Smell Loss and Its Impact on Enjoying Food

Like many people, I grew up savoring the smell of baking bread and simmering stews. When I started cooking, I learned to rely on scent—the first carbonic hint of a char, the ranked notes of a properly prepared spice blend. The more I thought critically about what I ate over the years, largely in order to figure out how to write about food, the more I picked up on and started to talk about food in terms of ingredients’ aromas. But I never actually thought about just how deeply scent guided my relationship with food until, a few years ago, I started slowly losing my sense of smell.

Though few people are born with a congenital lack of smell, it’s more common to lose this sense, at least partially and temporarily, than you might think. Smell loss is a common side effect of everything from head injuries and neurological disorders—the likely culprit behind my own smell loss—to certain medications or therapies, which mess with receptors in your nasal passageways or the nerve sending signals from them to your brain. Respiratory infections as basic as common colds or as severe as COVID-19 can knock out smell as well. Smell loss is even a routine part of aging for many, as nasal receptors suffer constant damage from environmental irritants and toxins and require constant replacement, a maintenance task our bodies get worse at over time. Several studies conducted in recent decades suggest that as many as one in five adults are dealing with some degree of smell loss at any given time—three in five, if we’re talking people over age 80.

Despite the prevalence of this issue, there’s shockingly little comprehensive information out there for those of us trying to grasp what our loss will mean for our lives in the kitchen and at our tables and how to navigate those changes. In an effort to rectify that, I reached out to a number of leading smell and taste researchers, as well as smell-loss advocates, to figure out what we currently do—and don’t—know about the effect of smell loss on our relationships with food.

Our sense of taste, which we detect using buds on our tongues, soft palates, and upper esophagi, is blunt and basic on its own—a tool for detecting presences and levels of bitterness, saltiness, sourness, sweetness, and umami. Smell is more complex. There’s lively debate among scientists about just how many distinct scents humans can pick up with estimates ranging from 10,000 to one trillion. But we know that the aromatic compounds we detect through our noses and the openings to our nasal passageways at the back of our mouths give most foods many of their unique flavors. Many researchers insist that smell makes up 80 to 90 percent of every food’s flavor.

Without scent, these statistics often seem to imply, foods lose their color and character. Carl Philpott, an expert on smell disorders at the University of East Anglia, has even gone so far as to liken eating without a sense of smell to “chewing cardboard,” a joyless self-maintenance chore.

Studies on people with smell loss do suggest that many find less joy and satisfaction in food than their smell-intact peers. “About 50 percent of people gain weight after they lose their senses of smell,” says Alan Hirsch of the Smell and Taste Treatment and Research Foundation, one of the few clinics in the world that focuses on smell loss, because they go wild on unhealthy foods rich in fats and sugars, desperate to indulge in their remaining senses of true taste. “Alternatively, 15 percent lose weight because they become depressed about their smell loss and lose their desire to eat or because they don’t get positive reinforcement from food anymore and lose interest.”

“This new relationship with food is not something I would wish on anyone,” says Chrissi Kelly, who lost her sense of smell in 2012 and now works with the smell-loss awareness and support organization Abscent. “It can be absolutely life-altering and have devastating consequences.”

But not everyone who suffers a loss of smell finds the experience equally traumatic or feels the same level of lost joy or satisfaction in their eating experiences. This makes sense, Hirsch and others say, as smell loss is not a monolithic experience. There are levels and shades to it.

Most people (myself included) experience hyposmia, a decrease in smell, instead of anosmia, a complete loss of smell. This, Kelly explains, “is not like turning the volume down on the radio.” It’s more like randomly scrambling a mixing board: You may not pick up one scent at all anymore (I’ve lost citruses entirely), only detect another at high levels (if I huff a bag of concentrated cacao, I might get something), have trouble distinguishing between two formerly distinct odors (most flowers now smell the same to me, if they smell at all), become hyperaware of a few smells (in my case, the smell of burning organic matter), and pick up on some odors the same as ever (why'd it have to be hot garbage?). As some scents can augment the way our brains process true taste (vanilla, for example, makes sweets taste sweeter), this chaotic remix can lead to unexpected changes in your physically intact sense of taste as well.

Many also experience parosmia, a distortion that makes your brain interpret one scent as another. (“Chocolate could smell like burning rubber, for example,” says Steven Munger of the University of Florida’s Center for Smell and Taste.) A fair number will also experience phantosmia, a distortion that makes you smell things that aren’t there—usually bad odors like must or feces.

The exact nature of a scramble depends on the specific damage to your smell circuits. But those circuits are so complex, and our ability to analyze them so limited, that every case of smell loss will likely be entirely unique in some way—and its progression is utterly unpredictable even for seasoned experts.

What’s more, few cases of smell loss are static. People with neurodegenerative disorders often experience ever-evolving loss, while people who recover from individual instance of damage to their smell systems slowly regain elements of scent at different rates—although few ever fully recover their prior senses of smell. “Every smell loss should be seen as an injury,” Kelly suggests. As after a big car crash, “you may heal. Your bones will knit. Your scars will close. But you will never look the same.”

Still, G. Neil Martin, author of The Neuropsychology of Smell & Taste, and many other smell researchers argue that the roughly one in 5,000 or 10,000 people who experience total smell loss at birth or later in life will have their “enjoyment and pleasure from eating decimated.”

And still, a number of people with anosmia, including chef Adam Cole, ice cream king Ben Cohen (of Ben and Jerry’s fame), and cookbook author Joke Boon have said that’s not the case for them or for many other anosmic individuals they have interacted with over the years.

This discrepancy reflects the fact that, while smell is important to our relationship with food, we have likely overinflated its role compared to other, less-discussed or -studied variables. Notably, in a 2015 journal article University of Oxford smell psychologist Charles Spence shredded the popular notion that smell makes up 80 to 90 percent of every food’s flavor, showing that this claim seems to stem from a 1989 pop science author’s misunderstanding of a study from 1977.

In addition to taste and smell, Spence and others have pointed out, many people experience food using sensors like the trigeminal nerve, which—unrelated to our smell and taste systems—detects sensations like the heat of peppers, the coolness of mint, and the astringent pungency of things like cinnamon, ginger, and onions, all technically irritants. Foods’ textures, notes Wageningen University smell researcher Sanne Boesveldt, “not just crunchy versus soft but variations in size and shape” as well as the exact nature of a crunch, also seem to have a huge impact on how we experience and engage with food. As does the sound a crunch or snap makes in our mouths as well as the sensations of actual heat, coolness, and the interplay between them. Food color and plating seem to modulate the way we perceive a dish or drink’s flavor as well. Dying white wine red, for instance, leads people to start describing it using terms associated with red wines.

This explains why some people with smell loss shy away from dishes like “macaroni and cheese because it’s purely savory, white, and doesn’t look terribly appetizing on a plate,” as Kelly puts it. It’s also “why Mexican, Indian, and Chinese food are really good” for people with smell loss, she says. “You often get a mixture of textures, hot and colds, and true tastes” in each dish.

What’s more, Boesveldt, Munger, and other researchers explain, our brains seem to color our experiences of food based on how engaged we are with them—for example, how involved we were in preparing them, whether we practiced any dinner-table traditions or rituals, and how much we paid attention as we ate. They also color our experiences based on how we’re eating—alone or around friends—while viewing or listening to something or in silence, and so on. They even color our present experiences, it seems, by drawing on memories from our past experiences with a dish.

And that’s just what we do know. Everyone I spoke to for this article gave me a laundry list of mysteries about how we perceive foods, and the role of smell therein, yet to be puzzled out. Chief among them: How do our brains process odors, alone or in combinations with each other?

“Some odors we perceive as normally unpleasant,” notes Martin, “like fecal odors are pleasant at low concentrations,” and we’re not entirely sure how or why that seems to be the case.

“If you smell three chemicals individually, we know that one smells like potatoes, one like cucumbers, and one like tomatoes,” adds Nancy Rawson, vice president of the Monell Center, a hub for research on smell and taste. “They don’t smell anything alike. But if you put those together in the right combination, what you get is a dead fish.” And no one understands why.

In order to account for all of these moving parts, University of North Carolina neuroradiologist Mauricio Castillo suggested in 2014 that we might want to move away from thinking about the flavor of any food as a synthesis of smell and taste in our brains and more of it as the gestalt product of a complex equation: (Smell + Taste + Mouth Sense + Sight + Sound) x (Emotion + Memory + Decisions + Plasticity + Language + Consciousness). This formula is loose and likely incomplete, but it does get to the heart of the matter: Smell is not a consistently key variable in our experience of food. Its salience varies by dish—it’s almost entirely negligible in many people’s appreciation of sushi, for example, compared to texture and context—and often by individual as well.

Whether due to genetics, developmental influences, cultural conditioning, or any other number of factors that we don’t yet fully understand, everyone grows up with their own unique pre-smell-loss constellations of nasal receptors and neural circuits and thus baseline sensitivity to certain smells. (This, Hirsch points out, makes it hard to actually measure smell loss as we usually measure people’s ability to smell against global averages as opposed to their own baseline.) They also start off with their own unique awarenesses and appreciations of every other variable we use to experience food.

These baselines probably explain why some people have a harder time engaging with food after a loss of smell: At one extreme, if you have a well-developed sense of smell, which you valued above all else, then suddenly and completely lose it, you will likely feel a greater sense of loss and have a harder time figuring out how to find joy in your food post-loss. At the other extreme, if you have a poor or under-trained sense of smell and instead enjoy food more for its visuals and texture, say, or the rituals and socialization around it, then start slowly losing your sense of smell, it might take you awhile to realize that you’re losing something at all.

And, of course, if you never had smell to begin with, you likely grew up more acutely aware of the non-smell elements of food than your smelling peers. You also likely still have as good a chance as anyone of developing a deep, meaningful connection to food, so long as you have the opportunity to engage and develop your relationship with the elements of it that bring you joy.

The deep sense of loss people with smell disorders who previously leaned on scent above all else to engage with food often feel is both valid and understandable. But, Kelly suggests, wallowing in it is often the greatest impediment to their continuing relationships with food. “Often, people report that they have zero sense of smell,” she says, likely because they feel they’ve lost so much compared to their baselines. “Then when you sit down with them, test them, and so on, they realize they actually still have much more of a sense of smell than they thought they did.”

So long as they have some sense of smell left, Kelly and a number of other smell advocates and researchers believe that individuals who have experienced any level of smell loss can use smell training, a relatively new therapy that involves huffing tins of concentrated odor several times a day with focus and intent to stimulate their remaining smell circuits. This is not a surefire process, Kelly cautions, and it almost never returns one’s full or pre-loss sense of smell. (Several researchers I spoke to noted that, while doctors and patients have reported some positive results, we have yet to see any truly solid studies on the approach’s short- or long-term effects relative to normal courses of recovery.) But, ideally, it can help them to build a new smell-based relationship to foods—and to enjoy those whose pleasure lies primarily in aromatic flavors.

Even if you lose your smell entirely and permanently—if the nerve connecting your nasal receptors and your brain is fully severed—most researchers agree that you can slowly develop the ability to recognize and appreciate elements of food you once undervalued or ignored.

Some anosmics describe developing a heightened sense of true taste almost incidentally, which makes them more attuned to tiny differences in what many think of as broad, basic flavors. “I could tell you probably down to the nearest grain how much sugar I’ve put into my cup of tea,” Duncan Boak, who founded Fifth Sense, a support and advocacy group for people with smell and taste disorders, in 2012, seven years after losing his sense of smell due to a head injury, explains.

Others have to work at fostering their awareness of, say, mouthfeel and sound gradually and constantly. But “in time,” says Kelly, “that can become a very satisfying way to eat for them.”

All of this is to say that there is no single experience, or even common set of experiences, of smell loss, its effects on cooking and eating, and how to navigate them. The more the sciences of smell and food perception evolve, the more we realize there’s infinite complexity, and boundless potential for idiosyncrasy, in the interplay between the two. That in turn means there is no clear path for someone like me, slowly losing his sense of smell, to look to for guidance.

This lack of certainty about what will change and how to react to shifts can be frustrating and frightening for many people. The fact that “many physicians are poorly educated about [smell and taste] disorders, and so are either dismissive,” as Munger acknowledges, or unable to offer context or insights, often compounds these emotions—and serves them with a side of isolation.

But you may be able find beauty and excitement in this uncertainty as well. Or, at least I do.

The one thing everyone with smell loss—especially those who have trouble facing food—must do is “get out and try foods” as Kelly puts it. “Even foods that you didn’t like before” your smell loss. From one vantage, this might seem like a depressing scrabble to make basic physical maintenance tolerable or mitigate a dire sense of loss. However, I and a few others prefer to see it as an opportunity to explore the world of food with fresh eyes.

It’s a chance to shake off assumptions and consciously build a new connection with food. This connection may inherently lack something. Yet it can perhaps run deeper and come to feel more profound than our old connection to food for the awareness and intent that goes into it.

That’s not to say the process of building this new connection is easy. I’m still mourning the loss of my ability to smell bubbling fat and blooming cheeses. I’m still not sure how to talk about the things I get out of a steak now, especially with folks obsessed with aroma. And I’ve been trying to get my head around this gradual shift in my food life for well over a year at this point.

Whenever I start to feel adrift, though, it helps to “recognize that I am not alone in feeling a sense of loss or of disconnection,” as Munger puts it. I’m one of millions of people working every day to comprehend a world increasingly devoid of fragrance, yet full of potential meaning.