Lingering Smell Loss Common Two Years Post-COVID,Study Finds
Even two years after a COVID-19 infection,a notable number of individuals experience a diminished sense of smell,ofen without realizing the extent of the impairment. A recent US study highlights alarming statistics and advocates for routine smell testing too better understand and address this underestimated long-term effect.
The acute phase of the COVID-19 pandemic has passed, but its health consequences continue to effect many. Research published in the jama Network Open journal reveals that many individuals experience a significantly reduced ability to smell two years after contracting the virus.
The study, conducted by a team led by Leora Horwitz from New York University, found that “80 percent of study participants who reported a change in their odor ability after a COVID-19 illness also scored low on a clinical smell test approximately two years later.” Moreover, nearly one-quarter of this group (23 percent) exhibited severe impairment or complete loss of smell.
Researchers conclude that individuals with a history of COVID-19 are at a heightened risk of developing a weakened sense of smell, a problem they believe has been historically underestimated.
Many Unaware of Smell Deficits
The study involved testing the sense of smell of around 3,500 adult men and women who had experienced COVID-19 in the preceding two years. Participants were asked to identify 40 different scents in a standardized test. Crucially, this study utilized objective measurement, unlike previous research relying on self-reported data which could be subject to underestimation or overestimation of symptoms.
Results were compared against a database of thousands of healthy volunteers of similar age and gender who underwent the same testing. A striking finding was that many individuals who had been sick were unaware of their reduced olfactory capacity. Specifically, 1563 participants (almost 45 percent) reported no change in their sense of smell after infection, yet 66 percent of these individuals demonstrated measurable deficits in the smell test, with approximately 8 percent experiencing severe restrictions.
Peter berlit, Secretary General of the german Society for Neurology (DGN), confirms this issue is also observed in Germany. He notes that since the beginning of the pandemic in 2020, he has observed the long-term consequences of COVID-19 and contributed to medical guidelines. ”We already know such a loss of the sense of smell from influenza. But it is much less frequent than during and after a corona infection.”
Smell Issues Even Without Known Infection
The study also revealed a surprising finding: approximately 60 percent of participants in the control group – those without a known prior infection – also exhibited limited smell perception. Researchers suggest this could be due to undetected infections leading to misclassification,or that smell disorders may be more prevalent in the general population than previously thought.
Study author Horwitz emphasizes that “Even if patients may not notice this immediately, a reduced perception of odors can have profound effects on their intellectual and physical well-being.”
Ongoing research is investigating potential therapies to improve the sense of smell,including odor training and nutritional supplements like vitamin A. based on these findings, the research team recommends incorporating formal smell tests into routine post-COVID-19 care, allowing for earlier recognition and improved treatment of long-term consequences.
