Health of smell should be taken more seriously
One of the most common, yet remarkable, symptoms of COVID-19 is the sudden loss of smell. Roses are no longer fragrant. Coffee tastes like bitter water, bread like cardboard. You don’t notice the burning roast until the kitchen fills with smoke.
Although most patients recover their ability to smell in days or weeks, for a significant number of people this loss may be long-term, or even permanent. Unfortunately, we currently lack effective therapies, let alone cures, for smell disorders.
The inability to smell – called anosmia – is more than just an inconvenience. Gas leaks and spoiled food become undetectable dangers. Meals can be unpalatable and a chore to eat without the important contribution aroma plays in the perception of flavor. Even the smell of your partner’s perfume or your baby’s freshly washed hair is gone.
Anosmia disconnects you from the world, and from other people, in a profound way.
However, despite this significant impact on both health and quality of life, smell disorders remain routinely undiagnosed and smell research remains seriously underfunded. It is probably not surprising that treatments are lacking.
To scientists studying the sense of smell, Covid-associated anosmia was not wholly surprising. We have known for decades that viruses causing upper respiratory disease such as the flu or the common cold can result in prolonged, and in some cases permanent, smell loss.
And viruses aren’t the only culprits. Sinonasal disease, traumatic brain injury, neurodegeneration associated with Alzheimer’s and Parkinson’s disease, toxins and even some genetic mutations can damage the neural tissues in the nose or brain that detect and interpret odors.
The pandemic has also seen a rise in smell distortion – known as parosmia – where innocuous odors can trigger perceptions of burning rubber or other noxious smells.
Smell disorders are also incredibly common. The 2011-2012 U.S. National Health and Nutrition Examination Survey provided the first national measure of smell dysfunction, finding that 12.4% of study participants age 40 and older had hyposmia (a reduced ability to smell) or anosmia.
That is more than 16 million adults in this country alone, not accounting for the perhaps millions more with Covid-associated smell loss. By comparison, a 2016 study found that approximately 4.2 million U.S. adults over 40 have an uncorrectable visual impairment.
If major medical licensing organizations required a basic knowledge of smell and taste disorders, it could create an incentive for training programs to include this subject.
Research resources trail far behind those available for other sensory disorders.
Some argue that anosmia and other smell and taste disorders are not significant enough health issues to be a priority for medical research. I disagree.
Smell disorders like anosmia can lead to depression and social withdrawal. Good nutrition is compromised, as some increase their intake of sugar, fat and salt to enhance food palatability while others find it challenging to eat at all. Older adults with hyposmia or anosmia even have a significantly higher rate of death over the long term. These are consequential health issues that cannot go unaddressed.
Steven Munger is director of the University of Florida Center for Smell and Taste and co-director of the UF Health Smell Disorders Program.