How does our sense of taste work?
The process of tasting begins with the release of molecules from food during chewing. The molecules stimulate taste cells housed in the taste buds of the tongue, palate and throat. Nerves travel from the taste buds to the brain, where specific tastes are identified.

The average person can identify at least five different taste sensations: sweet, sour, bitter, salty, and umami (the taste elicited by glutamate, which is found in chicken broth, meat extracts, and some cheeses). These tastes, along with texture and temperature, combine with odors to produce the perception of flavor. Flavor is what lets us know whether we are eating vanilla or chocolate ice cream. People are often surprised to learn that flavors are recognized mainly through the sense of smell. If you hold your nose while eating chocolate, for example, you will have trouble identifying the chocolate flavor – even though you can distinguish the food’s sweetness or bitterness.

What are taste disorders?
The most common taste complaint is phantom taste perceptions. Additionally, testing may demonstrate a reduced ability to taste sweet, sour, bitter, salty, and umami. This is called hypogeusia. Some people can detect no tastes, called ageusia. True taste loss is rare, and the perceived loss usually reflects a smell loss. Some patients suffer from distortion of taste, such as detecting a foul taste from a substance that is normally pleasant.

What causes taste disorders?
Some people are born with this disorder, but most develop it after an injury or illness. Upper respiratory infections are blamed for some losses, and injury to the head can also cause taste problems.

Disturbance of taste can also be caused by exposure to certain chemicals such as insecticides and by some medicines. Taste disorders may result from oral health problems and surgery. Many patients who receive radiation therapy for cancers of the head and neck develop a taste disorder.

Are taste disorders serious?
Patients experiencing taste disorders are challenged not only by quality-of-life issues, but are also deprived of early warning systems. Taste helps us detect spoiled food or beverages and, for some, the presence of food to which we're allergic. Perhaps more serious, loss of the sense of taste can also lead to depression and a reduced desire to eat.

Also, taste disorders may accompany and even signal the existence of several diseases or unhealthy conditions, including obesity, diabetes, hypertension, malnutrition and some degenerative diseases of the nervous system such as Parkinson's disease and Alzheimer's disease.

How are taste disorders diagnosed?
After gathering a patient’s general health information for initial clues, Dr. Kimmelman will first examine the nose, throat and neck. Dr. Kimmelman may then ask a patient to compare the tastes of different chemicals or to note how the intensity of a taste grows when a chemical's concentration is increased. This will help him to determine the severity and kind of taste disorder the patient may have.

Can taste disorders be treated?
Many of Dr. Kimmelman’s patients experience relief from their taste disorders. Depending on the cause and duration of the problem, treatments vary but may include surgical and/or medical therapies. Because certain medications can cause problems, Dr. Kimmelman may also recommend adjusting or changing that medicine to ease its effect on the sense of taste.

Disorders of Taste and Smell written by Charles Kimmelman, M.D. As an expert in Taste & Smell disorders, the American Academy of Otolaryngology has published Dr. Charles Kimmelman’s educational book, Disorders of Taste and Smell, for the past 20 years. The third edition of this classic has been updated in 2006. The book is distributed by the American Academy of Otolaryngology - Head and Neck Surgery Foundation, www.entnet.org. To purchase online one can click here.