Researchers have now found that we like certain scents because we are genetically wired to like them. The latest research shows that when it comes to smell, all of us live in different worlds and perceive odors based on our genetic make-up.
The study was conducted by a team of researchers led by Sara Jaeger, Jeremy McRae, and Richard Newcomb of Plant and Food Research in New Zealand. The team found that certain odors were liked by people because they had the genes that associated with them.
The study was based on sensitivity tests conducted on 200 people. The study participants had to sniff ten compounds that are found in food such as malt (isobutyraldehyde), apple (β-damascenone) and blue cheese (2-heptanone). They then searched the participants' genome for genes that differed in people who could smell some scents, but couldn't smell others. This study approach is called as genome-wide association study.
GWAS studies examine the link between genes and specific traits (mostly used to study human disease). In this kind of study, researchers look in the entire genome for variations in single nucleotide polymorphisms (SNP- pronounced as "snips) that occur in people who have the particular trait.
"We were surprised how many odors had genes associated with them. If this extends to other odors, then we might expect everyone to have their own unique set of smells that they are sensitive to. These smells are found in foods and drinks that people encounter every day, such as tomatoes and apples. This might mean that when people sit down to eat a meal, they each experience it in their own personalized way," said Jeremy McRae.
The scientists then looked to see if the place of origin had any relation with a person's ability to detect a particular smell. Surprisingly, they found that regional differences have no relation with odor preference by a person, meaning that a person in America may have the same ability to smell the compounds as another person in Asia or Africa. The odor-smelling -ability was also an independent factor, which means that a person who is good at smelling blue cheese may not be able to smell malt or apple compound.
Another study also found a genetic variation that led people to smell the compound in violets. Researchers found that people without this variant are more likely to describe the violet compound as sour and unpleasant.
The genetic variants that allow us to smell the world differently are located next to the genes that code for olfactory receptors present at the surface of the nerve cells in the nose. These receptors bind themselves to chemical compounds which leads the nerve cells to send signals to the brain.
"Knowing the compounds that people can sense in foods, as well as other products, will have an influence on the development of future products. Companies may wish to design foods that better target people based on their sensitivity, essentially developing foods and other products personalized for their taste and smell," said Richard Newcomb in a news release.
The study is published in the journal Current Biology.