Ever since his post-doctoral days at Johns Hopkins, AAAS Member Steven Munger has been studying how different groups of sensory cells in the nose help to identify components of the odor environment.
“If you smell a pizza, there is not a single pizza molecule that gives it its aroma,” he says. “Think of it more like a perfume, where a mixture of different odor compounds gives you that complex smell.”
He has been working on trying to understand how parts of the olfactory system help to pull apart information contained in “perfumes” in our environment, be it food or the scent of another animal, and then put it back together.
But when the novel coronavirus surfaced in the United States earlier this year Munger, who is also editor in chief of the journal Chemical Senses, pivoted.
“The field has known for a long time that people can lose their sense of smell as a response to viral infections – flu viruses, rhinoviruses, common coronaviruses – but the effect of COVID-19 on smell was certainly a surprise,” he says.
Earlier this year, Munger joined an international group of smell and taste scientists that make up what is called the Global Consortium of Chemosensory Research to study how, when and why people who have the coronavirus experience loss of smell and taste. They have since published their first paper, “More than smell: COVID-19 Is associated with severe impairment of smell, taste, and chemesthesis.”
Shortly after, Munger and his colleagues set out to confirm whether the olfactory loss occurs with COVID-19. A subsequent study, currently in review, tackled the question of whether smell loss is a good predictor of COVID-19.
“We found that those who had a COVID-19 diagnosis had a very pronounced decrease in their ability to smell, but also in their ability to taste and in their chemesthesis ability (sensitivity to compounds like capsaicin from chili peppers or menthol in mint),” he says.
They are now exploring whether testing for smell loss can be used as a screening or surveillance tool in those places where COVID-19 testing is not readily available. For instance, if someone who has always been able to smell strong scents, such as garlic, fish or cheese, and suddenly they are not able to smell those foods, Munger recommends they check in with their primary health care provider.
“That could be a warning sign that you could have COVID,” he says. “Change in ability to smell, or sudden smell loss altogether, is a strong predictor of COVID.”
Munger’s thirty years of experience in researching smell and taste has made him keenly aware of misperceptions in how people understand two of our most important senses. In the smell and taste community, for example, taste is described in specific terms as the sensation happening in the mouth to detect sweet, bitter, salty, sour and umami.
“But, when most people describe taste, they usually mean that full perception they get from eating or drinking something, which we would call flavor,” Munger says. And, when someone gets a cold, the nose is stuffy and one cannot smell anything, so food will taste bland and flat. Munger says that is because the odor part is missing.
“Even though you can still get the sweet and the salt and the sour, people will often say, ‘oh, I lost my sense of taste’ when actually what it is that they lost is their sense of smell,” he says.
Anosmia, which is the complete loss or absence of smell, is a disorder that is growing in awareness in North America. It is something Munger is eager to study more in-depth.
“If you exclude the recent pandemic, about 15% of individuals over the age of 40 have some clinically significant smell loss,” Munger says. “In addition to developing therapies, which are lacking now, we need to support those people who have lost their sense of smell or taste by giving them good quality information to help them understand how they can keep themselves safe – such as by installing natural gas detectors in their home – and improve the flavor of their food with spices and textures.”
As director of the University of Florida Center for Smell and Taste (UFCST) and professor of pharmacology and therapeutics, Munger says that his lab had not been heavily involved in human clinical research. “We have started to adjust our emphasis over the last 6 to 9 months to really push forward in that area.”
His lab is now working to support people with smell and taste disorders and is currently partnering with Fifth Sense, a UK-based charity, to address the needs of patients with smell and taste disorders.
“We have also launched the UF Health Smell Disorders Program, a combination of educational and research activities as well as a clinic specifically for people with smell disorders,” he says. “We are now able to initiate clinical studies directed at these types of health problems. With the advent of COVID-19, that really has just accelerated.”