Loss of smell from Covid-19 takes up to 3 years to return, study finds
- Far from a benign inconvenience, a coronavirus-induced sensory upheaval can make people not want to eat, leading to depression and weight loss
- Some 28 million Americans had endured a worse sense of smell after Covid
The loss of taste and smell – hallmarks of a coronavirus infection early in the pandemic – became a stubborn blight for many long Covid sufferers, but new research shows that the sensory problems gradually abate.
Smell and taste disturbances were reported in almost two-thirds of the 100 people who had caught a mild case of Covid-19 in the fall of 2020 in Trieste, Italy, and were randomly selected for studying alongside 100 uninfected people for comparison. Both groups were followed for three years.
About a quarter of the Covid cases could not taste properly a year after the acute illness but, after two years, there was little difference between them and controls.
The research, published on Thursday in a letter to the journal JAMA Otolaryngology, suggests that so-called gustatory dysfunction, linked to the taste bud-damaging immune response to lingering vestiges of Sars-CoV-2 in the tongue, resolves faster than problems with smell.
More than a quarter of the Covid group still experienced olfactory dysfunction two years after infection, but after three years, the condition wasn’t significantly more common than in controls, the researchers found.