Could candy help detect COVID cases? Researchers put tasty, cheap option to the test
Researchers at The Ohio State University hope candy will improve screening tools for COVID-19.
Because loss of smell and taste affects nearly 90% of people with the coronavirus, the team says cheap and widely available candy can help catch asymptomatic individuals before they spread the virus to more people.
The sweet treats wouldn’t replace other screening methods, but rather work alongside them.
“Who doesn’t like candy? It’s an ideal stimulus because for this to work, people have to want to do it,” project co-leader Christopher Simons, an associate professor of food science and technology at Ohio State, said in a news release.
The team plans on recruiting and following about 2,800 people, mostly Ohio State students, for 90 days. Participants will be asked to first sniff then eat a piece of hard candy with one of eight different flavors, once a day.
Candy-eaters will have to log what they smell and taste, as well as its intensity, into an app. If they report a “sudden drop in either sense,” they will get a text message suggesting they quarantine and get a COVID-19 test.
The researchers are currently testing whether their tasty screening tool is more effective at detecting coronavirus infections than other existing methods. Scratch-and-sniff cards or taste tests with the bitter antimalarial medication quinine are other alternatives to examine smell and taste loss, but the team notes candy is cheaper.
“Quinine isn’t long-term. No one will sip on that every day,” Simons said. “We see factors that potentially indicate our method will be a long-term effective tool for long-term tracking of sensitivity.”
The candy method could also give researchers insight into several smell pathways to get a more accurate picture of sensory loss. Smelling candy could help test how well your nose is working (orthonasal pathway), while eating it could reveal the status of taste through the back of the throat (retronasal pathway).
“Theoretically, it’s possible that you could have some smell loss that’s more or less prominent in the orthonasal or retronasal condition that you would miss if you were only doing scratch and sniff for detection,” Simons said.
Loss of smell, clinically known as anosmia, is often one of the first symptoms noticed by people infected with the coronavirus, and often one of the only ones to show up — especially in mild cases.
That’s why screening tools that involve loss of taste or smell could be a more beneficial alternative to temperature checks because loss of smell typically lasts longer (one to two weeks, maybe even months) than a fever (one to two days). Also, most people don’t notice their smell is malfunctioning until tested.
When asked about their symptoms, only about 50% of people with coronavirus report no smell, according to researchers from the University of Colorado Boulder who developed a scratch-and-sniff test for COVID-19. But when given a standard smell test with a range of scents, that percentage jumps to 80%, “even among people with no other symptoms.”
A separate study of about 2,500 COVID-19 patients found that a faulty nose affects mostly those with mild cases — nearly 86% — while only slightly affecting people with moderate illnesses (4.5%) and severe-to-critical cases (6.9%), McClatchy News reported.
The researchers aren’t sure why people with milder cases are more likely to lose their smell, but they say it might have something to do with their immune response.
Patients with mild COVID-19 infections might be better able to fight the virus locally, meaning the pathogen doesn’t spread much beyond the upper respiratory tract. This creates some inflammation that interferes with nearby cells that help process smells, blocking their ability to do their job.
People who lack their sense of smell for longer periods of time have likely suffered more “injuries” to their olfactory cells, the researchers said, but regeneration of these cells is possible, it just might take “several months.”
Many coronavirus patients also report nasal congestion symptoms similar to the common cold, which sometimes includes a lack of smell for about two to three weeks. Temporarily clogged noses during coronavirus infection could “partly explain” why some people recover their sense of smell more quickly than others.
This story was originally published January 28, 2021 at 4:53 PM with the headline "Could candy help detect COVID cases? Researchers put tasty, cheap option to the test."
