Asparagus. Genetics playing with our sense of smell

With the arrival of summer, surely one of the foods that is present in many of your recipes is asparagus. Have you ever wondered why after eating the urine has a different smell? Have you never noticed? In today's post we will try to find an explanation for this curious phenomenon. It turns out that not everyone processes asparagus in the same way, and not everyone is able to detect the smell in the same way.

Let's start at the base. Chemistry

Nutritionally, the most remarkable thing could be its amount of Vitamin A, potassium and folic acid (of special interest to pregnant women). Asparagus is a vegetable of the same family as garlic or onions and is a native plant of Europe, although subsequently cultivated throughout the world. By the way, that the etymology of the word asparagus derives from a Persian word meaning outbreak.

The most curious part of its composition is that when we eat asparagus, part of its components give as waste products derived from sulfur and ammonia. It seems that it is these compounds that cause the urine to have a characteristic smell after ingestion. And here begins the interesting.

The studies

This effect has been known for a long time and although several studies have been carried out to see the possible causes, there are still no sure conclusions about who are responsible, or how they work. But what's coming now may surprise you more, do you know that barely 1 in 4 people are able to detect this smell in the urine after consuming asparagus? Do you know that probably 1 in 4 people after eating asparagus do not produce urine with that peculiar smell?

That is, you may be able to detect the smell, but not produce it. Or to produce the smell and not detect it. Or neither, or both. The latter is my case, what is yours?

The studies are inconclusive in the case of people who are capable of producing the smell. That is, it could be that everyone metabolized asparagus in the same way, and that everyone produced odor metabolites, but that the amount was variable. What seems proven is that there are people who are not able to distinguish that smell in the urine. It can also influence the presence of "Asparagusic acid, S2 (CH2) 2CHCO2H" (I have not found the translation of this acid into Spanish), since in young shoots there is more quantity. It is precisely those sulfur atoms that are responsible for the smell, when combined in various forms after digestion.

To carry out

What is interesting about this whole matter? Beyond the simple curiosity about odors, I think it also invites a reflection on genetics and metabolism in relation to nutrition.

While it is true that we all share some general characteristics, it is no less true that there are also particular variations closely linked to genetics that manifest themselves in matters of no importance such as this, but which can be more serious as milk intolerance, celiac disease or rare metabolic diseases.

We know more and more about nutrition, but it is also necessary to remember that every time we discover more things that we don't know. And that is a great stimulus to continue investigating and to continue feeding our appetite, not only for food, but also for knowledge.

And you? Have you detected those smells? ;)

Images | By matt.hintsa Live on the palate | Asparagus in gastronomy Live on the palate | Green Asparagus Cream. Recipe with Thermomix

Video: Sniffing out significant Pee values: genome wide association study of asparagus anosmia (December 2019).