In the throes of the pandemic, people started noticing something odd: an uptick of negative reviews of scented candles, claiming they had no fragrance.
The trend line of the bad reviews coincided with spikes in COVID-19 cases. That鈥檚 because one of the symptoms of COVID is smell loss.
As of Sept. 2024, about 1 in 8 Americans over the age of 40 have measurable smell dysfunction, according to the National Institute on Deafness and Other Communication Diseases.
鈥淓specially after COVID, there's waves of patients with different smell dysfunction. And actually, there鈥檚 currently no effective treatment for that,鈥� said Kai Zhao, a professor of nasal physiology at Ohio State University鈥檚 Department of Otolaryngology - Head and Neck Surgery.
So, Zhao decided to make one.
The science of smell
Smell dysfunction can be triggered by head trauma, cancer, or infections. In general, it's caused by damage to the olfactory neurons, located at the upper back of the nasal cavity. We perceive smells when odor particles bump into and bind with those neurons. Zhao estimates only about 10% to 15% of particles actually reach that region, with the rest getting lost in the cavity.
鈥淪o, every breath only a few particles actually get into this region where they have the chance to trigger smell,鈥� Zhao said.
Zhao thought that getting more odor particles to that region would improve people鈥檚 ability to perceive and identify smells. He tested two devices on over 50 healthy people and over 50 patients with smell dysfunction.
Zhao first tested a swimmer鈥檚 nose clip. The clip is meant to narrow the inside of a person鈥檚 nose to create a tunnel that pushes odor particles right where they need to go.
Then Zhao tested a new device that uses an angled straw pointed right at the olfactory region.
鈥淚t鈥檚 basically made of foam ear plugs, but it has a straw embedded or channel embedded that鈥檚 diagonal,鈥� Zhao explained.
Impacts of smell loss
Losing the sense of smell has serious impacts on a person鈥檚 life. Smell loss impacts people鈥檚 safety and their ability to taste, Zhao said.
Josh Lieb of the Columbus suburb of Pickerington knows that first-hand. He lost his smell and taste when he contracted what he thought was a mild case of COVID.
鈥淚 was eating breakfast, and I realized I couldn鈥檛 taste my breakfast or smell anything in the room,鈥� Lieb said.
He thought his smell loss would be temporary 鈥� but it鈥檚 been four years.
鈥淲hen you eat you just eat based on texture. 鈥ou get like a sense of things that are in 鈥� that you think are in the room with you,鈥� Lieb said.
Lieb tries to stay positive, but he admits he misses certain tastes and smells. He said he still has a 鈥渇eel鈥� for things like chemicals in his nose. He mostly depends on his wife, however, to let him know if food has gone bad or if there鈥檚 smoke or a gas leak nearby.
Lieb was not part of the Ohio State study, but he鈥檚 tried lots of things to get his smell back, including smell retraining 鈥� repeatedly smelling the same scents in the hopes of establishing a memory of that smell and stimulating the olfactory system 鈥� and multivitamins. Lieb is now looking into more experimental treatments, but he said he鈥檇 also be willing to try smell aids like Zhao鈥檚 nasal plugs.
Promising results
Zhao鈥檚 study found that both devices did help.
Those with smell dysfunction could identify, on average, one more smell with the smell aids than without.
Only Zhao鈥檚 handmade nasal plugs seemed to help patients with COVID-related anosmia. Zhao thinks that might be because those patients have more significant smell loss and need a more direct enhancement of airflow.
The only group that wasn鈥檛 helped at all by the smell aids were people who already had near-perfect smell.
With all that in mind, I decided to try out the smell aids. I started with the swimmer鈥檚 nose clip. I slid it over the top of my nose and fussed with it until it pinched near the nostrils.
Zhao scraped off a scratch-and-sniff card and passed it to me. He used the scented cards to test patients with smell loss in the study. The goal was to correctly guess the smell 鈥� which I couldn鈥檛 do on the first try.
鈥淚t鈥檚 like 鈥� is it flowers?鈥� I asked Zhao.
鈥淣ope,鈥� he said, with a laugh.
Despite my average sense of smell and below-average scent-deduction skills, the clip did seem to make a difference. With it on, the card smelled more vibrant.
Next, I tried the plugs.
They extended about an inch out of my nose even after I jammed them up as far as possible. They felt a little weird at first, but didn鈥檛 impede my breathing or change my voice too much. They also seemed to help. I felt like I could smell more and that the scents were sharper. Zhao gave me more scratch-and-sniff cards which turned out to be lemon and chocolate-scented.
And while wearing the plugs, I also finally figured out that familiar smell from the first card:
鈥淚t smells like sugar,鈥� I puzzled, sniffing again. 鈥淎ctually, it smells like Play-Doh. That鈥檚 what I鈥檓 thinking of.鈥�
鈥淩ight,鈥� Zhao said, triumphantly, 鈥淧lay-Doh!鈥�
Zhao plans to do more research with the plugs and is looking at different materials to make them. Right now, the plugs are made by undergraduate students, so he can鈥檛 exactly mass-produce them. Zhao hopes one day they鈥檒l be commercially viable and ready for everyday use, so people with smell dysfunction will be able to use them to smell better.
