I’m in the throws of a bout of man flu at the moment and was wondering why it is that when I have a cold I lose my sense of taste (not that I wear weird clothes, I can’t taste food). A bit of Googling suggested that it was simply down to the smell receptors being blocked by mucus which prevents the body from being able to register taste, taste being a combination of data from the tongue and nose.
If this is correct and what we consider to be taste is made up of taste and smell then it seems that the relationship is about 95% smell to 5% taste because at the moment I can’t taste a damn thing but my tongue is working fine (as far as I know!).
So, what’s the Straight Dope here? Does the cold virus somehow prevent the tongue from registering taste or is the tongue just useless at determining taste without the help of smell receptors?
The taste buds on your tongue can feel sweetness, bitterness, sourness, saltiness (and, according to recent findings, possibly umami). Everything else that we call the “taste” of what we eat or drink are smells detected by the olfactory epithelium in the nose. If that is blocked by mucus or if the inside of your nose has swelled up for various reasons, blocking the passage of air from the pharynx, you just can’t sense them anymore and think the taste has gone.
I’m sure part of the problem is that you’re used to the normal range of taste/smell together and then become very aware of the difference when smell is removed. If you had to go without your nose your whole life, you’d probably adjust your thinking. Kind of like how many color blind people don’t constantly think about how many colors they’re missing out on.
But, yeah, smell is a very key component of what we call taste. I would definitely agree that the tongue is contributing to the nose rather than the other way around.
It’s more like 99% smell to 1% taste, based on the complexity of discriminations we can make. We have only 5 kinds of taste receptors, sweet, salt, sour, bitter, and savory (umami). In contrast, humans have about 400 different genes coding for olfactory receptors. Each one of these 400 receptor types has a differential response to particular odor chemicals. Each odor chemical will trigger a different combination of receptors, responding with different intensity. This means that a very large number of different odors can be distinguished.
So, if we lost our sense of smell entirely we would be able to tell, with eyes closed, if something was salty or not but not if it was a salty chip or some salty pasta? (disregarding the difference in texture).
Texture, for me at least, is a large component of the “taste” of food. It’s quite easy for me to differentiate similar tasting foods based on differing texture, and foods of a certain flavor may only be appealing with certain textures. For instance, I generally like banana products (banana bread in particular), but I don’t like bananas themselves.
And yes, we have only 5 different possible things we taste. Almost all non-texture food discrimination is olfactory based.
There are also the pungent chemicals in chiles (capsaicin), black pepper, horseradish, garlic, etc. which act not on the taste buds, but on sensory receptors involved in heat detection or pain. The “hot” or spicy sensation of these foods is thus not exactly either a taste or a smell.
Mittu, try taking a bite of food, chew it up a bit, then blow your nose before swallowing (if your nose is clear enough to force some air out). You’ll regain your perception of taste for a few seconds, which will illustrate just how much of “taste” is actually smell. I’d say it’s probably 95%.
I don’t have any sense of smell, and although I taste food, I’m pretty sure I’m not tasting it like everyone else. I’m always amazed when my husband can take a bite of something and identify the herbs or spices in it.
Yep, my gramma was born without a sense of smell, and she never was a very good cook because of it. She had to stick closely to recipes and herbs and spices were a mystery to her.
