Managing Side Effects of Chemotherapy


Cancer cells grow fast, and chemotherapy helps to kill fast-growing cancer cells. But as the whole body absorbs the drug, some normal cells are also killed by chemotherapy. It results in various side effects. Side effects can affect nutrition, health, and quality of life. It further affects the outcome of the disease. 

Some of the common side effects of chemotherapy are 2:

  • Dry mouth/throat
  • Mouth sores
  • Chewing/Swallowing difficulty
  • Lack of appetite 
  • Weight loss 
  • Changes in taste and smell that affects the intake
  • Nausea, vomiting 
  • Bloating and Gas
  • Constipation and
  • Diarrhoea 

Dry Mouth/throat

Dry mouth is a common side effect of cancer treatment and is caused due to damage to the salivary glands. It is common in patients taking chemo or radiotherapy in head and neck regions.

Tips to remain hydrated:

  • Ensure that you drink enough fluids to prevent dehydration
  • Carry a water bottle with you to stay hydrated
  • Avoid Caffeine, alcohol, and sugars as they cause dehydration

Tips to increase saliva:

  • Prepare foods in gravy form
  • Avoid breathing through your mouth
  • Take Ginger juice and Aloe vera juice
  • Chewing on carrom (ajwain) or fennel (sonf) seeds can increase saliva
  • Use citrus fruit juices or tamarind water in cooking
  • Limit dry hard-to-swallow foods 

Non-food tips:

  • Use a humidifier in the room; ensure that you clean the humidifier regularly.
  • Use petroleum jelly to keep lips moist.

Mouth Sores

Mouth-sore can occur due to chemo or radiotherapy medications affecting the cells that line the mouth. Even unchecked persistent cases of dry mouth can lead to mouth ulcers eventually

  • Choose foods that help soothe the mouth, like frozen fruits, curds, and buttermilk
  • Avoid foods that can irritate pepper, chillies, and tough foods
  • Rinse your mouth out before and after meals with a HOMEMADE BAKING SODA RINSE
    Prepare a new batch each day.
    •   ½ tsp salt
    • 1 tsp baking soda
    • 100 ml of water
      Swish and spit the rinse. Ensure that you don’t swallow it.

Chewing and swallowing problems

Mouth cancer patients or patients undergoing chemotherapy on the head and neck usually face this trouble.

Choose foods that are easier to chew and swallow:

  • Soft foods include khichdi, congee/gruels, oats, soups, and stews.
  • Puree or blenderize foods you have difficulty chewing or swallowing.
  • Cut food into small bites. 
  • Take your veggies and fruits in the form of smoothies, soups, and juice. 
  • Do not talk and swallow at the same time. 
  • Ensure to add softer proteins to your diet as nut butter, cooked sprouts, and dal soups. 
  • Take small meals at regular intervals. Large quantities of food will tire you.

Lack of appetite 

Lack of appetite is quite common in cancer patients. It occurs due to the treatment of cancer itself. Additionally, patients feel stressed due to the disease, increasing their feelings. 

Tips for managing Lack of appetite:

  • Eat 5-6 small meals instead of 3 big meals throughout the day.
  • Eat with friends or family or watch television while eating to take your mind off your lack of appetite.
  • Keep an eating and drinking schedule and set the alarm to remind you to eat.
  • Keep snacks next to you during chemotherapy or while in bed.
  • Spices may improve appetite if loss of appetite is due to lack of taste. Spices are also loaded with antioxidative and anti-inflammatory properties.
  • If not to eat, take your veggies and fruits as smoothies, soups, and juice and sip on them throughout the day. 

Weight loss

Weight loss in cancer patients is quite common. Cancer patients tend to eat less as inflammation in the body leads to the release of proteins, making people lose their appetite, pain, anxiety, and stress; it takes away the feeling of eating anything. Also, inflammation in the body keeps their metabolic rate up, due to which they use up more calories than they usually would. 

Tips for management 

  • Include more proteins in the diet. Include pulses, sprouts, nuts, and seeds
  • Take protein-rich snacks, especially from lentils, nuts, seeds, etc., which have specific amino acids glutamine, arginine, and lysine, which help prevent cachexia or unintentional weight loss in patients.
  • Include good fats in your diet available from avocado, cold-pressed oils, 
  • Keep a weighing machine at home and regularly check your weight to see progress or catch any sudden dip in weight.
  • Take small high-calorie high protein food at regular intervals.
  • Keep small snacks beside you, for example, during chemotherapy or while traveling.

Changes in taste and smell that affects the intake

Chemotherapy can affect the taste receptors in the mouth, which could be sensitive to chemotherapy. This problem is more common in patients receiving radiotherapy or chemotherapy in the head and neck region or due to specific chemotherapy drugs and targeted therapy. 

Tips for managing taste and smell changes 

  • Add intense flavours to foods.
  • Use pickles, condiments, sauces, dressings, vinegar, or citrus if you don’t have mouth or throat sores
  • Add spices, herbs, and seasonings (such as onion, garlic, cinnamon, cardamom, fennel seeds, and mint) to enhance the flavour of your food.
  • Clean your mouth with homemade baking soda rinse.
  • Use ceramic utensils instead of silverware/ stainless steel in case of a bitter taste.
  • Avoid being in the kitchen when food is being prepared.
  • Choose cold or room-temperature foods instead of hot foods with a strong smell.
  • A low level of the mineral zinc in the body can cause a lack of taste sensation. Get the same checked and corrected if needed.

Nausea and vomiting

Treatment-related nausea and vomiting are severe complications of chemotherapy and radiotherapy. Usually, nausea and vomiting are induced soon after the treatment and subsides in weeks. In most cases, preventive medications are given. But food can help prevent and manage nausea and vomiting. 

Tips for managing nausea and vomiting

  • An empty stomach can induce the feeling of nausea and vomiting.
  • Take small meals at regular intervals; viewing a large amount of food can again induce nausea. 
  • Avoid foods that can increase symptoms like lactose and gluten.
  • Eat and drink slowly. Take your time and chew your food well. 
  • Drink plenty of fluids like water, clear juices without sugar, and soups. 
  • A lemon shot made with the juice of a lemon and dry ginger powder helps subside nausea.
  • Use ginger in cooking; it can also be added to your tea and lemon juice.
  • Consume a light snack before going for chemotherapy and dehydrated snacks like a biscuit (gluten-free/sugar-free) to help with nausea. 
  • Avoid deep-fried, spicy, and strong-smelling foods.
  • Take foods in average or cold temperatures instead of hot. 

Gas and bloating

Chemotherapy can alter the digestive enzymes, which can affect digestion and cause gas or bloating 4. It can also change the “good microbes in the gut”, leading to more gas formation and the feeling of bloating.

Tips for managing gas and bloating 

  • Sit in an upright position while eating.
  • Chew food well and do not eat very fast.
  • Do not lie down soon after having a meal.
  • Walk for a while post-meal.
  • Avoid consuming a very spicy meal. 
  • Some foods help relieve gas and bloating, 
    • Ajwain (carom seeds) can be consumed with palm jaggery, or the same can be added to boiling water and consumed throughout the day. Just chewing on carom seeds will also be helpful.
    • Hing (Asafoetida) can also help prevent gas formation; add these to gas-forming food preparation, such as dals, potatoes, etc.
    • To improve the gut, add plenty of prebiotics 1 in onion, shallots, garlic, beans, legumes, and probiotics in plant-based curd, kefir, ragi ambali, etc.   
    • Some people will be prone to gas formation when they eat specific foods and maintain a diary to note down which foods, when consumed, cause more gas or bloating. 
    • Avoid dairy products as they can cause bloating.


Constipation is reduced frequency of bowel movements and dry hard stools, which are difficult to pass. It can occur as a side effect of cancer treatment, as chemotherapy may cause changes in the lining of intestinal walls.

Tips for managing constipation

  • Choose high fibre foods, such as whole grains, fruits, vegetables, nuts, and beans.
  • Try prunes and other dried fruits and juices in moderation, such as prune or apple juice. 
  • Drink hot beverages, such as herbal tea
  • Make sure you drink enough water. 
  • Avoid refined products like maida, sooji, sabudana (sago), etc
  • Move more if you are able – walk, stretch, or do yoga.
  • Get enough sleep.


Diarrhoea is a frequent passage of runny stools. It can happen soon after the treatment or a week after. Some patients, when given medications for constipation, may develop Diarrhoea later. It can also lead to loss of fluids, electrolytes, and overall calories. 

Tips for managing Diarrhoea 3

  • Avoid high fibre and fat foods, such as raw vegetables and excess fruits.
  • Avoid foods that have a high content of sugar.
  • Avoid oily, fried, and spicy foods, milk, alcohol, and caffeinated drinks.
  • Eat easy-to-digest foods like steamed apples, congee, stews, etc.
  • Consume a lot of fluids with electrolytes, such as coconut water, ORS, broth, lemon juice with salt, and diluted and stained fruit/vegetable juices. 
  • Carry a water bottle to stay hydrated.
  • Include probiotics such as plant-based yoghurt, kefir, and fermented foods in your diet.


  1. Davani-Davari, D., Negahdaripour, M., Karimzadeh, I., Seifan, M., Mohkam, M., Masoumi, S. J., … & Ghasemi, Y. (2019). Prebiotics: definition, types, sources, mechanisms, and clinical applications. Foods, 8(3), 92.
  2. Altun, I., & Sonkaya, A. (2018). The most common side effects experienced by patients were receiving first cycle of chemotherapy. Iranian journal of public health, 47(8), 1218-1219.
  3. Stein, A., Voigt, W., & Jordan, K. (2010). Chemotherapy-induced diarrhea: pathophysiology, frequency and guideline-based management. Therapeutic advances in medical oncology, 2(1), 51-63.

O’Reilly, M., Mellotte, G., Ryan, B., & O’Connor, A. (2020). Gastrointestinal side effects of cancer treatments. Therapeutic Advances in Chronic Disease, 11, 2040622320970354.


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