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Cancer and its treatments can change the way some foods taste or smell. Food may taste bitter or metallic, or may not have as much flavour as before. Taste changes can contribute to a loss of appetite (anorexia), weight loss and malnutrition. Taste changes may also be called taste blindness, hypogeusia (decrease in taste), dysgeusia (altered taste) or ageusia (loss of all taste).
Taste changes can be caused by different cancer treatments and their side effects. Dry mouth, damage to the nerves involved in tasting, mouth infections, nausea and vomiting, and dental or gum disease can also have an effect on the way food tastes.
Chemotherapy drugs can change the taste receptor cells in the mouth. They can also cause an increased sense of smell and sensitivity to certain smells, which can change the way food tastes. Chemotherapy drugs commonly associated with taste changes include:
- cyclophosphamide (Cytoxan, Procytox)
- dacarbazine (DTIC)
- doxorubicin (Adriamycin)
- 5-fluorouracil (Adrucil, 5-FU)
- mechlorethamine (nitrogen mustard, Mustargen)
- cisplatin (Platinol AQ)
- vincristine (Oncovin)
- paclitaxel (Taxol)
Radiation therapy to the head, neck and mouth area may damage the salivary glands and taste buds on the tongue.
Surgery to the nose, throat or mouth, especially when part or all of the tongue is removed, will affect the amount of taste buds available to sense the taste of food.
The agents used to preserve frozen stem cells for stem cell transplants can cause a strong garlic or creamed corn taste during the infusion of the stem cells.
Other medicines can also cause taste changes, including:
- strong painkillers (opioids)
- certain antibiotics
- biological therapies, such as interleukin-2 (IL-2, Aldesleukin, Proleukin)
Symptoms of taste changes can vary depending on their cause and other factors. They may include:
- foods do not taste the same as they did before treatment
- cravings for sweet foods
- foods or beverages taste too sweet
- sweet foods taste sour
- foods or beverages taste too bitter
- foods taste metallic, especially meat
- foods and beverages have no taste
- a sudden dislike for certain foods
Taste changes may continue over the course of chemotherapy or radiation therapy. This effect is often temporary. Taste and smell usually return to normal a few weeks or more after treatment is finished. Some people find that taste and smell do not return to normal, but this varies from person to person.
Managing taste changes
You can try the following to help you cope with taste changes. Check with the healthcare team or a registered dietitian for other suggestions on how to deal with taste changes. Your healthcare team can refer you to a registered dietitian.
Eat when hungry rather than at set meal times. Rinse your mouth before and after eating to help clear the taste buds. The healthcare team may suggest using club soda or different solutions of salt, baking soda and water. Different treatment centres will have different recommendations.
Citrus fruits, such as oranges or lemons, can help stimulate the taste buds. Avoid citrus fruits if they irritate the mouth or if mouth sores are present.
Try foods or beverages that are different than the ones you usually consume. If your senses of smell or taste are more sensitive, try bland foods, such as eggs, cheese, cooked cereal, puddings, toast, rice and cream soups. Try cold foods, such as cheese, milkshakes, cold cuts, tuna or egg salad. Try salty foods, like pizza, hot dogs, sausage, chilli, spaghetti sauce and ketchup. Try foods with strong flavours, such as bacon, pizza, barbecued chicken or other barbecued or charcoal-grilled foods.
Eliminate cooking smells by using an exhaust fan, cooking on an outdoor grill or buying pre-cooked foods. Serve foods cold or at room temperature to reduce strong tastes and smells.
Season foods with onion, garlic, chilli powder, basil, oregano, rosemary, tarragon, barbecue sauce, mustard, ketchup or mint. Seasonings may make the foods taste better. Be cautious with spices and seasonings as they can irritate a sore mouth and bother an upset stomach.
Marinate meats with teriyaki sauce, Italian dressing or fruit juice. If red meats don’t taste good, try other sources of protein, such as chicken, eggs, fish, peanut butter, beans or dairy products.
Suck on sugar-free lemon candies or mints, or chew gum, which can help get rid of unpleasant tastes that remain after eating.
Check with the healthcare team about the use of zinc sulphate supplements. These may help improve taste in some people.
Coping with metallic tastes
Try using plastic cutlery and glass cooking pots if foods have a metallic taste. Tart flavours from lemons and other citrus fruits, vinegar and pickled foods may also be helpful to overcome a metallic taste, but avoid them if you have a sore mouth. Sprinkle a little more sugar and salt on food if these are not restricted in the diet. Sugar and salt decrease metallic tastes.
Coping with bitter tastes
Try adding a little honey, artificial sweetener or sugar to decrease the salty, bitter or acid taste of foods. Add sweet fruits to meals. Drink ginger ale or mint tea to cover up bitter tastes and help in swallowing food.
Marinate meat, poultry or fish in wine, pineapple or lemon juice, soy sauce or barbecue sauce. If red meat tastes bitter, try substituting with chicken, fish, ham, eggs or cheese. Use these foods in casseroles or stews.
Coping with sweet tastes
Try adding a little salt or lemon juice to lower the sweetness of foods that taste sugary. Sometimes herbal tea, if held in the mouth for a short time before eating, can help decrease sweet tastes. Limit sweet fruits or try vegetables. Try diluting fruit juices or other sweet drinks with water or ice.