Why does asparagus make some people’s urine smell funny gas chamber jokes


Asparagus — a green vegetable belonging to the lily family — has one notorious side effect for some diners who eat enough of it. Within a half-hour of consumption, some people notice their urine has acquired a very pungent odor, often compared to rotting cabbage, ammonia, or rotten eggs. The effects of asparagus on urine are generally fleeting and harmless, but it’s not necessarily the consumer’s finest hour, bodily excretion-wise.

The good news is that asparagus does not affect everyone in this way. Studies conducted on the "asparagus urine" phenomenon (aren’t you glad you didn’t volunteer!) indicate that roughly 40 to 50 percent of those tested developed the distinctive odor. Surprisingly enough, there is also a segment of the population who cannot smell the sulphurous fumes of asparagus-laced urine. It is believed that both the generation of the odoriferous urine and the ability to smell it are based on genetics. Only those with a certain gene can break down the chemicals inside the asparagus into their smelly components, and only those with the proper gene can smell the results of that chemical breakdown. What’s more, the two abilities aren’t always embodied in one person. That is, those who produce it, can’t always smell it, and those who can smell it don’t necessarily produce it.

Scientists are still not entirely sure which set of chemical compounds contained in nutritious spring vegetable actually cause the smelly pee. The stalks themselves do not acquire a similar odor as they are prepared, so whatever happens most likely happens after ingestion. Experts believe that those with a certain gene produce a digestive enzyme which breaks down the asparagus into various chemical compounds. One of those compounds is called methyl mercaptan, which is the same chemical which gives a skunk its defensive smell. One theory suggests that the veggie breaks down quickly in the body and an enzyme releases methyl mercaptan, which eventually goes through the kidneys and is excreted as a waste product in the urine.

Others suggest that the smell is created by other chemical compounds called thioesters. There is also a compound called asparagusic acid, which, surprisingly, is not found primarily in asparagus. If these compounds are broken down and mixed with the genetically-created enzyme, the results could be a strong smelling urine. This smell is actually considered to be good news, since it proves that the asparagus eater’s kidneys are functioning as they should.

One commenter here noticed that, after reducing soda drinks to water and tea (decaf or caff?) that the strong odor disappeared nearly completely. That’s because soda is diuretic, meaning it causes your body to try to get rid of water. This is why after drinking coffee frequently, you’ll notice you’re making a lot more trips to the bathroom.

Unfortunately, while drinking diuretics and your urine appears more clear than before, this is not a good sign. It means your body is getting rid of water as fast as it’s coming in, and your actually causing yourself to become dehydrated. This is why removing caffeine from your beverages is highly suggested.

If your urine smells nutty, it’s not because of asparagus. Something else in your diet or kidneys is causing the smell. Ask a doctor. If it smells fishy, and looks cloudy, you probably have prostate trouble as semen from ejaculating is forced into your bladder instead of out of the penis.

If it smells musty, this may be a sign of UTI (Urinary Tract Infection). If you are a woman it is especially important that you see a doctor as this could cause sterility if it worsen and is untreated. Musty smell, only noticed on days you eat asparagus, is normal, and you will find that when you are properly hydrated, and have the extra genes this is the normal smell.

To Poster #150: the reason your daughters cannot smell asparagus on your urine, but on their own, is most likely that you have either, #1 urinated too close to eating and the chemicals have not sufficiently built up in the urine stored in the bladder to be detectable, or #2, your body does not contain the gene to break down the asparagus into the odorous chemicals.

Please people, understand: it takes two difference genes to smell and produce. Obviously if you smell it on your own urine, you have both genes. If you do not smell it on your own urine, you may have only one gene, or neither. Poster #150, please also note that drinking too much v-8 can actually poison you from exceedingly high doses of vitamins.

Some v-8 (available in my area) contains either 100 percent or nearly 100 percent of the DV (daily value) in one 8 oz cup. If you enjoy one with every meal and when you get thirsty, you could easily top 500 percent of your DV in one day. This is detrimental to your system. For the sake of your kidneys, do not do it.