Taste Disorders and Their Impact
Disorders or alterations in the sense of taste can have a significant impact on the lives of those who suffer from them. Taste plays an essential role in our body and directly affects a patient’s health. Its function goes beyond simply recognizing and enjoying flavors. Taste also stimulates the desire to eat, making it vital for maintaining good nutrition. Additionally, it helps detect spoiled food or beverages to avoid their consumption.
What is the Sense of Taste?
As we know, the sense of taste is primarily related to flavors.
There are various classifications of flavors, but the most widely accepted scientific categorization identifies five distinct tastes that contribute to our sense of taste: sweet, sour (acidic), bitter, salty, and umami (savory).
These flavors, combined with the sense of smell and sensations of temperature and texture, come together in the mouth to create our sense of taste.
What Are Taste Disorders?
The primary taste disorders can be grouped into Ageusia, Hypogeusia, and Dysgeusia.
Ageusia
Ageusia is a condition that completely prevents a person from perceiving taste. It is, therefore, the loss of the ability to detect any taste sensation in the mouth. Several factors can cause this, including:
- Viral infections
- Stroke
- Brain tumors
- Traumatic brain injury
- Sinus infections
- Radiation therapy treatments, among others
Hypogeusia
Hypogeusia is the partial loss of taste perception. This condition makes it difficult to distinguish between different flavors.
Some primary causes of hypogeusia include:
- Genetic factors
- Autoimmune diseases
- Radiation therapy treatments
Typically, individuals with hypogeusia struggle to detect sweet and salty flavors, although they can still identify sour tastes.
Dysgeusia
Dysgeusia is a taste disorder that causes food to taste sour, sweet, bitter, or metallic.
The causes of dysgeusia can vary and include:
- Infections (such as COVID-19)
- Medications or vitamin deficiencies
- Neurological disorders
- Tumors or issues with the central nervous system
- Psychosis
- Diseases like Sjögren’s syndrome
- Aging
- Habits such as smoking, among others
Diagnosing Taste Disorders
Taste disorders must be diagnosed by an otolaryngologist. This specialist will determine the severity of the taste disorder after an initial assessment of the case.
They may conduct various taste tests with different concentrations to evaluate which tastes a patient can detect and at what intensity. Chemicals may also be directly applied to the tongue during testing.
In addition to these tests, the specialist will examine the ears, nose, and throat and inquire about the patient’s medical history and oral hygiene habits.
Treating Taste Disorders
Treatment will depend on the underlying cause of the taste disorder. If a medication is responsible, the doctor will determine whether it is appropriate to discontinue the medication or replace it with an alternative that has less impact on taste. If a disease is the cause, the otolaryngologist will prescribe the appropriate treatment or refer the patient to another specialist if necessary.
In cases where the loss of taste is due to temporary conditions, such as respiratory infections or allergies, taste will recover once the primary condition is treated and resolved.
There are instances where taste disorders resolve spontaneously without treatment or improve with lifestyle changes, such as quitting smoking or altering one’s diet. Nutritional supplements or medications that stimulate saliva production may also be prescribed.
Why Do We Lose Taste When We Lose Smell?
The senses of taste and smell are so closely related that most people who visit a doctor believing they have lost their sense of taste are surprised to learn they have actually lost their sense of smell.
The perception of flavor is a complex sensory experience involving taste, smell, touch, and even sight.
When we eat or drink, we perceive smells through two different pathways: the external environmental pathway (anterior nasal pathway) and through the mouth and nasopharynx (retronasal pathway).
Scientific studies have shown that odors are perceived differently depending on the pathway through which they reach the receptors. Additionally, the retronasal pathway is known to play an essential role in identifying flavors, reflecting the evolutionary significance of the sense of smell in humans.
The aroma of food is the most significant factor in flavor identification, and it is common for patients to mistakenly attribute olfactory dysfunction to a problem with taste.