PHILADELPHIASmell is usually detected prior to taste, and now a new study shows that using the sense of smell to detect dietary fat in food is a possibility, according to a study appearing in PLOS ONE.
"The human sense of smell is far better at guiding us through our everyday lives than we give it credit for," said senior author Johan Lundström, Ph.D., cognitive neuroscientist at Monell. "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 evolutionary importance."
Researchers at Monell asked healthy subjects to smell milk containing either 0.125%, 1.4% or 2.7% of fat. Milk samples were presented to blindfolded subjects in three vials. Two of the vials contained milk with the same percent of fat, while the third contained milk with a different fat concentration. The subjects' task was to smell the three vials and identify which of the samples was different. This experiment was conducted three times using different test subjects. The first and third study was conducted in Philadelphia. The first set had healthy, normal weight subjects, while the third group had both normal-weight and overweight subjects. The second group consisted of healthy, normal weight subjects from Wageningen, an area in the Netherlands. In all three experiments, participants could use the sense of smell to discriminate different levels of fat in the milk. This ability did not differ in the two cultures tested, even though people in the Netherlands on average consume more milk on a daily basis than do Americans. There also was no relation between weight status and the ability to discriminate fat.
"We now need to identify the odor molecules that allow people to detect and differentiate levels of fat. Fat molecules typically are not airborne, meaning that they are unlikely to be sensed by sniffing food samples," said lead author Sanne Boesveldt, Ph.D., a sensory neuroscientist. "We will need sophisticated chemical analyses to sniff out the signal."