July 28, 2000 -- If you're such a sweets-lover that you swear the very aroma of goodies wafting in the bakery air can make you gain weight, think again. A new study shows that a vanilla-scented skin patch might actually help reduce people's cravings for chocolate and other sweets.
In the study, presented at a recent meeting of the Congress of Dietetics in Edinburgh, Scotland, researcher Catherine Collins reported that overweight people lost an average of 4.5 pounds after four weeks of wearing the patch on the back of their hands. Collins is chief dietician at St. George's Hospital in London.
Collins and colleagues divided 200 overweight volunteers into three groups, who either wore a vanilla patch, a lemon-scented placebo patch, or no patch. Over the four weeks, those who wore the vanilla patch showed a greater decrease in appetite -- as well as fewer cravings for chocolate and other high-calorie sweets -- when compared with volunteers in the other two groups.
The study is one of several that suggest we may be able to lose weight simply by smelling our favorite foods.
"It's very clear that odors can impact a person's behavior and appetite," says Alan Hirsch, MD, neurological director of the Smell and Taste Treatment and Research Center in Chicago.
Collins' findings make perfect "scents" to Hirsch, who has conducted many similar studies.
In one study of more than 100 people, participants either sniffed various food odors in tubes, or tubes with non-food scents, whenever they were hungry over a period of two weeks. Overall, people lost more weight when they smelled the odors than when they smelled the placebo tubes, the study showed.
In another, six-month study of almost 3,200 people, participants who inhaled either banana, peppermint, or cream pie scents when they were hungry lost an average of 30 pounds over six months, Hirsch says.
"You can use odors to facilitate weight loss. We are not sure why, but perhaps providing a smell may satisfy the cravings -- or perhaps participants were too busy smelling to eat," he jokes.
Hirsch notes that people who lose their sense of smell gain an average of 10 pounds. "There is a direct connection between sense of smell and satiety," he tells WebMD.
Another prominent taste and smell researcher, Beverly Cowart, PhD, clinical director of the Monell Jefferson Taste and Smell Clinic in Philadelphia, sees patients who have lost their sense of smell. About 16 million people in the U.S. suffer from chronic dysfunction of smell or taste.
"A substantial proportion of patients with smell loss do gain weight -- at least initially," she says. This may be because they do not get the same satisfaction out of food as they did when they had a sense of smell, she says.
The sense of taste only constitutes sweet, sour, bitter, or salty, so the sense of smell is a large part of food enjoyment, Cowart says. "If you can't smell, you can't tell the difference between vanilla or chocolate or other flavors," she explains.
But, she says: "Whether you can reduce a person's appetite by exposing them to smells is, however, a little more of a questionable proposition."