Researchers at Columbus-based Ohio State University have designed and developed the world’s first noninvasive devices aimed at improving a person’s ability to smell.
In a clinical trial, 58 healthy people and 54 patients with self-reported smell deficits received two “smell aids” — a nasal plug and a nasal clip that “pinched” the nose, according to an April 10 news release from the Ohio State University Wexner Medical Center. Each participant inhaled 100 parts per million of phenyl ethyl alcohol, a rose-scented odorant.
The researchers compared the control group’s odor detection thresholds to the patient cohort’s NIH Toolbox Odor ID scores.
Nearly 70% of patients with smell deficits said their loss of smell was related to COVID-19. Other causes included head trauma, head and neck cancer and surgery, and nasal polyps.
Both smell aids were associated with significantly higher odor ID scores, particularly among non-COVID-19 patients. Among long COVID patients, only the nasal plug showed improvement.
Compared to insects and other animals, humans “sniff much stronger and vigorously to detect a weak odor, so a common assumption is that stronger airflow during inhalation (sniffing) may benefit olfactory sensitivity,” the researchers wrote in BMC Medicine.
“But we often overlook the fact that due to the protective location of the human olfactory epithelium, only a small portion of inhaled air can reach there,” they said in conclusion. “So, potentially, modulating the distributions of the intranasal airflow can be more effective than increasing the overall airflow; however, until now, we have no effective way to test that. Both the ‘nasal plug’ and ‘pinch’ represent simple and innovative ways to modulate the intranasal airflow.”
