The human nose can do much more than appreciate perfume and ID spoiled milk, according to a new study published in the latest Journal Science. Until now, scientists believed that we could detect just 10,000 smells, but the new research finds the human nose can discern more than one trillion olfactory stimuli—many more than we’re known to be able to see or hear.
Winner By a Nose
“The number 10,000 had never really been tested,” explains study co-author Andreas Keller, PhD, a research associate from Rockefeller University in New York who studies olfactory variables.
“Everybody who works with odors knew this number was too low. We finally got annoyed enough to do some testing of our own.”
In the study, 28 people were exposed to 128 different odor molecules. And more than 200 pairs of odor cocktails over the course of four weeks, and were able to detect differences.
“We used only 128 odors and their combinations but there are clearly many more,” says Keller.
We may never know the exact number, however, because sense of smell is subjective. “Everybody smells the world differently,” Keller says.
Apparently the study of scent is more nuanced—it’s not as simple as identifying light waves for sight or sound waves for hearing.
What do these findings mean for the average person?
“People need to trust their sense of smell more and pay more attention to it,” Keller says. “We’re usually suspicious of our sense of smell. But we should rely on it more and realize that’s a great asset.”
Just two months ago, a study from the Monell Chemical Senses Center showed that the human nose can detect dietary fat. In that study, blindfolded participants could discriminate levels of fat in milk just by taking a whiff.
“Our noses can do a lot more than they get credit for doing,” said Keller. “It really is an incredibly valuable sense.”
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