This Study Might Finally Reveal Why COVID Makes You Lose Your Taste And Smell

Much about COVID-19 has been unexpected, from how capriciously it has affected different populations to the many and varied ways it's been known to present. One of the most baffling symptoms associated with COVID-19 is the loss of the ability to smell, which began emerging in some patients early on in the pandemic and remains among the most commonly-reported symptoms to this day, according to the authors of a 2022 study published in the journal Cell. The symptom is common enough that there's even a cookbook for people who lost their taste due to COVID. The study attempted to identify the reason why COVID-19 can affect one's sense of smell, and by extension, one's sense of taste.

Anosmia, as this condition is known scientifically, does not happen to everyone infected with COVID-19, but studies suggest that it does happen in as many as 50% of cases; it may occur in up to  67% of mild to moderate cases (per Gavi). COVID-related anosmia is usually temporary, lasting no more than six weeks or so, but in a small subset of patients, "resolution is elusive," as the authors of the 2022 study put it. And that can be devastating, but there may be hope on the horizon. The study referenced may help to explain why COVID can make you lose some of your senses. And that, as study co-author Jonathan Overdevest, M.D., Ph.D., tells Prevention, could be a helpful first step in finding a way to counteract this phenomenon.

It's a different mechanism from what happens in the common cold

It's not even the slightest bit unusual to lose your sense of smell and taste while dealing with the array of indignities presented by your typical common cold. In fact, it's appropriately "common." But that makes logical sense, according to the authors of a new study (via Cell). "Olfactory deficits," as the authors refer to anosmia in the common cold, are easily explained by the involvement of nasal inflammation and congestion that goes with most colds. As a result, one's "smell receptors" end up insulated from "airborne odor molecules that enter the nasal cavity." As a result, such odor molecules can't bind to the related receptors, and no smell is detected. But that's not why COVID-19 makes you lose your sense of taste and smell, in cases where it does.

As a matter of fact, anosmia in COVID-19 is entirely independent of such aforementioned "conductive interference," as the study authors put it. Rather, as the study revealed, infection with the novel coronavirus "causes widespread downregulation of olfactory receptors." In other words, the virus may directly attack the olfactory receptors, rendering them less capable of detecting the presence of airborne odor molecules. The study may explain the symptom experienced by COVID-positive TikTokers filming themselves eating without the ability to smell or taste.