Over the years, more and more research has been done to investigate why some people can smell the odor that asparagus gives their urine and others cannot. A new study found over 800 new reasons as to why this happens. Researchers studied the genes of roughly 7,000 people and found that there are ~870 genetic variants that are linked to the inability to smell the odor. When a group of random people were asked if they could smell the odor, 40% said yes, they could. Strange enough, more women than men said they could not smell the odor. Since the genes affecting this were already identified, they were able to tell which ones made it "possible" to smell the odor and which ones made it "not possible".
The study certainly has its limitations on how accurate it really is because you are asking a person (self-reported) if they can smell the odor. Once researchers find a new way to test this, other than by the person's self-reported answer, then it will be more accurate. However, I hope there is not much time spent on something like this considering all that can be discovered pertaining to genetics other than the genes that pertain to smelling the odor of asparagus of your urine. But maybe, something could come out of a it and it could lead to more discoveries.
Source: (other source is in text)
http://www.livescience.com/57199-why-some-people-cant-smell-asparagus-pee.html
