The Real Reason Asparagus Can Make Your Pee Smell Funny

Have you ever had a delicious and savory meal with asparagus only to be taken aback by the rancid smell produced by your urine the next time you use the restroom? Chances are this has happened to you at least once, or if it hasn't, there's a reason for that too.

Asparagus is one of the healthiest vegetables around, and is considered a superfood by some. It boasts many health benefits such as being rich in antioxidants, supporting the digestive tract due to its high fiber content, and having the potential for reducing blood pressure. It's also a good source of vitamins A, K, and C (via Healthline). Part of its appeal is the fact that asparagus is very versatile and can be easily incorporated into one's diet.

The unpleasant odor experienced by some after consuming asparagus is believed to be a result of aspargusic acid metabolism (via Cleveland Clinic). Within about 15 to 30 minutes of eating asparagus, aspargusic acid breaks down into sulfur by-products. Sulfur is well known for its awful rotten egg-like smell, and these by-products could make your urine smell for hours. While the percentages vary, one thing that is clear is that while many people can smell "asparagus pee," as it's fondly known as, there are quite a few people who don't smell it at all.

What it means if you can't smell 'asparagus pee'

Since everybody processes and metabolizes food differently, it's not surprising that some people do not smell the strong unpleasant odor emanating from their urine after eating asparagus. While the definitive cause of this lack of smell remains unknown, there are two circulating theories among the scientific community (via Healthline).

The first theory alleges that some individuals lack an enzyme critical to aspargusic acid metabolism, and thus cannot form the odor-causing sulfur by-products. The second theory proposes that certain individuals may carry genetic mutations which alter their olfactory receptors, which are responsible for your sense of smell. These individuals may very well be producing sulfur by-products, but simply cannot smell the odor.

Whether you're an unfortunate smeller or a lucky non-smeller, asparagus pee is real — but it is not harmful. So don't let the possibility of foul-odored urine stop you from firing up the grill and enjoy several stalks of asparagus at your next barbeque.