How to Get Rid of the Smell of Asparagus Pee

If you're curious about how to get rid of asparagus pee odor, you're probably one of the fortunate few who can actually detect it. A new study in the British Medical Journal identifies the genes most likely responsible for the distinctive smell in urine after consuming asparagus, along with the genetic ability to detect the compounds it creates.

And researchers discovered not just one, but hundreds of genetic variations across various genes. However, the study doesn't explain why asparagus, of all foods, causes such a pungent, egg-like stench in our urine, nor why our bodies have gone to such lengths to sense asparagus metabolites in our pee.

This phenomenon is widely recognized. In Gabriel García Márquez's novel "Love in the Time of Cholera," he portrays the disastrous day of Dr. Juvenal Urbino. His friend has taken his own life, his pet parrot is stuck in a tree, and the firemen called to rescue it end up wrecking his house — and in the chaos, his bird flies away.

Researchers didn't identify just a single gene variant, but rather hundreds spread across multiple genes. However, the study fails to explain why asparagus, of all foods, makes our urine smell like rotten eggs, nor why our bodies have gone to such lengths to detect metabolized asparagus in our pee.

Why Eating Asparagus Causes Smelly Urine

Previous studies dating back to the 1950s have found that some individuals produce asparagus-scented urine, while others do not, and some can detect the odor, while others cannot. Earlier research identified the two metabolites responsible for the unpleasant smell, but it hadn't explored whether the ability to smell these compounds, known as methanethiol and S-methyl thioesters, is genetic.

A research team led by Sarah Markt and Lorelei Mucci at the Harvard T.H. Chan School of Public Health discovered that, of the 6,909 participants (men and women of European-American descent), around 40 percent could detect these metabolites in their urine after eating asparagus, while 60 percent could not — these individuals were labeled as "asparagus anosmic." After analyzing 9 million genetic variants in those who were anosmic, they linked this inability to 871 specific genetic variations found in chromosome 1, on genes associated with our sense of smell.

Interestingly, although women are recognized for having a heightened sense of smell, able to identify odors more accurately and consistently than men, fewer women admitted to being able to detect the smell of their own asparagus pee. Since the study relied on participants' self-reports, the researchers are uncertain whether some women may have underreported the smell out of modesty, or if it was simply hard to detect due to the position they were in when they produced the urine.

The researchers acknowledge the limitations of the study. For example, it exclusively focused on individuals of European descent, so it’s uncertain whether the same genetic variations would be present in people of other ethnicities. Additionally, since participants self-reported the odor, there’s room for subjective interpretation. Furthermore, the study only examined the smell of participants' own urine, not whether they could detect the asparagus scent in others' urine, though a 1980 Israeli study examined that angle.

But don't be concerned if you're unable to smell asparagus in your urine — these researchers have you covered:

"Future replication studies are needed before considering targeted treatments to help anosmic individuals discover what they’re missing," the research team states in the report.

Neutralizing the Smell

While the science of asparagus pee is undoubtedly intriguing, it doesn’t do much for those looking to avoid smelly urine. Although there’s no way to completely eliminate asparagus pee, there are ways to reduce its effects and occurrences for those particularly sensitive to the odor, including:

Unraveling the Mystery of Asparagus Pee

The puzzling case of asparagus and its aromatic aftermath has intrigued and amused us for generations. Whether it’s Gabriel García Márquez’s literary reference to this strange phenomenon or the groundbreaking research from the Harvard T.H. Chan School of Public Health, the mystery behind asparagus pee offers more than just insight into our body’s peculiarities.

As science continues to untangle the complexities of our sense of smell and how our genetics shape our individual olfactory experiences, one thing is clear: the asparagus mystery highlights the diversity and wonder of human life. From the "super smellers" to those with "asparagus anosmia," we all have a unique story to share, even if it’s only in the privacy of our bathrooms.