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Diet Diva
Diet Diva

Get advice on healthy eating, nutrition, and weight loss from expert dietitian Tara Gidus. 

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Asparagus Urine

This might be kind of a weird blog today, but it is a question I actually get asked fairly often. Have you ever noticed that when you eat asparagus your urine smells different? Some of you may think I am crazy writing this because you have never experienced it and others are nodding your head and saying, “YES, I have always wondered why that is!” I finally did the research when I was asked yet again this week.

The reason for the smell is a sulfer compound called mercaptan. This compound is also found in rotten eggs, onion, garlic, and the secretions of skunks. When you eat asparagus, your digestive tract breaks down the mercaptan and the resulting by-products cause the smell. It happens quickly, and you may even be able to notice the smell as early as 15 minutes after eating it! Mercaptan and the resulting odor is not harmful in any way.

I figured that it had to be some kind of enzyme or compound, and now I know the exact name to tell people. What I find fascinating, though, is that not everyone has the gene to break down the mercaptan, so some people have no idea what you are talking about when you say your pee smells funny after eating asparagus! The studies vary, but it seems that certain ethnic populations have it more than others. This has not been highly studied, so don’t ask me exactly which people, but studies have been done on small groups of British, French, and Israeli Jews. It seems that all of the French had it and only about half of the Britains produced the odor. The Israeli Jews were also mixed, but some of them who did produce the odor could not smell it. Interesting…..

Fun Info on Asparagus:

  • Member of the lily family along with onions, leeks, and garlic
  • Can be eaten raw or cooked and can be canned or frozen for storage
  • Asparagus can grow 10 inches in a 24 hour period under ideal conditions
  • The larger the diameter, the better the quality
  • Asparagus was first cultivated 2500 years ago in Greece
  • Asparagus comes from the Greek word meaning stalk or shoot
  • Once planted, it must go through 3 growing seasons before it can be harvested
  • Asparagus is very low in calories at less than 4 calories per spear
  • It is the leading vegetable source of folic acid
  • It is a good source of potassium, fiber, vitamin B6, vitamin A, vitamin C, and thiamin
  • Contains no fat or cholesterol and very little sodium naturally
Click for more information on Asparagus or for some tasty asparagus recipes

Photo courtesy of Laurel Fan
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About the Author


Tara Gidus is a nationally recognized expert and spokesperson on nutrition and fitness.