati. They recently presented their findings at the annual meeting of the American Assn. for the Advancement of Science and concluded that scents can keep people more alert and improve performance of a routine task.
Subjects tackled a 40-minute vigilance test, which required them to watch a video screen and press a button whenever a certain line pattern appeared. While performing the task, some were intermittently given a whiff of peppermint or muguet (lily of the valley) through oxygen masks. Dember said that those workers receiving the fragrances performed 25% better than those given only whiffs of pure air. A replication study conducted by Raja Parasuramen at Catholic University, using only peppermint, achieved the same findings.
“Maybe what fragrance is doing is raising the level of physiological arousal,” Dember said. Another possibility, is that “there’s some sort of pharmacologic effect on the centers of the brain that affect alertness, something chemically special.” Thus it is conceivable that certain scents activate specific chemical messengers in the brain, called neurotransmitters.
Although it isn’t clear exactly how fragrance works, Dember believes his study may soon have practical applications. “Truck drivers, even passenger car drivers, who need to keep alert while traveling long distances, could find it helpful,” he said. An industry group, International Flavors and Fragrances, selected the scents and sponsored this study.
In Japan, fragrance is already used in the workplace. Shimizu, Japan’s largest architectural, engineering and construction firm, has developed an environmental fragrancing system that uses computerized techniques to deliver scents through air-conditioning ducts. The Japanese have found that scents enhance efficiency and reduce stress among office workers.
In one experiment in Japan, 13 key-punch operators were monitored eight hours a day for a month. When the office air was scented with lavender, errors per hour droped 21%. They dropped by 33% with a jasmine fragrance, and a stimulating lemon aroma reduced errors by 54%. Junichi Yagi, vice president of Shimizu’s Boston subsidiary S. Technology Center-America, said the key-punchers enjoyed the fragrances. “They reported feeling better than they did without it,” he maintains.
Yagi said that fragrances were selected based upon the principles of aromatherapy, an ancient form of herbal medicine. Aromatherapists believe that “essential oils,” the distilled “essences” of flowers, herbs and plants, can be used to make people feel better. Oils such as lavender and chamomile are considered relaxing; lemon and jasmine, stimulating; pine and eucalyptus invigorating. Aromatherapy is widely practiced in England, France, Belgium, Germany and Switzerland.
“These ideas have been around for a long time,” said Yagi, “and now (we’re) applying it in Japan.”
Other research is still in the laboratory phase. Peter Badia, a professor at Bowling Green State University, is finding that even when you are sleeping, your nose is wide awake. He’s worked with about 100 college subjects in the university sleep lab. Electrodes on test participants monitored brain-wave activity, heart rate, respiration and muscle tension.
“What we’ve determined is that we respond to odors in sleep,” Badia said. “Tests clearly showed subjects are able to detect the odors; typically their heart rate would increase slightly and their brain waves quicken slightly.”
Badia has discovered that most odors disrupt sleep. Can any fragrance enhance it? Badia has yet to find one, although he said that heliotropine (a vanilla/almond fragrance) is clearly “not disruptive, and might be somewhat beneficial for sleep.” Badia is using scents based upon earlier laboratory research findings and those selected by The Fragrance Foundation, an industry group that sponsored the study.
But Schwartz thinks that while he was at Yale University he may have found a relaxing scent: apple spice. Schwartz conducted the experiments over a five-year period, testing more than 400 subjects.
In 1989, Schwartz published findings that he terms “quite remarkable.” “We found spiced apple had relaxing effects as measured in brain waves, within a minute of (a subject’s) smelling the fragrance.”
In a separate study, respiration, muscle tension, heart rate and blood pressure were measured as a group of healthy volunteers were asked a series of stressful questions such as: “The kind of person I find sexually attractive is. . . ?” They received whiffs of spiced apple aroma, while a control group was given bursts of plain air. The spiced apple produced a drop in blood pressure, on average of 5 millimeters per person, Schwartz said.
“It’s not a big decrease, but could be the difference between taking medication and not taking medication; or reducing the dosage in medication.”
Schwartz, now at the University of Arizona, continues his work on scent. In one of his current studies, Schwartz is looking at “subliminal scent,” scent below the level of awareness.
“I think one of the reasons taking trips to pine forests makes us feel so good is the presence of the mixture of molecules in pine,” Schwartz said. “Equally important--if not more important--may be the absence of all these other molecules we’re not consciously aware our nose is picking up . . . smog molecules, gasoline, carpet, paint . . . putting a great strain on our nervous system.”
Schwartz points to so-called “sick” buildings as an example. They inhibit the circulation of fresh air, so people instead breathe a veritable soup of man-made chemicals. “The idea is that the nose can detect those molecules and that that information is fed to the brain and does activate brain centers to make us feel queasy or uncomfortable,” Schwartz said. “Yet we wouldn’t be able to attribute it to any scent we’re aware of it.”
At the Memorial Sloan-Kettering Cancer Center in New York, William H. Redd is winding up a study to see if aromas can control stress in people undergoing magnetic resonance imaging. “In MRI,” Redd said, “you’re put into a . . . small cylinder . . . inside a big machine that’s a 12-by-12-foot cube. . . . You have to be there as much as an hour and a half and you’re not supposed to move. People have claustrophobic reactions, anxiety, and panic attacks.” Redd said that 10% of people react adversely and have to terminate their scans--which means they just wasted about $1,500. “We calculate an average 15-minute delay may result in the loss of $62.5 million in scanning time a year nationwide,” Redd said.
In his study of 85 patients, Redd found that patients who received heliotropine during MRI scans experienced 63% less anxiety than the control group. The study was presented in March at the meeting of the Society of Behavioral Medicine in Washington, D.C.
With these and other experiments in progress, it is clear that the study of scent is positively blossoming. “It’s definitely on the increase,” Wysocki said. “We’ve learned a lot, but we’re a long way from fully understanding smell. We’re still on a great adventure.”
Feeling Better by Smell
Some fragrance studies have a basis in aromatherapy, a herbal medicine widely practiced in England, France, Belgium, Germany and Switzerland that uses “essential oils”-the distilled “essences” of flowers, herbs and plants-to make people feel better. Although some of the suggested uses include baths and massages, others primarily involve the sense of smell.
Some examples:
* Insomnia: basil, chamomile, clary sage, juniper, lavender or heliotropine (a vanilla/almond fragrance)
* Improve work efficiency: lavender, jasmine and lemon
* Study aids: basil to clear the head, rose to lift spirits, bergamot for freshness, cardamon to fight mental fatigue.
* Anxiety: basil, bergamot, cedarwood or hyssop
* Stress: rose
* Respiratory problems: frankincense, niaouli, rose, teatree
* Relaxing: lavender, chamomile, apple spice
* Stimulating: lemon, jasmine
* Invigorating: pine, eucalyptus
* Air fresheners: basil or peppermint in automobile for long-distance driving.
Sources include: “The Complete Book of Herbs” by Lesley Bremnes
