Developing New Treatments for Smell Loss

If you smell something, you learn something. The sense of smell is an important way to get information about yourself and the world around you. It helps you enjoy food and nature, and warns you of dangers like fire and spoiled milk.

Most people lose their sense of smell at some point, but there are some who never get it back—and, unfortunately, smell loss has no cure. Yet.

“People who have smell and taste issues need care just like people who have impairments in our other senses, like sight and hearing,” says Jonathan Overdevest, MD, an expert in rhinology and minimally invasive skull base surgery. “We currently have few validated resources for individuals with olfactory dysfunction. My team is working to correct that.”

We spoke to Dr. Overdevest about smell and the work his team at Columbia’s Department of Otolaryngology is doing to help people regain this vital sense.

Who may lose their sense of smell?

Many of us will develop some degree of smell loss during our lifetimes. Above the age of 70, nearly 30% of people have appreciable smell loss. Smell is like any other sense in our body: it can malfunction. 

When do people lose the sense of smell?

An inability to smell can be present at birth, or it could develop with chronic sinonasal issues (conditions affecting the nasal cavity and paranasal sinuses) or following viral infections, like COVID-19. A person could also lose their ability to smell as a result of aging, a head trauma, or neurological conditions, like Alzheimer’s or Parkinson’s disease.

How long does the loss of smell and/or taste last?

The duration of smell loss—and how well your sense of smell can be regained—varies by person and by the underlying cause of your smell loss.

What are treatments for smell loss?

There are almost none. That’s the challenge. 

If you develop vision issues, you can visit your optometrist and often leave with glasses the same day. The same is true for hearing issues. In addition, hearing testing is even more accessible with recent advancements in certain headphones. So far, it is not the same for the sense of smell or taste. But we are beginning to learn more about the various ways our senses of smell and taste become disrupted. In doing so, we can work toward offering treatment.

Currently, we use medications or surgical procedures to treat sinus disorders—the most correctable and common cause of smell loss. For other causes of smell loss, there are fewer treatments. The best existing therapy is olfactory training (also called olfactory enrichment) in which a person regularly smells known odors while remembering how they perceived the smell to enrich their sense of smell.

What are you working on now to help people who cannot smell?

Columbia has a rich history of research in understanding the fundamental way our sense of smell functions. Richard Axel, MD, and Linda Buck, PhD, won the Nobel Prize in Medicine in 2004 for their and their team's discovery of how genes for olfactory receptors in the brain facilitate the detection and perception of odors.

Our clinic—the Columbia Chemosensory (Smell and Taste) Center—works with more than 350 people who have smell or taste dysfunction. That number may sound small, but it increases regularly as awareness spreads about smell and taste dysfunction. People reach out to us from across the country.

In collaboration with the Zuckerman Institute, we are exploring the molecular mechanisms of smell loss. New treatments are the goal. We are one of the only sites in the New York metro area that provides a comprehensive smell and taste evaluation, plus neurocognitive assessments to support ongoing basic science research into smell and taste issues.

People who have lost their sense of smell can contact us to be evaluated. We have a close working relationship with our community, providing newsletter updates and hosting patient events that share information and techniques for managing olfactory dysfunction.

In collaboration with the Columbia CommonScents Team, I am working to understand how smell promotes health and becomes dysfunctional in disease. We have a number of ongoing studies people can participate in that focus on smell and taste as they relate to areas such as COVID-19 and smoking.

What’s the bottom line with correcting smell loss?

Smell loss is a common issue that has been poorly understood and under-appreciated.

Promoting a culture of awareness among the public, our research community, medical professionals, and policymakers will be the key to accelerating our understanding of smell loss and how we can go about correcting this sensory deficit.