POST-ASPARAGUS STINKY

URINE DISORDER

One last thing you may notice after your

asparagus has been eaten: That haunting smell—
haunting as in it comes back and surprises you long
after you thought it was gone—is caused by S-methyl
thioacrylate and S-methyl 3-
(methylthio)thiopropionate, chemicals identified in
1975 at the University of California at San Diego.
It’s not known exactly why some people seem unable
to digest them, but it is known that the degree of
“Post-Asparagus Stinky Urine Disorder” (a term I
just coined, PASUD for short) is related to your
genealogy. Fewer than half of Britons, apparently,
suffer from it, while almost 100 percent of the
French do. I know which country I’d rather be in for
sporting matches during asparagus season. But the
real kicker is that it turns out that not only do some
people not produce the odor, some people cannot
smell it, which means that in these self-reported
studies, it’s unclear whether or not the folks who
claimed that they don’t have asparagus pee actually
just don’t know that they do have it. It’s not easy to
find volunteers to check for it either.