Asparagus is a typical food of the Mediterranean diet, especially recommended for being a good source of fiber and antioxidants and low in calories . These are some of the questions to which we are going to answer with the help of nutrition experts: what are their nutritional characteristics ?, How are greens different from whites? Is their consumption contraindicated in some group of patients? Are they less healthy when canned ? And, of course, the star question : why does urine smell so bad after eating asparagus?
Before getting into the subject, nothing better than a little history. Asparagus are the young and tender stems of the asparagus, herbaceous plant of the lily family that reaches up to 1.5 m in height. The Spanish Nutrition Foundation explains in the book Spanish Food that it is believed that “they have their origin on the banks of the Tigris and the Euphrates, in present-day Iraq. In ancient Egypt it was already a commonly consumed vegetable, as reflected in paintings that have been found in graves. ”
Later, the Greeks and Romans “spread their cultivation throughout Europe. In the Middle Ages they were forgotten and in the Renaissance they became popular again ”. And so they have survived to this day.
Does color influence nutritional composition?
Green and white asparagus are not distinct species or varieties. The difference is simply in the maturation time . Daniel Ursúa, dietitian-nutritionist and author of the Nutrihabits blog , explains what this small nuance consists of: “White asparagus are cut when they have not yet left the ground (in fact, this makes the collection process more difficult and more expensive), while that, if they are let out of the ground, exposure to the sun activates the photosynthesis of their chlorophyll and turns them green ”. As it is the same plant, he adds, “its composition is practically the same.”
The fact that whites are consumed more frequently in canned food does not make much difference either. ” Canned vegetables guarantee their nutritional security and greatly extend their shelf life,” he says.
In this regard, Ramón de Cangas, dietitian-nutritionist and doctor in Molecular and Functional Biology, makes a small caveat: “By carrying water and salt, preserves enrich their sodium content , something that hypertensive patients must take into account .”
Why do they produce that smell in the urine?
Asparagus, says Ursúa, “are rich in molecules that are metabolized very quickly and, when eliminated in the urine, generate that characteristic odor.” Specifically, as Cangas indicates, “they contain asparagus acid, which, when metabolized by our body, produces a waste substance called methanothiol , which gives rise to that odor in the urine.”
Interestingly, it seems that the ability to generate it is subject to individual variability, that is, not all people are producers of this smell in the urine after eating asparagus. Likewise, there are studies that reveal that, for genetic reasons, there are individuals who are not able to perceive that smell , regardless of whether they generate it in their urine or not.
Ursúa clarifies that this scent characteristic that most people find unpleasant “does not mean that they are bad for our body or that they are purifying us .” In other words, it is a peculiarity that has no impact on nutrition or health.
Diet and constipation
Asparagus is a perfect vegetable for weight loss diets because it provides few calories and, in addition, its high fiber content favors satiety . Fiber is precisely what makes them good allies against constipation . “At the same time,” says Ursúa, “in some people they can cause gases.”
As regards the possibility of limiting intake in certain groups of patients, dietitians-nutritionists consider that asparagus can be considered an optimal food for any individual. If anything, de cangas warns that, logically, “people with an allergy to asparagus cannot consume them.”
Ursúa considers that, “in any pathology, the regimen should be personalized and guided by the specialist, so we cannot generalize any recommendation.” However, he adds that patients “with kidney disease should consult their specialist about how the consumption of this food should be.”
Gastronomic recommendations
Asparagus offers great versatility to foodies. Here are some gastronomic proposals from dietitians-nutritionists. “A different way to eat fresh asparagus is to add them in thin slices to any salad, but if you have the opportunity to buy fresh asparagus , the best way to enjoy them is simply cooked and with a little extra virgin olive oil .”
De Cangas suggests you prepare some wild asparagus sautéed with shrimp and mushrooms , for which you will need 200 grams of asparagus, 100 g of mushrooms, 80 g of shrimp, 10 g of olive oil, a tablespoon of garlic powder and a pinch of peppers.
