Asparagus makes your pee smell due to some of the particular chemicals it contains. This is actually a very common question, but the problem with it is that it has a very boring and complicated answer so it doesn’t spread around too much through word-of-mouth. The chemicals in asparagus that are in question are of a group called thioesters, and it took years of scientific research to discover this fact.
It was none other than Benjamin Franklin who most notably published the effects of different substances on the scent of human urine. Among his observations was that asparagus makes the urine smell very unpleasant and a bit of turpentine no bigger than a pea makes urine smell flowery, like violets.
Please, don’t try to experiment with swallowing turpentine. You will most likely land yourself in the emergency room or worse.
The first serious scientific study on the effects of asparagus on urine began way back in 1891. A scientist by the name of Nencki identified a substance in asparagus known as methanethiol. In another experiment conducted in 1956, it was discovered that not everyone’s urine was affected. It seems that smelly urine from eating asparagus is a genetic trait. In the experiment, only 46 people of the 115 that were tested had urine that was affected by the asparagus.
The most definitive study on the subject was in 1975 at the University of California at San Diego. Heading the study was researcher Robert White of the chemistry department. He analyzed urine after eating asparagus and found that the culprit was not methanethiol after all. It was, in fact, a combination of several chemicals all belonging to a group called thioesters.
Scientists are still not clear how the thioesters are formed in the body by asparagus, but I am sure science will eventually get to the bottom of this deep mystery.
Posted 2891 day ago