The Scientific Reasons You Might Be Able To Taste Without Your Sense Of Smell
Common wisdom says that when it comes to our food, if we aren't able to smell it, then it won't taste like anything. Some estimates, in fact, attribute as much as 95% of our food flavor not to our tongue but to our noses (per Flavour Journal). But is this actually true? Some people with anosmia — lacking the sense of smell entirely — can still pick up flavors of food, after all (via Mental Floss). So how does that work? It all relates to the taste and smell function in our noses and throats.
Anecdotal evidence certainly suggests that smell plays an important part in what we taste, and how much flavor we glean from our meal, as anyone who's ever had a cold can attest (via Beaumont). Loss of smell and, subsequently, taste is also a symptom of the virus that causes COVID-19. To truly understand how closely related these two important human senses actually are, let's begin with how each one works on a biological level.
Our sense of smell: How does it work?
Break it down to its most basic components, and how something smells is not much more than a series of signals sent from receptors inside our nose to our brain. There are microscopic odor molecules in the air, and as we breathe they travel into our nostrils and over those receptors. Any one particular odor can be made up of hundreds, if not thousands, of different stink molecules (via Science).
And yes, that means if you've smelled something bad, then there's a teeny tiny bit of whatever it is up your nose. (Think of that next time you're in a public restroom.) From there, our brains interpret the smell as either pleasant or otherwise, and urges us to act accordingly. In the instance of food, that might mean gorging ourselves or turning away in disgust. After all, smell is one sure fire way to tell if something has gone bad or rancid before we eat it and make ourselves sick.
How and why do we taste things?
Much like smell, how our food tastes largely comes down to electrical pulses sent from our taste buds to our brain. There are 4,000 taste buds all over our tongues, and even in our noses and throats. As our saliva breaks down the food that we eat into component molecules, those tiny molecules pass over these taste buds, and one of the five basic flavors emerges: salt, sweet, sour, bitter, or savory (via Food Insight). Another flavor, umami, is sometimes lumped under savory, but other times is sometimes called earthy or meaty, as Vox explains.
Like smell, taste is a crucially important biological function. It can tell us which foods are good or even safe to eat, and signals when food might have gone or when otherwise it should be avoided. It was once believed that certain segments of the tongue are responsible for tasting specific flavors. It's now largely been proven that the sense of taste is much more complicated than that.
Smell and its role in tasting our food
The mechanics of both taste and smell meet up in the back of our throats. It's easy to see then how food after its chewed up would pass by our olfactory system before that chewed-up food gets swallowed, according to WebMD. When this happens, the aroma receptors in our nose and at the back of our throats work in concert with taste buds on our tongue and elsewhere, telling us not just how something tastes but also what might be the flavor. But what's the difference?
To fully understand the reasons science says you might be able to taste without your sense of smell, it's important to clarify the crucial difference between how something tastes and its actual flavor. As WebMD explains, the flavor of something is picked up by your taste buds: Is it salty, sweet, sour, or bitter? How something tastes, on the other hand — as in, does it taste like apple? Do we like the taste of apples, and we should keep eating? — those are questions handled by our olfactory system. This is why we can sometimes still pick up taste, even if we can't smell our food.
Why colds affect our sense of taste
When we have colds, but also certain other kinds of viral or sinus infections, or even just blockages in nasal passages, the scent molecules are kept from our olfactory system, and therefore, we can't taste whatever it is that we're eating. For some people, the sense of taste may also decrease over time as they age and their olfactory system wears out. So, too, can our taste buds. But the experience losing the sense of taste is not the same for two different people. Nor is it the same each time we might catch a cold (via WebMD).
The reason this proves to be true is because our olfactory systems are often not completely shut off when we're sick, so some scent molecules will still reach it, especially in the back of the throat, as Science World explains. That's why some people can still taste — at least a little — with stuffed up noses. In instances like these, taste most often returns. In a bad case of anosmia when the sense of smell is permanently disrupted, people are most often limited to just flavor.
What is anosmia?
As is reported by Yale Medicine, anosmia is an umbrella term that encompasses loss of smell due to a cold, but also sometimes the permanent loss of smell for what might be a much more serious reason. In bad cases like these, people lose their sense of taste, but they can often still detect flavor, according to Mental Floss. With permanent anosmia, the taste buds still work, so foods will taste sweet, salty, savory, or bitter, but beyond a certain point, everything tastes pretty much the same.
On the bright side, those suffering from severe anosmia can sometimes handle spicier foods than they otherwise might be able to eat, but as far as the subtle difference in taste between certain dishes, they're at a loss. An estimated one in every 5,000 to 10,000 people suffers from anosmia, according to Mental Floss. All this means that while eating and smelling your food are closely related, just because you can't smell doesn't mean you'll be permanently cursed with a life of bland food.