Long COVID Taste Loss Tied to Molecular Changes, Not Structural Damage

A new study links persistent taste loss in long COVID to molecular changes-not structural damage. Researchers examined 28 non-hospitalized individuals with taste dysfunction more than 12 months after SARS-CoV-2 infection.

Objective taste testing showed most had normal overall scores-but 11 experienced complete loss of at least one taste quality. Sweet, bitter, and umami were most affected; salty and sour remained intact.

Biopsies of fungiform taste papillae revealed intact taste bud structure and nerve supply. No viral RNA was detected.

Molecular analysis found reduced expression of PLCβ2 and TAS1R3-genes essential for sweet, bitter, and umami signal transduction in type II taste cells. This suggests disrupted neural signaling, not tissue damage, underlies the dysfunction.