Written by Henry P. Barham, MD, Mohamed A. Taha, MD, and Marianne Madsen
Is this a weird question? You’re probably asking yourself, what could possibly be the relationship between a taste test (something I put on my tongue) and my response to COVID-19 (something that affects my lungs)? Where is the link? How can it determine my prognosis if I get infected? How can it tell me how long and how severe my symptoms will be?
Can it provide me with answers to some unresolved questions about this global pandemic with so many unknowns? Questions like: why do some family members contract the infection and develop severe symptoms that may require hospital admission, while other members living in the same house may not even get infected?
According to a new study just released to answer this question: YES! Results showed that an at-home taste test may help predict whether you’ll get severe COVID-19 symptoms and may need hospitalization or whether you’ll experience mild to moderate symptoms that can be addressed at home. It can also help determine what the duration of your symptoms may be.
Previous Retrospective Research
Earlier research showed, through a retrospective study, that inheriting and expressing a gene called TAS2R38—being a “supertaster”—could determine the duration and severity of symptoms of someone who contracted COVID-19. Out of 100 patients who tested positive for COVID-19, 21 were “non-tasters” (didn’t have or express the TAS2R38 gene), and 79 were “tasters” (expressed the TAS2R38 gene, but not as strongly as the supertasters). The 21 non-tasters were all hospitalized with severe symptoms; none of the 79 tasters were hospitalized and experienced only mild symptoms that could be addressed at home. None of the patients who tested positive for COVID-19 were “supertasters.”
Results of New Prospective Study
Intrigued by these results, Dr. Henry Barham decided to investigate further. The first study looked at the past; the next study tried to predict the future. This time almost 2,000 healthcare workers who were screened and determined to have never had COVID-19 (either at the time of study or long before it was conducted) were given the same bitterness taste test. Once again, the subjects who eventually contracted COVID-19 but hadn’t detected the bitter taste–non-tasters–had the worst outcomes. In fact, 85% of the test subjects who were later hospitalized with COVID-19 were non-tasters. Tasters fared better (only 15% of those hospitalized were tasters), but the supertasters did the best—not one of them was hospitalized. These results held true regardless of comorbidities such as diabetes, hypertension, obesity, etc.
In addition, status as a supertaster, taster, or non-taster affected the duration and intensity of COVID symptoms. On average, supertasters experienced mild symptoms for 5 days. Tasters experienced moderate to more serious symptoms for an average of 13.5 days. And—you guessed it—non-tasters had the worst outcomes, experiencing severe symptoms for an average of 23.7 days.
Another interesting finding was that the tasters who were hospitalized were all older—the youngest was 69 and the average age was 74. This shows that our taster status declines as we age and explains why COVID-19 is, generally, harder on older people than it is on children.
These studies are based on genetics, specifically the gene called TAS2R38. This gene has two forms, PAV (functional form) and AVI (non-functional form). You inherit two copies of this gene, one from your mother and one from your father. So, as a simple example, if you inherit the two functional forms (PAV/PAV) from your parents, then you’re classified as a supertaster. If you inherit the two non-functional forms (AVI/AVI), then you’re considered a non-taster. If you’re heterozygous–one of each form (PAV/AVI), then you display some degree of functionality of this gene, lying in the middle between the other two forms.
How Does Being A Supertaster Affect My COVID-19 Response?
It’s important to understand that being a supertaster isn’t the only thing going on here. If you’re a supertaster, it means that you likely have a better chance of combating respiratory tract pathogens, along with a lower frequency of respiratory infections in the past. You probably have many other genes that are helping out your innate immune system and actively working to protect you from infection. These genes are helping you produce more nitric oxide which later improves your ciliary response and mucus production, resulting in a better chance of eliminating pathogens before they take hold in your body.
Find Out if You’re a Supertaster
The results of this study hold true for many other infections that affect the upper respiratory tract, so if you’re interested in finding out if you’re a supertaster, it’s easy. The Phenomune test is an easy, at-home test that also provides customized education about your immune system.
Henry P. Barham, MD
Rhinologist
Dr. Barham is a board-certified ear, nose, and throat (ENT) physician who works as a dedicated rhinologist (nose, sinus, allergy, endoscopic sinus, and skull base surgery) at Sinus and Nasal Specialists of Louisiana, LLC. He is also a widely published researcher with over 100 publications and book chapters throughout his career.
Mohamed A. Taha, MD
Research Fellow
Dr. Taha is a consultant physician of ear, nose, and throat (ENT) at the Faculty of Medicine - Cairo University, where he got his MD degree in 2019. He is currently a Research Fellow at the Sinus and Nasal Specialists of Louisiana, LLC. Dr. Taha has published many studies in ENT, mainly about COVID-19. His latest publication linking bitter taste receptors to COVID-19 (published in JAMA) showed interesting results.