- The coronavirus can cause some patients to suddenly lose their sense of taste and smell.
- Many impacted patients have reported that typically flavorful food can suddenly start tasting like paper or cardboard.
- With the coronavirus spreading rapidly across the country, the CDC this week made a major change to its coronavirus safety guidelines.
The coronavirus and the flu may share many of the same symptoms, but there’s no question that the damage the coronavirus inflicts upon patients is far more severe and extensive. Aside from the expected range of respiratory symptoms such as coughing, fatigue, and troubled breathing, doctors are just now starting to understand the extent to which the coronavirus can impact a person’s cognitive abilities.
Beyond that, one of the more bizarre aspects of the coronavirus is that can cause people to suddenly lose their sense of taste and smell. And while this symptom certainly isn’t as life-threatening as some of the respiratory symptoms above, many patients who can longer taste their favorite foods or smell their favorite scents say the issue can take a huge emotional toll.
What’s interesting, though, is that the way the loss of taste and smell manifests varies ever so slightly from patient to patient. More precisely, in some instances, patients don’t experience a loss of taste and smell as much as they experience an altered sense of taste and smell. For instance, some coronavirus patients have reported that meat tastes like gasoline and that other foods can sometimes taste like grass.
By and large, though, most coronavirus patients who lose the ability to taste note that familiar food suddenly tastes like one of two things: paper or cardboard. While there’s of course no real alternative to a bona fide coronavirus test, food that suddenly tastes like paper or cardboard is a strong indicator of a positive coronavirus diagnosis.
With respect to the loss of smell, research has shown that an inability to smell peppermint or coconut oil can similarly be a strong indication of a coronavirus infection.
As to how and why the coronavirus hinders the ability for some to taste and smell, Scientific American this past June published a thorough explanation:
There is evidence that the virus can migrate into the central nervous system via the nose and olfactory bulbs as well as by other routes without invading the sensory neurons. However, the expression patterns of ACE2 and TMPRSS2 and the sudden onset and relatively fast recovery suggest that COVID-19 anosmia is not caused by damage to the central nervous system but rather by the loss of smell information before it gets to the brain. If the symptoms were centrally driven, we would expect a slower process and recovery as well as a more complex range of symptoms, including possibly parosmia or phantosmia (distorted or hallucinated smells), which have not been reported.
Inflammation in the sensory epithelium could restrict airflow to the relatively small olfactory cleft, high up in the nose, without causing the feeling of a stuffy nose or interruption of breathing, as demonstrated in a published case report. Damage to the sustentacular cells in the SE could also affect functioning of the sensory neurons in many ways (metabolic, structural, inflammatory), so that even if odors can get to the neurons, they may not be able to transmit signals.
It remains unclear, at this point, if people who lose the ability to taste and smell will ever regain the ability.