Why Does COVID Make You Lose Your Taste?

COVID-19 disrupts your sense of taste through a surprisingly tangled set of mechanisms, from direct viral infection of taste cells to inflammation that damages the nerves carrying flavor signals to the brain. But here is the twist that even many doctors missed early in the pandemic: much of what people describe as “losing taste” during COVID is actually loss of smell in disguise. The real picture involves both senses, several biological pathways, and a virus that seems almost uniquely suited to attacking the chemical senses.

Most of What You Experience as Taste Loss Is Really Smell Loss

When researchers formally tested COVID patients who complained of losing their taste, something unexpected emerged. In one study using validated psychophysical tests, all 24 patients had normal gustatory function on objective measures, yet about two-thirds of them reported their taste was impaired. Nearly all of them, however, had measurable olfactory dysfunction.

That makes sense once you consider how flavor works. What you experience when eating a meal is a fusion of true taste (sweet, salty, sour, bitter, umami) and retronasal smell, which is the aroma that rises from food in your mouth up into the nasal cavity. Without that olfactory component, a strawberry just tastes mildly sweet and a little sour. The complex “strawberry-ness” vanishes. So when COVID patients say food tastes like cardboard, most of them are describing an olfactory loss they mistakenly attribute to their tongue.¹

This discrepancy also shows up at the population level. A meta-analysis of studies that used objective smell tests found that roughly 77% of COVID-positive patients had measurable smell loss, compared with only about 45% when patients were simply asked whether they noticed anything wrong. People underestimate their own smell loss, which means they also misidentify it as taste loss.²

None of this means true taste loss doesn’t happen with COVID. It does, and recent research has uncovered several ways the virus can damage the taste system directly. But the dominant experience for most patients is olfactory, and understanding that distinction matters for both diagnosis and recovery expectations.

How the Virus Gets Into Taste Cells

SARS-CoV-2 enters human cells by latching onto a protein called ACE2 on their surface. Researchers quickly wondered whether taste cells carry ACE2, which would give the virus a direct entry point into the taste system. The answer turned out to be yes, but with some nuance.

Studies using human tissue found that ACE2 is present on a specific subpopulation of taste receptor cells, the type II cells that sit inside taste buds on the tongue’s papillae. These are the cells responsible for detecting sweet, bitter, and umami flavors.³ Confirmation came from work showing that these type II cells could actually be infected by SARS-CoV-2.⁴

Interestingly, a mouse study found a different distribution: ACE2 was enriched on epithelial cells in the nongustatory (non-taste) papillae but was absent from taste buds themselves.⁵ Mouse and human tongues aren’t identical, and the human tissue work is considered more directly relevant, but the mouse data is a reminder that the picture isn’t perfectly clean. The virus may also damage the surrounding tissue environment of taste buds rather than always infecting the taste cells themselves.

Nerve Damage and Inflammation

Direct infection of taste cells is only one pathway. The virus also appears to attack the nerves that relay taste signals from the tongue to the brain. Anatomical studies of the glossopharyngeal and vagus nerves, the ninth and tenth cranial nerves that carry taste information from the back of the tongue and throat, found that all the key viral entry proteins (ACE2, NRP1, and TMPRSS2) were present throughout these nerve structures. ACE2 appeared in nerve sheaths, connective tissue, blood vessels, axons, and even parts of the myelin coating.⁶ This means the virus has multiple points of access to nerve tissue, and infection there could interrupt the taste signal on its way to the brain.

Beyond direct nerve infection, COVID triggers a surge of inflammatory molecules. The immune system’s response to the virus can itself become destructive. The so-called cytokine storm that accompanies severe COVID doesn’t just cause fever and fatigue; it also inflicts secondary damage on taste cells. Proinflammatory cytokines and interferons can trigger cell death in taste receptor cells and disrupt the ongoing renewal process that normally keeps taste buds refreshed. Taste bud cells have a short lifespan, typically turning over every couple of weeks, and their stem cells need to keep producing replacements. When that cycle gets interrupted by inflammation, taste function suffers.⁷

One idea that circulated early on was that the virus might damage taste centers in the brain itself. But that explanation hasn’t held up well. Chemical sense impairment tends to correlate with milder COVID cases, not severe ones involving brain inflammation. Direct central nervous system invasion by SARS-CoV-2 remains uncommon, making it an unlikely primary explanation for the widespread taste complaints.⁸

The Saliva and Zinc Connection

Your sense of taste doesn’t operate in a vacuum; it depends on the chemical environment of your mouth. Saliva dissolves taste molecules so they can reach taste receptors, and the composition of that saliva matters. COVID can cause salivary gland dysfunction, leading to dry mouth, which alone can impair taste perception.⁹

Zinc plays a specific role here. An enzyme called carbonic anhydrase VI, found in both taste bud cells and salivary glands, requires zinc to function. If SARS-CoV-2 infection depletes zinc inside oral tissues, this enzyme may not work properly, which would impair both taste perception and saliva production at once.¹⁰ Supporting this idea, researchers found that COVID patients with taste disturbances had significantly lower salivary zinc levels than controls, and those levels rose after recovery.¹¹

The zinc angle has attracted therapeutic interest. In one study of long COVID patients with persistent smell and taste problems, treatment with oral zinc and steroids produced modest improvement, though a substantial fraction remained symptomatic.¹² The evidence for zinc supplementation as a reliable fix is still thin, but the biological rationale is plausible enough that research continues.

Why COVID Hits Taste Harder Than Other Viruses

It’s worth pausing on something that puzzled researchers early in the pandemic. Plenty of respiratory viruses can temporarily dull your sense of taste and smell, as anyone with a bad cold knows. But COVID did it at far higher rates and with more dramatic severity. A matched comparison of COVID and influenza patients found that smell and taste disorders were about 11 times more common after COVID than after the flu over a three-month window.¹³ Reviews of the broader literature confirmed the pattern: chemical sense disturbances appear earlier in COVID than in other respiratory infections and persist longer afterward.¹⁴

This likely reflects the fact that SARS-CoV-2 has a particular affinity for the tissues involved in chemical sensing. The olfactory epithelium is rich in ACE2, and as described above, taste cells carry it too. Most cold viruses cause congestion that physically blocks airflow to olfactory receptors; COVID instead damages the cells themselves. That’s why COVID patients often lose smell without noticeable nasal congestion, which was one of the earliest clinical clues that something mechanistically different was going on.

Not All Variants Are Equal

The frequency of taste and smell loss has shifted dramatically across different SARS-CoV-2 variants. The Delta variant, dominant in mid-2021, was the worst offender. In a large Japanese study, about 32% of Delta-era patients reported smell or taste disorders, compared with roughly 21% during the wild-type period, about 18% during Alpha dominance, and just 4% during the Omicron wave.¹⁵ English contact-tracing data told a similar story: Omicron infections were far less likely than Delta to produce smell or taste loss.¹⁶

Why the difference? Omicron shifted its entry strategy somewhat, relying less on ACE2 in certain tissue types and more on alternative cell entry pathways. It also tended to replicate more efficiently in the upper airways and less in the olfactory epithelium compared with earlier variants. The practical upshot is that if you catch COVID today, you’re much less likely to lose your taste or smell than you would have been in 2020 or 2021, though it can still happen.

Who Loses Taste More Often

Not everyone is equally susceptible. Several demographic patterns have emerged consistently across studies. Younger adults are more likely to report taste loss than older adults, and women are more affected than men. One large study found that people in the 10-to-20-year age group were more than six times as likely to present with smell or taste dysfunction compared with 30-to-40-year-olds, and the proportion of affected women was roughly double that of men.¹⁷ Multivariate analyses confirm younger age and female sex as consistent predictors, along with higher body mass index and having milder overall illness.¹⁸

The age finding might seem counterintuitive, since you’d expect older people to be more vulnerable to everything COVID throws at them. But the connection between smell/taste loss and mild disease suggests these symptoms reflect a specific local immune response rather than systemic severity. In people with mild infections, the virus may linger in the upper airway and oral tissues for longer before being cleared, giving it more time to damage chemosensory cells without triggering the kind of overwhelming systemic illness seen in severe cases.

How Long Recovery Takes

For most people, taste and smell begin returning within the first week or two. A systematic review found that symptoms generally start to improve after about a week, with significant recovery in the first two weeks, though roughly a third of patients in some studies were still symptomatic at the one-week mark.¹⁹

A large meta-analysis using recovery-curve modeling put more precise timelines on it. By 30 days, about three-quarters of patients had recovered their sense of smell and nearly 80% had recovered taste. By six months, those numbers climbed to about 96% for smell and 98% for taste. The estimated share of patients who may develop persistent dysfunction was roughly 5-6% for smell and about 4% for taste.²⁰

Certain factors predict slower recovery. Women were less likely to recover both smell and taste than men. Patients who had more severe initial dysfunction or nasal congestion also took longer to get their smell back. This is where the distinction between smell and taste matters practically: since most “taste loss” is really olfactory, your taste recovery is often tied to how well your olfactory system heals.²⁰

When It Lasts Months or Years

For a minority of patients, taste and smell disturbances become a long COVID symptom that lasts months or longer. About 10% of people in one large survey reported persistent problems including not just loss of smell or taste but distortions: parosmia (familiar smells registering as wrong or unpleasant), phantosmia (phantom smells), and dysgeusia (basic tastes like sweet, sour, salty, or bitter tasting different than they should).²¹ These distortions can be more distressing than complete loss, because food actively tastes bad rather than just bland.

Recent molecular work has shed light on what may be happening in these persistent cases. Researchers found that people with long-lasting taste loss showed reduced expression of key genes (PLCβ2 and TAS1R3) that are essential for type II taste cell function, the cells responsible for sweet, umami, and bitter perception. The taste loss wasn’t random; it selectively affected the flavors that depend on these specific molecular pathways, while salty and sour perception (which use different cell types) remained intact.²² This suggests the virus, or the inflammatory aftermath, permanently downregulates part of the taste cell machinery in some people.

The Ripple Effects of Losing Flavor

Losing taste and smell sounds minor compared with breathing difficulties or organ damage, but the everyday consequences can be significant. Diminished flavor reduces appetite and strips meals of pleasure, which affects social life since so much human connection happens around food. People with long-term taste distortion sometimes compensate by adding extra salt or sugar to make food palatable, which can nudge them toward higher cardiovascular and metabolic risk over time.²³

Safety risks also come into play. Without a functioning sense of smell, you may not detect gas leaks, smoke, or spoiled food. Some long COVID patients have described anxiety around cooking for others because they can’t tell whether something has burned or gone off. The psychological burden is real: studies have documented increased rates of depressive symptoms and reduced quality of life in people with persistent chemosensory dysfunction after COVID.

Taste Receptors and Immunity Beyond the Tongue

One of the more unexpected chapters in this story involves taste receptors that exist outside the mouth entirely. Bitter and sweet taste receptors have been found in the lining of the upper airway, where they act as a first-line pathogen detection system. Bitter receptors in the nose and sinuses can detect bacterial compounds and trigger defensive responses like releasing nitric oxide, which kills microbes. Sweet receptors, conversely, seem to detect bacterial glucose consumption and modulate the immune response accordingly.²⁴

This raises an intriguing question that researchers are still working through: could SARS-CoV-2 infection of these extraoral taste receptors weaken the airway’s initial immune defenses, giving the virus a foothold? And could variation in these receptors between individuals help explain why some people get hit so much harder with chemosensory symptoms? The research connecting airway taste receptors specifically to COVID outcomes is still early, but the biology suggests that the virus’s affinity for taste cell machinery may have consequences well beyond whether your dinner tastes right.