FRIDAY, Aug. 2 (HealthDay News) -- Genetic differences appear to explain why some people can smell certain odors and others can't, researchers say.

Using 10 different odors, the researchers tested nearly 200 people for their smell sensitivity and then analyzed the participants' DNA. For four of the odors tested, there was a link between smell sensitivity and certain genetic variants.

The four odors are malt, apple, blue cheese and violets, according to the findings, published online Aug. 1 in the journal Current Biology.

"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," research team co-leader Jeremy McRae, of Plant and Food Research in New Zealand, said in a journal news release.


He and his colleagues also found that people's ability to smell these four odors was the same worldwide. That means that someone in Asia is just as likely to be able to smell one of the odors as someone in Africa or Europe.

The ability to smell one of these odors doesn't predict the ability to smell the others, the study also found. So if someone is good at smelling blue cheese, it doesn't mean they'll be good at smelling an apple next to it.

The genetic variants that affect the ability to smell these four odors are in or near genes that encode odorant receptors. The researchers explained that odor receptor molecules sit on the surface of sensory nerve cells in the nose. When certain chemical compounds float in the air, the nerve cells send a signal to the brain and give you the perception of a smell.

Richard Newcomb, co-leader of the project, said that knowing the compounds that people can sense in foods, as well as other products, will influence 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," he said in the news release.

More information

The U.S. National Institute on Deafness and Other Communication Disorders has more about smell and smell disorders.