Good to know: Why our urine stinks after eating asparagus

Asparagus is being made again.

Good to know: Why our urine stinks after eating asparagus

Asparagus is being made again. You can see it in the supermarket and smell it in the toilet. Because with the asparagus season, the specific smells that come with the enjoyment come back. But what in asparagus makes your urine stink after eating it and makes every trip to the toilet an olfactory challenge? What can you do about the typical smell? And why aren't everyone affected by asparagus urine?

Asparagus is popular. This is not only due to the taste, but also to its inner values. The bars consist of more than 90 percent water and are low in calories, but at the same time they also contain lots of vitamins and minerals. These include iron, magnesium, calcium, potassium and copper as well as antioxidants such as beta-carotene, vitamins C and E. However, another ingredient is responsible for the typical asparagus urine: aspartic acid.

Aspargusic acid is a sulfur-containing carboxylic acid. This acid ensures that asparagus can grow particularly quickly underground. Aspargusic acid is present in all varieties of asparagus - whether white, green or purple - and is mainly found in the tips of asparagus. White asparagus in particular is said to cause particularly intense asparagus urine. This is because white asparagus, unlike green or purple asparagus, only grows underground. The more sunlight the stalks are exposed to, the less aspartic acid they will have when harvested.

The acid in asparagus acts like a natural repellent against predators. The acid also inhibits or completely prevents the growth of other plants around the poles. The amino acid itself does not smell. It is the processes in the body that begin after eating asparagus that cause asparagus urine to develop. The decomposition of the amino acid creates sulfur-containing degradation products. It is precisely this sulfur that causes the typical smell that causes some people to curl their toenails just a few minutes after consumption.

There is (almost) nothing you can do about the smell. The only way to avoid asparagus urine is to stop eating asparagus. It is not possible to “neutralize” the smell by combining it with other foods or special food ingredients. A report from the Federal Center for Nutrition (BzfE) caused excitement in April. It said that asparagus urine could be reduced with strawberries. That's not true. It was an April Fool's joke. What can actually help, however, is to drink a lot. The more you drink, the more watery your urine is. This causes the asparagus urine to lose its intensity. But why do some people develop asparagus urine and others not? When you get right down to it, there is a defect behind this. More than half of the population benefits from lacking the enzyme necessary to break down the acid. If this process does not take place, the sulfur and therefore the stinky asparagus urine smell does not develop. So it's already in our cradle whether our urine smells particularly good after eating asparagus or not. It is now also known that there are people who cannot smell asparagus urine. As a team of researchers from the USA discovered, “selective not smelling” is also hereditary.

Source: BzfE, Study NIH, Study 2 NIH, AOK, Techniker Krankenkasse, Geo