Taste & Smell Changes During Treatment

The senses of smell and taste combine at the back of the throat. We commonly distinguish taste as one sense and smell as another, but they work together to create the perception of flavour. If one’s sense of smell is not functional, then the sense of taste will also not function. Your body uses taste and smell mechanisms to help you survive. They warn you to stay away from spoiled food and substances that could harm you. But these senses are also there to entice you to eat, so when food tastes and/or smells different, it may turn off your appetite. 

These changes can include food and drinks tasting bitter or like metal, being “put off” by certain foods, or a change in the taste of your favourite foods. The exact reason for taste changes is not clear, although it is thought that it is a result of the damage to the cells in the oral cavity, which are especially sensitive to chemotherapy. About half of people receiving chemotherapy have taste changes. This usually stops about 3 to 4 weeks after treatment ends. This is the same if you are having immunotherapy.

Radiotherapy to the head and neck can harm the taste buds and salivary glands, causing taste changes. It may also cause changes to the sense of smell. Changes to the sense of smell may affect how foods taste. Taste changes caused by radiation treatment usually start to improve 3 weeks to 2 months after treatment ends. Taste changes may continue to improve for about a year. If salivary glands are harmed, then the sense of taste may not fully return to the way it was before treatment.

Other causes for taste changes: 

  • Surgery to the nose, throat, or mouth
  • Dry Mouth 
  • Damage to the nerves involved in tasting
  • Mouth Sores 
  • Dental or gum problems 
  • Nausea and vomiting 
  • Dehydration 
  • Allergies
  • Gastric reflux

    Taste changes can impact your enjoyment of eating or drinking. In turn, you may not eat or drink enough for proper nutrition. Although the problem with taste changes often gets better over time after therapy ends, it can last for a year or longer. There are some things you can do to help manage taste changes and, in the process, decrease or prevent weight loss and even lower nausea symptoms. 

    Tips:

    • If you are sensitive to smells, use an exhaust fan, cook on an outdoor grill, or buy precooked foods. Or try cold or room-temperature foods.
    • Avoid cold foods if you are receiving chemotherapy with oxaliplatin (Eloxatin). This drug can make you sensitive to the cold.

    • Try sugar-free gum or hard candies with flavours such as mint, lemon, or orange. These flavours can help mask a bitter or metallic taste in the mouth.

    • Marinate meats in fruit juices, sweet wines, salad dressings, or other sauces.

    • Flavour foods with herbs, spices, sugar, lemon, or sauces.

    • Avoid eating 1 to 2 hours before and up to 3 hours after chemotherapy. This helps prevent food aversions caused by nausea and vomiting.

    • Keep a clean and healthy mouth.

    • Think about taking zinc sulfate supplements, which may improve taste for some people. Talk with your doctor before taking any dietary supplements, especially during active cancer treatment.

    I experienced some taste changes during chemotherapy. The main taste change for me was tomatoes, which tasted like paracetamol. Most patients will experience something similar, and is normally called a metallic taste. This happens especially after eating meat or other high-protein foods. Using plastic utensils and glass cookware can lessen the metallic taste. 

    Follow this recipe to help reduce this side effect even more: 

    Use this solution before eating.  

    • Half a teaspoon of salt and baking soda  
    • 1 cup of warm water
    • Mix together