Last night I made an amazing discovery, an aspect of myself of which I had hitherto been unaware. Or perhaps now I am a septuagenarian it has developed as part of the general unravelling one has to expect. To adapt the words of the Bard of Wisconsin:
THERE are two kinds of people on earth to-day
Just two kinds of people, no more, I say.
Not the humble and proud, for in life’s little span,
Who puts on vain airs, is not counted a man.
Not the happy and sad, for the swift flying years
Bring each man his laughter and each man his tears.
No; the two kinds of people on earth I mean,
Are those whose pee stinks, and those whose is clean.
Last night, you see, I had a pasta dish from Woolworths that contained quite a bit of asparagus, a vegetable I rarely eat because as a child I found the following version slimy and repulsive:
I am sure that is a really excellent product, by the way. I speak only of my taste as a child. I didn’t like pumpkin much either, but I do now. And the Woolies pasta dish was not too bad either.
However, on peeing later on – more than once being a septuagenarian – I encountered The Phenomenon. There was more than a whiff of sulphur in the air, reminiscent of but not quite as strong as the hydrogen sulphide or rotten egg gas that we no doubt have all experienced at some time. And it was definitely coming from my pee!
Is this some dreadful disease, I wondered briefly, until thinking ASPARAGUS! And maybe shiraz as well…
No less an institution than the Smithsonian confirmed my suspicions. And so did the ABC’s Dr Karl.
We humans have been eating asparagus for thousands of years. Indeed, asparagus is shown on a 5000-year-old Egyptian stone carving.
The ancient Romans and Greeks prized asparagus. And it was easy to find. Some 300 different species grow naturally between Siberia and Southern Africa.
Now when some of us eat asparagus, shortly afterwards our urine smells very stinky, something like rotten or boiled cabbage, or even ammonia. But not all of us can generate, or make, this odour.
Now here’s something surprising. Not everybody can detect, or smell, this odour.
There is apparently a genetic element at work here, by which some are smellers and some are not. Not entirely simple though, as John H McDonald, a geneticist from the University of Delaware explains in considerable detail.
After they eat asparagus, some people notice that their urine has a strong, unusual odor. Other people don’t notice anything unusual. This was first thought to result from genetic variation in whether or not sulfur compounds in asparagus were secreted into the urine, with the allele for secreting being dominant. Later it was suggested that everyone secretes the compounds in their urine, but only some people can smell the compounds. Better-controlled experiments have shown that there is variation in both traits; some people secrete the compounds in their urine but can’t smell them, while some people don’t secrete the compounds but can smell them in other people’s urine. This complication means that the ability to smell stinky compounds in one’s own urine after eating asparagus is not a simple genetic trait. It is not known whether the two separate traits, secreting the compounds and being able to smell them, have a simple genetic basis.
I wish Americans would learn how to spell sulphur though…