is that food in front of you? Your nose knows, a new study suggests.
The study, which found that people's sense of smell is adept at gauging
foods' fat content, might have real-world uses. For example, it might be
possible to manipulate food products' odour to make low-fat items more
appealing, thereby cutting the amount of fat in people's diets, and said
researchers at the Monell Chemical Senses Centre in Philadelphia.
"The human sense of smell is far better at guiding us through our
everyday lives than we give it credit for," study senior author and
neuroscientist Johan Lundstrom said in a centre news release. "That we
have the ability to detect and discriminate minute differences in the fat
content of our food suggests that this ability must have had considerable
Fat is "calorie dense" and has been an important source of energy
for humans through much of evolution, the researchers said. This means it would
have been to our advantage to be able to detect the nutritional value of food.
Sniffing out the fat level
To test people's ability to smell fat in food, the researchers had
volunteers smell milk with three amounts of fat found in a typical milk
product: 0.125%, 1.4% or 2.7% fat.
The test was conducted three times using different sets of participants: in
Philadelphia with normal-weight people, in the Netherlands with normal-weight
people; and again in Philadelphia with both normal-weight and overweight
In all three experiments, people were able to use their sense of smell to
detect the different levels of fat in the milk, regardless of their culture or
weight, according to the study, which was published in the journal PLoS One.
Study lead author Sanne Boesveldt, a sensory neuroscientist, said the next
step is identifying the odour molecules in the food that allow people to detect
"Fat molecules typically are not airborne, meaning they are unlikely to
be sensed by sniffing food samples," Boesveldt said in the news release.
"We will need sophisticated chemical analyses to sniff out the
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