In This ArticleView AllIn This ArticleSearching for Lost ScentsHelping Others Regain TheirsThe Connection Between Scent and MemoryA Sign of HopeHow You Can Work on Your Own Sense of Smell at Home
In This ArticleView All
View All
In This Article
Searching for Lost Scents
Helping Others Regain Theirs
The Connection Between Scent and Memory
A Sign of Hope
How You Can Work on Your Own Sense of Smell at Home
Every morning, before opening his eyes, Crippa prayed not to smell that awful scent. But all he could smell was wet cigarette ash. Eventually, in December 2020, he entered a new phase, calledparosmia. He began sensing some odors, but they were all distorted: lemons and oranges smelled like soap, peaches like basil, coffee like sewage, and vanilla like vomit.
According to a 2020 study published inChemical Senses, about 10% of those who experienced smell loss because of COVID-19 still suffered from different stages of smell distortions after six months.
Crippa, who had built his life around the use of his nose, took an unusual approach to guide his olfactory neuron regeneration, something nobody had tried before. He went a bit further than smelling flasks of distilled scents to awaken his olfactory bulbs.
Since September 3, 2021, when Crippa started training on himself and vanilla was an unbearable scent, his method has helped him and others to partially recover. “I can now smell vanilla,” he said victoriously.
Crippa’s students have been experiencing slow improvements as well, and his training method has attracted attention from around the world, including from scientists and researchers at Harvard Medical School and the Monell Chemical Senses Center.
“Close your eyes and think of the smell of coffee,” Crippa said, then paused, waiting for me to evoke a memory linked to that smell. “Can you think of it?” I nodded. “That’s something,” he said with a smile.
On November 6, 2021, Crippa invited me to attend one of his Smell Education classes in Muggiò, on the outskirts of Milan. He welcomed me in his father’s architecture office, in the basement of his family’s house. On the weekends, in between folders of building projects and large-scale printers, a corner of the space hosts smell-seekers who have been contacting Crippa since international press coverage spotlighted his work.
“What we will do is qualitative work, not quantitative work,” Crippa said as we waited for attendees to show up for his class. The goal of the course is not to enhance the way people smell but to educate them and hopefully give them tools to teach their noses how to perceive in the right way again.
Usually, theolfactory sensory neuronsin our noses detect odor molecules from food or other things around us. The neurons then send a signal to our brain. Immediately afterward, the brain decodes the signal and tells us that what we are smelling is, for example, coffee. Those who have problems with their sense of smell because of long COVID-19 suffered from inflammation that caused neuronal damage to the cells that maintain the health of olfactory neurons.
“If we destroy the plastic that keeps together a keyboard, the keys get disassembled,” Genovese said. “Some will get lost, others will get disconnected, and we won’t be able to introduce inputs in our computer.” And this is what COVID-19 does: it affects the supporting cells of the olfactory neurons and leads to the loss of olfactory function. Later, according to Genovese, when the regeneration begins, neurons try to reconnect to the olfactory bulb all at the same time, but the crowding increases the possibility of errors and causes the perception of distorted smells (parosmia).
“It’s impossible to forget about my condition because we eat at least three times a day,” Iannace said. “And the problem is that others do not understand what you are going through,” Vergnanini added. Every Sunday, when he has lunch with his parents, they routinely ask him: “Isn’t this very good? Have you smelled that great perfume?”
“But when I eat, I only feel like I am eating cardboard,” Vergnanini said dejectedly, remembering the time when he used to love eating chocolate.
Not a doctor, nor a therapist, Crippa made sure they understood his role as an educator. He was aware of the psychological strain that people in his situation suffered. “I am not a psychologist, but it happened that people burst into tears during the class,” Crippa said.
“This study amazed me because it showed how smell and taste are functions we would never expect to lose, and when we do lose them, our vision of the world changes,” Parma said.
Vergnanini showed signs of tiredness, mixed with hints of resignation, while describing all the therapies he had attempted through the past year. Nothing worked, but a lot of money was spent, he said.
“Sensory analysis is the description of the measurement of what you perceive. It’s a mix of techniques and methods that make objective something that for nature is subjective,” Odello said.
Novella Bagna, a professor of sensory analysis and the founder ofGood Senses, a sensory analysis consulting firm, was the one who suggested Crippa try smell training, something many doctors worldwide were recommending for cases like this, per a 2021 publication inMedicine. But to help Crippa, she added a booklet to the Sensory Box that described specific everyday situations or memories with the scent that an average Italian person might relate to.
According to Genovese, from the moment we are born, our brain registers every smell we stumble upon, and to make it stick more and codify it, our brain associates it with objects, memories and emotions: the time we fell in love, that time we took a nice trip and the memory of that much-loved relative, are all linked to smell memories. And, according to Crippa, each culture shares a specific set of those odors.
Lemon Granita in Sicily
The class went like this: First, Crippa gave the numbered flasks to Vergnanini and Iannace, asking them to open and smell each for three seconds and then write down what they smelled or what the smell reminded them of. He flipped the hourglass and whispered to me that this was the most challenging exercise, but it would tell him how much they could not perceive, and most importantly, it would stress them to use their nose.
They both got a few smells right, left a few blank and filled in with memories for others. Vergnanini wrote “grass” next to what was supposed to be the mushroom smell and “urine” for honey. It was not that Vergnanini was smelling urine, but his brain was incorrectly decoding the signal for honey. Iannace filled in “breakfast with friends” for the coffee smell.
Then, Crippa distributed a sheet with the names of the 20 flasks. He flipped the hourglass and asked them to smell again and place the correct number of the flask next to the food they thought the smell belonged to. If they couldn’t guess the right one, Crippa would tell them what that smell related to: “Bring your mind to the shortcrust pastry, custard and cakes. You are making shortcrust pastry. How do you make it? Bring your mind to your childhood, school, games, candies, moments of joy and happiness. This perfume evokes the world of pastry and cakes,” Crippa read out loud from the sensory booklet’s page connected to that smell.
“Ahh, wait …” Iannace said. “I think it’s butter.” Vergnanini looked flabbergasted when instead of urine, he could recognize something that reminded him of the natural perfume of honey.
Finally, after the students' senses had been awakened, Crippa got rid of the sensory box and substituted each scent with natural products. He doesn’t want people to train only on one specific molecule, like the limonene molecule for lemon, because genuine products have a complex variety of odor molecules that compose their scent. Otherwise, if people identify one molecule as the scent of a lemon, they might recognize all citrus as that lemon molecule.
“Look into that memory of eating a lemon granita in Sicily with your grandparents,” he said. He explained how to find fresh products, close them in airtight jars and concentrate on doing this training every day, week after week, to train to reestablish that lost connection from the inside out.
“And then, with time, you might find lemon again,” he said.
According toStella Lee, a rhinologist at Harvard Medical School in Boston, what Crippa is doing is quite sophisticated. “What’s really interesting is how he’s looking at the interaction between smell and memory, and that’s what he’s using to help people to regain a smell,” said Lee.
That said, there is currently little scientific explanation for what Crippa is experimenting with. While excited about Crippa’s work, all the researchers I talked to warned me that time would be needed to understand whether the improvements are related to Crippa’s method or to the natural healing of the olfactory system.
“The discourse of recalling memories can be valid, yes, but [only] up to a certain point because we know that we have physical damage,” Genovese said. But she believes that training and stimulating the olfactory neurons might help recover the lost smells. With her team, she’s looking forward to giving a more scientific context to Crippa’s trials.
Crippa is openly sharing his data with researchers worldwide, hoping that others around the world will develop sensory boxes linked to their specific cultures. As he explained, Americans might not recognize the smell of violet, porcini mushrooms or licorice, but will most likely perceive scents like cinnamon or other memories connected to cultural smell cornerstones, like those filling a grandmother’s kitchen for Thanksgiving dinner.
Crippa’s class is not the final solution for what countless people are suffering from; he and the researchers know this well. But it is a novel approach.
“I noticed that something has happened,” said Greta Seregno, a 29-year-old who attended Crippa’s first class on October 15, 2021. “My nose has done its homework and is able to perceive many more smells than 30 days ago.”
While there’s no guarantee that everyone who does olfactory training will regain their sense of smell, trying Crippa’s at-home training can be a break in the clouds for some.
Crippa himself, even after a year and a half of training, has not healed completely, but he said he’ll keep trying morning after morning, lemon rind after vanilla bean. Besides, according to 2022 research published inJAMA Otolaryngology–Head & Neck Surgery,almost 90% of people who reported dysfunctions in their sense of smell or taste due to COVID-19 fully regained normal function within two years.
“Take care of this sense…because losing it means losing memories, not making new ones and losing a part of oneself,” Crippa said.
Choose Your Stimuli
Use a Manageable Number of Products
Prepare the Products
Crippa recommends doing the smell training every morning after waking up (with your clean and rested nose after a night’s rest) and at night before going to sleep.
Step 1
Step 2
When you smell the product, look at it and take notes in a notebook:
Step 3
Repeat this simple training every day, in the morning and at night. By noting down each training, you will be able to go back and check eventual improvements. The more consistent you are, the more likely you will witness some results and progress.
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