WHY YOU CAN'T TASTE anything WHEN YOU'RE SICK
Your mouth and your nose are connected, literally.
While your tongue is responsible for identifying the five primary tastes, your nose informs you of the sumptuous flavors in food.
Taste and smell may be separate senses with their own receptors, but they are intricately connected; the nasal and oral cavities literally run into each other. That's why when you get a stuffy nose i.e. mucus clogging your nasal pathways, your taste buds can’t pick up even basic flavors in food.
Receptor cells in the mouth and nose
The tongue has thousands of taste buds that identify the five primary tastes: salty, sweet, sour, bitter, and savory or umami. Meanwhile, the olfactory receptor cells in the nasal cavity measure odors that provide cues to the different flavors in food. When stimulated, these smell-sensing cells send signals to specific areas of the brain, making us conscious of the perception of taste. In this way, the messages that process taste and smell converge, giving us a rounded sensation of what we consume.
Mucus blockade
If mucus in your nasal passages turns too thick, molecules from the air and food can't reach your olfactory receptor cells. Therefore, your brain receives no signal identifying the odor, and everything you eat seems to taste the same. You can still feel the texture and temperature of the food, though, since this information is processed on the tongue.
The lack of taste may be accompanied by post-nasal drip, a condition where mucus drips down the back of the throat instead of out through the nostrils. Post-nasal drip is normally caused by an illness such as the cold, a flu virus or nasal allergies. All of these can wipe the flavor right out of tasty foods.
Tastants and odorants
Chemicals in foods, called tastants, are detected by taste buds, the special structures embedded in the tongue. Every person has between 5,000 to 10,000 taste buds. Each bud consists of 50 to 100 specialized sensory cells, which become piqued by tastants like salts, sugars or acids.
Meanwhile, odorants, or odor molecules, are identified by the specialized sensory neurons in a small patch of mucus membranes lining the roof of the nose. To get these flavors - whether savory or not so savory - the odorants get stimulated by smells or chemicals in food that initiate a pattern of activity sent to the olfactory bulb. After passing to the primary olfactory cortex at the part of the frontal lobe in the brain, the message is relayed to adjacent parts of the orbital cortex where the combination of odor and taste information helps create the perception of flavor.
Same but different
To summarize, the inability to taste foods when you have a cold is intimately related to all that sniffling. Both tastes and smells are the perception of chemicals in the air, food or drink we process. But don't blame your taste buds for the loss of flavor. It's the fault of your stuffed-up nose.
