Ageusia (from negative prefix a- and Ancient Greek γεῦσις geûsis 'taste') is the loss of taste functions of the tongue, particularly the inability to detect sweetness, sourness, bitterness, saltiness, and umami (meaning 'savory taste'). It is sometimes confused with anosmia – a loss of the sense of smell. True ageusia is relatively rare compared to hypogeusia – a partial loss of taste – and dysgeusia – a distortion or alteration of taste.
Even though ageusia is considered relatively rare it can impact individuals of any age or demographic.
Symptoms
The complete loss of taste.
- Issues with the water-soluble molecules responsible for taste, causing oral dryness or damage to taste buds.
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!Patients Additionally, in South Korea, out of approximately 2,000 recorded cases of individuals with ageusia related infection from COVID-19, only 30% exhibited ageusia.
Ageusia could also possibly occur due to changes in the abundance or lack of saliva that can eventually cause damage to the cells on the tongue's surface.<!--Some research has suggested that COVID-19-induced ageusia (and anosmia) may be effectively treated with a single 1000mg dose of turmeric supplement. See WP:MED discussion-->
Saliva and taste perception
Saliva is essential in taste sensation and perception. Studies have indicated that saliva plays a critical role in detecting a COVID-19 infection, and ageusia can serve as an indication of an infection that is affecting the salivary glands.
Zinc deficiency
In cases of zinc deficiency, a shortage of zinc-binding proteins that help with the growth and development of taste buds, could result in taste bud issues associated with ageusia, hypogeusia, and hyposalivation.
An example of a test used by researchers and doctors is electrogustometry. This test involves applying mild electric currents to specific tongue areas, to assess taste sensitivity in patients exhibiting ageusia and its symptoms.