Taste, or gustation, is one of our most robust senses. Unlike the sense of smell, normal aging does not greatly affect our sense of taste.

Taste helps us recognize when food is good or bad for us. But, even more important, loss of taste can cause a loss of appetite, especially in the elderly, which can lead to loss of weight, poor nutrition, weakened immunity, and even death.

Our sense of taste, along with our sense of smell, is part of our chemical sensing system. Normal taste occurs when tiny molecules released by chewing or the digestion of food stimulate special sensory cells in the mouth and throat. These taste cells, or gustatory cells, send messages through three specialized taste nerves to the brain, where specific tastes are identified. Damage to these nerves following head injury can lead to taste loss.

The taste cells are clustered within the taste buds of the tongue and roof of the mouth, and along the lining of the throat. Many of the small bumps that can be seen on the tip of the tongue contain taste buds. At birth, we have about 10,000 taste buds scattered on the back, side, and tip of the tongue. After age 50, we may start to lose taste buds.

We can experience five basic taste sensations: sweet, sour, bitter, salty, and umami, or savory. Umami was discovered by a Japanese scientist in the early part of the twentieth century. It is the taste of glutamate, a building block of protein found in chicken broth, meat stock, and some cheeses. Umami is the taste associated with MSG (monosodium glutamate) that is often added to foods as a flavor enhancer.

The five taste qualities combine with other oral sensations, such as texture, spiciness, temperature, and aroma to produce what is commonly referred to as flavor. It is flavor that lets us know whether we are eating an apple or a pear. Many people are surprised to learn that we recognize flavors largely through our sense of smell. Try holding your nose while eating chocolate. You will be able to distinguish between its sweetness and bitterness, but you can't identify the chocolate flavor. That's because the distinguishing characteristic of chocolate is largely identified by our sense of smell as aromas are released during chewing. Food flavor is affected by a head cold or nasal congestion because the aroma of food does not reach the sensory cells that detect odors. More information on this topic can be found in the chapter "Problems with Smell."

Smell and taste are closely linked senses. Many people mistakenly believe they have a problem with taste, when they are really experiencing a problem with smell. It is common for people who lose their sense of smell to say that food has lost its taste. This is incorrect; the food has lost its aroma, but taste remains. In older people, there is a normal decline in the sense of smell and the taste of food shifts toward blandness. This is why people often believe they have a taste problem.

Some people are able to taste a bitter compound known as phenylthiocarbamide, or PTC, while other people are not. About 25 percent of Americans are nontasters of the chemical compound, 50 percent are medium tasters, and 25 percent are supertasters. This information is important because ones sensitivity to bitter-tasting substances affects the choices a person makes about which foods to eat. Supertasters tend to find many tastes more intense than other people do, and avoid strong-tasting foods, especially bitter-tasting vegetables, coffee, and alcohol.

A distorted sense of taste can be a serious 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 us to eat too much sugar or salt to make our 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.

When an older person has a problem with taste, it is often temporary and minor. True taste disorders are uncommon. When a problem with taste exists, it is usually caused by medications, disease, some cancer treatments, or injury.

Many older people believe that there is nothing they can do about their weakened sense of taste. Depending on the cause of your problem, your doctor may be able to suggest ways to regain your sense of taste or to cope with the loss of taste. In many cases, the loss of taste turns out to be a loss of smell. If you think you have a problem with your sense of taste, see your doctor.

1. The sense of taste declines sharply in older people and taste disorders are common.

2. The taste cells are found in the taste buds of the mouth, tongue, and throat.

3. The five taste sensations are sweet, salty, bitter, sour, and tangy.

4. Many people who seem to have a problem with taste actually have a problem with smell.

Loss of taste may be permanent or temporary, depending on the cause. As with vision and hearing, people gradually lose their ability to taste as they get older, but it is usually not as noticeable as loss of smell. Medications and illness can make the normal loss of taste worse.

Problems with taste are caused by anything that interrupts the transfer of taste sensations to the brain, or by conditions that affect the way the brain interprets the sensation of taste. The most common causes of taste disorders are

• medications
• infections
• head injuries
• dental problems.

Other causes are radiation therapy for head and neck cancers, mouth dryness, heavy smoking, vitamin deficiencies, Bell's palsy, and Sjogren's syndrome.

Taking medications can affect our ability to taste. Some antibiotics and some blood pressure pills can cause a bad taste in the mouth or a loss of taste. If you think your medication is causing a problem with your sense of taste, talk to your doctor about it.

Gum disease can cause problems with taste, as can dentures and inflammation or infections in the mouth. If you take several medications, your mouth may produce less saliva. This causes dry mouth, which can make swallowing and digestion difficult and increase dental problems. Practice good oral hygiene, keep up to date with your dental appointments, and tell your dentist if you notice any problems with your sense of taste.

Problems with taste can have serious consequences because taste affects the amount and type of food we eat. Loss of smell and taste can cause weight loss in the elderly. In some cases, loss of taste can accompany or signal a more serious condition, such as diabetes or some degenerative diseases of the central nervous system such as multiple sclerosis, Alzheimer's disease, or Parkinson's disease.

One type of taste disorder is characterized by a persistent bad taste in the mouth, such as a bitter or salty taste. This is called dysgeusia and it occurs in older people, usually because of medications or oral health problems. The medicines that most frequently cause dysgeusias are drugs to lower cholesterol, antibiotics, blood pressure pills, medications to lower anxiety, and antidepressants.

Taste problems that appear with normal aging cannot be prevented. In many cases, people regain their sense of taste when they stop taking medications or when the illness or injury clears up.

Smokers often report an improved sense of taste after quitting. Sometimes exposure to certain chemicals, such as insecticides and solvents, can impair taste. Avoid contact with these substances, and if you do come in contact with them and experience a problem, see your doctor.

You can help prevent problems with taste caused by respiratory infections by washing your hands frequently, especially during the winter months. If your taste disorder is made worse by allergies, you should avoid allergens, such as ragweed, grasses, and pet dander. Also, get a flu shot every year to prevent influenza and other serious respiratory conditions that can result from the flu.

Be sure to see your doctor if you have had a taste problem for a while or if you notice that your problem with taste is associated with other symptoms. Let your doctor know if you are taking any medications that might affect your sense of taste. You may be able to change or adjust your medicine to one that will not cause a problem with taste. Your doctor will work with you to get the medicine you need while trying to reduce unwanted side effects.

1. The most common causes of taste disorders are

2. Taking medications can

3. Problems with taste can have serious health consequences because

4. A persistent, chronic bad taste in the mouth is

There are several types of taste disorders depending on how the sense of taste is affected. People who have taste disorders usually lose their ability to taste or can no longer perceive taste in the same way. The most common taste complaint is "phantom taste perception" -- tasting something when nothing is in the mouth.

Some people have hypogeusia, or the reduced ability to taste. This disorder is usually temporary. True taste disorders are rare. Most changes in the perception of food flavor result from the loss of smell.

Other people can't detect taste at all, which is called ageusia. This type of taste disorder can be caused by head trauma; some surgical procedures, such as middle ear surgery or extraction of the third molar; radiation therapy; and viral infections. More often, people with taste disorders experience a specific ageusia of one or more of the five taste categories: sweet, sour, bitter, salty, and umami, or savory.

If you think you have a taste disorder, try to identify and record the circumstances surrounding it. Ask yourself the following questions:

• When did I first become aware of it?
• What changes in my taste do I notice?

Ask yourself these questions:

• Do all foods and drinks taste the same?
• Have there been any changes in my sense of smell?
• Does the change in taste affect my ability to eat normally?

Bring this information with you when you visit the doctor. Also, be prepared to tell him or her about your general health and any medication you are taking. Your doctor may ask if you recently have had a cold or the flu. Sometimes these conditions can affect taste.

Your doctor may refer you to an otolaryngologist, a specialist in diseases of the ear, nose, and throat. After conducting a complete medical history and physical examination, your doctor may run special tests to find out what type of taste disorder you have and how serious it is.

Some tests are designed to measure the lowest concentration of a substance that a person can detect or recognize. Your doctor may ask you to compare the tastes of different substances or to note how the intensity of a taste grows when a substances concentration is increased.

Scientists have developed taste tests in which the patient responds to different concentrations of a substance. This may involve a simple "sip, spit, and rinse" test or the application of a substance directly to your tongue using an eye dropper. By using these tests, your doctor can determine if you have a true taste disorder and what type it is.

If your doctor suspects that nerves in your mouth or head may be affected, he or she may order an X-ray, usually a CAT scan, to look further into the head and neck area.

If you think you have a taste disorder, see your doctor. Loss of taste can be a sign of a more serious condition. It also can deprive us of an early warning system that most of us take for granted. Taste helps us detect spoiled food and beverages. Perhaps more serious, loss of the sense of taste can lead to depression and a reduced desire to eat. This can be especially serious for older people with chronic illnesses.

Diagnosis of a taste disorder is important because once the cause is found, your doctor may be able to treat your taste disorder. Many types of taste disorders are reversible, but, if not, counseling and self-help techniques may help you cope.

1. People who have no taste at all have hypogeusia.

2. In order to diagnose a taste disorder, your doctor may give you a test designed to measure the lowest concentration of a substance you can taste.

3. If your doctor suspects that the nerves in your mouth or head may be affected, he or she may order a physical examination.

4. Loss of taste can lead to depression and a decreased desire to eat.

Although there is no treatment for any gradual loss of taste that occurs with aging, relief from taste disorders is possible for many older people. Depending on the cause of your problem with taste, your doctor may be able to treat it or suggest ways to cope with it. Scientists are studying how loss of taste occurs so that treatments can be developed.

Often, a certain medication is the cause of a taste disorder, and stopping or changing the medicine may help eliminate the problem. If you take medications, ask your doctor if they can affect your sense of taste. If so, ask if you can take other medications or safely reduce the dose.

Do not stop taking your medications unless directed by your doctor. Your doctor will work with you to get the medicines you need while trying to reduce unwanted side effects.

Some patients regain their sense of taste when the condition or illness that is causing the loss of taste is over. For example, a middle ear infection often affects taste temporarily. Often, correcting the general medical problem can restore the sense of taste.

Because your sense of taste may gradually decline, you may not even notice the change. But your diet may change, and not for the better. You may lose interest in food and eat less, but you may choose foods that are high in fat and sugars. Or, you may eat more than you should, hoping to get more flavor from every bite.

If you lose some or all of your sense of taste, there are things you can do 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 food

There are more things you can do to make your food taste better:

• If your diet permits, use small amounts of cheese, bacon bits, or butter on vegetables, as well as olive oil or toasted nuts
• Avoid combination dishes, such as casseroles, that can hide individual flavors and dilute taste

If you cannot regain your sense of taste, there are things you can do to ensure your safety. Take extra care to avoid food that may have spoiled. If you live with other people, ask them to smell and taste food to make sure it is fresh. People who live alone should discard food if there is a chance it is spoiled.

For those who wish to have additional help, there may be support groups in your area. These are often associated with smell and taste clinics in medical school hospitals. Some online bulletin boards also allow people with smell and taste disorders to share their experiences. Not all people with taste disorders will regain their sense of taste, but most can learn to live with it.

1. If medication is causing a taste disorder, you should

2. Taste is often regained when

3. If your sense of taste cannot be regained, you should

4. If you need additional help to cope with your taste disorder try

The National Institute on Deafness and Other Communication Disorders, a component of the National Institutes of Health, funds basic and clinical studies of smell and taste disorders. This type of research is leading to a fuller understanding of how our sense of taste works and how we detect and taste sensations at the molecular level.

Scientists have made progress in understanding how our sense of taste changes as we age. For example, we now know that age takes a much greater toll on smell than it does on taste. Also, taste cells -- and smell cells -- are the only sensory cells that are regularly replaced throughout life. Understanding why this happens may help researchers find ways to replace damaged sensory cells.

Older adults often decide what to eat based on how much they like or dislike certain tastes. Scientists are looking at how and why this happens in order to develop more effective ways to help older people cope better with taste problems.

Scientists are also working to find out why some medications and medical procedures can have a harmful effect on our sense of taste and our sense of smell. They hope to come up with treatments to help restore the sense of taste to people who have lost it. Possible solutions include medicines and artificial food products that will allow older adults with taste disorders to enjoy food again.

1. As we age, our sense of taste usually declines more than our sense of smell.

2. As we age, our bodies stop making new taste and smell cells.

3. Older adults often decide what to eat based on how much they like or dislike certain tastes.

4. Scientists are looking at ways to help restore the sense of taste in older adults who have lost their ability to taste.

Taste is the ability to detect different sensations in the mouth, such as sweet or salty. It is part of your bodys chemical sensing system. Taste combines with other oral sensations, such as texture, spiciness, temperature, and aroma to produce what is commonly referred to as flavor.

There is a small decline in taste in people over 60. Most older people will not notice it, because normal aging does not greatly affect our sense of taste. Problems with taste occur less frequently than problems with smell.

Roughly 200,000 people each year visit a doctor for a chemosensory problem such as a taste disorder. Many more taste disorders go unreported.

Taste contributes greatly to our ability to enjoy food and beverages. Problems with taste can have a big impact on older people's lives. When taste is impaired we tend to eat poorly and socialize less, and our general feeling of well-being can be affected. Many social functions involve coming together to enjoy a meal, and people with taste loss tend to avoid such situations.

Normal taste occurs when tiny molecules released by the food we eat stimulate sensory cells in the mouth or throat. These taste cells, or gustatory cells, send messages through nerves to the brain, where specific tastes are recognized.

We can identify five basic taste sensations: sweet, sour, bitter, salty, and umami, or savory. Umami was discovered by a Japanese scientist in the early part of the twentieth century. It is the taste of glutamate, a building block of protein found in chicken broth, meat extracts, and some cheeses.

There are several types of taste disorders depending on how the sense of taste is affected. If you have a taste disorder, you may experience a loss in your ability to taste or changes in the way you perceive taste sensations. Or you may not be able to detect any taste at all. The most common true taste complaint is called "phantom taste perception," which is tasting something when nothing is in the mouth.

The most common causes of taste disorders are medications, infections, head trauma, and dental problems. Most people who have a problem with taste are taking certain medications or they have had a head or neck injury. Gum disease, dry mouth, and dentures can contribute to taste problems, too. Other causes are radiation therapy for head and neck cancers, heavy smoking, vitamin deficiencies, Bell's palsy, and Sjogren's syndrome.

Sometimes. Problems with taste that occur with aging cannot be prevented. Loss of taste due to a respiratory infection can be prevented by washing your hands frequently, especially during the winter months. Quitting smoking and practicing good oral hygiene also can help prevent loss of taste.

Yes. Certain medicines can cause a change in our ability to taste. The medicines that most frequently do this are medications to lower cholesterol, antibiotics, blood pressure pills, medications to lower anxiety, and antidepressants. If you are taking any of these and notice a change in your sense of taste, see your doctor. You may be able to adjust or change your medicine to one that will not cause a problem with taste.

In some cases, loss of taste can accompany or signal conditions such as malnutrition or diabetes. Sometimes a problem with taste can be a sign of a more serious health problem, such as multiple sclerosis, Alzheimer's disease, Parkinsons disease, and other diseases of the nervous system.

Total loss of taste is rare, but can occur. It may result from radiation treatment to the mouth area, and has been associated with head trauma, severe oral health problems, upper respiratory infection, and exposure to chemicals.

Yes. Losing your sense of taste can be more than a quality-of-life issue. Loss of taste deprives us of an early warning system that most of us take for granted. Taste helps us detect spoiled food or beverages and, for some, the presence of food to which they are allergic. Perhaps more serious, loss of the sense of taste also can lead to depression and a reduced desire to eat.

If you lose some or all of your sense of taste, there are things you can do 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, or butter on vegetables, as well as olive oil or toasted nuts
• Avoid combination dishes, such as casseroles, that can hide individual flavors and dilute taste

Doctors can diagnose a taste disorder by measuring the lowest concentration of a substance that a person can detect. The doctor may also ask a patient to compare the tastes of different substances or to note how the intensity of a taste grows when a substance's concentration is increased.

Scientists have developed taste tests in which a person responds to different concentrations of a substance. This may involve a simple "sip, spit, and rinse" test, or the application of a substance directly to the tongue with an eye dropper. By using these tests, your doctor can determine if you have a true taste disorder and what type it is.

Depending on the cause of your taste disorder, your doctor may be able to treat your problem or suggest ways to cope with it. If a certain medication is the cause of the problem, your doctor may be able to adjust or change your medicine. Your doctor will work with you to get the medicine you need while trying to reduce unwanted side effects.

Some patients with respiratory infections regain their sense of taste when the illness is over. Often, correcting a general medical problem can restore the sense of taste. Occasionally, the sense of taste returns to normal on its own without any treatment.

If your medicine is causing a problem with your sense of taste, your doctor may be able to adjust or change your medicine. If not, he or she may suggest ways to manage your problem. Do not stop taking your medications unless directed by your doctor. Your doctor will work with you to get the medicine you need while trying to reduce unwanted side effects.

The best thing you can do is see your doctor. Proper diagnosis by a trained professional, such as an otolaryngologist, is important. These physicians specialize in disorders of the head and neck, especially those related to the ear, nose, and throat. Diagnosis may lead to an effective treatment of the underlying cause of your taste disorder. Many types of taste disorders are curable, and for those that are not, counseling is available to help people cope.

You can help your doctor make a diagnosis by writing down important information about your problem beforehand and giving the information to your doctor during your visit.

Write down answers to the following questions:

• When did I first become aware of my taste problem?
• What changes in my sense of taste did I notice?

• Do all foods and drinks taste the same?
• Have there been any changes in my sense of smell?
• Does the change in taste affect my ability to eat normally?

• What medicines do I take? What are the names of the medicines? How much do I take? What is the health condition for which I take the medicine?
• Have I recently had the cold or flu?

The National Institute on Deafness and Other Communication Disorders supports basic and clinical studies on smell and taste disorders. This type of research is leading to a fuller understanding of how our sense of taste works and how we detect and taste sensations at the molecular level. Findings from this work may result in the development of medicines and artificial food products that will allow older adults with taste disorders to enjoy food again.

Also, scientists are working to discover why certain medications can have a harmful effect on our sense of taste. They are looking at why and how this takes place in order to develop more effective ways to help older people cope better with taste problems.