How COVID-19 has decimated people's sense of smell, taste

One of COVID-19's defining characteristic when it first began spreading in 2020 was a loss of smell. Around 80% of infected individuals reported losing their sense of smell, at least for the short term. Since then, millions of people have experienced a loss of smell or taste due to COVID-19.

In a new study published in The Laryngoscope, researchers analyzed data from 29,696 adults who participated in National Health Interview Survey in 2021. In total, 14% of respondents said they had been diagnosed with COVID-19. Of this group, over 60% reported a loss of smell, and 58% reported a loss of taste.

Although around 75% of people who lost their sense of smell or taste reported later recovering, the remainder had either a partial or no return of their sense of smell or taste. In general, those who had more severe COVID-19 symptoms were more likely to report losing their sense of smell or taste and had a lower likelihood of recovery.

"If you lost your sense of smell, did you get it back? There's about a one in four chance you didn’t. That’s terrible," said Neil Bhattacharyya, a professor of otolaryngology at Mass Eye and Ear.

Many people who have lost their ability to smell or taste say they struggle in their day-to-day life without these senses, particularly when it comes to eating and enjoying food.

For example, Lisa Milne, a 59-year-old software marketing professional, said losing her sense of smell has been disorienting and depressing. She can no longer taste wine, and her favorite foods no longer make her feel better since she can't really taste them.

"That is missing — the mental reward you get using food," Milne said.

Similarly, Claudia Gathercole, said cooking no longer brings her pleasure and that going out to eat feels like a waste of money after losing her ability to taste. According to Gathercole, everything that's not sweet or salty tastes "like you're eating a spoonful of nothing."

"The classic thing patients tell me is that food tastes like cardboard," Bhattacharyya said.

These symptoms aren't "as benign as you may think," he added. They can "lead to decreased eating for pleasure and, in more extreme cases, it can lead to depression and weight loss." In addition, some patients may not be able to detect smells from gas leaks, smoke, and other potential dangers.

"I really hope somebody can crack this and find a way to make our tastebuds reappear," Gathercole said.

Long COVID treatments remain lacking

Currently, long COVID treatments, particularly for patients who have lost their sense or smell or taste, remain limited. And the few treatments that are available may not be effective for everyone.

For example, Pamela Dalton, a researcher at the Monell Chemical Senses Center, said providers are recommending long COVID patients try smell training, where they systematically and routinely smell items in their kitchens, since "there's no risk except for maybe boredom and frustration."

However, there is no definitive evidence that smell training actually works. Bhattacharyya said he has seen it work only in a "minority of cases."

Other potential, but still unproven, treatments include giving people their own platelet-rich plasma in their nasal cavity, a numbing procedure called a stellate ganglion block, and zinc supplements.

Although there are currently very few available treatments, Bhattacharyya said doctors and others should not dismiss the issue. Bhattacharyya hopes to learn more about the demographics of people who've lost their sense of smell or taste, those who eventually regained these senses, and the quality of the impact. "We've identified it, now we want to do a more detailed analysis to see what the effect on their life is," he said. "It's not something you want to take lightly in the long run." (Weintraub, USA Today, 6/14; Prater, Fortune, 6/12) 

An infection from the omicron variant is significantly less likely to lead to long Covid than an infection from the delta variant, according to a  study published in The Lancet — findings that add to the growing body of research looking into the potential causes of the chronic condition.