For most people, the loss of taste caused by COVID-19 fades within weeks. But for some, taste disturbances persist long after the infection clears. New research published in the journal Chemical Senses suggests the lingering problem may be linked to subtle molecular changes in taste receptor cells rather than visible damage to the taste buds themselves.
Researchers studied people who continued experiencing taste issues more than a year after their initial infection. While the structure of their taste buds appeared mostly normal, many participants had lost sensitivity to certain flavors — particularly sweet, umami and bitter tastes. Tissue samples revealed reduced expression of key genes involved in taste signaling, including those linked to the PLCβ2 pathway, which plays a central role in how taste receptor cells detect these flavors.
The findings suggest that long COVID taste disturbances may stem from lasting changes in how taste cells function rather than from ongoing viral infection. Scientists believe inflammation or immune-related changes triggered during the illness may alter the molecular machinery responsible for taste perception. Although the condition appears relatively uncommon, persistent taste loss can affect appetite, nutrition and quality of life, highlighting the need for further research into long-term effects of the virus.
SOURCE:
News Medical, March 5, 2026