Here’s an interesting one for you. Many of us know that eating asparagus makes your pee smell bad, but did you know that some people are unable to smell a difference? The reason for the smell is due to the break down of asparagusic acid (How can you tell they discovered this acidic compound first from asparagus? The name has asparagus right in it! Asparagus ic acid). The body metabolizes this acid into some stinky compounds (methanethiol, dimethyl sulfide, di methyl disulfide are three of these compounds and are all thiol containing compounds. Thiol refers to functional group -SH, and most compounds containing thiols smell bad… think skunk stink ).
Researchers found that not everyone could smell these compounds as well, and this was due to small changes in the sequence of an olfactory receptor (olfactory receptors are molecules on the surface of neurons in your nose that literally bind “oderants” aka things that have a smell). Even more interestingly they found that women were more likely then men to be unable to smell the asparagus pee stink. Odd and interesting.
For more check out the following links:
An interview with a member of the research team:
The actual research article: