When the taste cells are stimulated, they send messages through three specialized taste nerves to the brain, where specific tastes are identified. Taste cells have receptors that respond to one of at least five basic taste qualities: sweet, sour, bitter, salty, and umami [oo-MOM-ee]. Umami, or savory, is the taste you get from glutamate, which is found in chicken broth, meat extracts, and some cheeses. A common misconception is that taste cells that respond to different tastes are found in separate regions of the tongue. In humans, the different types of taste cells are scattered throughout the tongue.

Taste quality is just one way that you experience a certain food. Another chemosensory mechanism, called the common chemical sense, involves thousands of nerve endings, especially on the moist surfaces of the eyes, nose, mouth, and throat. These nerve endings give rise to sensations such as the coolness of mint and the burning or irritation of chili peppers. Other specialized nerves create the sensations of heat, cold, and texture. When you eat, the sensations from the five taste qualities, together with the sensations from the common chemical sense and the sensations of heat, cold, and texture, combine with a food’s aroma to produce a perception of flavor. It is flavor that lets you know whether you are eating a pear or an apple.

Most people who think they have a taste disorder actually have a problem with smell. When you chew food, aromas are released that activate your sense of smell by way of a special channel that connects the roof of the throat to the nose. If this channel is blocked, such as when your nose is stuffed up by a cold or flu, odors can’t reach sensory cells in the nose that are stimulated by smells. As a result, you lose much of our enjoyment of flavor. Without smell, foods tend to taste bland and have little or no flavor.

Some people are born with taste disorders, but most develop them after an injury or illness. Among the causes of taste problems are:

• Upper respiratory and middle ear infections
• Radiation therapy for cancers of the head and neck
• Exposure to certain chemicals, such as insecticides and some medications, including some common antibiotics and antihistamines
• Head injury
• Some surgeries to the ear, nose, and throat (such as middle ear surgery) or extraction of the third molar (wisdom tooth)
• Poor oral hygiene and dental problems. 

Diagnosis by an otolaryngologist is important to identify and treat the underlying cause of your disorder. If a certain medication is the cause, stopping or changing your medicine may help eliminate the problem. (Do not stop taking your medications unless directed by your doctor, however.) Often, the correction of a general medical problem can correct the loss of taste. For example, people who lose their sense of taste because of respiratory infections or allergies may regain it when these conditions resolve. Occasionally, a person may recover his or her sense of taste spontaneously. Proper oral hygiene is important to regaining and maintaining a well-functioning sense of taste. If your taste disorder can’t be successfully treated, counseling may help you adjust to your problem.

If you lose some or all of your sense of taste, here are things you can try to make your food taste better:

• Prepare foods with a variety of colors and textures.
• Use aromatic herbs and hot spices to add more flavor; however, avoid adding more sugar or salt to foods.
• If your diet permits, add small amounts of cheese, bacon bits, butter, olive oil, or toasted nuon vegetables.
• Avoid combination dishes, such as casseroles, that can hide individual flavors and dilute taste.

Taste disorders can weaken or remove an early warning system that most of us take for granted. Taste helps you detect spoiled food or liquids and, for some people, the presence of ingredients to which they are allergic.

Loss of taste can create serious health issues. A distorted sense of taste can be a risk factor for heart disease, diabetes, stroke, and other illnesses that require sticking to a specific diet. When taste is impaired, a person may change his or her eating habits. Some people may eat too little and lose weight, while others may eat too much and gain weight.

Loss of taste can cause you to add too much sugar or salt to make food taste better. This can be a problem for people with certain medical conditions, such as diabetes or high blood pressure. In severe cases, loss of taste can lead to depression.