Another food post.
Lately we've been eating a lot of asparagus. I mean like 2 or 3 times a week.
I thought asparagus gave everyone smelly pee. But that's not so.
Asparagus contains a sulfur compound called mercaptan. (It's also found in rotten eggs, onions, garlic, and in the secretions of skunks.) When your digestive tract breaks down this substance, by-products are released that cause the funny scent.
Only some people appear to have the gene for the enzyme that breaks down mercaptan into its more pungent parts. A study published in the May 1989 British Journal of Clinical Pharmacology found that 46% of 115 people tested produced the odor in one group of British citizens, while 100% of 103 people produced it in a group of French citizens.
Another study published in the same journal found that 10% of a group of 300 Israeli Jews could not detect the odor. In other words, a person's urine could smell, but he or she might not know it.