IN SEARCH OF LOST TASTE: WHERE HAS MY SENSE OF SMELL GONE?

Giuditta Padoan

anosmia alla-ricerca-sapore-perduto

Many of you, like me, will have lost your sense of smell due to Coronavirus.

Electrified by the fact that we survived the epidemic and full of gratitude for having been lucky enough to only experience “this one silly symptom” – which, by the way, is actually a sign you’re getting better- we’ve now found ourselves bang slap in the center of a silent, ultra-invisible personal drama.

Yes, because life without your sense of smell, and therefore without your sense of taste, is not life.

Forget that sweet smell of coffee that woke you up in the morning, the curiosity you’d feel when opening a new bottle of wine, the childish joy that would come over you when an ad for chicken nuggets came on TV and you’d rush to the kitchen to rustle some up for home cinema night.

You can Forget all that! (N.B. “Forget” with a capital “F”).

Even if… that’s exactly it: the flavors and odors of your favorite dishes, even when they are not perceivable, are right there, immortalized in a point that you can’t quite put your finger on, between your saliva and your memories. 

And for your palate, that tasty plate of spaghetti cacio e pepe or aubergine Parmesan becomes something that tastes like something you remember and smells like nostalgia.

Oh, alright then, I’ll stop being such a drama queen – but only because on television they say that I will get my sense of smell back. And I will, won’t I? If there are any doctors out there, please let me know. In the meantime, this situation drove me to research how our sense of smell and our olfactory memory work.

Why is it that, despite having the memory of a goldfish, I can still remember the smell of those ham and pea rolls my Mum used to make for me when I was little? Or the taste of certain spices, so much so that I’m apparently still quite a good cook, even now that I’m anosmic?… At least, that’s what my flatmate says (he’s actually my husband, but during the lockdown, we’ve decided to keep as far away from each other as possible and stay in our own respective spaces).

I posed this question to Viola, the girl from Vinhood who is researching the perception of tastes worldwide and actually studying how much our personal taste memory determines which flavors we prefer. 

HOW THE OLFACTORY MEMORY WORKS 

THE GENESIS OF TASTE

As everyone knows, the taste is the sense that enables us to identify what foods are like. It plays a key role in allowing us to understand what we can and can’t eat, and the way it works is relatively simple: the oral cavity contains many receptors that are connected to the brain and work rather like a mother: they tell us whether food is good (with a sweet taste) or bad (with a bitter or acidic taste).

Nothing more, nothing less.

The taste buds alone are not responsible for determining the flavor of food. And they are not even selective, like in the old taste map that showed the areas of the tongue that perceived different tastes. 

Of course, it’s obvious that the sense of smell is also needed to ensure that pasta tastes like pasta but, in fact, it’s something else that really gives our dishes their flavor: the brain.

When we eat, with the mouth we inhale the odor of the food as we chew it. This rises as far as the nasal cavities and the olfactory receptors, which convey this information to the brain. The original scent-bearing molecules are therefore turned into “images of the odor” in our elaborate mental centers and, as a result, we “perceive” their taste. Then, the olfactory image is also modified by the behavioral condition we are in, at that precise moment in time. So it’s not always the same. 

This explains why we might find a certain dish delicious, or fall in love with a certain wine, and the next day finds them totally different.

However, the part of the process that is truly decisive for defining taste occurs when we exhale the odors, the famous retronasal smell, obviously along with the tactile sensations a food produces… such as, for example, the heat released by a hot chili, or the astringency of the tannin in the wine. 

In my case, for instance, these tactile sensations, known as chemesthetic, were still there despite my losing my sense of smell, and to give myself a bit of a kick I actually ended up taking a bite out of a lemon. Something I don’t recommend.

The development of the retronasal smell was a fundamental process in the evolution of man and it’s the one thing that makes us truly unique as a species.

Our retronasal smell is much more effective than that of dogs for example, although it is always said that animals have a more sophisticated sense of smell than ours because it is 10,000 times more sensitive. To tell the truth, much of our four-legged friends’ sensitivity is due to the fact that its mechanisms are in proximity to the scent-bearing molecules. 

Man, who stands in an erect position, is less susceptible to any potentially harmful molecules on the ground, and to infections. 

A concept which I imagine could probably do with being reviewed after a lockdown spent lying supine on the couch. One positive thing is that, once this is all over, we might all be capable of hunting for truffles ourselves.

HOW THE SENSE OF SMELL WORKS…MORE OR LESS

Right, let’s start from a consideration: nobody really knows exactly how the sense of smell works. 

This lets me off the hook quite a lot in explaining it to you, because I, for one, just can’t get my head around Luca Turin’s quantum theory applied to the sense of smell.

What is clear, on the other hand, is that the sense of smell is very complex, and it resembles our ability to see more than our ability to taste.

For instance, it works based on combination codes: one stimulus activates a combination of receptors, and the different patterns with which this occurs determine the response and identification of the olfactory stimulus.

In other words, if an odor molecule activates 5 olfactory receptors, potentially there are over 30 billion other combinations. Additionally, different concentrations of the same molecule activate different receptors…we know, it’s enough to drive you nuts.

The smell is certainly the most enigmatic sense that deeply modifies our subconscious. 

THE SENSE OF SMELL AND ITS LINK WITH MEMORY

Don’t try to tell me that you’ve never caught a whiff of something and been instantly catapulted into a memory of your childhood. A journey through time and space to one of the many episodes of your life.

Some call this the Proust phenomenon because Proust was the first to mention it in his famous book (the title of which I have casually plagiarized): In Search of Lost Time. 

His time machine was a Madeleine, the tiny soft French sponge cake.

Yes, because tastes and odors are memory and they are strongly connected with our emotions. 

And this is not just a moving cliché, churned out, time after time, in the world of haute cuisine. The recognition of odors goes back a long way and is closely linked with the history of our species which, in millions of years of evolution, has classified the scent-bearing cells and now uses what it has learned.

Let me explain.

Our sense of smell, from when we were young, helps us to catalog all the scent-bearing molecules with which it comes into contact, so enabling us to recognize what we like and instead what might be a danger (fire, rotten food, unhealthy air, etc.). And it is precisely in this period of our life that we accrue the majority of our taste memories.

So olfactory memory is a conscious process, but one that then influences how we behave throughout our whole life. It’s what really makes us determine what we like and what we don’t. 

 

Why is this powerful result instinctive? 

Because, ladies and gentlemen, the sense of smell is one of the first senses we develop, and the part of the brain that processes its signals is one of the oldest.

In fact, the olfactory system is directly connected to the limbic system, both the hippocampus (the brain structure that manages the memory) and the amygdala, the part of the brain tasked with governing the emotions.

 

So depending on our experience of a certain foodstuff, the memory we associate with it and our cultural environment, we distinguish foods as tasty or even disgusting.

And this begs the question… whatever happens to people the first time they eat broccoli that makes them hates them for the rest of their lives? Mothers, take a long hard look at yourselves and fess up.

 

In any case, I must have had a fantastic childhood because I like everything!

 

And basking in those tasty memories of mine, which are, after all, all I’ve got left, I want to express my solidarity with all of you who have had my same problem… we’ll make up for it, guys.

 

Meanwhile, if you want to try a virtual taste experience, take one of our tests on wine or coffee to discover the #Character of your palate.

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