Why Your Urine Hates Asparagus


When pre­paring a meal for a room full of guests, you may want to choose another vege­table.

Asparagus is Unfriendly


There are reasons why asparagus will not be a crowd pleaser. We assume every human body functions similarly. Some­times things happen we cannot easily explain. Take biochemical reactions to certain vegetables.

Does Your Urine Hate Asparagus?

Some persons notice a putrid smell during urina­tion after ingesting vegetables within the brassica family. A subset of people have something called tri­methyla­minu­ria. This condition inter­feres with the break­down of a chemical called tri­methyla­mine in choline-rich foods like asparagus or cauli­flower (47 mg/cup), broccoli (30 mg), Brussels sprouts (17 mg) and cabbage (7.5 mg). The condition irrespective of whether you are a woman or man.

But what about people who only have a fetid reaction to aspara­gus? It turns out there is a chemical unique to this vege­table, fittingly called aspara­gusic acid. Studies are incon­clu­sive because some partici­pants notice their own foul urine, while some smell it in others but not themselves. Remaining indivi­duals have no idea why we are even talking about this.

This is not a wholesale disparage­ment. The nutrition within asparagus is undeniable. Compounds within asparagus root called steroidal glyco­sides may help reduce inflam­mation. Asparagus also contains calcium, magnesium and iodine. It is an excellent source of folic acid, vitamins A, C and E.

Scientists investi­gat­ing this olfac­tory phenome­non believe that some people convert aspara­gusic acid into a sulfur com­pound similar to rotten eggs with other pungent notes. Only about one-quarter of the popula­tion appears to have the special gene that allows them to smell the sulfuric com­pounds emitted by nearly everyone else. This can be awkward. You may be the individual unknowingly stinking up the place. It is not harmful, just off-putting.

If your urine is smelly after eating aspara­gus, you are not alone. What you or others smell is paradoxically common and un­natural. So when pre­paring a meal for a room full of guests, to be on the safe side, you may want to choose a vege­table other than aspara­gus. Or stock up on bath­room air freshener.

To support the writing of useful articles about nutrition, ClinicalPosters sells human anatomy posters, scientific posters and other products online. You may sponsor specific articles, remit a small donation, or leave an encouraging comment to keep the work going. Stay safe and A Bit More Healthy.

Login Remind

Kevin Williams is a health advocate and writer of hundreds of articles for multiple web­sites, including: A Bit More Healthy, KevinMD (WebMD), and Sue’s Nutrition Buzz. He is a prior 15-year con­sul­tant for Neutrogena Research and Scientific Affairs.

Join Discussion