BEING ABLE to enjoy the taste of food is often taken for granted. However, we do not realize how precious our food palate really is. Relishing the umami flavor of a freshly grilled steak or the sweet and sour notes of a succulent fruit tart are pleasant consequences attributable to a chemical chain reaction. The science behind our perception of taste is both complex and fascinating, and understanding it may greatly raise our appreciation for our taste receptors. 

How does our sense of taste work? 

   The work of our taste receptors starts with the tongue. Hundreds of papillae, the small bumps that give the tongue its rough texture, cover the top and side surfaces of the tongue. Besides helping the tongue grip food particles and consume food more comfortably, papillae also contain our taste buds, temperature sensors, and little glands that produce saliva. Looking closer at the composition of taste buds, we see that they are composed of several different cells, each playing an important role that ensures the proper functioning of the taste buds. These cells include basal cells, which are responsible for producing new skin cells, structural cells, and between 10 to 50 taste receptor cells which renew every nine to ten days. 

   Thanks to the papillae’s structure, our taste buds are well protected beneath their surface; only tiny hairs called microvilli peak out of the papillae, and these microvilli form part of taste receptor proteins. Additionally, the taste buds are further specialized as there are five types of taste receptor proteins, each type responsible for identifying salty, sweet, bitter, savory, and sour tastes. Aside from recognizing different taste profiles, taste buds also help detect spoiled foods, which are usually sour, thus preventing stomach problems[1]. The common myth that taste buds for each profile are clustered in different parts of the tongue is erroneous; the truth is that taste buds can detect any taste, regardless of their region[2].  

   Since the taste receptor proteins are the parts of the taste buds exposed by the papillae, they are the first to come in contact with food particles and then send information about a particular taste. The receptors are stimulated when chewed food mixes with saliva and connects with the tongue. Neural pathways stored in our tongues notify the brain about the food particles through an intricate process: taste bud cells start working, charging rapidly shifting ions that produce an electrical current which the neural pathways promptly detect. These neural pathways connect our taste receptors to other nerves located on the way to the gustatory cortex, a brain component responsible for recognizing tastes. Once the information is sent along the neural pathways, the brain tells you what you tasted, and you can thoroughly enjoy eating your food. 

The differences between people’s taste buds

   All people have different levels of sensitivity to each of the five basic tastes. For instance, some people may be more affected by bitter foods and, therefore, less likely to enjoy eating certain vegetables, like broccoli. This is because people have different numbers of taste buds. The higher the number of taste buds for one of the five tastes is, the more sensitive you are to that particular taste. It is important to note that while people have different tolerance to spicy foods, spice tolerance should not be confused with the function of taste buds. Spiciness is not a taste but a sensation. It is a combination of heat and pain sensations that are perceived by different kinds of receptors. However, spicy foods can numb your taste buds, temporarily decreasing your ability to taste the other five tastes. Yet, unlike what many myths say, spicy foods are not capable of destroying your taste buds[3].

   Another aspect that affects individual perception of taste is age. As we grow older, our taste buds become dull and less responsive to foods. Older people have fewer taste buds as humans gradually lose them due to the slower regeneration process of basal cells. However, aside from the number, the function of our taste buds degenerates with age as well. The remaining taste buds decrease in size and become number[4], which explains why children and elders taste things differently and may have different food preferences. 

What can lead to a loss of taste?

   There are many ways a person can lose their sense of taste. The most common cause behind the loss of taste is flu and colds. Any type of infection affecting the upper respiratory tract, which provides a route for air to enter our lungs, can lead to a temporary loss of taste. The sense of taste will gradually recover as a patient gets better, even without taking medication that specifically targets the improvement of taste perception. However, the recovery of a patient’s sense of taste depends on the severity of the infection. For instance, people infected with acute COVID-19 have reported experiencing a persisting temporary loss of taste even after recovery[5]. Though the causes for this phenomenon are still being researched, a recent 2022 study connects this condition to the presence of a genetic link, where people with UGT2A1 and UGT2A2 genetic risk factors are reported to be 11% more likely to develop a loss of taste[6]. 

   Though temporary taste loss may be treated lightly, a permanent loss of taste should warrant grave concern. Some head injuries can lead to the damage of nerves that transmit information about consumed food from the tongue to the brain, resulting in a temporary loss of taste. More severe head injuries, however, can lead to permanent damage. A permanent loss of taste can cause serious health problems since diagnosed patients struggle to control their salt and sugar intake due to their inability to adequately judge whether they have over-seasoned their food[7]. The potential mental health struggles are equally concerning as a permanent loss of taste can result in depression and avoidance of food altogether since the patient can no longer enjoy the taste of food[8]. Such a drastic change in physiological perception bears a strong shock value and may be too much for a person to endure. Unfortunately, in such cases, recovery is rare, but there are various coping methods. Adding seeds or nuts to a dish may not improve its taste profile, but a crunchy texture will make it more interesting. To avoid food poisoning, it is important to keep track of the products’ expiration dates since a loss of taste prevents you from detecting the rotten taste[8]. Adjusting to a life without a sense of taste may be challenging, but such methods can make it more bearable. 

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   Knowing that some individuals are void of the ability to enjoy life’s most simple pleasures puts our sense of taste in a completely different perspective. The chance of losing it one day—not just temporarily—instills immense gratitude for possessing something we find joy in but is usually underappreciated. Being mindful of this sensory ability may lead you to savor the flavor of your meal a bit more carefully the next time you sit down to eat. 

[1] Australian Academy of Science

[2] Brain Facts

[3] Owlcation

[4] The Conversation

[5] Healthline

[6] Nature Genesis

[7] Headway

[8] Flint Rehab