Some people can smell the distinctive odor that asparagus gives to urine, while others can't. Now, a study has revealed more than 800 new reasons why this strange phenomenon occurs.
Researchers analyzed the genes of about 6,900 people and found 871 new genetic variants associated with not detecting the smell.
It was an associate professor of epidemiology at Harvard's T.H. Chan School of Public **** Health, and her colleagues, whose dinner included asparagus, who came up with the idea for the study at a scientific conference in 2010.Mucci and her American colleagues discussed the strange phenomenon of the asparagus urine odor.
"To our surprise, our Scandinavian colleagues and our Irish colleagues had no idea what we were talking about," she told Live Science. [Seven Mysteries of the Human Body]
The experience inspired Mucci and her colleagues to research the topic. In their study, the researchers asked 2,500 men and 4,400 women, all U.S. citizens of European descent, if they had ever smelled the odor.
Among the findings, 40 percent of the study participants said they could smell the odor in their urine after eating asparagus, and the researchers found that 60 percent of the women said they couldn't smell it,
more women than men. Specifically, 58 percent of men and 61.5 percent of women couldn't smell the odor, the researchers said in the study published today (Dec. 13) in the Christmas edition of the British Medical Journal. The Wall Street Journal's annual Christmas issue is dedicated to real medical research on less serious topics.
The researchers' analysis of the participants' genes revealed hundreds of DNA variations associated with the inability to detect odors.
The researchers note that the study has some limitations. For example, participants self-reported their ability to detect odors, which the researchers did not objectively measure. In addition, all of the participants were of European ancestry, so it's not clear if the genetic results apply to other races, the researchers said. [Tongue: 7 (Other) Flavors Humans Might Taste]
It's not clear how the genes prevent some people from detecting the odor, the researchers said. Scientists say more research is needed to test this.
Originally published in the journal Life Sciences.