- Diseases, Disorders & Conditions
How Smell Affects Taste
By Joan Whetzel
Remember the last time you had a stuffy nose from a cold or allergy? Did it make your food tasteless? Quit blaming it on the food , or your taste buds. Turns out there's a connection between sense of smell and sense of taste. So without your sense of smell, food really doesn't taste as good.
How Taste Works
Whenever you put food in your mouth, it triggers salivation. The saliva helps break down the food, which triggers the nerve receptors in the taste buds to send messages to the brain. The taste buds on your tongue and along the roof of your mouth can only perceive part of the flavor palette perceived by the brain: salty, sweet, bitter and sour. If these were the only four flavors available, food would indeed taste rather bland and boring. Moreover, as we get older, the intensity of food flavors decrease, so that foods that once seemed too strong in flavor when we were young, will not have enough flavor once we get into our 60s or older.
How Smell Works
The sense of smell is as primal in humans as it is in animals. For humans, smell not only signals fear and danger, it also senses many of life's pleasures - the aroma of baked bread, for instance. In fact about 70 to 75% of what our brain perceives as taste comes through our nose as smell. The noses olfactory receptors are responsible for spotting and distinguishing over 10,000 smells. After picking up the scents and translating them into nerve impulses, the nerves send the info on up to the brain.
How Smell and Taste Work Together
When eating, the food's aromas rise up through the air passages connecting the mouth and nose, where the olfactory nerves pick up the scents. So both the olfactory (smell) and gustatory (taste) receptors work together when stimulated by certain molecules. The combined receptor stimulation carries the flavor messages to the brain. The sense of smell contributes to the overall sensation of taste by make available the information that the tongue's receptors lack.
So when your nose gets stuffed up, the olfactory receptors cannot function properly. The smells offered up by food when it's cooking and being eaten are not transmitted by the olfactory nerves, and the only messages getting through are those being sent by the tongue.
So our sense of taste is indeed largely a function of smell. So the loss of smell - caused by colds, allergies, smoking, polyps, infections or even radiation treatments - can and do affect the sensation of taste.