NCBI ROFL: Asparagus, urine, farts, and Benjamin Franklin (Part I)

By ncbi rofl | January 13, 2010 9:00 am

A polymorphism of the ability to smell urinary metabolites of asparagus.

“The urinary excretion of (an) odorous substance(s) after eating asparagus is not an inborn error of metabolism as has been supposed. The detection of the odour constitutes a specific smell hypersensitivity. Those who could smell the odour in their own urine could all smell it in the urine of anyone who had eaten asparagus, whether or not that person was able to smell it himself. Thresholds for detecting the odour appeared to be bimodal in distribution, with 10% of 307 subjects tested able to smell it at high dilutions, suggesting a genetically determined specific hypersensitivity.”

asparagus_pee

Face it: your pee smells after you eat asparagus. (And if you think yours doesn’t, it’s because you can’t smell it.) This phenomenon (which is caused by various malodorous sulfur-containing compounds) has tickled the fancies of many researchers, as well as such luminaries as Proust, who wrote of asparagus: “exquisite creatures who had been pleased to assume vegetable form, and whose precious essence when, all night long after a dinner at which I had partaken of them, they played (lyrical and coarse in their jesting like a fairy-play by Shakespeare) at transforming my chamber pot into a vase of aromatic perfume (translated from Du côté de chez Swann, Gallimard, 1988, I, 119; I, 131).

But our favorite allusion to the asparagus-pee phenomenon has to be from Benjamin Franklin, who, in 1871 1781, wrote a letter asking researchers to come up with a solution to fart smells (the letter is definitely worth reading in full: To the Royal Academy of Farting):

“Certain it is also that we have the Power of changing by slight Means the Smell of another Discharge, that of our Water. A few Stems of Asparagus eaten, shall give our Urine a disagreable Odour; and a Pill of Turpentine no bigger than a Pea, shall bestow on it the pleasing Smell of Violets. And why should it be thought more impossible in Nature, to find Means of making a Perfume of our Wind than of our Water?”

So, now that we understand why our pee stinks when we eat asparagus, can we address Benjamin’s larger concern? Check back tomorrow for some cutting-edge research on fart-smell-reduction!

  • Richard

    Fact check: Ben Franklin was dead in 1871. Is that meant to be 1771?

  • Pat

    Aspara”gas”

  • Brian

    Now I want to experiment with turpentine pills!

  • Alan

    I found some other references to the turpentine phenomenon:
    http://www.agonys.com/facts/urine.shtml (talks about rose scent resulting)
    http://www.ehow.com/way_5805113_turpentine-cold-remedy.html (other strange urine related uses for turpentine)
    http://www.jstor.org/pss/20267317 (here a medical case, including violet scent, lasting at at least 24 days from ingestion of the turpentine, but with very bad side-effects)

  • Lov4art

    Drinking turpentine is said to make urine smell like a rose, so hundreds of years ago, women would drink turpentine so their pee would smell sweet.

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Discoblog

Quirky, funny, and surprising science news from the edge of the known universe.

About ncbi rofl

NCBI ROFL is the brainchild of two Molecular and Cell Biology graduate students at UC Berkeley and features real research articles from the PubMed database (which is housed by the National Center for Biotechnology information, aka NCBI) that they find amusing (ROFL is a commonly-used internet acronym for "rolling on the floor, laughing"). Follow us on twitter: @ncbirofl

ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »