Can Omega-3 Fatty Acid Supplementation Treat Anosmia?

In early 2020, when the COVID-19 pandemic reached New York City, patients began presenting at hospitals within the Mount Sinai Health System with virus-associated anosmia. Although most of these patients regained their sense of smell as they recovered from the virus, approximately one-third continue to experience some degree of anosmia months later. To address this condition, Alfred Marc Carlo Iloreta, MD, Co-Director of Endoscopic Skull Base Surgery and Assistant Professor of Otolaryngology - Head and Neck Surgery and Neurosurgery at the Icahn School of Medicine at Mount Sinai, has launched a therapeutic study to assess the impact of daily omega-3 fatty acid supplementation among patients who have experienced COVID-19-associated anosmia.

“Our hypothesis is that this phenomenon is caused by COVID-19-related damage to the olfactory nerve due to an inflammation, a neuroinvasive issue, or both,” explains Dr. Iloreta. “Given the anti-inflammatory and neuroprotective properties of omega-3 fatty acids, and previous research demonstrating that it resulted in the quicker recovery of sense of smell among patients who underwent skull surgery, we believe it could have a therapeutic application among patients who have experienced COVID-19-related anosmia.”

Dr. Iloreta is testing this theory in a double-blind placebo controlled study that is open to those ages 18 or older. Patients in the study have self-reported new-onset olfactory dysfunction and have had a laboratory-confirmed or clinically suspected COVID-19 infection. Excluded from the study are patients who were hospitalized with severe COVID-19, have a history of omega-3 fatty acids supplementation, or have a history of chronic nasal infections or endoscopic sinus surgery as they may confound the study’s findings.

Once enrolled, all study participants will complete a brief smell identification test (BSIT) and a baseline email survey about their medical history and the anosmia they are experiencing. They are then randomized into two cohorts—a control group that is prescribed a six-week daily regimen of 2000 milligrams of omega-3 fatty acids and a placebo group. At the end of the six-week study, patients will receive a second BSIT and undergo additional testing every three months for a year.

“We will be looking for differences between the two cohorts in terms of smell recovery, BSIT scores, and questionnaires to assess their current psychosocial state,” Dr. Iloreta says. “Given that we are following them for a year, we will also be able to look at the long-term impacts of treatment and explore the natural history of COVID-19-related anosmia, giving us more insight into the recovery process.”

Dr. Iloreta aims to recruit 200 patients for the study and, if it proves successful, he will explore the potential of other therapeutic modalities—such as pharmaceutical-grade omega-3 fatty acids—among patients who have experienced COVID-19-related anosmia. Irrespective of the results, he sees this phenomenon as the impetus for more research related to sense of smell.

Says Dr. Iloreta, “We know that the sense of smell is vital to quality of life, psychological wellness, and safety; but it is a relatively understudied area. The anosmia we are seeing among COVID-19 patients is a reminder that we need to step up our efforts and we will be looking at engaging in collaborative studies with our colleagues in neurology and psychology to address that.”