Sense of smell or taste returns within six months for 4 out of every 5 COVID-19 survivors who have lost these senses, and those under 40 are more likely to recover these senses than older adults, an ongoing Virginia Commonwealth University study found.

Among 798 respondents to the ongoing COVID-19 smell and taste loss survey who had tested positive for COVID-19 and reported a loss of smell or taste, participants who were younger than 40 recovered their sense of smell at a higher rate than those older than 40, according to study results published in the American Journal of Otolaryngology last month. The VCU study requires survey participants to be 18 years or older.

Evan Reiter, MD, medical director of the Smell and Taste Disorders Center at VCU Health and a co-investigator on the study, said the latest data show 4 in 5 participants, regardless of age, regained their smell and taste within six months.

“With our cohort, we did see about an 80% recovery rate in a six-month period or longer,” said Reiter, a professor and vice chair in the Department of Otolaryngology — Head and Neck Surgery at the VCU School of Medicine. “However, 20% is still a lot of people, given the millions that have been afflicted with COVID-19.”

What symptoms COVID-19 survivors experienced and what pre-existing conditions they had also offered insights into their recovery. Those with a history of head injury were less likely to recover their sense of smell. Recovery was also less likely for those who had shortness of breath during COVID-19. However, those with nasal congestion had a higher likelihood of smell recovery.

“Increased likelihood of recovering smell in subjects with nasal congestion stands to reason simply because you can lose your sense of smell because you’re badly congested and odors can’t get into your nose,” Reiter said. “Certainly a subset of those people who are congested might have just lost their sense of smell because they were badly congested, rather than because of nerve damage due to the virus, as in other cases.”

There have been more than 230 million cases of COVID-19 worldwide, according to the World Health Organization. If estimates from the survey reflect populations worldwide, more than 20 million people could have a lingering loss of smell or taste more than six months after their COVID-19 diagnosis.

Since April 2020 when news reports of smell and taste loss as a symptom of COVID-19 became widespread, researchers at VCU have been working to determine how long COVID-19-related smell or taste loss might last to help identify treatments or other considerations for the health of those who’ve lost these senses. To date, nearly 3,000 people across the U.S. have participated in the survey, which tracks symptoms over time.

Smell and Taste Disorders Center researchers for this ongoing study include Daniel Coelho, MD, lead author and a professor in the Department of Otolaryngology — Head and Neck Surgery; Richard Costanzo, PhD, senior author, the center’s research director and professor emeritus in the Department of Physiology and Biophysics; Zachary Kons, a medical student at VCU School of Medicine; and Reiter. Co-authors on the latest paper also include Yongyun Shin, PhD, an associate professor, and Serenity Budd, a PhD student, both from the Department of Biostatistics at VCU School of Medicine.

Previous survey results published in April showed 43% of participants reported feeling depressed and 56% reported decreased enjoyment of life in general while experiencing loss of smell or taste. The most common quality-of-life concern was reduced enjoyment of food, with 87% of respondents indicating it was an issue. An inability to smell smoke was the most common safety risk, reported by 45% of those surveyed. Loss of appetite (55%) and unintentional weight loss (37%) continue to pose challenges for patients, Coelho says.

“The more we learn from those who’ve been affected, the better we can advise their health care providers and even individuals themselves on how to manage those symptoms,” Coelho said. “Through this study, we continue to gain a clearer picture of the risks COVID-19 poses to quality of life, safety and long-term health and well-being while seeking answers on treatment.”